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Sample records for spray pyrolysis synthesis

  1. Flame spray pyrolysis synthesis and aerosol deposition of nanoparticle films

    DEFF Research Database (Denmark)

    Tricoli, Antonio; Elmøe, Tobias Dokkedal

    2012-01-01

    The assembly of nanoparticle films by flame spray pyrolysis (FSP) synthesis and deposition on temperature‐controlled substrates (323–723 K) was investigated for several application‐relevant conditions. An exemplary SnO2 nanoparticle aerosol was generated by FSP and its properties (e.g., particle...

  2. Nanoparticle synthesis using flame spray pyrolysis for catalysis

    DEFF Research Database (Denmark)

    Høj, Martin

    processes based on renewable feedstock, new or improved ways of preparing catalysts and a better understanding of the catalyst structure at operating conditions. This thesis explores flame spray pyrolysis (FSP) as a novel one-step preparation method for heterogeneous catalysts and investigates structure...

  3. Synthesis of MgO Nanoparticles by Solvent Mixed Spray Pyrolysis Technique for Optical Investigation

    OpenAIRE

    Nemade, K. R.; Waghuley, S. A.

    2014-01-01

    Solvent mixed spray pyrolysis technique has attracted a global interest in the synthesis of nanomaterials since reactions can be run in liquid state without further heating. Magnesium oxide (MgO) is a category of the practical semiconductor metal oxides, which is extensively used as catalyst and optical material. In the present study, MgO nanoparticles were successfully synthesized using a solvent mixed spray pyrolysis. The X-ray diffraction pattern confirmed the formation of MgO phase with a...

  4. An alternative fluorine precursor for the synthesis of SnO2:F by spray pyrolysis

    International Nuclear Information System (INIS)

    Arca, E.; Fleischer, K.; Shvets, I.V.

    2012-01-01

    An alternative, non-toxic precursor was employed for the synthesis of SnO 2 :F transparent conducting oxide. The performance of benzenesulfonyl fluoride (BSF) as F source for spray pyrolysis was investigated. Its decomposition and the actual incorporation of fluorine in the tin oxide matrix were confirmed by X-ray photoelectron spectroscopy while its effect on the electrical properties was investigated by resistance and Hall measurements. Results were compared with respect to samples grown using a common fluorine source (NH 4 F), a commercial available sample and a sample grown by spray pyrolysis at an independent laboratory. We show that BSF leads to actively doped conductive SnO 2 with good carrier mobility, though the fluorine incorporation rate and hence overall conductivity of the films is lower than for fluorine precursors commonly used in spray pyrolysis.

  5. Synthesis and characterization of Yttria-stabilized zirconia (YSZ) thin films using spray pyrolysis technique

    International Nuclear Information System (INIS)

    Jamale, A.P.; Chourasiya, M.G.; Chavan, A.U.; Patil, S.P.; Jadhav, L.D.

    2009-01-01

    Micro solid oxide fuel cells (SOFC) are of great potential, which require components in film form. We are reporting the spray pyrolysis of 8YSZ films as solid electrolyte for micro-SOFC. The process parameters of the technique were optimized to get stoichiometric films of YSZ. The micro-structural and electrical properties of the films were studied. The elemental analysis of the film showed the desired composition in the film. The conductivity of the film was 0.05 S/cm at 500 deg C with activation energy of 0.90eV. (author)

  6. Synthesis and hyperthermia property of hydroxyapatite-ferrite hybrid particles by ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Inukai, Akihiro; Sakamoto, Naonori; Aono, Hiromichi; Sakurai, Osamu; Shinozaki, Kazuo; Suzuki, Hisao; Wakiya, Naoki

    2011-01-01

    Biocompatible hybrid particles composed of hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2 , HAp) and ferrite (γ-Fe 2 O 3 and Fe 3 O 4 ) were synthesized using a two-step procedure. First, the ferrite particles were synthesized by co-precipitation. Second, the suspension, which was composed of ferrite particles by a co-precipitation method, Ca(NO 3 ) 2 , and H 3 PO 4 aqueous solution with surfactant, was nebulized into mist ultrasonically. Then the mist was pyrolyzed at 1000 o C to synthesize HAp-ferrite hybrid particles. The molar ratio of Fe ion and HAp was (Fe 2+ and Fe 3+ )/HAp=6. The synthesized hybrid particle was round and dimpled, and the average diameter of a secondary particle was 740 nm. The cross section of the synthesized hybrid particles revealed two phases: HAp and ferrite. The ferrite was coated with HAp. The synthesized hybrid particles show a saturation magnetization of 11.8 emu/g. The net saturation magnetization of the ferrite component was calculated as 32.5 emu/g. The temperature increase in the AC-magnetic field (370 kHz, 1.77 kA/m) was 9 o C with 3.4 g (the ferrite component was 1.0 g). These results show that synthesized hybrid particles are biocompatible and might be useful for magnetic transport and hyperthermia studies. - Research Highlights: → Biocompatible hybrid particles composed of hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2 , HAp) and ferrite (γ-Fe 2 O 3 and Fe 3 O 4 ) were synthesized using a two-step synthesis, which is comprised of co-precipitation and ultrasonic spray pyrolysis. → Cross sectional TEM observation and X-ray diffraction revealed that synthesized hybrid particles showed two phases (HAp and ferrite), and the ferrite was coated with HAp. → The saturation magnetization of ferrite in the HAp-ferrite hybrid was 32.49 emu/g. → The increased temperature in the AC-magnetic field (370 kHz, 1.77 kA/m) was 9 o C with 3.4 g (the ferrite component was 1.0 g).

  7. Two-Nozzle Flame Spray Pyrolysis (FSP) Synthesis of CoMo/Al2O3 Hydrotreating Catalysts

    DEFF Research Database (Denmark)

    Høj, Martin; Pham, David K.; Brorson, Michael

    2013-01-01

    and the hydrodenitrogenation activity improved from 70 to 90 % relative activity. This suggests that better promotion of the active molybdenum sulfide phase was achieved when using two-nozzle FSP synthesis, probably due to less formation of the undesired phase CoAl2O4, which makes Co unavailable for promotion.......Two-nozzle frame spray analysis (FSP) synthesis of CoMo/Al2O3 where Co and Al are sprayed in separate flames was applied to minimize the formation of CoAl2O4 observed in one-nozzle flame spray pyrolysis (FSP) synthesis and the materials were characterized by N2-adsorption (BET), X-ray diffraction...... (XRD), UV–vis diffuse reflectance spectroscopy, Raman spectroscopy, transmission electron microscopy, and catalytic performances in hydrotreating. By varying the flame mixing distances (81–175 mm) the amount of CoAl2O4 could be minimized. As evidenced by UV–vis spectroscopy, CoAl2O4 was detected only...

  8. Synthesis of ZnO nanorods by spray pyrolysis for H2S gas sensor

    International Nuclear Information System (INIS)

    Shinde, S.D.; Patil, G.E.; Kajale, D.D.; Gaikwad, V.B.; Jain, G.H.

    2012-01-01

    Highlights: ► Hexagonal pillar shaped ZnO nanorods with different sizes have been successfully synthesized by spray pyrolysis technique. ► ZnO nanorods thin films showed much better sensitivity and stability than the conventional materials to H 2 S gas (100 ppm) at 50 °C. ► This ZnO thin film has potential in application of room temperature H 2 S gas sensing. - Abstract: Hexagonal pillar shaped ZnO nanorods with different sizes have been successfully synthesized by spray pyrolysis technique (SPT). The equal amount of methanol and water is used as a solvent to dissolve the AR grade Zinc acetate for precursor solution. This solution is sprayed on to the glass substrate heated at 350 °C. The films were characterized by ultra-violet spectroscopy (UV), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The deposition of thin films results in a layer comprising well-shaped hexagonal ZnO nanorods with diameter of 90–120 nm and length of up to 200 nm. The gas sensing properties of these films have been investigated for various interfering gases such as CO 2 , CO, ethanol, NH 3 and H 2 S, etc. at operating temperature from 30° (room temperature) to 450 °C. The results indicate that the ZnO nanorods thin films showed much better sensitivity and stability than the conventional materials to H 2 S gas (100 ppm) at 50 °C. The hexagonal pillar shaped ZnO nanorods can improve the sensitivity and selectivity of the sensors.

  9. Size Tunable Synthesis of Highly Crystalline BaTiO3 Nanoparticles using Salt-Assisted Spray Pyrolysis

    International Nuclear Information System (INIS)

    Itoh, Yoshifumi; Lenggoro, I. Wuled; Okuyama, Kikuo; Maedler, Lutz; Pratsinis, Sotiris E.

    2003-01-01

    Highly crystalline, dense BaTiO 3 nanoparticles in a size range from 30 to 360nm with a narrow size distribution (σ g = 1.2-1.4) were prepared at various synthesis temperatures using a salt-assisted spray pyrolysis (SASP) method without the need for post-annealing. The effect of synthesis temperature on particle size, crystallinity and surface morphology of the nanoparticles were characterized by X-ray diffraction and scanning/transmission electron microscopy. The nature of the crystalline structure was analyzed by Rietveld refinement and Raman spectroscopy. The particle size decreased with decreasing operation temperature. The crystal phase was transformed from tetragonal to cubic at a particles size of about 50nm at room temperature. SASP can be used to produce high weight fraction of tetragonal BaTiO 3 nanoparticles down to 64nm in a single step

  10. Synthesis of conductive semi-transparent silver films deposited by a Pneumatically-Assisted Ultrasonic Spray Pyrolysis Technique

    Energy Technology Data Exchange (ETDEWEB)

    Zaleta-Alejandre, E.; Balderas-Xicoténcatl, R. [Centro de Investigación y de Estudios Avanzados-IPN, Departamento de Física, , Apdo. Postal 14-470, Del, Gustavo A. Madero, C.P. 07000, México, D.F. (Mexico); Arrieta, M.L. Pérez [Universidad Autónoma de Zacatecas, Unidad Académica de Física, Calzada Solidaridad esq. Paseo, La Bufa s/n, C.P. 98060, Zacatecas, México (Mexico); Meza-Rocha, A.N.; Rivera-Álvarez, Z. [Centro de Investigación y de Estudios Avanzados-IPN, Departamento de Física, , Apdo. Postal 14-470, Del, Gustavo A. Madero, C.P. 07000, México, D.F. (Mexico); Falcony, C., E-mail: cfalcony@fis.cinvestav.mx [Centro de Investigación y de Estudios Avanzados-IPN, Departamento de Física, , Apdo. Postal 14-470, Del, Gustavo A. Madero, C.P. 07000, México, D.F. (Mexico)

    2013-10-01

    Highlights: • We deposited metallic silver films without post-deposition annealing. • The spray pyrolysis technique is of low cost and scalable for industrial applications. • We obtained deposition rate of 60 nm min{sup −1} at 300 °C. • The average resistivity was 1E−7 Ω m. • Semi-transparent silver films were obtained at 350 °C and deposition time of 45 s. -- Abstract: The synthesis and characterization of nanostructured silver films deposited on corning glass by a deposition technique called Pneumatically-Assisted Ultrasonic Spray Pyrolysis are reported. Silver nitrate and triethanolamine were used as silver precursor and reducer agent, respectively. The substrate temperatures during deposition were in the range of 300–450 °C and the deposition times from 30 to 240 s. The deposited films are polycrystalline with cubic face-centered structure, and crystalline grain size less than 30 nm. Deposition rates up to 600 Å min{sup −1} were obtained at substrate temperature as low as 300 °C. The electrical, optical, and morphological properties of these films are also reported. Semi-transparent conductive silver films were obtained at 350 °C with a deposition time of 45 s.

  11. Synthesis of conductive semi-transparent silver films deposited by a Pneumatically-Assisted Ultrasonic Spray Pyrolysis Technique

    International Nuclear Information System (INIS)

    Zaleta-Alejandre, E.; Balderas-Xicoténcatl, R.; Arrieta, M.L. Pérez; Meza-Rocha, A.N.; Rivera-Álvarez, Z.; Falcony, C.

    2013-01-01

    Highlights: • We deposited metallic silver films without post-deposition annealing. • The spray pyrolysis technique is of low cost and scalable for industrial applications. • We obtained deposition rate of 60 nm min −1 at 300 °C. • The average resistivity was 1E−7 Ω m. • Semi-transparent silver films were obtained at 350 °C and deposition time of 45 s. -- Abstract: The synthesis and characterization of nanostructured silver films deposited on corning glass by a deposition technique called Pneumatically-Assisted Ultrasonic Spray Pyrolysis are reported. Silver nitrate and triethanolamine were used as silver precursor and reducer agent, respectively. The substrate temperatures during deposition were in the range of 300–450 °C and the deposition times from 30 to 240 s. The deposited films are polycrystalline with cubic face-centered structure, and crystalline grain size less than 30 nm. Deposition rates up to 600 Å min −1 were obtained at substrate temperature as low as 300 °C. The electrical, optical, and morphological properties of these films are also reported. Semi-transparent conductive silver films were obtained at 350 °C with a deposition time of 45 s

  12. Synthesis of V2O5 microspheres by spray pyrolysis as cathode material for supercapacitors

    Science.gov (United States)

    Yin, Zhendong; Xu, Jie; Ge, Yali; Jiang, Qiaoya; Zhang, Yaling; Yang, Yawei; Sun, Yuping; Hou, Siyu; Shang, Yuanyuan; Zhang, Yingjiu

    2018-03-01

    Vanadium oxide (V2O5) microspheres have attracted considerable attention in the energy field due to their unique properties such as high stability and electrochemical activity. Here, massive V2O5 microspheres with smooth surface, hollow cavity and uniform particle sizes (0.4–1.5 μm), were synthesized by a facile spray pyrolysis process. Post-treatment at predefined temperatures effectively turned the microsphere shell into stacked nanorods with widths of 100 nm and lengths of 500 nm when processed at 500 °C for 3 h under nitrogen atmosphere, with enhanced crystallinity. When applied as cathode materials for supercapacitors, the post-treated V2O5 microspheres at 500 °C exhibited improved specific capacitance and longer discharge time. This is an effective method to manufacture massive V2O5 microspheres with tailored structure and potential applications in high-performance energy storage materials.

  13. Synthesis and characterization of cobalt doped nickel oxide thin films by spray pyrolysis method

    Science.gov (United States)

    Sathisha, D.; Naik, K. Gopalakrishna

    2018-05-01

    Cobalt (Co) doped nickel oxide (NiO) thin films were deposited on glass substrates at a temperature of about 400 °C by spray pyrolysis method. The effect of Co doping concentration on structural, optical and compositional properties of NiO thin films was investigated. X-ray diffraction result shows that the deposited thin films are polycrystalline in nature. Surface morphologies of the deposited thin films were observed by FESEM and AFM. EDS spectra showed the incorporation of Co dopants in NiO thin films. Optical properties of the grown thin films were characterized by UV-visible spectroscopy. It was found that the optical band gap energy and transmittance of the films decrease with increasing Co doping concentration.

  14. Synthesis and characterization of Yttria-stabilized-zirconia by spray pyrolysis

    International Nuclear Information System (INIS)

    Melo Halmenschlager, Cibele; Vieira, Ramaugusto; Shigueaki Takimi, Antonio; Lima da Silva, Aline; De Fraga Malfatti, Celia; Perez Bergmann, Carlos

    2003-01-01

    Yttria-stabilized-zirconia (YSZ) has been object of many studies due to its great chemical stability and excellent ionic conduction in high temperature. One of the applications of YSZ films is the use as electrolyte in solid oxide fuel cells (SOFC). The great challenge of the SOFC is the development of a intermediary temperature solid oxide fuel cell (ITSOFC) to work in a temperature around 700 o C with the same efficiency of high temperature SOFC, with this aim fuel cells utilizing thin electrolyte films ha been developed. Traditional techniques of thin films deposition as Combustion Vapour Deposition (CVD) and Sputtering are very expensive, the reagents must be very pure and it is necessary to use a system of vacuum. Spray pyrolysis is a good alternative to deposit dense films with thickness between 0,1 and 10 . This technique has a lot of advantages front to classic methods of deposition because of the simplicity of the process and the equipment, low cost, and minimal waste production. In this process, when the parameters are very well controlled, it is possible to obtain oxide films with high quality. In the present work, amorphous films consisted of a layer of 8 mol% Yttria-stabilized zirconia were produced by spray pyrolysis and heat treated to obtain crystalline films. The film was prepared with zirconium acetylacetonate (Zr(C 6 H 7 O 2 ) 4 ) and yttrium chloride (YCl 3 .6H 2 O), dissolved in ethanol (C 2 H 6 O) and diethylene glycol butyl ether (C 8 H 18 O 3 ) mixed in the volume ratio of 1:1, and a disk of steel 316L was used as substrate. The amorphous film was deposited in the substrate heat until 280 o C ± 50 o C and after deposition from thermal treatment at 700 o C, the amorphous film was changed into Yttria-stabilized-zirconia crystalline film. The precursor solution was characterized for the Differential Thermal Analysis (DTA). The morphology and crystallinity of the films was investigated by scanning electron microscopy (SEM) and X-ray diffraction

  15. Synthesis of Nanocrystalline ZnS Thin Films via Spray Pyrolysis for Optoelectronic Devices

    Directory of Open Access Journals (Sweden)

    F. Rahman

    2013-02-01

    Full Text Available ZnS thin films were deposited on the glass substrates at a temperature of 350 °C by a low cost spray pyrolysis technique and annealed at 450 °C and 550 °C in a closed furnace. The as-deposited and annealed films were characterized by Energy Dispersive X-ray, X-ray Diffraction and UV-VIS spectrophotometer and dc conductivity by four probe van der Pauw method. The X-ray diffraction spectra of as-deposited films showed amorphous nature and after annealing at 450 °C and 550 °C the films were found polycrystalline nature with wurtzite hexagonal structure. The optical transmission spectra suggest that the fundamental absorption edge in the films is formed by the direct allowed transition. The optical band gap was decreased from 3.75 to 2.5 eV when the as-deposited films were annealed. The existing results of electrical conductivity and the activation energy reveal the semi-conducting behaviour of the samples.

  16. Synthesis of electrochromic vanadium oxide by pulsed spray pyrolysis technique and its properties

    International Nuclear Information System (INIS)

    Patil, C E; Tarwal, N L; Shinde, P S; Patil, P S; Deshmukh, H P

    2009-01-01

    A new improved pulsed spray pyrolysis technique (PSPT) was employed to deposit a vanadium oxide (V 2 O 5 ) thin film from a methanolic vanadium chloride precursor onto glass and conducting F : SnO 2 coated glass substrates. The structural, morphological, electrical, optical and spectroscopic properties of the film deposited at 573 K were studied. Infrared spectroscopy and x-ray diffraction confirmed the presence of the V 2 O 5 phase. The V 2 O 5 film (thickness ∼118 nm) is polycrystalline with a tetragonal crystal structure. Scanning electron microscopy reveals compact granular morphology consisting of ∼80-100 nm size grains. The film is transparent in the visible region (average %T ∼70%) with an optical band gap energy of 2.47 eV involving both direct and indirect optical transitions. The room temperature electrical resistivity (conductivity) of the film is 1.6 x 10 8 Ω cm (6.25 x 10 -9 S cm -1 ) with an activation energy of 0.67 eV in the temperature range 300-550 K. It exhibited cathodic electrochromism in the lithium containing electrolyte (0.5 M LiClO 4 + propylene carbonate).

  17. Synthesis and characterization of Fe doped cadmium selenide thin films by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Abhijit A., E-mail: aay_physics@yahoo.co.in [Thin Film Physics Laboratory, Department of Physics, Electronics and Photonics, Rajarshi Shahu Mahavidyalaya, Latur 413 512, Maharashtra (India)

    2012-12-05

    Highlights: Black-Right-Pointing-Pointer Simple and inexpensive method to dope trivalent Fe in CdSe thin films. Black-Right-Pointing-Pointer Fe doped CdSe thin films are highly photosensitive. Black-Right-Pointing-Pointer AFM analysis shows uniform deposition of film over the entire substrate surface. Black-Right-Pointing-Pointer The band gap energy decreases from 1.74 to 1.65 eV with Fe doping. Black-Right-Pointing-Pointer Film resistivity decreases to 6.76 Multiplication-Sign 10{sup 4} {Omega}-cm with Fe doping in CdSe thin films. - Abstract: Undoped and Fe doped CdSe thin films have been deposited onto the amorphous and fluorine doped tin oxide coated glass substrates by spray pyrolysis. The Fe doping concentration has been optimized by photoelectrochemical (PEC) characterization technique. The structural, surface morphological, compositional, optical and electrical properties of undoped and Fe doped CdSe thin films have been studied. X-ray diffraction study reveals that the as deposited CdSe films possess hexagonal crystal structure with preferential orientation along (1 0 0) plane. AFM analysis shows uniform deposition of the film over the entire substrate surface with minimum surface roughness of 7.90 nm. Direct allowed type of transition with band gap decreasing from 1.74 to 1.65 eV with Fe doping has been observed. The activation energy of the films has been found to be in the range of 0.14-0.19 eV at low temperature and 0.27-0.44 eV at high temperature. Semi-conducting behavior has been observed from resistivity measurements. The thermoelectric power measurements reveal that the films are of n type.

  18. One-step synthesis of bismuth molybdate catalysts via flame spray pyrolysis for the selective oxidation of propylene to acrolein

    DEFF Research Database (Denmark)

    Schuh, K.; Kleist, W.; Høj, Martin

    2014-01-01

    Flame spray pyrolysis (FSP) of Bi(III)-and Mo(VI)-2-ethylhexanoate dissolved in xylene resulted in various nanocrystalline bismuth molybdate phases depending on the Bi/Mo ratio. Besides alpha-Bi2Mo3O12 and gamma-Bi2MoO6, FSP gave direct access to the metastable beta-Bi2Mo2O9 phase with high surfa...

  19. Influence of the process parameters on the spray pyrolysis technique, on the synthesis of gadolinium doped-ceria thin film

    International Nuclear Information System (INIS)

    Halmenschlager, C.M.; Neagu, R.; Rose, L.; Malfatti, C.F.; Bergmann, C.P.

    2013-01-01

    Graphical abstract: Gas-tight CGO made by spray pyrolysis suitable to be used as SOFC electrolyte. Display Omitted Highlights: ► Dense and crystalline CGO films deposited by spray pyrolysis on various substrates. ► Solvent did not have a strong influence on the film microstructure, defect concentration or thickness. ► The substrate did not have a strong influence on the film microstructure, defect concentration or thickness. ► Films with at least 2.5 μm of thickness presented high impermeability. ► The films obtained are suitable to use as a SOFC electrolyte. -- Abstract: This work presents the results of a process of optimization applied to gadolinia-doped ceria (Ce 0.8 Gd 0.2 O 1.9−x , or CGO) thin films, deposited by spray pyrolysis (SP). Spray pyrolysis is a high thermal deposition method that combines material deposition and heat treatment. This combination is advantageous since the post-deposition heat treatment step is not necessary. However, stresses are solidified in the coating during the deposition, which may lead to the initiation of a crack in the coating. The aim of this work was to achieve thin, dense, and continuous CGO coatings, which may be used as gas separation membranes and as a solid state electrochemical interfaces. Dense, flat, low-defect substrates such as silica slides, silicon mono crystal wafers, and porous substrates were used as substrates in this work. Cerium ammonium nitrate and gadolinium acetylacetonate were dissolved in ethanol and butyl carbitol to form a precursor solution that was sprayed on the heated substrates. Process parameters such as solvent composition, deposition rate and different heating regimes were analyzed. The microstructure was analyzed by secondary electron microscopy (SEM) and was found that thin, dense, and defect-free films could be produced on dense and porous substrates. The results obtained show that it is possible to obtain a CGO dense film deposited by spray pyrolysis. X-ray diffraction

  20. Rapid synthesis of spherical-shaped green-emitting MgGa2O4:Mn2+ phosphor via spray pyrolysis

    International Nuclear Information System (INIS)

    Choi, Sungho; Kim, Kyoungun; Moon, Young-Min; Park, Byung-Yoon; Jung, Ha-Kyun

    2010-01-01

    Simple, one-step synthesis of spherical-shaped powder phosphors with aqueous precursors via a spray pyrolysis method is reported. Green-emitting MgGa 2 O 4 :Mn 2+ phosphor with a controlled shape was successfully obtained by spraying under a reductive atmosphere (N 2 + H 2 carrier gas) without high-temperature post-heat treatment. In addition, the corresponding powder phosphors were well dispersed and showed a clean surface morphology compared to an existing cumbersome process using high-temperature post-annealing. The new method may help to prevent surface residual non-radiative defect sites. The result of highly luminescent and spherical morphology, non-aggregated powder phosphor by this procedure holds promise for a cost-effective and rapid synthesis process for conventional inorganic phosphors.

  1. Synthesis and characterization of nanosized calcium phosphates by flame spray pyrolysis, and their effect on osteogenic differentiation of stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Ataol, Sibel; Tezcaner, Ayşen [Middle East Technical University, Department of Biomedical Engineering (Turkey); Duygulu, Ozgur [TUBITAK Marmara Research Center, Materials Institute (Turkey); Keskin, Dilek [Middle East Technical University, Department of Biomedical Engineering (Turkey); Machin, Nesrin E., E-mail: nesrinmachin@gmail.com [Kocaeli University, Department of Chemical Engineering (Turkey)

    2015-02-15

    The present study evaluates the synthesis of biocompatible osteoconductive and osteoinductive nano calcium phosphate (CaP) particles by industrially applied, aerosol-derived flame spray pyrolysis method for biomedical field. Calcium phosphate nanoparticles were produced in a range of calcium-to-phosphorus ratio, (1.20–2.19) in order to analyze the morphology and crystallinity changes, and to test the bioactivity of particles. The characterization results confirmed that nanometer-sized, spherical calcium phosphate particles were produced. The average primary particle size was determined as 23 nm by counting more than 500 particles in TEM pictures. XRD patterns, HRTEM, SAED, and SEM analyses revealed the amorphous nature of the as-prepared nano calcium phosphate particles at low Ca/P ratios. Increases in the specific surface area and crystallinity were observed with the increasing Ca/P ratio. TGA–DTA analysis showed that the thermally stable crystal phases formed after 700 °C. Cell culture studies were conducted with urine-derived stem cells that possess the characteristics of mesenchymal stem cells. Synthesized amorphous nanoparticles did not have cytotoxic effect at 5–50 μg/ml concentration range. Cells treated with the as-prepared nanoparticles had higher alkaline phosphatase (ALP) enzyme activity than control cells, indicating osteogenic differentiation of cells. A slight decrease in ALP activity of cells treated with two highest Ca:P ratios at 50 μg/ml concentration was observed at day 7. The findings suggest that calcium phosphate nanoparticles produced in this work have a potential to be used as biomaterials in biomedical applications.

  2. Synthesis and characterization of nanosized calcium phosphates by flame spray pyrolysis, and their effect on osteogenic differentiation of stem cells

    Science.gov (United States)

    Ataol, Sibel; Tezcaner, Ayşen; Duygulu, Ozgur; Keskin, Dilek; Machin, Nesrin E.

    2015-02-01

    The present study evaluates the synthesis of biocompatible osteoconductive and osteoinductive nano calcium phosphate (CaP) particles by industrially applied, aerosol-derived flame spray pyrolysis method for biomedical field. Calcium phosphate nanoparticles were produced in a range of calcium-to-phosphorus ratio, (1.20-2.19) in order to analyze the morphology and crystallinity changes, and to test the bioactivity of particles. The characterization results confirmed that nanometer-sized, spherical calcium phosphate particles were produced. The average primary particle size was determined as 23 nm by counting more than 500 particles in TEM pictures. XRD patterns, HRTEM, SAED, and SEM analyses revealed the amorphous nature of the as-prepared nano calcium phosphate particles at low Ca/P ratios. Increases in the specific surface area and crystallinity were observed with the increasing Ca/P ratio. TGA-DTA analysis showed that the thermally stable crystal phases formed after 700 °C. Cell culture studies were conducted with urine-derived stem cells that possess the characteristics of mesenchymal stem cells. Synthesized amorphous nanoparticles did not have cytotoxic effect at 5-50 μg/ml concentration range. Cells treated with the as-prepared nanoparticles had higher alkaline phosphatase (ALP) enzyme activity than control cells, indicating osteogenic differentiation of cells. A slight decrease in ALP activity of cells treated with two highest Ca:P ratios at 50 μg/ml concentration was observed at day 7. The findings suggest that calcium phosphate nanoparticles produced in this work have a potential to be used as biomaterials in biomedical applications.

  3. Synthesis and property of powders of oxide superconductor by the spray drying and the mist pyrolysis method

    Energy Technology Data Exchange (ETDEWEB)

    Awano, M.; Takagi, H.; Torii, Y.; Tsuzuki, A.; Murayama, N.; Ishii, E. (Government Industrial Research Inst., Nagoya (Japan)); Sudo, E. (Tokyo Kokyu Rozai Co. Ltd., Fukuoka (Japan))

    1989-01-01

    Powders of oxide superconductor (Ba-Y-Cu-O and Bi-Pb-Sr-Ca-Cu-O systems) were synthesized by the spray drying and the mist pyrolysis methods. Fine Ba{sub 2}YCu{sub 3}O{sub 7-y} particles with diameter of 0.1-0.3 {mu}m were produced by the spray drying of the oxalates coprecipitated slurry and following calcination at 800deg C. By the pyrolyzing of nitrates mist containing Ba{sup 2+},Y{sup 3+},Cu{sup 2+} ions in the reaction zone heated at 950-980deg C fine particles were also produced. For Bi-Pb-Sr-Ca-Cu-O system, above mentioned methods were effective to produce fine homogeneous particles of compound at intermediate stage to high Tc phase. Sintered body made from these fine homogeneous powders were densified to about 95-98% of theoretical densitiy. (orig.).

  4. Spray pyrolysis process for preparing superconductive films

    International Nuclear Information System (INIS)

    Hsu, H.M.; Yee, I.Y.

    1991-01-01

    This paper describes a spray pyrolysis method for preparing thin superconductive film. It comprises: preparing a spray pyrolysis solution comprising Bi,Sr,Ca and Cu metals in a solvent; heating a substrate to a first temperature; spraying the solution onto the heated substrate to form a film thereon; heating the film and substrate to a second temperature of about 700 degrees-825 degrees C, the second temperature being higher than the first temperature; heating the film and substrate to a third temperature of about 870 degrees-890 degrees C to melt the film; once the film and substrate reach the third temperature, further heat treating the film and substrate; cooling the film and substrate to ambient temperature. This patent also describes a spray pyrolysis method for preparing thin superconductive films. It comprises: preparing a spray pyrolysis solution comprising Bi, Ca and Cu metals and fluxing agent in a solvent; heating a substrate to a first temperature; spraying the solution onto the heated substrate to form a film thereon; heating the film and substrate to a second temperature about 700 degrees-825 degrees C, the second temperature being higher than the first temperature; heating the film and substrate at a third temperature about 840 degrees-860 degrees C; and cooling the film and substrate to ambient temperature

  5. Low Temperature Synthesis of Fluorine-Doped Tin Oxide Transparent Conducting Thin Film by Spray Pyrolysis Deposition.

    Science.gov (United States)

    Ko, Eun-Byul; Choi, Jae-Seok; Jung, Hyunsung; Choi, Sung-Churl; Kim, Chang-Yeoul

    2016-02-01

    Transparent conducting oxide (TCO) is widely used for the application of flat panel display like liquid crystal displays and plasma display panel. It is also applied in the field of touch panel, solar cell electrode, low-emissivity glass, defrost window, and anti-static material. Fluorine-doped tin oxide (FTO) thin films were fabricated by spray pyrolysis of ethanol-added FTO precursor solutions. FTO thin film by spray pyrolysis is very much investigated and normally formed at high temperature, about 500 degrees C. However, these days, flexible electronics draw many attentions in the field of IT industry and the research for flexible transparent conducting thin film is also required. In the industrial field, indium-tin oxide (ITO) film on polymer substrate is widely used for touch panel and displays. In this study, we investigated the possibility of FTO thin film formation at relatively low temperature of 250 degrees C. We found out that the control of volume of input precursor and exhaust gases could make it possible to form FTO thin film with a relatively low electrical resistance, less than 100 Ohm/sq and high optical transmittance about 88%.

  6. Synthesis of ZnO nanorods by spray pyrolysis for H{sub 2}S gas sensor

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, S.D.; Patil, G.E. [Materials Research Lab., K.T.H.M. College, Nashik 422 005 (India); Kajale, D.D. [Materials Research Lab., Arts, Commerce and Science College, Nandgaon 423 106 (India); Gaikwad, V.B. [Materials Research Lab., K.T.H.M. College, Nashik 422 005 (India); Jain, G.H., E-mail: gotanjain@rediffmail.com [Materials Research Lab., K.T.H.M. College, Nashik 422 005 (India)

    2012-07-05

    Highlights: Black-Right-Pointing-Pointer Hexagonal pillar shaped ZnO nanorods with different sizes have been successfully synthesized by spray pyrolysis technique. Black-Right-Pointing-Pointer ZnO nanorods thin films showed much better sensitivity and stability than the conventional materials to H{sub 2}S gas (100 ppm) at 50 Degree-Sign C. Black-Right-Pointing-Pointer This ZnO thin film has potential in application of room temperature H{sub 2}S gas sensing. - Abstract: Hexagonal pillar shaped ZnO nanorods with different sizes have been successfully synthesized by spray pyrolysis technique (SPT). The equal amount of methanol and water is used as a solvent to dissolve the AR grade Zinc acetate for precursor solution. This solution is sprayed on to the glass substrate heated at 350 Degree-Sign C. The films were characterized by ultra-violet spectroscopy (UV), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The deposition of thin films results in a layer comprising well-shaped hexagonal ZnO nanorods with diameter of 90-120 nm and length of up to 200 nm. The gas sensing properties of these films have been investigated for various interfering gases such as CO{sub 2}, CO, ethanol, NH{sub 3} and H{sub 2}S, etc. at operating temperature from 30 Degree-Sign (room temperature) to 450 Degree-Sign C. The results indicate that the ZnO nanorods thin films showed much better sensitivity and stability than the conventional materials to H{sub 2}S gas (100 ppm) at 50 Degree-Sign C. The hexagonal pillar shaped ZnO nanorods can improve the sensitivity and selectivity of the sensors.

  7. One-Pot Synthesis of CoSex -rGO Composite Powders by Spray Pyrolysis and Their Application as Anode Material for Sodium-Ion Batteries.

    Science.gov (United States)

    Park, Gi Dae; Kang, Yun Chan

    2016-03-14

    A simple one-pot synthesis of metal selenide/reduced graphene oxide (rGO) composite powders for application as anode materials in sodium-ion batteries was developed. The detailed mechanism of formation of the CoSe(x)-rGO composite powders that were selected as the first target material in the spray pyrolysis process was studied. The crumple-structured CoSe(x)-rGO composite powders prepared by spray pyrolysis at 800 °C had a crystal structure consisting mainly of Co0.85 Se with a minor phase of CoSe2. The bare CoSe(x) powders prepared for comparison had a spherical shape and hollow structure. The discharge capacities of the CoSe(x)-rGO composite and bare CoSe(x) powders in the 50th cycle at a constant current density of 0.3 A g(-1) were 420 and 215 mA h g(-1), respectively, and their capacity retentions measured from the second cycle were 80 and 46%, respectively. The high structural stability of the CoSe(x)-rGO composite powders for repeated sodium-ion charge and discharge processes resulted in superior sodium-ion storage properties compared to those of the bare CoSe(x) powders. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Synthesis of nano-structured tin oxide thin films with faster response to LPG and ammonia by spray pyrolysis

    Science.gov (United States)

    PrasannaKumari, K.; Thomas, Boben

    2018-01-01

    Nanostructured SnO2 thin film have been efficiently fabricated by spray pyrolysis using atomizers of different types. The structure and morphology of as-prepared samples are investigated by techniques such as x-ray diffraction, and field-emission scanning electron microscopy. Significant morphological changes are observed in films by modifying the precursor atomization as a result of change of spray device. The optical characterization indicates that change in atomization, affects the absorbance and the band gap, following the varied crystallite size. Gas sensing investigations on ultrasonically prepared tin oxide films show NH3 response at operating temperatures lower down to 50 °C. For 1000 ppm of LPG the response at 350 °C for air blast atomizer film is about 99%, with short response and recovery times. The photoluminescence emmision spectra reveal the correlation between atomization process and the quantity of oxygen vacancies present in the samples. The favorable size reduction in microstructure with good crystallinity with slight change in lattice properties suggest their scope in gas sensing applications. On the basis of these characterizations, the mechanism of LPG and NH3 gas sensing of nanostructured SnO2 thin films has been proposed.

  9. Magnetic-luminescent spherical particles synthesized by ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Michel, Norma L; Hirata, Gustavo A; Flores, Dora L

    2015-01-01

    The combination of magnetic and luminescent properties in a single particle system, opens-up a wide range of potential applications in biotechnology and biomedicine. In this work, we performed the synthesis of magnetic-luminescent Gd 2 O 3 :Eu 3+ @Fe 2 O 3 particles by ultrasonic spray pyrolysis performed in a tubular furnace. In order to achieve the composite formation, commercial superparamagnetic Fe 3 O 4 nanoparticles were coated with a luminescent Eu 3+ -doped Gd 2 O 3 shell in a low-cost one-step process. The spray pyrolysis method yields deagglomerated spherical shape magneto/luminescent particles. The photoluminescence spectra under UV excitation (λ Exc = 265 nm) of the magnetic Gd 2 O 3 :Eu 3+ @Fe 2 O 3 compound showed the characteristic red emission of Eu 3+ (λ Em = 612 nm). This magneto/luminescent system will find applications in biomedicine and biotechnology. (paper)

  10. Zinc oxide films prepared by spray pyrolysis

    Directory of Open Access Journals (Sweden)

    Maciąg Andrzej

    2017-01-01

    Full Text Available In this work we developed and tested spray pyrolysis system for layers deposition. In the system we have used ultrasonic apparatus (nebulizator as a sprayer. A zinc nitrate aqueous solution has been used as a precursor solution. The idea of the method is the decomposition of nitrate on a hot substrate according to the reaction Zn(NO32 → ZnO +2 NO2 +1/2O2. The layers were grown on glass, (001Si and KCl substrates at the temperatures 300 – 500°C. The thickness of the obtained layers was in the range 50 – 500 nm, depending on the growth time and rate. The influence of substrate temperature on the morphology of the layers has been studied by SEM method. The energy gap of the layers was found to be the range of 3.26-3.3 eV from their absorption spectra.

  11. Effect of precursor concentration and spray pyrolysis temperature upon hydroxyapatite particle size and density.

    Science.gov (United States)

    Cho, Jung Sang; Lee, Jeong-Cheol; Rhee, Sang-Hoon

    2016-02-01

    In the synthesis of hydroxyapatite powders by spray pyrolysis, control of the particle size was investigated by varying the initial concentration of the precursor solution and the pyrolysis temperature. Calcium phosphate solutions (Ca/P ratio of 1.67) with a range of concentrations from 0.1 to 2.0 mol/L were prepared by dissolving calcium nitrate tetrahydrate and diammonium hydrogen phosphate in deionized water and subsequently adding nitric acid. Hydroxyapatite powders were then synthesized by spray pyrolysis at 900°C and at 1500°C, using these calcium phosphate precursor solutions, under the fixed carrier gas flow rate of 10 L/min. The particle size decreased as the precursor concentration decreased and the spray pyrolysis temperature increased. Sinterability tests conducted at 1100°C for 1 h showed that the smaller and denser the particles were, the higher the relative densities were of sintered hydroxyapatite disks formed from these particles. The practical implication of these results is that highly sinterable small and dense hydroxyapatite particles can be synthesized by means of spray pyrolysis using a low-concentration precursor solution and a high pyrolysis temperature under a fixed carrier gas flow rate. © 2015 Wiley Periodicals, Inc.

  12. Synthesis and characterization of Gd0.1Ce0.9O1.95 thin films by spray pyrolysis technique

    DEFF Research Database (Denmark)

    Chourashiya, M. G.; Pawar, S. H.; Jadhav, L. D.

    2008-01-01

    The Gd doped ceria (CGO) in thin layers is of great interest for low temperature operation. In the present investigation, we report on the use of spray pyrolysis technique for the synthesis of CGO thin films. The process parameters were optimized for synthesizing Gd0.1Ce0.9O1.95 films. Films were...... characterized by XRD, EDS, SEM, and AFM and are observed to be phase pure and dense with surface roughness of the order of ∼5 nm. The d.c. conductivity was also measured and is observed to be ∼0.5 S/cm at 623 K....

  13. Synthesis and characterization of ZnO–CuO nanocomposites powder by modified perfume spray pyrolysis method and its antimicrobial investigation

    Science.gov (United States)

    Saravanakkumar, D.; Sivaranjani, S.; Kaviyarasu, K.; Ayeshamariam, A.; Ravikumar, B.; Pandiarajan, S.; Veeralakshmi, C.; Jayachandran, M.; Maaza, M.

    2018-03-01

    Pure ZnO, ZnO–CuO nanocomposites can be synthesized by using a modified perfume spray pyrolysis method (MSP). The crystallite size of the nanoparticles (NPs) has been observed by X-ray diffraction pattern and is nearly 36 nm. Morphological studies have been analyzed by using Field Emission Scanning Electron Microscopy (FESEM) and its elemental analysis was reported by Elemental X-ray Analysis (EDX); these studies confirmed that ZnO and CuO have hexagonal structure and monoclinic structure respectively. Fourier Transform Infrared (FTIR) spectra revealed that the presence of functional frequencies of ZnO and CuO were observed at 443 and 616 cm‑1. The average bandgap value at 3.25 eV using UV–vis spectra for the entitled composite has described a blue shift that has been observed here. The antibacterial study against both gram positive and negative bacteria has been studied by the disc diffusion method. To the best of our knowledge, it is the first report on ZnO–CuO nanocomposite synthesized by a modified perfume spray pyrolysis method.

  14. Preparation of YBCO superconducting films by spray pyrolysis method

    International Nuclear Information System (INIS)

    Mora Alonso, M.; Leyva Fabelo, A.; Rubio Frias, E.; Pupo Gonzalez, I.; Lopez Sanchez, D.

    1994-01-01

    The methodology for the preparation of YBCO superconducting films on Zr 2O (Y) substrates by spray pyrolysis method is reported. The transition temperature of these films is superior than the boiling temperature of liquid 2N . Other critical parameters are similar to those reported by other authors using the same technique

  15. Barium strontium titanate powders prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    Brankovic, G.; Brankovic, Z.; Goes, M.S.; Paiva-Santos, C.O.; Cilense, M.; Varela, J.A.; Longo, E.

    2005-01-01

    Ultasonic spray pyrolysis (SP) has been investigated for the production of the barium strontium titanate (BST) powders from the polymeric precursors. The processing parameters, such as flux of aerosol and temperature profile inside the furnace, were optimized to obtain single phase BST. The powders were characterized by the methods of X-ray diffraction analysis, SEM, EDS and TEM. The obtained powders were submicronic, consisting of spherical, polycrystalline particles, with internal nanocrystalline structure. Crystallite size of 10 nm, calculated using Rietveld refinement, is in a good agreement with results of HRTEM

  16. Spray pyrolysis synthesis of γ-Al_2O_3 supported metal and metal phosphide catalysts and their activity in the hydrodeoxygenation of a bio-oil model compound

    International Nuclear Information System (INIS)

    Ly, Hoang Vu; Im, Kyungmin; Go, Youngchae; Galiwango, Emmanuel; Kim, Seung-Soo; Kim, Jinsoo; Choi, Jae Hyung; Woo, Hee Chul

    2016-01-01

    Highlights: • Spherical γ-Al_2O_3 supported metal and metal phosphide catalysts were synthesized by spray pyrolysis method. • Hydrodeoxygenation (HDO) of 2-furyl methyl ketone (FMK) was conducted using metal/metal phosphide catalysts. • FMK was converted into 2-allyl furan and methyl cyclohexane. • The highest FMK conversion of 83% was achieved over 10 wt% Ni/γ-Al_2O_3 catalysts at reaction temperature of 400 °C. - Abstract: In this study, spherical γ-Al_2O_3 supported metal and metal phosphide (Ni, Co, Ni_2P and CoP) catalysts were successfully prepared by combining sol-gel and spray pyrolysis methods. First boehmite sol was prepared based on the Yoldas process and then the corresponding metal salts were added to the sol at the desired concentration, followed by spray pyrolysis of the mixed solution. As the well-mixed solution was transformed to spherical γ-Al_2O_3 supported metal and metal phosphide catalysts during spray pyrolysis process, the metal species were uniformly distributed in the mesoporous γ-Al_2O_3 supports. The product catalysts were investigated under different conditions for hydrodeoxygenation of bio-oil model compound, 2-furyl methyl ketone (FMK), which is the main component of the bio-oil product from pyrolysis of Saccharina japonica. Among the investigated catalysts, the 10 wt% Ni/γ-Al_2O_3 catalyst after calcination at 800 °C showed the highest FMK conversion of 83.02% at the reaction temperature of 400 °C. The gas and liquid products were analyzed by gas chromatography (GC) with TCD/FID detectors and GC–MS, respectively, to determine the product compositions.

  17. Photoluminescence of spray pyrolysis deposited ZnO nanorods

    Directory of Open Access Journals (Sweden)

    Mikli Valdek

    2011-01-01

    Full Text Available Abstract Photoluminescence of highly structured ZnO layers comprising well-shaped hexagonal rods is presented. The ZnO rods (length 500-1,000 nm, diameter 100-300 nm were grown in air onto a preheated soda-lime glass (SGL or ITO/SGL substrate by low-cost chemical spray pyrolysis method using zinc chloride precursor solutions and growth temperatures in the range of 450-550°C. We report the effect of the variation in deposition parameters (substrate type, growth temperature, spray rate, solvent type on the photoluminescence properties of the spray-deposited ZnO nanorods. A dominant near band edge (NBE emission is observed at 300 K and at 10 K. High-resolution photoluminescence measurements at 10 K reveal fine structure of the NBE band with the dominant peaks related to the bound exciton transitions. It is found that all studied technological parameters affect the excitonic photoluminescence in ZnO nanorods. PACS: 78.55.Et, 81.15.Rs, 61.46.Km

  18. Development of granular powder manufacturing technology by spray pyrolysis

    International Nuclear Information System (INIS)

    Katoh, Yoshiyuki; Kawase, Keiichi; Takahashi, Yoshiharu; Todokoro, Akio

    1996-01-01

    For shortening of mixed-oxide (MOX) fuel manufacturing process and improvement in treatment of MOX-powder, we have been developing the granular powder production technology. Since the granular powders have excellent fluidity owing to the spherical shape, there is the possibility of modifying scattering and adcering of the powder in the process equipment. In this paper, spray pyrolysis process in adopted as the process of manufacturing the granular powders and the basic feasibility study has been carried out. The experimental results show that the manufactured granular powders have excellent fluidity and the diameter of the powders is controllable. Furthermore, high density pellets are formed by sintering the powders. Thus, it is clarified that this process is promising for the actual MOX fuel fabrication. (author)

  19. Morphology and formation mechanism of ceria nanoparticles by spray pyrolysis

    International Nuclear Information System (INIS)

    Shih, Shao-Ju; Wu, Ying-Ying; Chen, Chin-Yi; Yu, Chin-Yang

    2012-01-01

    Ceria-based materials are used in industrial applications such as catalyst supports, carbon monoxide reduction catalysts, and solid oxide fuel cell electrolytes. Various applications require different morphological particles. The ceria particles with various morphologies from the precursors of cerium(III) acetate hydrate, cerium(IV) nitrate hydrate, and cerium(IV) ammonium nitrate were prepared by spray pyrolysis (SP) because SP has the potential for simple and continuous process. The precursor behaviors and the particle morphologies were characterized by thermogravimetric analysis and by transmission electron microscopy. Four main morphologies of solid spherical, hollow spherical with a single pore, hollow concave, and hollow spherical with multiple pores were observed. The experimental results suggest that the morphological formation mechanism is highly correlated with the factors of precursor solubilities, solvent evaporation rates (droplet diameters), and precursor melting temperatures. In addition, total concentrations of cerium(III) in the ceria particles from various precursors were examined using X-ray photoelectron spectroscopy.

  20. ZnO layers prepared by spray pyrolysis

    Science.gov (United States)

    Messaoudi, C.; Abd-Lefdil, S.; Sayah, D.; Cadene, M.

    1998-02-01

    Highly transparent undoped and indium doped ZnO thin films have been grown on glass substrates by using the spray pyrolysis process. Conditions of preparation have been optimized to get good quality and reproducible films with required properties. Polycrystalline films with an hexagonal Wurtzite-type structure were easily obtained under the optimum spraying conditions. Both of samples have shown high transmission coefficient in the visible and infrared wavelength range with sharp absorption edge around 380 nm which closely corresponds to the intrinsic band-gap of ZnO (3.2 eV). Orientation and crystallites size were remarkably modified by deposition temperature and indium doping. Des couches minces de ZnO, hautement transparentes, non dopées et dopées à l'indium ont été élaborées sur un substrat en verre par le procédé de pulvérisation chimique réactive spray. Les conditions de préparation ont été optimisées pour l'obtention de couches reproductibles, de bonne qualité et ayant les propriétés requises. Des films polycristallins, présentant une structure hexagonale de type Wurtzite, ont été aisément obtenus dans les conditions optimales de pulvérisation. Tous les échantillons ont présenté un coefficient de transmission élevé dans le domaine du visible et du proche infrarouge, avec une absorption brutale au voisinage de 380 nm, correspondant au gap optique du ZnO (3,2 eV). L'orientation et la taille des cristallites ont été remarquablement modifiées par la température du dépôt et par le dopage à l'indium.

  1. Morphological, structural and electrochemical properties of lithium iron phosphates synthesized by Spray Pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, L.S. [Universidad Carlos III de Madrid and IAAB, Avda. de la Universidad, 30, 28911 Leganes, Madrid (Spain); Meatza, I. de [Dpto. Energia, CIDETEC, Po Miramon 196, Parque Tecnologico de San Sebastian, 20009 Donostia-San Sebastian (Spain); Martin, M.I., E-mail: imartin@ietcc.csic.e [Universidad Carlos III de Madrid and IAAB, Avda. de la Universidad, 30, 28911 Leganes, Madrid (Spain); Bengoechea, M. [Dpto. Energia, CIDETEC, Po Miramon 196, Parque Tecnologico de San Sebastian, 20009 Donostia-San Sebastian (Spain); Cantero, I. [Dpto. I-D-i Nuevas Tecnologias, CEGASA, Artapadura, 11, 01013 Vitoria-Gasteiz (Spain); Rabanal, M.E., E-mail: mariaeugenia.rabanal@uc3m.e [Universidad Carlos III de Madrid and IAAB, Avda. de la Universidad, 30, 28911 Leganes, Madrid (Spain)

    2010-03-01

    In the field of materials for lithium ion batteries, the lithium iron phosphate LiFePO{sub 4} has been proven for use as a positive electrode due to its good resistance to thermal degradation and overcharge, safety and low cost. The use of nanostructured materials would improve its efficiency. This work shows the results of the synthesis of nanostructured materials with functional properties for lithium batteries through aerosol techniques. The Spray Pyrolysis method allows synthesizing nanostructured particles with spherical geometry, not agglomerates, with narrow distribution of particle size and homogeneous composition in respect to a precursor solution. Experimental techniques were focused on the morphological (SEM and TEM), structural (XRD and HRTEM-SAED), chemical (EDS) and electrochemical characterization.

  2. Morphological, structural and electrochemical properties of lithium iron phosphates synthesized by Spray Pyrolysis

    International Nuclear Information System (INIS)

    Gomez, L.S.; Meatza, I. de; Martin, M.I.; Bengoechea, M.; Cantero, I.; Rabanal, M.E.

    2010-01-01

    In the field of materials for lithium ion batteries, the lithium iron phosphate LiFePO 4 has been proven for use as a positive electrode due to its good resistance to thermal degradation and overcharge, safety and low cost. The use of nanostructured materials would improve its efficiency. This work shows the results of the synthesis of nanostructured materials with functional properties for lithium batteries through aerosol techniques. The Spray Pyrolysis method allows synthesizing nanostructured particles with spherical geometry, not agglomerates, with narrow distribution of particle size and homogeneous composition in respect to a precursor solution. Experimental techniques were focused on the morphological (SEM and TEM), structural (XRD and HRTEM-SAED), chemical (EDS) and electrochemical characterization.

  3. Properties of Spray Pyrolysied Copper Oxide Thin Films

    Directory of Open Access Journals (Sweden)

    S. S. Roy

    2017-02-01

    Full Text Available Copper oxide (CuO thin films were deposited on well cleaned glass substrates by spray pyrolysis technique (SPT from cupric acetate (Cu(CH3COO2.H2O precursor solutions of 0.05 – 0.15 M molar concentrations (MC at a substrate temperature of 350 °C and at an air pressure of 1 bar. Effect of varying MC on the surface morphology, structural optical and electrical properties of CuO thin films were investigated. XRD patterns of the prepared films revealed the formation of CuO thin films having monoclinic structure with the main CuO (111 orientation and crystalline size ranging from 8.02 to 9.05 nm was observed. The optical transmission of the film was found to decrease with the increase of MC. The optical band gap of the thin films for 0.10 M was fond to be 1.60 eV. The room temperature electrical resistivity varies from 31 and 24 ohm.cm for the films grown with MC of 0.05 and 0.10 M respectively. The change in resistivity of the films was studied with respect to the change in temperature was shown that semiconductor nature is present. This information is expected to underlie the successful development of CuO films for solar windows and other semi-conductor applications including gas sensors.

  4. Investigation of discharged aerosol nanoparticles during chemical precipitation and spray pyrolysis for developing safety measures in the nano research laboratory.

    Science.gov (United States)

    Kolesnikov, Еvgeny; Karunakaran, Gopalu; Godymchuk, Anna; Vera, Levina; Yudin, Andrey Grigorjevich; Gusev, Alexander; Kuznetsov, Denis

    2017-05-01

    Nowadays, the demands for the nanoparticles are increasing due to their tremendous applications in various fields. As a consequence, the discharge of nanoparticles into the atmosphere and environment is also increasing, posing a health threat and environmental damage in terms of pollution. Thus, an extensive research is essential to evaluate the discharge of these nanoparticles into the environment. Keeping this in mind, the present investigation aimed to analyze the discharge of aerosol nanoparticles that are synthesized in the laboratory via chemical precipitation and spray pyrolysis methods. The results indicated that the chemical precipitation method discharges a higher concentration of nanoparticles in the work site when compared to the spray pyrolysis method. The aerosol concentration also varied with the different steps involved during the synthesis of nanoparticles. The average particle's concentration in air for chemical precipitation and spray pyrolysis methods was around 1,037,476 and 883,421particles/cm 3 . In addition, the average total discharge of nanoparticles in the entire laboratory was also examined. A significant variation in the concentration of nanoparticles was noticed, during the processing of materials and the concentration of particles (14-723nm) exceeding the daily allowed concentration to about 70-170 times was observed over a period of 6 months. Thus, the results of the present study will be very useful in developing safety measures and would help in organizing the rules for people working in nanotechnology laboratories to minimize the hazardous effects. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Study on condensation of biomass pyrolysis gas by spray bio-oil droplets

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Kun; Cheng, Wen-Long [University of Science and Technology of China (China)], email: wlcheng@ustc.edu.cn; Chen, Jing [Anhui Electric Power Design Institute (China); Shi, Wen-Jing [Anhui Heli Co., Ltd (China)

    2011-07-01

    This is a study of bio-oil generated by fast pyrolysis; a biomass feedstock is heated to pyrolyze at a rapid rate, the gas pyrolyzed is then condensed rapidly. The interesting result is a potential alternative fuel oil. An analysis was made of the effects of the initial pyrolysis gas temperatures, the initial bio-oil droplets temperatures and diameters, and the flow ratio of the gas and the liquid droplets on the heat and mass transfer between the gas and the liquid droplets. A few criterion equations were achieved with respect to the spray condenser. This paper established the gas-liquid phase equilibrium of an aqueous multi-composition system and the spray condensation model coupling heat and mass transfer. Model calculation and analysis showed that: spray condensation can effectively cool the high-temperature pyrolysis gas quickly; with gas liquid flowing, mass transfer rate reduces; and the relationship of gas and liquid flow ratio can achieve good accuracy.

  6. Stoichiometry and superconductive properties of YBaCuO films deposited by spray pyrolysis

    International Nuclear Information System (INIS)

    Conde-Gallardo, A.; Falcony, C.; Ortiz, A.

    1994-01-01

    The dependence of the stoichiometry and the superconducting characteristics of YBaCuO films deposited by spray pyrolysis on the spraying solution composition and the deposition conditions is reported. It has been found that a proper optimization of the starting materials concentration in the spraying solution results in superconducting films with zero resistance temperature of 91 K and a transition to superconducting state within a 3 K range. X-ray diffraction and resistance vs temperature measurements have been used to monitor the crystal composition and the conductive characteristics of the films as a function of the spraying solution composition and the deposition parameters

  7. Large-scale manufacture of ZnO nanorods by flame spray pyrolysis

    International Nuclear Information System (INIS)

    Hembram, K.; Sivaprakasam, D.; Rao, T. N.; Wegner, K.

    2013-01-01

    Large quantities of ZnO nanorods (>3 kg/h throughput) were produced in the gas-phase by flame spray pyrolysis (FSP) of a zinc nitrate–ethanol precursor solution without employing any catalysts or dopants. The nanorods with diameters of 20–30 nm and aspect ratios as high as seven were collected as a dry powder. Several rods self-aligned by forming junctions at the basal planes, while some even assembled into tetrapods. The aspect ratio of the nanorods could be controlled by the concentration of the Zn ions in the starting precursor solution, its delivery rate, and the oxygen flow into the reactor. To the best of our knowledge, this is the first time that synthesis of high aspect ratio ZnO nanorods by FSP is reported. Previous lab-scale experiments always yielded rather spherical albeit slightly elongated nanoparticles unless dopants were added. Such a product powder was obtained here when the ethanol in the precursor solution was replaced by methanol at otherwise constant process conditions. This is attributed to different temperature–time histories of the particles in the flame based on which a mechanism for ZnO nanorod formation in spray flames is proposed.

  8. Nanocrystalline Pt-doped TiO2 thin films prepared by spray pyrolysis ...

    Indian Academy of Sciences (India)

    Administrator

    Spray pyrolysis techniques; TiO2 thin films; hydrogen gas response. 1. Introduction ... tion is necessary during the production, storage and use of hydrogen. It is also ..... ient, and 'green': it may be used to large scale industrial application for ...

  9. Fabrication of ZnO nanorod using spray-pyrolysis and chemical bath deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Ramadhani, Muhammad F., E-mail: brian@tf.itb.ac.id; Pasaribu, Maruli A. H., E-mail: brian@tf.itb.ac.id; Yuliarto, Brian, E-mail: brian@tf.itb.ac.id; Nugraha, E-mail: brian@tf.itb.ac.id [Advanced Functional Materials Laboratory, Engineering Physics Department Faculty of Industrial Technology, Institut Teknologi Bandung (Indonesia)

    2014-02-24

    ZnO thin films with nanorod structure were deposited using Ultrasonic Spray Pyrolysis method for seed growth, and Chemical Bath Deposition (CBD) for nanorod growth. High purity Zn-hydrate and Urea are used to control Ph were dissolved in ethanol and aqua bidest in Ultrasonic Spray Pyrolysis process. Glass substrate was placed above the heater plate of reaction chamber, and subsequently sprayed with the range duration of 5, 10 and 20 minutes at the temperatures of 3500 C. As for the Chemical Bath Deposition, the glass substrate with ZnO seed on the surface was immerse to Zn-hydrate, HMTA (Hexa Methylene Tetra Amine) and deionized water solution for duration of 3, 5 and 7 hour and temperatures of 600 C, washed in distilled water, dried, and annealed at 3500 C for an hour. The characterization of samples was carried out to reveal the surface morphology using Scanning Electron Microscopy (SEM). From the data, the combination of 5 minutes of Ultrasonic Spray Pyrolysis process and 3 hour of CBD has showed the best structure of nanorod. Meanwhile the longer Spraying process and CBD yield the bigger nanorod structure that have been made, and it makes the films more dense which make the nanorod collide each other and as a result produce unsymetric nanorod structure.

  10. Spectroscopic and luminescent properties of Co2+ doped tin oxide thin films by spray pyrolysis

    Directory of Open Access Journals (Sweden)

    K. Durga Venkata Prasad

    2016-07-01

    Full Text Available The wide variety of electronic and chemical properties of metal oxides makes them exciting materials for basic research and for technological applications alike. Oxides span a wide range of electrical properties from wide band-gap insulators to metallic and superconducting. Tin oxide belongs to a class of materials called Transparent Conducting Oxides (TCO which constitutes an important component for optoelectronic applications. Co2+ doped tin oxide thin films were prepared by chemical spray pyrolysis synthesis and characterized by powder X-ray diffraction, SEM, TEM, FT-IR, optical, EPR and PL techniques to collect the information about the crystal structure, coordination/local site symmetry of doped Co2+ ions in the host lattice and the luminescent properties of the prepared sample. Powder XRD data revealed that the crystal structure belongs to tetragonal rutile phase and its lattice cell parameters are evaluated. The average crystallite size was estimated to be 26 nm. The morphology of prepared sample was analyzed by using SEM and TEM studies. Functional groups of the prepared sample were observed in the FT-IR spectrum. Optical absorption and EPR studies have shown that on doping, Co2+ ions enter in the host lattice as octahedral site symmetry. PL studies of Co2+ doped SnO2 thin films exhibit blue and yellow emission bands. CIE chromaticity coordinates were also calculated from emission spectrum of Co2+ doped SnO2 thin films.

  11. Highly doped ZnO films deposited by spray-pyrolysis. Design parameters for optoelectronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Garcés, F.A., E-mail: felipe.garces@santafe-conicet.gov.ar [Instituto de Física del Litoral (UNL-CONICET), Güemes 3450, Santa Fe S3000GLN (Argentina); Budini, N. [Instituto de Física del Litoral (UNL-CONICET), Güemes 3450, Santa Fe S3000GLN (Argentina); Schmidt, J.A.; Arce, R.D. [Instituto de Física del Litoral (UNL-CONICET), Güemes 3450, Santa Fe S3000GLN (Argentina); Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829, Santa Fe S3000AOM (Argentina)

    2016-04-30

    Synthesis and preparation of ZnO films are relevant subjects for obtaining transparent and conducting layers with interesting applications in optoelectronics and photovoltaics. Optimization of parameters such as dopant type and concentration, deposition time and substrate temperature is important for obtaining ZnO layers with optimal properties. In this work we present a study about the induced effects of deposition time on optical and electrical properties of ZnO thin films. These films were deposited by spray pyrolysis of a suitable Zn precursor, obtained through the sol–gel method. The deposition time has direct incidence on internal stress in the crystal structure, generating defects that may affect transparency and electrical transport into the layers. We performed mosaicity measurements, through X-ray diffraction, and used it as a tool to get an insight on structural characteristics and homogeneity of ZnO layers. Also, through this technique, we analyzed thickness and doping effects on crystallinity and carrier transport properties. - Highlights: • Al-doped ZnO films with high conductivity and moderate Hall mobility were obtained. • Mosaicity between crystalline domains increased with film thickness. • Lattice parameters a and c diminished linearly as a function of Al concentration. • First steps for developing porous silicon/doped ZnO heterojunctions were presented.

  12. Highly doped ZnO films deposited by spray-pyrolysis. Design parameters for optoelectronic applications

    International Nuclear Information System (INIS)

    Garcés, F.A.; Budini, N.; Schmidt, J.A.; Arce, R.D.

    2016-01-01

    Synthesis and preparation of ZnO films are relevant subjects for obtaining transparent and conducting layers with interesting applications in optoelectronics and photovoltaics. Optimization of parameters such as dopant type and concentration, deposition time and substrate temperature is important for obtaining ZnO layers with optimal properties. In this work we present a study about the induced effects of deposition time on optical and electrical properties of ZnO thin films. These films were deposited by spray pyrolysis of a suitable Zn precursor, obtained through the sol–gel method. The deposition time has direct incidence on internal stress in the crystal structure, generating defects that may affect transparency and electrical transport into the layers. We performed mosaicity measurements, through X-ray diffraction, and used it as a tool to get an insight on structural characteristics and homogeneity of ZnO layers. Also, through this technique, we analyzed thickness and doping effects on crystallinity and carrier transport properties. - Highlights: • Al-doped ZnO films with high conductivity and moderate Hall mobility were obtained. • Mosaicity between crystalline domains increased with film thickness. • Lattice parameters a and c diminished linearly as a function of Al concentration. • First steps for developing porous silicon/doped ZnO heterojunctions were presented.

  13. Spray pyrolysis deposition and photoelectrochemical properties of n-type BiOI nanoplatelet thin films.

    Science.gov (United States)

    Hahn, Nathan T; Hoang, Son; Self, Jeffrey L; Mullins, C Buddie

    2012-09-25

    Bismuth oxy-iodide is a potentially interesting visible-light-active photocatalyst; yet there is little research regarding its photoelectrochemical properties. Herein we report the synthesis of BiOI nanoplatelet photoelectrodes by spray pyrolysis on fluorine-doped tin oxide substrates at various temperatures. The films exhibited n-type conductivity, most likely due to the presence of anion vacancies, and optimized films possessed incident photon conversion efficiencies of over 20% in the visible range for the oxidation of I(-) to I(3)(-) at 0.4 V vs Ag/AgCl in acetonitrile. Visible-light photons (λ > 420 nm) contributed approximately 75% of the overall photocurrent under AM1.5G illumination, illustrating their usefulness under solar light illumination. A deposition temperature of 260 °C was found to result in the best performance due to the balance of morphology, crystallinity, impurity levels, and optical absorption, leading to photocurrents of roughly 0.9 mA/cm(2) at 0.4 V vs Ag/AgCl. Although the films performed stably in acetonitrile, their performance decreased significantly upon extended exposure to water, which was apparently caused by a loss of surface iodine and subsequent formation of an insulating bismuth hydroxide layer.

  14. Surfactant Assisted Stabilization of Carbon Nanotubes Synthesized by a Spray Pyrolysis Method

    Directory of Open Access Journals (Sweden)

    D. Mendoza-Cachú

    2017-01-01

    Full Text Available Surface modification of carbon nanotubes has been an interesting issue from a composites materials point of view. A nanotubes agglomeration has to be avoided to achieve a homogeneous dispersion in a composite matrix. In this research, we report on the synthesis of carbon nanotubes using a variant of the chemical vapor deposition technique known as spray pyrolysis method. X-ray diffraction (XRD, transmission electron microscopy (TEM, and scanning electron microscopy (SEM studies showed that the synthesized products had an aligned structure with low purity degree, high content of catalyst particles, and a smaller amount of amorphous carbon. A secondary method was applied, which involves an acidic treatment that dissolves contaminant particles to enhance the purity of the nanotubes. Microstructural analysis, which includes XRD and SEM, indicates an effective reduction of impurities. Dispersion of the nanotubes was assessed using different surfactants, such as sodium dodecyl-sulfate (SDS and ethylenediaminetetraacetic acid (EDTA. Finally, Raman spectroscopy, UV-Vis, and SEM techniques confirm that better results were obtained with EDTA. For EDTA and SDS surfactants, low concentrations of 0.3 mg/mL and 0.2 mg/mL were most efficient, respectively.

  15. Optical and electrical characteristics of zirconium oxide thin films deposited on silicon substrates by spray pyrolysis

    International Nuclear Information System (INIS)

    Aguilar-Frutis, M.; Araiza, J.J.; Falcony, C.; Garcia, M.

    2002-01-01

    The optical and electrical characteristics of zirconium oxide thin films deposited by spray pyrolysis on silicon substrates are reported. The films were deposited from a spraying solution of zirconium acetylacetonate in N,N-dimethylformamide using an ultrasonic mist generator on (100) Si substrates. The substrate temperature during deposition was in the range of 400 to 600 grad C. Deposition rates up to 16 A/sec were obtained depending on the spraying solution concentration and on the substrate temperature. A refraction index of the order of 2.0 was measured on these films by ellipsometry. The electrical characteristics of the films were determined from the capacitance and current versus voltage measurements. The addition of water mist during the spraying deposition process was also studied in the characteristics of the films. (Authors)

  16. Spray pyrolysis of doped-ceria barrier layers for solid oxide fuel cells

    DEFF Research Database (Denmark)

    Szymczewska, Dagmara; Chrzan, Aleksander; Karczewski, Jakub

    2017-01-01

    Gadolinium doped ceria (Ce0.8Gd0.2O2 − x-CGO) layer fabricated by spray pyrolysis is investigated as the diffusion barrier for solid oxide fuel cell. It is deposited between the La0.6Sr0.4FeO3 − δ cathode and the yttria stabilized zirconia electrolyte to mitigate harmful interdiffusion...

  17. Macro controlling of copper oxide deposition processes and spray mode by using home-made fully computerized spray pyrolysis system

    Science.gov (United States)

    Essa, Mohammed Sh.; Chiad, Bahaa T.; Shafeeq, Omer Sh.

    2017-09-01

    Thin Films of Copper Oxide (CuO) absorption layer have been deposited using home-made Fully Computerized Spray Pyrolysis Deposition system FCSPD on glass substrates, at the nozzle to substrate distance equal to 20,35 cm, and computerized spray mode (continues spray, macro-control spray). The substrate temperature has been kept at 450 °c with the optional user can enter temperature tolerance values ± 5 °C. Also that fixed molar concentration of 0.1 M, and 2D platform speed or deposition platform speed of 4mm/s. more than 1000 instruction program code, and specific design of graphical user interface GUI to fully control the deposition process and real-time monitoring and controlling the deposition temperature at every 200 ms. The changing in the temperature has been recorded during deposition processes, in addition to all deposition parameters. The films have been characterized to evaluate the thermal distribution over the X, Y movable hot plate, the structure and optical energy gap, thermal and temperature distribution exhibited a good and uniform distribution over 20 cm2 hot plate area, X-ray diffraction (XRD) measurement revealed that the films are polycrystalline in nature and can be assigned to monoclinic CuO structure. Optical band gap varies from 1.5-1.66 eV depending on deposition parameter.

  18. Influence of nature of the substrate in the deposition of yttria-stabilized zirconia by spray pyrolysis

    International Nuclear Information System (INIS)

    Halmenschlager, C.M.; Malfatti, C.F.; Bergmann, C.P.; Neagu, R.

    2012-01-01

    Spray pyrolysis technique consist in spraying a precursor solution on a heated substrate. In the last few decades this process has attracted much attention because of its versatility. Controlling the parameters is possible to produce dense or porous film. Spray pyrolysis has been applied to obtain several materials such as electrodes or electrolytes for SOFC, semiconductors, materials for solar cells and so on. However, some behaviors such as Leidenfrost effect have been poorly considered and it may affect the coating quality. This work aims to evaluate the influence of the substrate and how Leidenfrost effect affects the coating by spray pyrolysis. To achieve this goal yttria-stabilized zirconia solutions made with different solvents were deposited on different substrates at different temperatures. These coatings were characterized by X-ray diffraction and scanning electron microscopy. The results show that there is a limit temperature which is related to properties of the solvent and the surface of the substrates where films are continuous. (author)

  19. Ceria based protective coatings for steel interconnects prepared by spray pyrolysis

    DEFF Research Database (Denmark)

    Szymczewska, Dagmara; Molin, Sebastian; Chen, Ming

    2014-01-01

    Stainless steels can be used in solid oxide fuel/electrolysis stacks as interconnects. For successful long term operation they require protective coatings, that lower the corrosion rate and block chemical reactions between the interconnect and adjacent layers of the oxygen or the hydrogen electrode....... One of the promising coating materials for the hydrogen side is ceria. Using standard sintering techniques, ceria sinters at around 1400°C which even for a very short exposure would destroy the interconnect. Therefore in this paper a low temperature deposition method, i.e. spray pyrolysis, is used...

  20. The growth of aligned carbon nanotubes on quartz substrate by spray pyrolysis of hexane

    International Nuclear Information System (INIS)

    Sadeghian, Zahra

    2008-01-01

    Vertically aligned multiwall carbon nanotubes were grown by spray pyrolysis of hexane as the carbon source in the presence of ferrocene as catalyst precursor on a quartz substrate. In recent work we used optimal experimental parameters for the feeding method, reactor conditions, reaction temperature and time, concentration of catalyst and flow rate of feed and gas. The process parameters were chosen so as to obtain multiwall carbon nanotubes and aligned multiwall carbon nanotubes. The tubes are around 15-80 nm in diameter. The morphology and structure of the samples were characterized by x-ray diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy analyses

  1. Electron microscopy and EXAFS studies on oxide-supported gold-silver nanoparticles prepared by flame spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Hannemann, Stefan [Institute of Chemical and Bioengineering, Swiss Federal Institute of Technology, ETH Hoenggerberg, CH-8093 Zurich (Switzerland); Grunwaldt, Jan-Dierk [Institute of Chemical and Bioengineering, Swiss Federal Institute of Technology, ETH Hoenggerberg, CH-8093 Zurich (Switzerland)]. E-mail: grunwaldt@chem.ethz.ch; Krumeich, Frank [Laboratory of Inorganic Chemistry, Swiss Federal Institute of Technology, ETH Hoenggerberg, CH-8093 Zurich (Switzerland); Kappen, Peter [Department of Physics, La Trobe University, Victoria 3086 (Australia); Baiker, Alfons [Institute of Chemical and Bioengineering, Swiss Federal Institute of Technology, ETH Hoenggerberg, CH-8093 Zurich (Switzerland)

    2006-09-15

    Gold and gold-silver nanoparticles prepared by flame spray pyrolysis (FSP) were characterized by electron microscopy, in situ X-ray absorption spectroscopy (XANES and EXAFS), X-ray diffraction (XRD) and their catalytic activity in CO oxidation. Within this one-step flame-synthesis procedure, precursor solutions of dimethyl gold(III) acetylacetonate and silver(I) benzoate together with the corresponding precursor of the silica, iron oxide or titania support, were sprayed and combusted. In order to prepare small metal particles, a low noble metal loading was required. A loading of 0.1-1 wt.% of Au and Ag resulted in 1-6 nm particles. The size of the noble metal particles increased with higher loadings of gold and particularly silver. Both scanning transmission electron microscopy (STEM) combined with energy dispersive X-ray spectroscopy (EDXS) and X-ray absorption spectroscopy (XAS) studies proved the formation of mixed Au-Ag particles. In case of 1% Au-1% Ag/SiO{sub 2}, TEM combined with electron spectroscopic imaging (ESI) using an imaging filter could be used in addition to prove the presence of silver and gold in the same noble metal particle. CO oxidation in the presence of hydrogen was chosen as a test reaction sensitive to small gold particles. Both the influence of the particle size and the alloying of gold and silver were reflected in the CO oxidation activity.

  2. Electron microscopy and EXAFS studies on oxide-supported gold-silver nanoparticles prepared by flame spray pyrolysis

    International Nuclear Information System (INIS)

    Hannemann, Stefan; Grunwaldt, Jan-Dierk; Krumeich, Frank; Kappen, Peter; Baiker, Alfons

    2006-01-01

    Gold and gold-silver nanoparticles prepared by flame spray pyrolysis (FSP) were characterized by electron microscopy, in situ X-ray absorption spectroscopy (XANES and EXAFS), X-ray diffraction (XRD) and their catalytic activity in CO oxidation. Within this one-step flame-synthesis procedure, precursor solutions of dimethyl gold(III) acetylacetonate and silver(I) benzoate together with the corresponding precursor of the silica, iron oxide or titania support, were sprayed and combusted. In order to prepare small metal particles, a low noble metal loading was required. A loading of 0.1-1 wt.% of Au and Ag resulted in 1-6 nm particles. The size of the noble metal particles increased with higher loadings of gold and particularly silver. Both scanning transmission electron microscopy (STEM) combined with energy dispersive X-ray spectroscopy (EDXS) and X-ray absorption spectroscopy (XAS) studies proved the formation of mixed Au-Ag particles. In case of 1% Au-1% Ag/SiO 2 , TEM combined with electron spectroscopic imaging (ESI) using an imaging filter could be used in addition to prove the presence of silver and gold in the same noble metal particle. CO oxidation in the presence of hydrogen was chosen as a test reaction sensitive to small gold particles. Both the influence of the particle size and the alloying of gold and silver were reflected in the CO oxidation activity

  3. Low-temperature growth of highly crystallized transparent conductive fluorine-doped tin oxide films by intermittent spray pyrolysis deposition

    Energy Technology Data Exchange (ETDEWEB)

    Fukano, Tatsuo; Motohiro, Tomoyoshi [Toyota Central Research and Development Laboratories Inc., Nagakute, Aichi 480-1192 (Japan)

    2004-05-30

    Following the procedure by Sawada et al. (Thin Solid Films 409 (2002) 46), high-quality SnO{sub 2}:F films were grown on glass substrates at relatively low temperatures of 325-340C by intermittent spray pyrolysis deposition using a perfume atomizer for cosmetics use. Even though the substrate temperature is low, as-deposited films show a high optical transmittance of 92% in the visible range, a low electric resistivity of 5.8x10{sup -4}{omega}cm and a high Hall mobility of 28cm{sup 2}/Vs. The F/Sn atomic ratio (0.0074) in the films is low in comparison with the value (0.5) in the sprayed solution. The carrier density in the film is approximately equal to the F-ion density, suggesting that most of the F-ions effectively function as active dopants. Films' transmittance and resistivity show little change after a 450C 60min heat treatment in the atmosphere, evidencing a high heat resistance. The SnO{sub 2}:F films obtained in this work remove the difficulty to improve the figure of merit at low synthesis temperatures.

  4. Influence of solvent on the morphology and microstructure of YSZ films obtained by spray pyrolysis technique

    International Nuclear Information System (INIS)

    Falcade, T.; Oliveira, G.B.; Mueller, I.L.; Malfatti, C.F.

    2010-01-01

    This work aims to investigate the influence of solvent used for the deposition of thin films of yttria stabilized zirconia (YSZ) on porous substrate. The films were obtained directly on the porous LSM substrate by spray pyrolysis technique, which consists of spraying a precursor solution containing salts of zirconium (Zr (C 6 H 7 O 2 ) 4) and yttrium (YCl 3 .6H 2 O), dissolved in specific solvents, on the heated substrate. The use of solvents with different boiling points and viscosity aims the optimization of experimental operating parameters to obtain homogeneous and dense films suitable for application as electrolyte in fuel cells, solid oxide (SOFC). The films were characterized by scanning electron microscopy, infrared spectroscopy and X-ray diffraction. (author)

  5. Growth and properties of ZnO films on polymeric substrate by spray pyrolysis method

    Energy Technology Data Exchange (ETDEWEB)

    Kriisa, Merike; Kärber, Erki [Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Krunks, Malle, E-mail: malle.krunks@ttu.ee [Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Mikli, Valdek [Centre for Materials Research, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Unt, Tarmo; Kukk, Mart; Mere, Arvo [Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia)

    2014-03-31

    The growth of ZnO layers deposited by spray pyrolysis on polymeric substrate was studied. Zinc acetate precursor solution was sprayed onto preheated polyimide (PI) and glass reference substrates at 380 °C. The structural, morphological, optical and electrical properties of the layers were measured by X-ray diffraction, scanning electron microscopy, optical spectroscopy and van der Pauw and Hall method. ZnO:In layers could be grown on PI when deposited onto undoped ZnO layer acting as a buffer layer on PI. Independent of the substrate type, the ZnO/ZnO:In bilayer showed a mixed morphology from smooth canvas-like surface to large scrolled belt grains dependent on buffer layer morphology. Due to the formation of scrolled belts, the ZnO:In layer shows no preferential orientation, yet the preferred orientation of the ZnO buffer crystallites is (100) plane parallel to the substrate. The bilayers deposited on PI exhibit high light scattering capability (haze factor of 85–95% in the spectral region of 350–1500 nm). The resistivity of the ZnO:In film in bilayer on PI is 4.4 × 10{sup −2} Ω cm mainly due to low carrier mobility of 1.5 cm{sup 2}/Vs, the carrier concentration is 10{sup 20} cm{sup −3}. - Highlights: • ZnO:In layers were grown on polyimide substrate by spray pyrolysis. • The buffer layer morphology is controlled by the layer thickness and spray rate. • ZnO/ZnO:In bilayer morphology is dependent on the surface of buffer layer. • Rough buffer layer leads to rough bilayer with scrolled belts (diameter of 2–6 μm). • Due to scrolled belts layers show no preferential growth yet highly scatter light.

  6. Photoluminescence in Spray Pyrolysis Deposited β-In2S3 Thin Films

    Science.gov (United States)

    Jayakrishnan, R.

    2018-04-01

    Spray pyrolysis deposited In2S3 thin films exhibit two prominent photoluminescent emissions. One of the emissions is green in color and centered at around ˜ 540 nm and the other is centered at around ˜ 690 nm and is red in color. The intensity of the green emission decreases when the films are subjected to annealing in air or vacuum. The intensity of red emission increases when films are air annealed and decreases when vacuum annealed. Vacuum annealing leads to an increase in work function whereas air annealing leads to a decrease in work function for this thin film system relative to the as deposited films indicating changes in space charge regions. Surface photovoltage analysis using a Kelvin probe leads to the conclusion that inversion of band bending occurs as a result of annealing. Correlating surface contact potential measurements using a Kelvin probe, x-ray photoelectron spectroscopy and photoluminescence, we conclude that the surface passivation plays a critical role in controlling the photoluminescence from the spray pyrolysis deposited for In2S3 thin films.

  7. Synthesis of carbon nanomaterials from different pyrolysis techniques: a review

    Science.gov (United States)

    Umer Zahid, Muhammad; Pervaiz, Erum; Hussain, Arshad; Shahzad, Muhammad Imran; Niazi, Muhammad Bilal Khan

    2018-05-01

    In the current age, the significance of carbon-based nanomaterials for many applications has made the efforts for the facile synthesis methods from abundantly available wastes in a cost-effective way. Pyrolysis in a broad spectrum is commonly employed for the synthesis of carbon nanostructures by thermally treating the organic waste. The mechanism of growth of the nanoparticles determines the functional distribution of nanoparticles based on the growing size, medium, and physio-chemical properties. Carbon nanomaterial’s growth is a complicated process which is profoundly influenced by temperature, catalyst, and type of precursor. Nowadays, significant progress has been made in improving nanomaterial’s growth techniques, opening new paths for commercial production of carbon-based nanomaterials. The most promising are the methods involving hydrocarbon-rich organic waste as the feed source. In this review, synthesis of carbon-based nanomaterials, specifically carbon nanotubes (CNTs), Carbon nanofibers (CNFs) and Graphene (G) are discussed by different pyrolysis techniques. Furthermore, the review explores recent advancements made in the context of pyrolysis.

  8. Coal pyrolysis under synthesis gas, hydrogen and nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Ariunaa, A.; Li Bao-Qing; Li Wen; Purevsuren, B. (and others) [Chinese Academy of Sciences, Taiyuan (China)

    2007-02-15

    Chinese Xundian, Mongolian Shiveeovoo lignites and Khoot oil shale are pyrolyzed under synthesis gas (SG) at temperature range from 400 to 800{sup o}C for lignite and from 300 to 600{sup o}C for oil shale with heating rate of 10{sup o}C/min in a fixed bed reactor. The results were compared with those obtained by pyrolysis under hydrogen and nitrogen. The results showed that unlike pyrolysis at high pressure, there are only slight different in the yields of char and tar among pyrolyses under various gases at room pressure for lignite, while higher liquid yield with lower yields of char and gas was obtained in pyrolysis of oil shale under SG and H{sub 2} than under N{sub 2}. It is found that the pyrite S can be easily removed to partially convert to organic S under various gaseous atmosphere and the total sulfur removal for oil shale is much less than lignite, which might be related to its high ash content. The higher total sulfur removal and less organic S content in the presence of SG in comparison with those under N{sub 2} and even under H{sub 2} in pyrolysis of Xundian lignite might result from the action of CO in SG. However, CO does not show its function in pyrolysis of Khoot oil shale, which might also be related to the high ash content. The results reported show the possibility of using synthesis gas instead of pure hydrogen as the reactive gas for coal hydropyrolysis. 11 refs., 4 figs., 6 tabs.

  9. Photovoltaic properties of undoped ZnO thin films prepared by the spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Ikhmayies, S.J. [Applied Science Private Univ., Amman (Jordan). Dept. of Physics; Abu El-Haija, N.M.; Ahmad-Bitar, R.N. [Jordan Univ., Amman (Jordan). Dept. of Physics

    2009-07-01

    Zinc oxide (ZnO) can be used as a window material, transparent electrode and active layer in different types of solar cells, UV emitters, and UV sensors. In addition to being low cost, ZnO is more abundant than indium tin oxide. ZnO is non toxic and has a high chemical stability in reduction environments. When ZnO films are made without any intentional doping, they exhibit n-type conductivity. ZnO thin films can be prepared by reactive sputtering, laser ablation, chemical-vapour deposition, laser molecular-beam epitaxy, thermal evaporation, sol-gel, atomic layer deposition and spray pyrolysis, with the latter being simple, inexpensive and adaptable to large area depositions. In this work ZnCl{sub 2} was used as a source of Zn where it was dissolved in distilled water. The structural, electrical and optical properties of the films were investigated due to their important characteristic for solar cell applications. Polycrystalline ZnO thin films were deposited on glass substrate by spray pyrolysis using a home-made spraying system at substrate temperature of 450 degrees C. The films were characterized by recording and analyzing their I-V plots, their transmittance, X-ray diffraction and SEM micrographs. There resistivity was found to be about 200 ohms per cm and their bandgap energy about 3.27 eV. X-ray diffraction patterns revealed that the films have a hexagonal wurtzite structure and are highly ordered with a preferential orientation (002). SEM images revealed that the substrates are continuously covered and the surface of the film is uniform. 16 refs., 4 figs.

  10. Low-cost plasmonic solar cells prepared by chemical spray pyrolysis

    Directory of Open Access Journals (Sweden)

    Erki Kärber

    2014-12-01

    Full Text Available Solar cells consisting of an extremely thin In2S3/CuInS2 buffer/absorber layer uniformly covering planar ZnO were prepared entirely by chemical spray pyrolysis. Au nanoparticles (Au-NPs were formed via thermal decomposition of a gold(III chloride trihydrate (HAuCl4·3H2O precursor by spraying 2 mmol/L of the aqueous precursor solution onto a substrate held at 260 °C. Current–voltage scans and external quantum efficiency spectra were used to evaluate the solar cell performance. This work investigates the effect of the location of the Au-NP layer deposition (front side vs rear side in the solar cell and the effect of varying the volume (2.5–10 mL of the sprayed Au precursor solution. A 63% increase (from 4.6 to 7.5 mA/cm2 of the short-circuit current density was observed when 2.5 mL of the precursor solution was deposited onto the rear side of the solar cell.

  11. Emission and structure varieties in ZnO:Ag nanorods obtained by ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Lozada, E Velázquez; Torchynska, T V; Espinola, J L Casas

    2014-01-01

    Scanning electronic microscopy (SEM), X ray diffraction (XRD) and photoluminescence (PL) have been applied to the study of the structural and optical properties of ZnO nanocrystals prepared by the ultrasonic spray pyrolysis (USP) at different temperatures. The variation of temperatures and times at the growth of ZnO films permits modifying the ZnO phase from the amorphous to crystalline, to change the size of ZnO nanocrystals (NCs), as well as to vary their photoluminescence spectra. The study has revealed three types of PL bands in ZnO NCs: defect related emission, the near-band-edge (NBE) PL, related to the LO phonon replica of free exciton (FE) recombination, and FE second-order diffraction peaks. The PL bands related to the LO phonon replica of FE in PL spectra measured at room temperature testify on the high quality of ZnO films prepared by the USP technology.

  12. Electrical properties of the n-ZnO/c-Si heterojunction prepared by chemical spray pyrolysis

    International Nuclear Information System (INIS)

    Romero, R.; Lopez, M.C.; Leinen, D.; Martin, F.; Ramos-Barrado, J.R.

    2004-01-01

    Electrical, structural and compositional properties of n-ZnO/c-Si heterojunctions prepared by chemical spray pyrolysis on single-crystal n-type and p-type monocrystalline silicon(1 0 0) substrates are examined with the C-V method and admittance spectroscopy at temperature ranges between 223 and 373 K. The n-ZnO/c-Si heterojunctions show a height barrier consistent with the difference in energy of the work functions of Si and ZnO; however, the n-ZnO:Al/c-Si heterojunctions present a more complex behavior due to the defects at or near the n-ZnO:Al/c-Si interface, causing a Fermi energy pinning

  13. Properties of antimony doped ZnO thin films deposited by spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Sadananda Kumar, N., E-mail: sadanthara@gmail.com; Bangera, Kasturi V.; Shivakumar, G. K. [National Institute of Technology Karnataka, Surathkal, Thin Films Laboratory, Department of Physics (India)

    2015-07-15

    Antimony (Sb) doped zinc oxide (ZnO) thin films were deposited on the glass substrate at 450°C using spray pyrolysis technique. Effect of Sb doping on surface morphology structural, optical and electrical properties were studied. X-ray diffraction (XRD) analysis showed that both the undoped and doped ZnO thin films are polycrystalline in nature with (101) preferred orientation. SEM analysis showed a change in surface morphology of Sb doped ZnO thin films. Doping results in a marked increase in conductivity without affecting the transmittance of the films. ZnO films prepared with 3 at % Sb shows the lowest resistivity of 0.185 Ohm cm with a Hall mobility of 54.05 cm{sup 2} V{sup –1} s{sup –1}, and a hole concentration of 6.25 × 10{sup 17} cm{sup –3}.

  14. Deposition of gold nanoparticles on glass substrate by ultrasonic spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Garza, Maria de la; Hernandez, Tomas [Laboratorio de Materiales I, Centro de Laboratorios Especializados, Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon. Av. Universidad s/n Cd. Universitaria, C.P. 66451, San Nicolas de los Garza, Nuevo Leon (Mexico); Colas, Rafael [Programa Doctoral en Ingenieria de Materiales, Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon. Av. Universidad s/n Cd. Universitaria, C.P. 66451, San Nicolas de los Garza, Nuevo Leon (Mexico); Gomez, Idalia, E-mail: mgomez@fcq.uanl.mx [Laboratorio de Materiales I, Centro de Laboratorios Especializados, Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon. Av. Universidad s/n Cd. Universitaria, C.P. 66451, San Nicolas de los Garza, Nuevo Leon (Mexico)

    2010-10-25

    Ultrasonic spray pyrolysis was used to deposit gold nanoparticles on a glass substrate using ZrO{sub 2} as a surrounding medium. The deposition was made using three flow rates of caring gas. The characterization was made by UV-Vis spectroscopy, X-ray diffraction, scanning electronic microscopy and atomic force microscopy. The UV-Vis spectra showed that the surface plasmon resonance peak, indicative of the presence of gold nanoparticles, was shown to shift towards the red spectrum as the flow rate increased; this shift can be associated to the change in size of the particles, which are assumed to grow on a {l_brace}1 1 1{r_brace} planes, as was detected by X-ray diffraction. Gold nanoparticles of spheroidal morphology with a relation of around 2:1 were detected by scanning electron microscopy, these observations were confirmed by atomic force microscopy.

  15. Structure of alumina supported vanadia catalysts for oxidative dehydrogenation of propane prepared by flame spray pyrolysis

    DEFF Research Database (Denmark)

    Høj, Martin; Jensen, Anker Degn; Grunwaldt, Jan-Dierk

    2013-01-01

    .%. The catalysts were subsequently characterized by BET surface area, X-ray diffraction (XRD), Raman, UV–vis diffuse reflectance and X-ray absorption spectroscopy (XAS) as well as measurement of the catalytic performance. The catalysts had specific surface areas from 143 to 169 m2/g corresponding to average......A series of five vanadia on alumina catalysts for oxidative dehydrogenation of propane to propene were synthesized by flame spray pyrolysis (FSP) using vanadium(III)acetylacetonate and aluminium(III)acetylacetonate dissolved in toluene as precursors. The vanadium loading was 2, 3, 5, 7.5 and 10wt...... X-ray absorption near edge structure (XANES) spectroscopy showed that the vanadia can be reduced when operating at low oxygen concentrations. The catalyst performance was determined in fixed bed reactors with an inlet gas composition of C3H8/O2/N2=5/25/70. The main products were propene, CO and CO2...

  16. Growth and characterization of the ZnO/ZnS bilayer obtained by chemical spray pyrolysis

    International Nuclear Information System (INIS)

    Lopez, M.C.; Espinos, J.P.; Leinen, D.; Martin, F.; Centeno, S.P.; Romero, R.; Ramos-Barrado, J.R.

    2008-01-01

    ZnO/ZnS bilayer antireflection coatings have been prepared by spray pyrolysis using aqueous solutions of zinc acetate and thiourea or zinc chloride and thiourea. The structure, surface morphology, chemical composition and optical transmittance of the bilayer have been examined as a function of the composition of the initial solution. X-ray photoelectron spectroscopy analysis and Ar ion-beam sputter etching was carried out to obtain a depth profile of bilayer. Neither carbon nor other by-products, which could alter the optical transmittance of the bilayer were found in either the interface or bulk. The differences between the bilayers arise from the annealing of the ZnS underlayer, as well as the precursor used to prepare it.

  17. Resistance to Corrosion of Zirconia Coatings Deposited by Spray Pyrolysis in Nitrided Steel

    Science.gov (United States)

    Cubillos, G. I.; Olaya, J. J.; Bethencourt, M.; Cifredo, G.; Blanco, G.

    2013-10-01

    Coatings of zirconium oxide were deposited onto three types of stainless steel, AISI 316L, 2205, and tool steel AISI D2, using the ultrasonic spray pyrolysis method. The effect of the flux ratio on the process and its influence on the structure and morphology of the coatings were investigated. The coatings obtained, 600 nm thick, were characterized using x-ray diffraction, scanning electron microscopy, confocal microscopy, and atomic force microscopy. The resistance to corrosion of the coatings deposited over steel (not nitrided) and stainless steel nitrided (for 2 h at 823 K) in an ammonia atmosphere was evaluated. The zirconia coating enhances the stainless steel's resistance to corrosion, with the greatest increase in corrosion resistance being observed for tool steel. When the deposition is performed on previously nitrided stainless steel, the morphology of the surface improves and the coating is more homogeneous, which leads to an improved corrosion resistance.

  18. Gas Sensing of Fluorine Doped Tin Oxide Thin Films Prepared by Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    A. A. YADAV

    2008-05-01

    Full Text Available Fluorine doped tin oxide (F: SnO2 films have been prepared onto the amorphous glass substrates by a spray pyrolysis. XRD studies reveal that the material deposited is polycrystalline SnO2 and have tetragonal structure. It is observed that films are highly orientated along (200 direction. The direct optical band gap energy for the F: SnO2 films are found to be 4.15 eV. Gas sensing properties of the sensor were checked against combustible gases like H2, CO2 CO, C3H8, CH4.The H2 sensitivity of the F-doped SnO2 sensor was found to be increased. The increase in the sensitivity is discussed in terms of increased resistivity and reduced permeation of gaseous oxygen into the underlying sensing layer due to the surface modification of the sensor.

  19. Deposition of gold nanoparticles on glass substrate by ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Garza, Maria de la; Hernandez, Tomas; Colas, Rafael; Gomez, Idalia

    2010-01-01

    Ultrasonic spray pyrolysis was used to deposit gold nanoparticles on a glass substrate using ZrO 2 as a surrounding medium. The deposition was made using three flow rates of caring gas. The characterization was made by UV-Vis spectroscopy, X-ray diffraction, scanning electronic microscopy and atomic force microscopy. The UV-Vis spectra showed that the surface plasmon resonance peak, indicative of the presence of gold nanoparticles, was shown to shift towards the red spectrum as the flow rate increased; this shift can be associated to the change in size of the particles, which are assumed to grow on a {1 1 1} planes, as was detected by X-ray diffraction. Gold nanoparticles of spheroidal morphology with a relation of around 2:1 were detected by scanning electron microscopy, these observations were confirmed by atomic force microscopy.

  20. Structural, optical and electrical properties of indium tin oxide thin films prepared by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Benamar, E.; Rami, M.; Messaoudi, C.; Sayah, D.; Ennaoui, A. [Deptartmento de Physique, Laboratoire de Physique des Materiaux, Faculte des Sciences, BP 1014, Ave Inb Battouta, Rabat (Morocco)

    1998-11-27

    Spray pyrolysis process has been used to deposit highly transparent and conducting films of tin-doped indium oxide onto glass substrates. The electrical, structural and optical properties have been investigated as a function of various deposition parameters namely dopant concentrations, temperature and nature of substrate. The morphology of the surface as a function of the substrate temperature has been studied using atomic force microscopy. XRD has shown that deposited films are polycrystalline without second phases and have a preferred orientation (4 0 0). Indium tin oxide layers with low resistivity values around 4x10{sup -5} {Omega} cm and transmission coefficients in the visible and near-infrared range of about 85-90% have been easily obtained

  1. Spectroscopic ellipsometry studies of index profile of indium tin oxide films prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    El Rhaleb, H.; Benamar, E.; Rami, M.; Roger, J.P.; Hakam, A.; Ennaoui, A.

    2002-01-01

    Spectroscopic ellipsometry (SE) has proven to be a very powerful diagnostic for thin film characterisation. It was used to determine thin film parameters such as film thickness and optical functions of polycrystalline tin-doped indium oxide (ITO) films deposited by spray pyrolysis onto Pyrex substrates. Dielectric ITO films often present microstructures which give rise to a variation of the refractive index with the distance from substrate. In this work, it was found that the fit between ellipsometric data and optical models results could be significantly improved when it was assumed that the refractive index of ITO films varied across the upper 60 nm near the film surface. Also, the surface roughness was modelled and compared with that given by the atomic force microscope (AFM)

  2. Spectroscopic ellipsometry studies of index profile of indium tin oxide films prepared by spray pyrolysis

    Science.gov (United States)

    El Rhaleb, H.; Benamar, E.; Rami, M.; Roger, J. P.; Hakam, A.; Ennaoui, A.

    2002-11-01

    Spectroscopic ellipsometry (SE) has proven to be a very powerful diagnostic for thin film characterisation. It was used to determine thin film parameters such as film thickness and optical functions of polycrystalline tin-doped indium oxide (ITO) films deposited by spray pyrolysis onto Pyrex substrates. Dielectric ITO films often present microstructures which give rise to a variation of the refractive index with the distance from substrate. In this work, it was found that the fit between ellipsometric data and optical models results could be significantly improved when it was assumed that the refractive index of ITO films varied across the upper 60 nm near the film surface. Also, the surface roughness was modelled and compared with that given by the atomic force microscope (AFM).

  3. Raman spectra of TiO2 thin films deposited electrochemically and by spray pyrolysis

    International Nuclear Information System (INIS)

    Shishiyanu, S.; Vartic, V.; Shishiyanu, T.; Stratan, Gh.; Rusu, E.; Zarrelli, M.; Giordano, M.

    2013-01-01

    In this paper we present our experimental results concerning the fabrication of TiO 2 thin films by spray pyrolysis and electrochemical deposition method onto different substrates - Corning glass, Si and optical fibers. The surface morphology of the TiO 2 thin films have been investigated by Atomic Force Microscopy. Raman shift spectra measurements have been done for the optical characterization of the fabricated titania thin films. The post-growth rapid photothermal processing (RPP) at temperatures of 100-800 degrees Celsius for 1-3 min have been applied. Our experimental results prove that by the application of post-growth RPP is possible to essentially improve the crystallinity of the deposited TiO 2 films. (authors)

  4. Studies on annealed ZnO:V thin films deposited by nebulised spray pyrolysis method

    Science.gov (United States)

    Malini, D. Rachel

    2018-04-01

    Structural, optical and photoluminescence properties of annealed ZnO:V thin films deposited by nebulized spray pyrolysis technique by varying vanadium concentration are studied. Thickness of thin films varies from 1.52µm to 7.78µm. V2O5, VO2 and ZnO peaks are observed in XRD patterns deposited with high vanadium concentration and the intensity of peaks corresponding to ZnO decreases in those samples. Morphological properties were studied by analysing SEM images and annealed thin films deposited at ZnO:V = 50:50 possess dumb bell shape grains. Emission peaks corresponding to both Augur transition and deep level transition are observed in the PL spectra of the samples.

  5. Characterization of cubic yttria-stabilized zirconia obtained by spray pyrolysis

    International Nuclear Information System (INIS)

    Halmenschlager, Cibele M.; Nunes, Marilia; Vieira, Ramaugusto; Bergmann, Carlos Perez; Falcade, Tiago; Malfatti, Celia de Fraga

    2009-01-01

    Yttria-stabilized-zirconia (YSZ) has been the object of many studies as a SOFC electrolyte. The aim of this work is to produce, by spray pyrolysis process, thin and dense films of YSZ. A disk of steel 316L, previously heated, was used as substrate. The film was obtained with zirconium acetylacetonate (Zr(C 6 H 7 O 2 ) 4 ) and yttrium chloride (YCl 3.6 H 2 O), dissolved in a mixture of ethanol + butyl carbitol with volume ratio (1:1). ZrO 2 amorphous films were deposited in the substrate heated at many temperatures. After thermal treatment at 700 deg C the films were changed into cubic yttria-stabilized-zirconia structure. The thin films obtained were characterized by thermal analysis, scanning electron microscopy, transmission electron microscopy, X-ray diffraction and micro-Raman spectroscopy. (author)

  6. Indium oxide thin-film transistors processed at low temperature via ultrasonic spray pyrolysis

    KAUST Repository

    Faber, Hendrik

    2015-01-14

    The use of ultrasonic spray pyrolysis is demonstrated for the growth of polycrystalline, highly uniform indium oxide films at temperatures in the range of 200-300 °C in air using an aqueous In(NO3)3 precursor solution. Electrical characterization of as-deposited films by field-effect measurements reveals a strong dependence of the electron mobility on deposition temperature. Transistors fabricated at ∼250 °C exhibit optimum performance with maximum electron mobility values in the range of 15-20 cm2 V -1 s-1 and current on/off ratio in excess of 106. Structural and compositional analysis of as-grown films by means of X-ray diffraction, diffuse scattering, and X-ray photoelectron spectroscopy reveal that layers deposited at 250 °C are denser and contain a reduced amount of hydroxyl groups as compared to films grown at either lower or higher temperatures. Microstructural analysis of semiconducting films deposited at 250 °C by high resolution cross-sectional transmission electron microscopy reveals that as-grown layers are extremely thin (∼7 nm) and composed of laterally large (30-60 nm) highly crystalline In2O3 domains. These unique characteristics of the In2O3 films are believed to be responsible for the high electron mobilities obtained from transistors fabricated at 250 °C. Our work demonstrates the ability to grow high quality low-dimensional In2O3 films and devices via ultrasonic spray pyrolysis over large area substrates while at the same time it provides guidelines for further material and device improvements.

  7. Cathodoluminescence emission study of nanocrystalline indium oxide films deposited by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Korotcenkov, G. [Technical University of Moldova, Chisinau (Moldova, Republic of)], E-mail: ghkoro@yahoo.com; Nazarov, M. [Technical University of Moldova, Chisinau (Moldova, Republic of); Gwangju Institute of Science and Technology (Korea, Republic of); Zamoryanskaya, M.V. [A.F.Ioffe Physical Technical Institute, RAS, St. Petersburg (Russian Federation); Ivanov, M. [Technical University of Moldova, Chisinau (Moldova, Republic of)

    2007-07-31

    The results of analysis of In{sub 2}O{sub 3} film cathodoluminescence (CL) spectra are presented in this paper. In{sub 2}O{sub 3} films, aimed for gas sensor application, were deposited by spray pyrolysis from 0.2 M InCl{sub 3}-water solutions. The influence of grain size (10-60 nm), film thickness (20-400 nm), pyrolysis temperature (T{sub pyr} = 400-520 deg. C), and annealing in the air or nitrogen atmospheres (T{sub an} = 600-1100 deg. C) on CL emission of In{sub 2}O{sub 3} is discussed. CL spectra of as-deposited In{sub 2}O{sub 3} films were characterized by a broad band centered at {lambda} {approx} 570-600 nm. The annealing of studied films leads to a considerable increase of CL intensity. High annealing temperature of In{sub 2}O{sub 3} films (T{sub an} > 850 deg. C) is being accompanied by the appearance of additional bands centered at {lambda} {approx} 400, 550, and 650 nm, which are peculiar to single-crystalline In{sub 2}O{sub 3} nanobelts, or nanowires with perfect crystal structure. It was concluded that the improvement of crystal structure and the decrease of the concentration of oxygen vacancies are the main factors determining the change of CL spectra of In{sub 2}O{sub 3} films and the appearance of edge luminescence.

  8. Photocatalytically active Au/TiO2 films deposited by two-step spray pyrolysis

    International Nuclear Information System (INIS)

    Balashev, Konstantin; Georgiev, Petar; Simeonova, Sylvia; Stambolova, Irina; Blaskov, Vladimir; Vassilev, Sasho; Eliyas, Alexander

    2016-01-01

    Nanocrystalline TiO 2 and surface gold-modified films (Au/TiO 2 ) are obtained by two step spray pyrolysis process. Titanium tetrachloride (TiCl 4 ) was used as inorganic titanium precursor. The Au nanoparticles were deposited on the surface of sprayed TiO 2 films, obtained by the classical Turkevich method. The AFM analyses have revealed that the roughness of Au/TiO 2 is twice lower than that of the reference titania film. Some globular species are visible on the surface, which could be either individual Au nanoparticles or Au nanoparticles’ agglomerates embedded into the TiO 2 film. The photocatalytic activity in the oxidative degradation of Reactive Black 5 dye under visible light of the Au/TiO 2 films was estimated in a semi-batch reactor. Surface gold modified TiO 2 films revealed higher photocatalytic efficiency than the reference sample. Key words: Au nanoparticles, photocatalysis, azo dye, titania, nanosized

  9. The route of liquid precursor to ZnO nanoparticles in premixed combustion spray pyrolysis

    Science.gov (United States)

    Widiyastuti, W.; Machmudah, Siti; Nurtono, Tantular; Winardi, Sugeng

    2018-04-01

    Zinc oxide nanoparticles had been successfully synthesized by premixed combustion spray pyrolysis. Zinc acetate was dissolved in distilled water was selected as a liquid precursor. Zinc nitrate was also used for comparison the effect of precursor type on the generated particles morphology and the crystallinity. The premixed combustion reaction used liquefied petroleum gas (LPG) mainly consisting of butane and propane as a fuel and compressed air used as an oxidizer. The liquid precursor was atomized using a custom two fluid nozzle to generate droplets. Then, the droplets were sprayed by the flow of air as a carrier gas into the premixed combustion reactor. The zinc precursor was decomposed to zinc oxide due to the high temperature as a result of combustion reaction inside the reactor resulting in nanoparticles formation. The particle size decreased with the increase of the fuel flow rate. In addition, it can be found that at the same flow rate of fuel, the particle size of zinc oxide synthesized using zinc nitrate is larger than that of the use of zinc acetate as a precursor.

  10. Doped nanocrystalline ZnO powders for non-linear resistor applications by spray pyrolysis method.

    Science.gov (United States)

    Hembram, Kaliyan; Vijay, R; Rao, Y S; Rao, T N

    2009-07-01

    Homogeneous and doped nanocrystalline ZnO powders (30-200 nm) were synthesized by spray pyrolysis technique. The spray pyrolysed powders were calcined in the temperature range of 500-750 degrees C. Formation of insulating pyrochlore phase started from 700 degrees C during the calcination itself. The calcined powders were compacted and sintered at different temperatures ranging from 900-1200 degrees C for 0.5-4 h. The densification behavior was found to be dependent on calcination temperature of the nanopowder. The resulting discs were found to have density (5.34-5.62 g/cc) in the range of 96-99% of theoretical density. The breakdown voltage value obtained for the nanopowder based non-linear resistor is 10.3 kV/cm with low leakage current density of 0.7 microA/cm2 and coefficient of nonlinearity as high as 193. The activation energy for grain growth of the doped ZnO nanopowder powders is 449.4 +/- 15 kJ/mol.

  11. Investigation on the effect of Zr doping in ZnO thin films by spray pyrolysis

    International Nuclear Information System (INIS)

    Gokulakrishnan, V.; Parthiban, S.; Jeganathan, K.; Ramamurthi, K.

    2011-01-01

    Zirconium doped zinc oxide thin films with enhanced optical transparency were prepared on Corning 1737 glass substrates at the substrate temperature of 400 o C by spray pyrolysis method for various doping concentrations of zirconium (IV) chloride in the spray solution. The X-ray diffraction studies reveal that the films exhibit hexagonal crystal structure with polycrystalline grains oriented along (0 0 2) direction. The crystalline quality of the films is found to be deteriorating with the increase of doping concentration and acquires amorphous state for higher concentration of 8 at.% in precursor solution. The average transmittance for 5 at.% (solution) zirconium doped ZnO film is significantly increased to ∼92% in the visible region of 500-800 nm. The room temperature photoluminescence (PL) spectra of films show a band edge between 3.41 and 3.2 eV and strong blue emission at 2.8 eV irrespective of doping concentration and however intensity increases consistently with doping levels. The vacuum annealing at 400 o C reduced the resistivity of the films significantly due to the coalescence of grains and the lowest resistivity of 2 x 10 -3 Ω cm is observed for 3 at.% (solution) Zr doped ZnO films which envisages that it is a good candidate for stable TCO material.

  12. Deposition and characterization of ZnO thin films by modified pulsed-spray pyrolysis

    International Nuclear Information System (INIS)

    Thilakan, Periyasamy; Radheep, D Mohan; Saravanakumar, K; Sasikala, G

    2009-01-01

    Zinc oxide (ZnO) thin films were deposited using modified pulsed-spray pyrolysis on glass substrates. Depositions were carried out using N 2 as the carrier gas and analysed with respect to the rate of deposition. X-ray analysis revealed the presence of mixed crystallization with a nanocrystalline structure of about 6.9 nm dispersed in the amorphous matrix. A negative trend between the bandgap and resistivity was observed with the decrease in the deposition rate. A lowest bandgap of 3.1 eV with a resistivity value of 1.6 × 10 −2 Ω cm was achieved at a lowest deposition rate of 1.3 nm min −1 . Hot-probe measurement revealed the p-type conductivity for the film deposited at a lowest deposition rate of 1.3 nm min −1 . Details about the influence of pulsed-spray deposition for the achievement of this negative trend between bandgap and resistivity will be discussed in this paper

  13. Synthesis of yttria powders by electrospray pyrolysis

    International Nuclear Information System (INIS)

    Rulison, A.J.; Flagan, R.C.

    1994-01-01

    Electrospray atomization of high-concentration (∼400 g/L) chemical precursor solutions was applied to the synthesis of yttria powders. Conditions were found which led to high-quality powders, composed of dense, spheroidal, submicrometer, and nanocrystalline oxide particles. The precursor solutions were hydrated yttrium nitrates dissolved in n-propyl alcohol at concentrations ranging from 44.1 to 455 g/L. Electrospray atomization produced submicrometer precursor droplets which were dispersed in air and carried through an electric furnace for thermal decomposition at 500 C for several seconds residence time. X-ray powder diffraction patterns indicated the expected cubic phase. Transmission electron micrographs showed that the particle structure varied with solution composition, ranging from hollow, inflated spheres for 6-hydrated nitrates to dense spheroids for 5-hydrated nitrates. The use of 6-hydrated nitrates in the solutions appeared to form particle surfaces which were impermeable to alcohol vapor evolved during thermal decomposition, leading to hollow, inflated spheres

  14. A study on the sensing of NO(sub2) and O(sub2) utilizing ZnO films grown by aerosol spray pyrolysis

    CSIR Research Space (South Africa)

    Mhlongo, GH

    2015-07-01

    Full Text Available The present paper addresses the preparation and characterization of ZnO nanostructured thin films obtained using aerosol spray pyrolysis method at different deposition periods. Aiming at understanding the chemical composition, structural...

  15. Effect of annealing on the electrical, optical and structural properties of cadmium stannate thin films prepared by spray pyrolysis technique

    International Nuclear Information System (INIS)

    Kumaravel, R.; Krishnakumar, V.; Gokulakrishnan, V.; Ramamurthi, K.; Jeganathan, K.

    2010-01-01

    Polycrystalline thin films of cadmium stannate (Cd 2 SnO 4 ) were deposited by spray pyrolysis method on the Corning substrates at substrate temperature of 525 o C. Further, the films were annealed at 600 o C in vacuum for 30 min. These films were characterized for their structural, electrical and optical properties. The experimental results showed that the post-deposition annealing in vacuum has a significant influence on the properties of the films. The average grain size of the film was increased from 27.3 to 35.0 nm on heat treatment. The average optical transmittance in the visible region (500-850 nm) is decreased from 81.4% to 73.4% after annealing in vacuum. The minimum resistivity achieved in the present study for the vacuum annealed films is the lowest among the reported values for the Cd 2 SnO 4 thin films prepared by spray pyrolysis method.

  16. Layer-by-layer deposition of superconducting Sr-Ca-Cu-O films by the spray pyrolysis technique

    International Nuclear Information System (INIS)

    Pawar, S.H.; Pawaskar, P.N.; Ubale, M.J.; Kulkarni, S.B.

    1995-01-01

    Layer-by-layer deposition of Sr-Ca-Cu-O films has been carried out using the spray pyrolysis technique. Reagent-grade nitrates of strontium, calcium and copper were used to prepare starting solutions for spray pyrolysis. A two-step procedure was used for every layer of the constituents in the sequence Sr-Cu-Ca-Cu-Sr: first, deposition onto silver substrate at 350 C, then firing at T≥450 C, both at atmospheric pressure. The films were 2-3 μm thick and showed adequate adhesion to the substrate. The films were then characterised by studying their electron micrographs, X-ray diffraction patterns and electrical resistivity. The films showed superconductivity below 104 K. ((orig.))

  17. Fabrication and properties of samarium doped calcium sulphate thin films using spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Reghima, Meriem [Université Tunis El Manar, Faculté des Sciences de Tunis, Département de Physique, LR99ES13 Laboratoire de Physique de la Matière Condensée (LPMC), 2092 Tunis, Tunisie (Tunisia); Institut d' Electronique et des systèmes, Unité Mixte de Recherche 5214 UM2-CNRS (ST2i) – Université Montpellier, 860 rue de Saint Priest, Bâtiment 5, 34097 Montpellier (France); Faculté des Sciences de Bizerte, Université de Carthage, Zarzouna 7021 (Tunisia); Guasch, Cathy [Institut d' Electronique et des systèmes, Unité Mixte de Recherche 5214 UM2-CNRS (ST2i) – Université Montpellier, 860 rue de Saint Priest, Bâtiment 5, 34097 Montpellier (France); Azzaza, Sonia; Alleg, Safia [Laboratoire de Magnétisme et Spectroscopie des Solides (LM2S), Département de Physique, Faculté des Sciences, Université Badji Mokhtar Annaba, B.P. 12, 23000 Annaba (Algeria); Kamoun-Turki, Najoua [Université Tunis El Manar, Faculté des Sciences de Tunis, Département de Physique, LR99ES13 Laboratoire de Physique de la Matière Condensée (LPMC), 2092 Tunis, Tunisie (Tunisia)

    2016-10-01

    Using low cost spray pyrolysis technique, polycrystalline CaSO{sub 4} thin films were successfully grown on a glass substrate with a thickness of about 1 μm. Samarium doping has been performed on CaSO{sub 4} thin films to explore luminescence properties. The characterizations of these films were carried out using X-ray diffraction, Scanning Electron Microscopy and optical measurements. The structural analyses reveal the existence of hexagonal CaSO{sub 4} phase with a (200) preferred orientation belonging to CaS compound for substrate temperatures below 350 °C. It is shown that the crystallinity of the sprayed thin films can be improved by increasing substrate temperature up to 250 °C. Warren-Averbach analysis has been applied on X-ray diffractogram to determine structural parameters involving the phase with its amount, the grain size and the lattice parameters using Maud software. The surface topography shows a rough surface covered by densely packed agglomerated clusters having faceted and hexagonal shapes. Energy dispersive microscopy measurements confirm the presence of calcium and sulfur in equal proportions as well as high percentage of oxygen. Photoluminescence at room temperature revealed that luminescence peaks are attributed to the intrinsic emission of pure CaSO{sub 4} phase. - Highlights: • Warren Averbach analysis reveal the presence of hcp structure of CaSO{sub 4} phase. • A mixture of CaSO{sub 4} and CaHO{sub 4.5}S phases has been detected for lower T{sub s}. • For increasing T{sub s}, the CaHO{sub 4.5}S phase has been disappeared. • The origin of PL peaks has been identified.

  18. Properties of NiO thin films deposited by chemical spray pyrolysis using different precursor solutions

    Energy Technology Data Exchange (ETDEWEB)

    Cattin, L. [Universite de Nantes, Nantes Atlantique Universites, LAMP, EA 3825, Faculte des Sciences et des Techniques, 2 rue de la Houssiniere, BP 92208, Nantes F-44000 (France); Reguig, B.A.; Khelil, A. [Universite d' Oran Es-Senia, LPCM2E (Algeria); Morsli, M. [Universite de Nantes, Nantes Atlantique Universites, LAMP, EA 3825, Faculte des Sciences et des Techniques, 2 rue de la Houssiniere, BP 92208, Nantes F-44000 (France); Benchouk, K. [Universite d' Oran Es-Senia, LPCM2E (Algeria); Bernede, J.C. [Universite de Nantes, Nantes Atlantique Universites, LAMP, EA 3825, Faculte des Sciences et des Techniques, 2 rue de la Houssiniere, BP 92208, Nantes F-44000 (France)], E-mail: Jean-Christian.Bernede@univ-nantes.fr

    2008-07-15

    NiO thin films have been deposited by chemical spray pyrolysis using a perfume atomizer to grow the aerosol. The influence of the precursor, nickel chloride hexahydrate (NiCl{sub 2}.6H{sub 2}O), nickel nitrate hexahydrate (Ni(NO{sub 3}){sub 2}.6H{sub 2}O), nickel hydroxide hexahydrate (Ni(OH){sub 2}.6H{sub 2}O), nickel sulfate tetrahydrate (NiSO{sub 4}.4H{sub 2}O), on the thin films properties has been studied. In the experimental conditions used (substrate temperature 350 deg. C, precursor concentration 0.2-0.3 M, etc.), pure NiO thin films crystallized in the cubic phase can be achieved only with NiCl{sub 2} and Ni(NO{sub 3}){sub 2} precursors. These films have been post-annealed at 425 deg. C for 3 h either in room atmosphere or under vacuum. If all the films are p-type, it is shown that the NiO films conductivity and optical transmittance depend on annealing process. The properties of the NiO thin films annealed under room atmosphere are not significantly modified, which is attributed to the fact that the temperature and the environment of this annealing is not very different from the experimental conditions during spray deposition. The annealing under vacuum is more efficient. This annealing being proceeded in a vacuum no better than 10{sup -2} Pa, it is supposed that the modifications of the NiO thin film properties, mainly the conductivity and optical transmission, are related to some interaction between residual oxygen and the films.

  19. Structural, electrical and optical properties of indium chloride doped ZnO films synthesized by Ultrasonic Spray Pyrolysis technique

    International Nuclear Information System (INIS)

    Zaleta-Alejandre, E.; Camargo-Martinez, J.; Ramirez-Garibo, A.; Pérez-Arrieta, M.L.; Balderas-Xicohténcatl, R.; Rivera-Alvarez, Z.; Aguilar-Frutis, M.; Falcony, C.

    2012-01-01

    Indium chloride doped zinc oxide (ZnO:In) thin films were deposited onto glass substrates using zinc acetate by Ultrasonic Spray Pyrolysis technique. The effect of substrate temperature, deposition time and acetic acid added to the spraying solution on the structural, electrical and optical properties of these ZnO:In films is reported. The films were in all cases polycrystalline with a hexagonal (wurtzite) structure, a transparency over 80% and resistivity of the order of 10 −3 –10 −2 Ω·cm. The resistivity was dependent on the volume % of acetic acid added to the spraying solution. The minimum resistivity value was obtained with a 5 vol.% acetic acid (pH = 3.71) at substrate temperature of 450 °C. The deposition rates obtained were as high as 180 Å·min −1 at a substrate temperature of 450 °C. - Highlights: ► Conductive ZnO:In thin films were deposited by Ultrasonic Spray Pyrolysis (USP). ► USP is of low cost, high growth rates and scalable for industrial applications. ► USP is appropriate for the deposition of metallic oxide films. ► We studied the effect of acetic acid, time deposition and substrate temperature. ► Zinc acetate and indium chloride were used as precursor materials.

  20. Structural, electrical and optical properties of indium chloride doped ZnO films synthesized by Ultrasonic Spray Pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Zaleta-Alejandre, E., E-mail: ezaleta@fis.cinvestav.mx [Centro de Investigacion y de Estudios Avanzados-IPN, Departamento de Fisica, Apdo, Postal 14-470, Del. Gustavo A. Madero, C.P. 07000, Mexico, D.F. (Mexico); Camargo-Martinez, J.; Ramirez-Garibo, A. [Centro de Investigacion y de Estudios Avanzados-IPN, Departamento de Fisica, Apdo, Postal 14-470, Del. Gustavo A. Madero, C.P. 07000, Mexico, D.F. (Mexico); Perez-Arrieta, M.L. [Universidad Autonoma de Zacatecas, Unidad Academica de Fisica, Calzada Solidaridad esq. Paseo, La Bufa s/n, C.P. 98060, Zacatecas, Mexico (Mexico); Balderas-Xicohtencatl, R.; Rivera-Alvarez, Z. [Centro de Investigacion y de Estudios Avanzados-IPN, Departamento de Fisica, Apdo, Postal 14-470, Del. Gustavo A. Madero, C.P. 07000, Mexico, D.F. (Mexico); Aguilar-Frutis, M. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada-IPN, Legaria 694, Col. Irrigacion, Del. Miguel Hidalgo, Mexico, D.F. (Mexico); Falcony, C. [Centro de Investigacion y de Estudios Avanzados-IPN, Departamento de Fisica, Apdo, Postal 14-470, Del. Gustavo A. Madero, C.P. 07000, Mexico, D.F. (Mexico)

    2012-12-01

    Indium chloride doped zinc oxide (ZnO:In) thin films were deposited onto glass substrates using zinc acetate by Ultrasonic Spray Pyrolysis technique. The effect of substrate temperature, deposition time and acetic acid added to the spraying solution on the structural, electrical and optical properties of these ZnO:In films is reported. The films were in all cases polycrystalline with a hexagonal (wurtzite) structure, a transparency over 80% and resistivity of the order of 10{sup -3}-10{sup -2} Ohm-Sign {center_dot}cm. The resistivity was dependent on the volume % of acetic acid added to the spraying solution. The minimum resistivity value was obtained with a 5 vol.% acetic acid (pH = 3.71) at substrate temperature of 450 Degree-Sign C. The deposition rates obtained were as high as 180 A{center_dot}min{sup -1} at a substrate temperature of 450 Degree-Sign C. - Highlights: Black-Right-Pointing-Pointer Conductive ZnO:In thin films were deposited by Ultrasonic Spray Pyrolysis (USP). Black-Right-Pointing-Pointer USP is of low cost, high growth rates and scalable for industrial applications. Black-Right-Pointing-Pointer USP is appropriate for the deposition of metallic oxide films. Black-Right-Pointing-Pointer We studied the effect of acetic acid, time deposition and substrate temperature. Black-Right-Pointing-Pointer Zinc acetate and indium chloride were used as precursor materials.

  1. Comparative study of ITO and FTO thin films grown by spray pyrolysis

    International Nuclear Information System (INIS)

    Ait Aouaj, M.; Diaz, R.; Belayachi, A.; Rueda, F.; Abd-Lefdil, M.

    2009-01-01

    Tin doped indium oxide (ITO) and fluorine doped tin oxide (FTO) thin films have been prepared by one step spray pyrolysis. Both film types grown at 400 deg. C present a single phase, ITO has cubic structure and preferred orientation (4 0 0) while FTO exhibits a tetragonal structure. Scanning electron micrographs showed homogeneous surfaces with average grain size around 257 and 190 nm for ITO and FTO respectively. The optical properties have been studied in several ITO and FTO samples by transmittance and reflectance measurements. The transmittance in the visible zone is higher in ITO than in FTO layers with a comparable thickness, while the reflectance in the infrared zone is higher in FTO in comparison with ITO. The best electrical resistivity values, deduced from optical measurements, were 8 x 10 -4 and 6 x 10 -4 Ω cm for ITO (6% of Sn) and FTO (2.5% of F) respectively. The figure of merit reached a maximum value of 2.15 x 10 -3 Ω -1 for ITO higher than 0.55 x 10 -3 Ω -1 for FTO.

  2. Photocatalytic activities of heterostructured TiO2-graphene porous microspheres prepared by ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Yang, Jikai; Zhang, Xintong; Li, Bing; Liu, Hong; Sun, Panpan; Wang, Changhua; Wang, Lingling; Liu, Yichun

    2014-01-01

    Highlights: • USP method is used to prepare TiO 2 -graphene porous microspheres. • XPS shows GO sheets in the composites has been reduced to graphene. • TiO 2 -graphene microspheres display a red-shifted absorption edge. • PL spectra indicate graphene can accept the photoexcited electrons from TiO 2 . • TiO 2 -graphene shows higher photocatalytic activity than TiO 2 under solar light. -- Abstract: TiO 2 -graphene porous microspheres were prepared by ultrasonic spray pyrolysis (USP) of aqueous suspension of graphene oxide containing TiO 2 nanoparticles (Degussa P25). The composite microspheres were characterized with SEM, XPS, photoluminescence, Raman and UV–Vis absorption spectra. TiO 2 -graphene porous microspheres displayed higher photocatalytic activity for the degradation of methylene blue solution than pristine TiO 2 microspheres under the irradiation of Xe lamp, and the highest activity was obtained at a weight percentage of graphene around 1%. The effect of graphene on photocatalytic activity of porous microsphere was discussed in terms of the enhanced charge separation by TiO 2 -graphene heterojunction, increased absorption of the visible light, as well as the possible hindrance of mass transportation in microspheres

  3. Thickness dependent electrical properties of CdO thin films prepared by spray pyrolysis method

    International Nuclear Information System (INIS)

    Murthy, L.C.S.; Rao, K.S.R.K.

    1999-01-01

    A large number of thin films of cadmium oxide have been prepared on glass substrates by spray pyrolysis method. The prepared films have uniform thickness varying from 200-600 nm and good adherence to the glass substrate. A systematic study has been made on the influence of thickness on resistivity, sheet resistance, carrier concentration and mobility of the films. The resistivity, sheet resistance, carrier concentration and mobility values varied from 1.56-5.72x10 -3 Ω-cm, 128-189 Ω/□, 1.6-3.9x10 21 cm -3 and 0.3-3 cm 2 /Vs, respectively for varying film thickness. A systematic increase in mobility with grain size clearly indicates the reduction of overall scattering of charge carriers at the grain boundaries. The large concentration of charge carriers and low mobility values have been attributed to the presence of Cd as an impurity in CdO microcrystallites. Using the optical transmission data, the band gap was estimated and found to vary from 2.20-2.42 eV. These films have transmittance around 77% and average reflectance is below 2.6% in the spectral range 350-850 nm. The films are n-type and polycrystalline in nature. SEM micrographs of the CdO films were taken and the films exhibit clear grains and grain boundary formation at a substrate temperature as low as 523 K. (author)

  4. Conductivity study of nitrogen-doped calcium zinc oxide prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    Hsu, Yu-Ting; Lan, Wen-How; Huang, Kai-Feng; Lin, Jia-Ching; Chang, Kuo-Jen

    2016-01-01

    In this study, the spray pyrolysis method was used to prepare unintentionally doped and nitrogen-doped calcium zinc oxide films by using zinc acetate, calcium nitrate precursor, and ammonium acetate precursor. Morphological and structural analyses were conducted using scanning electron microscopy and X-ray diffraction. The results indicated that film grain size decreased as the nitrogen doping was increased. Both calcium oxide and zinc oxide structures were identified in the unintentionally doped calcium zinc oxide. When nitrogen doping was introduced, the film mainly exhibited a zinc oxide structure with preferred (002) and (101) orientations. The concentration and mobility were investigated using a Hall measurement system. P-type films with a mobility and concentration of 10.6 cm"2 V"−"1 s"−"1 and 2.8×10"1"7 cm"−"3, respectively, were obtained. Moreover, according to a temperature-dependent conductivity analysis, an acceptor state with activation energy 0.266 eV dominated the p-type conduction for the unintentionally doped calcium zinc oxide. By contrast, a grain boundary with a barrier height of 0.274–0.292 eV dominated the hole conduction for the nitrogen-doped calcium zinc oxide films.

  5. Optical and electrical characterization of AgInS2 thin films deposited by spray pyrolysis

    International Nuclear Information System (INIS)

    Calixto-Rodriguez, M.; Martinez, H.; Calixto, M.E.; Pena, Y.; Martinez-Escobar, Dalia; Tiburcio-Silver, A.; Sanchez-Juarez, A.

    2010-01-01

    Silver indium sulfide (AgInS 2 ) thin films have been prepared by spray pyrolysis (SP) technique using silver acetate, indium acetate, and N, N-dimethylthiourea as precursor compounds. Films were deposited onto glass substrates at different substrate temperatures (T s ) and Ag:In:S ratios in the starting solutions. Optical transmission and reflection as well as electrical measurements were performed in order to study the effect of deposition parameters on the optical and electrical properties of AgInS 2 thin films. X-ray diffraction measurements were used to identify the deposited compounds. It was found that different compounds such as AgInS 2 , Ag 2 S, In 2 O 3 , and In 2 S 3 can be grown only by changing the Ag:In:S ratio in the starting solution and T s . So that, by carefully selecting the deposition parameters, single phase AgInS 2 thin films can be easily grown. Thin films obtained using a molar ratio of Ag:In:S = 1:1:2 and T s = 400 o C, have an optical band gap of 1.9 eV and n-type electrical conductivity with a value of 0.3 Ω -1 cm -1 in the dark.

  6. Emission of ZnO:Ag nanorods obtained by ultrasonic spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Velázquez Lozada, E., E-mail: evlozada5@yahoo.com.mx [ESIME – Instituto Politécnico Nacional, México D.F. 07738 (Mexico); Torchynska, T.V.; Casas Espinola, J.L. [ESFM – Instituto Politécnico Nacional, México D.F. 07738 (Mexico); Pérez Millan, B. [UPIITA – Instituto Politécnico Nacional, México D.F. 07738 (Mexico)

    2014-11-15

    Scanning electronic microscopy (SEM), X ray diffraction (XRD), photoluminescence (PL) and its temperature dependence have been studied in ZnO:Ag nanorods (NRs) prepared by the ultrasonic spray pyrolysis (USP) method. The time variation at the growth of ZnO:Ag films permits modifying the ZnO phase from the amorphous to crystalline, to change the size of ZnO:Ag NRs and to vary their emission spectra. PL spectra of ZnO:Ag NRs versus temperature has been investigated. This study reveals that the PL band related to the acceptor Ag{sub Zn} (LO phonon replicas of an acceptor bound exciton, ABE (2.877 eV)), and its second-order diffraction peak (1.44 eV) disappeared in the temperature range of 10–170 K with the formation of free exciton (FX). The PL intensity of defect related PL bands decreases monotonously in the range 10–300 K with the activation energy of 13 meV. The PL band (3.22 eV), related to the LO phonon replica of free exciton (FX-2LO) and its second-order diffraction peak (1.61 eV) increase monotonously in the range 10–300 K. FX related peak dominates in PL spectra at room temperature that testifies on the high quality of ZnO:Ag films prepared by the USP technology.

  7. Preparation and characterization of tin sulphide thin films by a spray pyrolysis technique

    International Nuclear Information System (INIS)

    Ben Haj Salah, H.; Bouzouita, H.; Rezig, B.

    2005-01-01

    We have attempted the preparation and characterization of Sn 2 S 3 thin films by using the spray pyrolysis technique. We started with acidic aqueous solutions including tin (II) chloride and thiourea, which were atomized with compressed air as carrier gas. The Sn 2 S 3 thin films were obtained on glass substrates. Thin layers of Sn-S have been grown at various temperatures in the range of 275-325 deg. C and various [S/Sn] ratios. The structural properties have been determined by using X-ray diffraction (XRD). The changes observed in the structural phases during the film formation in dependence of growth temperatures are reported and discussed. The optical constants of the deposited films were obtained using the experimentally recorded transmission and reflectance spectral data as functions of the wavelength, in the range of 300-1800 nm. An analysis of the deduced spectral absorption of the deposited films revealed an optical indirect band gap energy of 1.9-2.2 eV for Sn 2 S 3 layers

  8. Evaluation of Nd-Loaded SnO2:F Films Coated via Spray Pyrolysis

    Science.gov (United States)

    Turgut, G.

    2018-07-01

    Thin layers of single (F)- and double (F/Nd)-incorporated tin oxide have been coated on glass substrate via spray pyrolysis. The structural, morphological, electrical, and optical features of F-incorporated samples were evaluated depending on the Nd loading. X-ray diffraction analysis revealed that samples had tetragonal tin oxide structure with (211) and (200) preferential directions. The crystallite size and strain values varied from 37.98 nm and 1.21 × 10-3 to 52.12 nm and 1.88 × 10-3. Scanning electron microscopy analysis showed that the samples consisted of pyramidal, polyhedral, and needle-shaped granules. The lowest sheet resistance value of 1.22 Ω was found for 1.8 at.% Nd + 25 at.% F-coloaded SnO2. However, the widest optical bandgap of 4.01 eV was observed for the single 25 at.% F-loaded sample. The Urbach tail and figure of merit also changed in the ranges of 664 meV to 1296 meV and 6.4 × 10-2 Ω-1 to 2.3 × 10-3 Ω-1, respectively. The results presented herein indicate that the character of F-doped tin oxide films can be controlled by Nd loading and that these films could be useful for technological applications.

  9. Optical and Electrical Properties of Copper Oxide Thin Films Synthesized by Spray Pyrolysis Technique

    Directory of Open Access Journals (Sweden)

    S. S. Roy

    2015-08-01

    Full Text Available Copper oxide (CuO thin films have been synthesized on to glass substrates at different temperatures in the range 250-450 °C by spray pyrolysis technique from aqueous solution using cupric acetate Cu(CH3COO2·H2O as a precursor. The structure of the deposited CuO thin films characterized by X-ray diffraction, the surface morphology was observed by a scanning electron microscope, the presence of elements was detected by energy dispersive X-ray analysis, the optical transmission spectra was recorded by ultraviolet-visible spectroscopy and electrical resistivity was studied by Van-der Pauw method. All the CuO thin films, irrespective of growth temperature, showed a monoclinic structure with the main CuO (111 orientation, and the crystallite size was about 8.4784 Å for the thin film synthesized at 350 °C. The optical transmission of the as-deposited film is found to decrease with the increase of substrate temperature, the optical band gap of the thin films varies from 1.90 to 1.60 eV and the room temperature electrical resistivity varies from 30 to18 Ohm·cm for the films grown at different substrate temperatures.

  10. An investigation on the In doping of ZnO thin films by spray pyrolysis

    Science.gov (United States)

    Mahesh, Devika; Kumar, M. C. Santhosh

    2018-04-01

    Indium doped zinc oxide (IGZO)thin films are gaining much interest owing to its commercial application as transparent conductive oxide thin films. In the current study thin films indium doped ZnO thin films have been deposited on glass substrates by chemical spray pyrolysis technique with an indium concentration of 1, 2.5 and 4% in Zinc source. The films show a peak shift in the X-Ray Diffraction patterns with varying indium doping concentration. The (101) peak was enhanced for the 2.5 % indium doped films and variation in grain size with the different doping levels was studied. The as-deposited films are uniform and shown high transparency (>90%) in the visible region. Average thicknesses of films are found to be 800nm, calculated using the envelope method. The film with 2.5 % of indium content was found to be highly conducting than the rest, since for the lower and higher concentrations the conductivity was possibly halted by the limit in carrier concentration and indium segregation in the grain boundaries respectively. The enhancement of mobility and carrier concentration was clearly seen in the optimum films.

  11. Nanostructured CdS thin films deposited by spray pyrolysis method

    Energy Technology Data Exchange (ETDEWEB)

    Kerimova, A.; Bagiyev, E.; Aliyeva, E.; Bayramov, A. [Institute of Physics, Azerbaijan National Academy of Sciences, Baku (Azerbaijan)

    2017-06-15

    Influence of solution pH on the structural and optical properties of CdS films deposited by conventional spray pyrolysis technique was studied. X-Ray Diffraction (XRD), Atomic Force Microscopy (AFM), Photoluminescence spectroscopy (PLS), and Spectroscopic Ellipsometry (SE) methods were used for the characterization of the deposited films. PL spectrum of the film deposited from the solution with pH = 10.2 shows broad-band PL emission located at 460 nm (2.7 eV), which can be attributed to the quantum size effect at grain sizes of <10 nm. No shifts of ε{sub 1} and ε{sub 2} due to the quantum size effect are observed in dielectric function spectra, what can be caused by low concentration of nano-sized (<10 nm) CdS grains. The change in the film properties with the pH of the solution was analyzed in terms of variation of grain sizes of the polycrystalline films. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Characterization of luminescent samarium doped HfO2 coatings synthesized by spray pyrolysis technique

    International Nuclear Information System (INIS)

    Chacon-Roa, C; Guzman-Mendoza, J; Aguilar-Frutis, M; Garcia-Hipolito, M; Alvarez-Fragoso, O; Falcony, C

    2008-01-01

    Trivalent samarium (Sm 3+ ) doped hafnium oxide (HfO 2 ) films were deposited using the spray pyrolysis deposition technique. The films were deposited on Corning glass substrates at temperatures ranging from 300 to 550 deg. C using chlorides as raw materials. Films, mostly amorphous, were obtained when deposition temperatures were below 350 deg. C. However, for temperatures higher than 400 deg. C, the films became polycrystalline, presenting the HfO 2 monoclinic phase. Scanning electron microscopy of the films revealed a rough surface morphology with spherical particles. Also, electron energy dispersive analysis was performed on these films. The photoluminescence and cathodoluminescence characteristics of the HfO 2 : SmCl 3 films, measured at room temperature, exhibited four main bands centred at 570, 610, 652 and 716 nm, which are due to the well-known intra-4f transitions of the Sm 3+ ion. It was found that the overall emission intensity rose as the deposition temperature was increased. Furthermore, a concentration quenching of the luminescence intensity was also observed

  13. The role of palladium in iron based Fischer-Tropsch catalysts prepared by flame spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Minnermann, M.; Zielasek, V.; Baeumer, M. [Bremen Univ. (DE). Inst. of Applied and Physical Chemistry (IAPC); Pokhrei, S.; Maedler, L. [Bremen Univ. (DE). Foundation Inst. of Materials Science (IWT); Thiel, K. [Fraunhofer Institute for Manufactoring Technology and Applied Materials Research, Bremen (Germany)

    2011-07-01

    Flame spray pyrolysis (FSP) is a novel technique for the fabrication of nanostructured catalysts with far-reaching options to control structure and composition even in cases where complex composites need to be prepared. In this study, we took advantage of this technique to synthesize highly dispersed pure and Pd-doped iron oxide nanoparticles and investigated them as Fischer-Tropsch (FT) catalysts. By systematically varying the Pd content over a large range from 0.1 wt % to 10 wt %, we were able to directly analyze the influence of the Pd content on activity and selectivity. In addition to catalytic measurements, the structure and composition of the particles were characterized before and after these measurements, using transmission electron microscopy, adsorption measurements, X-ray diffraction and EXAFS. The comparison revealed, on the one hand, that small Pd clusters (diameter: 1-2 nm) evolve from initially homogeneously distributed Pd and, on the other hand, that the iron oxide transforms into iron carbides depending on the Pd content. The presence of Pd influences the particle size in the pristine samples (8 - 11 nm), resulting in specific surface areas that increase as the Pd content increases. However, after activation and reaction the specific surface areas become similar due to partial agglomeration and sintering. In a fixed bed FT reaction test, enhanced FT activity was observed with increasing Pd content while the selectivity shifts to longer chain hydrocarbons, mainly paraffins. (orig.)

  14. Selenization of CIS and CIGS layers deposited by chemical spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Babu, B. J.; Egaas, B.; Velumani, S.

    2018-03-21

    Cu(In1-xGax)Se2 (CIGS) thin films with x=0 (CIS) and x=0.3 (CIGS) were prepared on Mo-coated glass substrate by using chemical spray pyrolysis at a substrate temperature of 350 degrees C, followed by selenization treatment at 550 degrees C in selenium environment under N2 gas flow. X-ray diffraction patterns of as-deposited CIGS layers on Mo showed polycrystalline chalcopyrite phase with an intense (112) plane. Splitting of (204)/(220) and (116)/(312) planes for the film with x=0.3 reveals deviation of tetragonal nature. Field emission scanning electron microscopy cross-sectional images of selenized films showed clear re-crystallization of grains. During the selenization process of the CIGS absorber, a thin interface layer of MoSe2 is formed. Line mapping of Mo/CIGS layer showed more gallium segregation at the interface of back contact resulting in band gap grading. Chemical composition and mapping of the as-deposited and selenized samples were determined by energy dispersive analysis of X-rays. This work leads to fabrication of low cost and large scale Mo/CIGS/CdS/ZnO/ZnO:Al device structure.

  15. Deposition of Ni-CGO composite anodes by electrostatic assisted ultrasonic spray pyrolysis method

    International Nuclear Information System (INIS)

    Chen, J.-C.; Chang, C.-L.; Hsu, C.-S.; Hwang, B.-H.

    2007-01-01

    Deposition of composite films of Ni and Gd-doped ceria was carried out using the electrostatic assisted ultrasonic spray pyrolysis method for the first time. The composite films were highly homogeneous, as revealed by element mapping via energy-dispersive spectrometry. Scanning electron microscope examinations revealed that deposition temperature and electric field strength had profound influence on resultant microstructure, while composition of the precursor solution had little effect. A highly porous cauliflower structure ideal for solid oxide fuel cell anode performance was obtained with a deposition temperature of 450 deg. C under an electric field introduced by an applied voltage of 12 kV. Films obtained with a lower deposition temperature of 250 deg. C or a higher applied voltage of 15 kV resulted in denser films with low porosity, while lower applied voltages of 7 or 5 kV resulted in thinner or discontinuous films due to the insufficient electrostatic attraction on the aerosol droplets. As revealed by AC impedance measurement, the area specific resistances of the Ni-CGO anode with porous cauliflower structure were rather low and a value of 0.09 Ω cm 2 at 550 deg. C was obtained

  16. Evolution of Zinc Oxide Nanostructures Grown on Graphene by Ultrasonic Spray Pyrolysis and Its Statistical Growth Modelling

    Science.gov (United States)

    Ali, Amgad Ahmed; Hashim, Abdul Manaf

    2015-11-01

    The evolution of zinc oxide nanostructures grown on graphene by alcohol-assisted ultrasonic spray pyrolysis was investigated. The evolution of structures is strongly depended on pyrolysis parameters, i.e., precursor molarity, precursor flow rate, precursor injection/deposition time, and substrate temperature. Field-effect scanning electron microscope analysis, energy dispersive X-ray spectroscopy, X-ray diffraction, and transmission electron microscopy were used to investigate the properties of the synthesized nanostructures and to provide evidence for the structural changes according to the changes in the pyrolysis parameters. The optimum parameters to achieve maximum density and well-defined hexagonally shaped nanorods were a precursor molarity of 0.2 M, an injection flow rate of 6 ml/min, an injection time of 10 min, and a substrate temperature of 250-355 °C. Based on the experimental results, the response surface methodology (RSM) was used to model and optimize the independent pyrolysis parameters using the Box-Behnken design. Here, the responses, i.e., the nanostructure density, size, and shape factor, are evaluated. All of the computations were performed using the Design-Expert software package. Analysis of variance (ANOVA) was used to evaluate the results of the model and to determine the significant values for the independent pyrolysis parameters. The evolution of zinc oxide (ZnO) structures are well explained by the developed modelling which confirms that RSM is a reliable tool for the modelling and optimization of the pyrolysis parameters and prediction of nanostructure sizes and shapes.

  17. Microemulsion flame pyrolysis for hopcalite nanoparticle synthesis: a new concept for catalyst preparation

    OpenAIRE

    Kaskel, Stefan; Biemelt, Tim; Wegner, Karl; Teichert, Johannes

    2016-01-01

    A new route to highly active hopcalite catalysts via flame spray pyrolysis of an inverse microemulsion precursor is reported. The nitrate derived nanoparticles are around 15 nm in diameter and show excellent conversion of CO under ambient conditions, outperforming commercial reference hopcalite materials produced by co-precipitation.

  18. Microemulsion flame pyrolysis for hopcalite nanoparticle synthesis: a new concept for catalyst preparation.

    Science.gov (United States)

    Biemelt, T; Wegner, K; Teichert, J; Kaskel, S

    2015-04-07

    A new route to highly active hopcalite catalysts via flame spray pyrolysis of an inverse microemulsion precursor is reported. The nitrate derived nanoparticles are around 15 nm in diameter and show excellent conversion of CO under ambient conditions, outperforming commercial reference hopcalite materials produced by co-precipitation.

  19. Ultrasonic spray pyrolysis growth of ZnO and ZnO:Al nanostructured films: Application to photocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Kenanakis, G., E-mail: gkenanak@iesl.forth.gr [Institute of Electronic Structure and Laser, Foundation for Research and Technology – Hellas, P.O. Box 1385, Vassilika Vouton, 711 10 Heraklion, Crete (Greece); Center of Materials Technology and Photonics, School of Applied Technology, Technological Educational Institute of Crete, 710 04 Heraklion, Crete (Greece); Katsarakis, N. [Institute of Electronic Structure and Laser, Foundation for Research and Technology – Hellas, P.O. Box 1385, Vassilika Vouton, 711 10 Heraklion, Crete (Greece); Center of Materials Technology and Photonics, School of Applied Technology, Technological Educational Institute of Crete, 710 04 Heraklion, Crete (Greece)

    2014-12-15

    Highlights: • Al–ZnO thin films and nanostructures were obtained by ultrasonic spray pyrolysis. • The texture and morphology of the samples depend on the deposition parameters. • The photocatalytic degradation of stearic acid was studied upon UV-A irradiation. - Abstract: Pure and Al-doped ZnO (Al = 1, 3, 5%) nanostructured thin films were grown at 400 °C on glass substrates by ultrasonic spray pyrolysis, a simple, environmental-friendly and inexpensive method, using aqueous solutions as precursors. The structural and morphological characteristics of the samples depend drastically on deposition parameters; ZnO nanostructured films, nanopetals and nanorods were systematically obtained by simply varying the precursor solution and/or the spraying time. Transmittance measurements have shown that all samples are transparent in the visible wavelength region. Finally, the photocatalytic properties of the samples were investigated against the degradation of stearic acid under UV-A light illumination (365 nm); both pure and Al-doped ZnO nanostructured thin films show good photocatalytic activity regarding the degradation of stearic acid, due to their good crystallinity and large surface area.

  20. UV and VUV characteristics of (YGd)2O3:Eu phosphor particles prepared by spray pyrolysis from polymeric precursors

    International Nuclear Information System (INIS)

    Kim, E.J.; Kang, Y.C.; Park, H.D.; Ryu, S.K.

    2003-01-01

    Red-emitting (YGd) 2 O 3 :Eu phosphor particles, with high luminescence efficiency under vacuum ultraviolet (VUV) and ultraviolet (UV) excitation, were prepared by a large-scale spray pyrolysis process. To control the morphology of phosphor particles under severe preparation conditions, spray solution with polymeric precursors were introduced in spray pyrolysis. The prepared (YGd) 2 O 3 :Eu phosphor particles had spherical shape and filled morphology even after post-treatment irrespective of Gd/Y ratio. In the case of solution with polymeric precursors, long polymeric chains formed by esterification reaction in a hot tubular reactor; the droplets turned into viscous gel, which retarded the precipitation of nitrate salts and promoted the volume precipitation of droplets. The brightness of (YGd) 2 O 3 :Eu phosphor particles increased with increasing gadolinium content, and the Gd 2 O 3 :Eu phosphor had the highest luminescence intensity under UV and VUV excitation. The maximum peak intensity of Gd 2 O 3 :Eu phosphor particles under UV and VUV were 118 and 110% of the commercial Y 2 O 3 :Eu phosphor particles, respectively

  1. Zirconium doped TiO{sub 2} thin films deposited by chemical spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Juma, A. [Laboratory of Thin Film Chemical Technologies, Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Department of Physics and Astronomy, Botswana International University of Science and Technology, Private bag 16, Palapye (Botswana); Oja Acik, I., E-mail: ilona.oja@ttu.ee [Laboratory of Thin Film Chemical Technologies, Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Oluwabi, A.T.; Mere, A. [Laboratory of Thin Film Chemical Technologies, Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Mikli, V.; Danilson, M. [Chair of Semiconductor Materials Technology, Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Krunks, M. [Laboratory of Thin Film Chemical Technologies, Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia)

    2016-11-30

    Highlights: • Mean crystallite size of TiO{sub 2}:Zr film decreases with increasing [Zr] in the solution. • Zr doping supresses the anatase to rutile transformation process in TiO{sub 2} films. • Band gap of TiO{sub 2}:Zr film is 3.4 eV irrespective of the annealing temperature. - Abstract: Chemical spray pyrolysis (CSP) is a flexible deposition technique that allows for mixing of the precursor solutions in different proportions suitable for doping thin films. The CSP method was used to dope TiO{sub 2} thin films with Zr by adding zirconium(IV) acetylacetonate into a solution of titanium(IV) isopropoxide in ethanol stabilized by acetylacetone at [Zr]/[Ti] of 0, 5, 10 and 20 at%. The Zr-doped TiO{sub 2} thin films were uniform and homogeneous showing much smaller grains than the undoped TiO{sub 2} films. Zr stabilized the anatase phase to temperatures above 800 °C depending on Zr concentration in the spray solution. The concentration of Zr determined by XPS was 6.4 at% for the thin film deposited from the 20 at% solution. According to AFM studies, Zr doping decreased the root mean square roughness of TiO{sub 2} film from 5.9 to 1.1 nm. An XRD study of samples with the highest Zr amount showed the ZrTiO{sub 4} phase started forming after annealing at 800 °C. The optical band gap for TiO{sub 2} decreased from 3.3 eV to 3.0 eV after annealing at 800 °C but for the TiO{sub 2}:Zr(20) film it remained at 3.4 eV. The dielectric constant increased by more than four times with Zr-doping and this was associated with the change in the bond formations caused by substitution of Ti by Zr in the lattice.

  2. Influence of solution deposition rate on properties of V_2O_5 thin films deposited by spray pyrolysis technique

    International Nuclear Information System (INIS)

    Abd–Alghafour, N. M.; Ahmed, Naser M.; Hassan, Zai; Mohammad, Sabah M.

    2016-01-01

    Vanadium oxide (V_2O_5) thin films were deposited on glass substrates by using a cost-efficient spray pyrolysis technique. The films were grown at 350° through thermal decomposition of VCl_3 in deionized water with different solution spray rates. The high resolution X-ray diffraction results revealed the formation of nanocrystalline films having orthorhombic structures with preferential orientation along (101) direction. The spray rate influenced the surface morphology and crystallite size of the films. The crystallite size was found to increase whereas the micro-strain was decreased by increasing the spray deposition rates. The increase in crystallite size and decrease in the macrostrain resulted in an improvement in the films’ crystallinity. The UV-Visible spectroscopy analysis indicated that the average transmittance of all films lies in the range 75-80 %. The band gap of V_2O_5 film was decreased from 2.65 to 2.46 eV with increase of the spray deposition rate from 5 ml/min to 10 ml/min. first, second, and third level headings (first level heading).

  3. Characterization of cobalt oxide thin films prepared by a facile spray pyrolysis technique using perfume atomizer

    Energy Technology Data Exchange (ETDEWEB)

    Louardi, A.; Rmili, A.; Ouachtari, F.; Bouaoud, A. [Laboratoire des Hautes Energies, Sciences de l' Ingenierie et Reacteurs (LHESIR), Equipe Ingenierie et Materiaux (INMA), Departement de Physique, Faculte des Sciences, Kenitra (Morocco); Elidrissi, B., E-mail: e.bachir@mailcity.com [Laboratoire des Hautes Energies, Sciences de l' Ingenierie et Reacteurs (LHESIR), Equipe Ingenierie et Materiaux (INMA), Departement de Physique, Faculte des Sciences, Kenitra (Morocco); Erguig, H. [Laboratoire des Hautes Energies, Sciences de l' Ingenierie et Reacteurs (LHESIR), Equipe Ingenierie et Materiaux (INMA), Departement de Physique, Faculte des Sciences, Kenitra (Morocco)

    2011-09-15

    Highlights: > Co{sub 3}O{sub 4} thin films show a micro porous structure. > Co{sub 3}O{sub 4} thin films are formed with spherical grains less than 50 nm in diameter. > The porous structure of Co{sub 3}O{sub 4} films is expected to have promising application in electrochromism. - Abstract: Cobalt oxide (Co{sub 3}O{sub 4}) thin films were prepared by a facile spray pyrolysis technique using perfume atomizer from aqueous solution of hydrated cobalt chloride salt (CoCl{sub 2}.6H{sub 2}O) as source of cobalt. The films were deposited onto the amorphous glass substrates kept at different temperatures (300-500 deg. C). The influences of molar concentration of the starting solution and substrate temperature on the structural, morphological and optical properties of (Co{sub 3}O{sub 4}) thin films were studied. It was found from X-ray diffraction (XRD) analysis that the films prepared with molar concentration greater than 0.025 M/L were polycrystalline spinel type cubic structure. The preferred orientation of the crystallites of these films changes gradually from (6 2 2) to (1 1 1) when the substrate temperature increases. By Raman spectroscopy, five Raman active modes characteristic of Co{sub 3}O{sub 4} spinel type cubic structure were found and identified at 194, 484, 522, 620 and 691 cm{sup -1}. The scanning electron microscopy (SEM) images showed micro porous structure with very fine grains less than 50 nm in diameter. These films exhibited also a transmittance value of about 70% in the visible and infra red range.

  4. Formation of self-assembled quantum dots of iron oxide thin films by spray pyrolysis from non-aqueous medium

    International Nuclear Information System (INIS)

    Desai, J.D.; Pathan, H.M.; Min, Sun-Ki; Jung, Kwang-Deog; Joo, Oh-Shim

    2006-01-01

    Quantum dots (QDs) of iron oxide have been deposited onto ITO coated glass substrates by spray pyrolysis technique, using ferric chloride (FeCl 3 .7H 2 O) in non-aqueous medium as a starting material. The non-aqueous solvents namely methanol, ethanol, propanol, butanol and pentanol were used as solvents. The effect of solvents on the film structure and morphology was studied. The structural, morphological, compositional and optical properties were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive analysis of X-rays (EDAX), and optical absorption measurement techniques

  5. Defect-induced magnetism in undoped and Mn-doped wide band gapzinc oxide grown by aerosol spray pyrolysis

    CSIR Research Space (South Africa)

    Motaung, DE

    2014-08-01

    Full Text Available Surface Science Vol. 311, pp 14-26 Defect-induced magnetism in undoped and Mn-doped wide band gapzinc oxide grown by aerosol spray pyrolysis D.E. Motaunga,∗, I. Kortidise, D. Papadakie, S.S. Nkosib,∗∗, G.H. Mhlongoa,J. Wesley-Smitha, G.F. Malgasc, B....W. Mwakikungaa, E. Coetseed, H.C. Swartd,G. Kiriakidise,f, S.S. Raya aDST/CSIR Nanotechnology Innovation Centre, National Centre for Nano-Structured Materials, Council for Scientific and Industrial Research, P.O. Box 395,Pretoria 0001, South Africa b...

  6. Suppression of the green photoluminescence band in ZnO embedded into porous opal by spray pyrolysis

    International Nuclear Information System (INIS)

    Abrarov, S.M.; Yuldashev, Sh.U.; Lee, S.B.; Kang, T.W.

    2004-01-01

    The photoluminescence (PL) and transmittance characteristics of the zinc oxide embedded into voids of FCC sub-micron packed silicon dioxide spheres by using technologically simple and inexpensive spray pyrolysis are reported. The uniform formation of ZnO nanocrystalline particles inside of the porous opal takes place after deposition in aqueous solution with zinc nitrite hexahydride precursor followed by thermal annealing. The decrease of green PL is observed due to the inhibition of spontaneous emission through oxygen vacancies in ZnO. The strong red shift of the transmittance characteristics signifies the essential filling of voids in the opal matrix

  7. Direct growth of vertically aligned carbon nanotubes on silicon substrate by spray pyrolysis of Glycine max oil

    Directory of Open Access Journals (Sweden)

    K. T. Karthikeyan

    2017-11-01

    Full Text Available Vertically aligned carbon nanotubes have been synthesized by spray pyrolysis from Glycine max oil on silicon substrate using ferrocene as catalyst at 650 °C. Glycine max oil, a plant-based hydrocarbon precursor was used as a source of carbon and argon as a carrier gas. The as-grown vertically aligned carbon nanotubes were characterized by scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, thermogravimetric analysis, and Raman spectroscopy. Scanning electron microscopic images reveal that the dense bundles of aligned carbon nanotubes. High resolution transmission electron microscopy and Raman spectroscopy observations indicate that as-grown aligned carbon nanotubes are well graphitized.

  8. Preparation of nanostructured ZrO2 thin films by using spray pyrolysis technique for gas sensing application

    International Nuclear Information System (INIS)

    Deshmukh, S.B.; Bari, R.H.; Jain, G.H.

    2013-01-01

    In present work the nano-structured pure ZrO 2 thin films were prepared using spray pyrolysis techniques. The aqueous solution of ZrCl 4 , was used as a precursor with flow rate controlled 5 mI/min. The films were synthesized on glass substrate between temperature 250-400℃ and subjected to different analytical characterization like SEM, XRD, TEM, FTIR, UV, TGA-DTA/DSC. The gas sensing performances of various gases were tested in different operating temperature range. The sensitivity, selectivity, response and recovery time for H 2 S gas was discussed. Also nano structured grain size discussed. (author)

  9. MgO thin films deposited by electrostatic spray pyrolysis for protecting layers in AC-plasma display panel

    CERN Document Server

    Kim, S G

    1999-01-01

    MgO thin films were deposited on SiO sub 2 (100) substrates by using electrostatic spray pyrolysis and Mg(tmhd) sub 2 as the precursor. The growth rates of the films varyed from 34 to 87 A/min and were measured for various substrate and guide temperatures. X-ray diffraction analysis provide evidence that the MgO films deposited at temperatures as low as 400 approx 500 .deg. C had preferred orientation to (100) plane perpendicular to the substrate surface. X-ray photoelectron spectroscopy and Auger electron spectroscopy data indicated that there were few organics incorporated in the films.

  10. LiCoO/sub 2/ structures by spray pyrolysis technique for rechargeable Li-ion battery

    International Nuclear Information System (INIS)

    Yilmaz, M.; Turgut, G.; Aydin, S.; Ertugrul, M.

    2012-01-01

    As the lithium-ion batteries have high energy density, Lithium-batteries have become a very attractive field of study for the researchers. Batteries' high energy density is up to the anode and cathode materials used in the batteries and the technique which is chosen for getting these materials. In this study, LiCoO/sub 2/, used for cathode active material in lithium ion batteries, has been prepared with spraying on a glass base by spray pyrolysis technique. LiCoO/sub 2 /was annealed at 600 deg. C for 3h in an air atmosphere; and crystal structures of the obtained samples were examined with XRD, the surface morphology of them was examined with SEM. Effect of annealing on crystallization has been investigated in prepared samples. (author)

  11. Surfactant-assisted ultrasonic spray pyrolysis of nickel oxide and lithium-doped nickel oxide thin films, toward electrochromic applications

    Energy Technology Data Exchange (ETDEWEB)

    Denayer, Jessica [Group of Research in Energy and Environment for MATerials (GREENMAT), University of Liège, allée de la chimie 3, 4000 Liège (Belgium); Bister, Geoffroy [Environmental and Material Research Association (CRIBC-INISMa), avenue gouverneur cornez 4, 7000 Mons (Belgium); Simonis, Priscilla [Laboratory LPS, University of Namur, rue de bruxelles 61, 5000 Namur (Belgium); Colson, Pierre; Maho, Anthony [Group of Research in Energy and Environment for MATerials (GREENMAT), University of Liège, allée de la chimie 3, 4000 Liège (Belgium); Aubry, Philippe [Environmental and Material Research Association (CRIBC-INISMa), avenue gouverneur cornez 4, 7000 Mons (Belgium); Vertruyen, Bénédicte [Group of Research in Energy and Environment for MATerials (GREENMAT), University of Liège, allée de la chimie 3, 4000 Liège (Belgium); Henrist, Catherine, E-mail: catherine.henrist@ulg.ac.be [Group of Research in Energy and Environment for MATerials (GREENMAT), University of Liège, allée de la chimie 3, 4000 Liège (Belgium); Lardot, Véronique; Cambier, Francis [Environmental and Material Research Association (CRIBC-INISMa), avenue gouverneur cornez 4, 7000 Mons (Belgium); Cloots, Rudi [Group of Research in Energy and Environment for MATerials (GREENMAT), University of Liège, allée de la chimie 3, 4000 Liège (Belgium)

    2014-12-01

    Highlights: • Surfactant-assisted USP: a novel and low cost process to obtain high quality nickel oxide films, with or without lithium dopant. • Increased uniformity and reduced light scattering thanks to the addition of a surfactant. • Improved electrochromic performance (coloration efficiency and contrast) for lithium-doped films by comparison with the undoped NiO film. - Abstract: Lithium-doped nickel oxide and undoped nickel oxide thin films have been deposited on FTO/glass substrates by a surfactant-assisted ultrasonic spray pyrolysis. The addition of polyethylene glycol in the sprayed solution has led to improved uniformity and reduced light scattering compared to films made without surfactant. Furthermore, the presence of lithium ions in NiO films has resulted in improved electrochromic performances (coloration contrast and efficiency), but with a slight decrease of the electrochromic switching kinetics.

  12. Deposition of tin oxide doped with fluorine produced by sol-gel method and deposited by spray-pyrolysis

    International Nuclear Information System (INIS)

    Maia, Paulo Herbert Franca; Lima, Francisco Marcone; Sena, Aline Cosmo de; Silva, Alvaro Neuton; Almeida, Ana Fabiola Leite de; Freire, Francisco Nivaldo Aguiar

    2014-01-01

    Solar energy is one of the most important sources of renewable energy today, but its production is based on silicon cells, expensive and difficult to produce, so the research seek new materials to replace them. This work aims to deposit tin oxide doped with fluorine on the glass substrate using the sol-gel method to provide a working solution and spray pyrolysis technique to perform the deposition. F-SnO2 (FTO) were synthesized by sol-gel method, employing NH_4F and SnCl_2 precursor in an ethanol solution. Before the formation of the gel phase, the entire solution was sprayed, with the aid of a pistol aerographic substrate under heated at 600 °C divided by 50 applications and cooled in the furnace. The substrates had resistances between 10 and 30 S.cm. The energy dispersive x-ray (EDS) revealed the presence of fluorine in the SnO_2 network. (author)

  13. Preparation of mesoporous alumina particles by spray pyrolysis and application to double bond migration of 2-butene.

    Science.gov (United States)

    Song, Ki Chang; Kim, Joo Hyun; Kim, Jin Han; Jung, Kyeong Youl; Park, Young-Kwon; Jeon, Jong-Ki

    2011-07-01

    The objective of the present study is to investigate the catalytic performance of mesoporous alumina that were prepared via spray pyrolysis for double bond migration from 2-butene to 1-butene. The mesoporous alumina particles were prepared via spray pyrolysis by changing the types of organic surfactants and Al precursors. The texture and acidic properties of mesoporous alumina were analyzed through N2 adsorption, SEM, ammonia-temperature programmed desorption, and FT-IR of adsorbed pyridine. The morphologies and texture properties of the mesoporous alumina were found to have been strongly influenced by the combination of the Al precursor and the structure-directing agents. The mesoporous alumina samples had two kinds of acidic sites: a Lewis acid site and a H-bonded weak acid site. 1-Butene was produced selectively through double bond migration of 2-butene over all of the mesoporous alumina catalysts. The catalyst prepared by using a chloride compound as an aluminium precursor and CTAC as a structure-directing agent showed the highest activity in the double bond migration of 2-butene, which was attributed to its large surface area and an overall high amount of acid sites.

  14. O3 Layers via Spray Pyrolysis at Low Temperatures and Their Application in High Electron Mobility Transistors

    KAUST Repository

    Isakov, Ivan

    2017-04-06

    The growth mechanism of indium oxide (InO) layers processed via spray pyrolysis of an aqueous precursor solution in the temperature range of 100-300 °C and the impact on their electron transporting properties are studied. Analysis of the droplet impingement sites on the substrate\\'s surface as a function of its temperature reveals that Leidenfrost effect dominated boiling plays a crucial role in the growth of smooth, continuous, and highly crystalline InO layers via a vapor phase-like process. By careful optimization of the precursor formulation, deposition conditions, and choice of substrate, this effect is exploited and ultrathin and exceptionally smooth layers of InO are grown over large area substrates at temperatures as low as 252 °C. Thin-film transistors (TFTs) fabricated using these optimized InO layers exhibit superior electron transport characteristics with the electron mobility reaching up to 40 cm V s, a value amongst the highest reported to date for solution-processed InO TFTs. The present work contributes enormously to the basic understanding of spray pyrolysis and highlights its tremendous potential for large-volume manufacturing of high-performance metal oxide thin-film transistor electronics.

  15. O3 Layers via Spray Pyrolysis at Low Temperatures and Their Application in High Electron Mobility Transistors

    KAUST Repository

    Isakov, Ivan; Faber, Hendrik; Grell, Max; Wyatt-Moon, Gwenhivir; Pliatsikas, Nikos; Kehagias, Thomas; Dimitrakopulos, George P.; Patsalas, Panos P.; Li, Ruipeng; Anthopoulos, Thomas D.

    2017-01-01

    The growth mechanism of indium oxide (InO) layers processed via spray pyrolysis of an aqueous precursor solution in the temperature range of 100-300 °C and the impact on their electron transporting properties are studied. Analysis of the droplet impingement sites on the substrate's surface as a function of its temperature reveals that Leidenfrost effect dominated boiling plays a crucial role in the growth of smooth, continuous, and highly crystalline InO layers via a vapor phase-like process. By careful optimization of the precursor formulation, deposition conditions, and choice of substrate, this effect is exploited and ultrathin and exceptionally smooth layers of InO are grown over large area substrates at temperatures as low as 252 °C. Thin-film transistors (TFTs) fabricated using these optimized InO layers exhibit superior electron transport characteristics with the electron mobility reaching up to 40 cm V s, a value amongst the highest reported to date for solution-processed InO TFTs. The present work contributes enormously to the basic understanding of spray pyrolysis and highlights its tremendous potential for large-volume manufacturing of high-performance metal oxide thin-film transistor electronics.

  16. Crumpled rGO-supported Pt-Ir bifunctional catalyst prepared by spray pyrolysis for unitized regenerative fuel cells

    Science.gov (United States)

    Kim, In Gyeom; Nah, In Wook; Oh, In-Hwan; Park, Sehkyu

    2017-10-01

    Three-dimensional (3D) crumpled reduced graphene oxide supported Pt-Ir alloys that served as bifunctional oxygen catalysts for use in untized regenerative fuel cells were synthesized by a facile spray pyrolysis method. Pt-Ir catalysts supported on rGO (Pt-Ir/rGOs) were physically characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA) to observe change in composition by heat treatment, alloying, and morphological transition of the catalysts. Their catalytic activities and stabilities for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) conditions were electrochemically investigated using cyclic voltammetry (CV), linear sweep voltammetry (LSV), potential cycling and hold tests on the rotating disk electrode (RDE). Pt-Ir/rGO with no post heat-treatment (Pt-Ir/rGO_NP) showed a lower activity for ORR and OER although metal nanoparticles decorated on the support are relatively small. However, Pt-Ir/rGO showed remarkably enhanced activity following heat treatment, depending on temperature. Pt-Ir/rGO heat-treated at 600 °C after spray pyrolysis (Pt-Ir/rGO_P600) exhibited a higher activity and stability than a commercially available Pt/C catalyst kept under the ORR condition, and it also revealed a comparable OER activity and durability versus the commercial unsupported Ir catalyst.

  17. Boron doped nanostructure ZnO films deposited by ultrasonic spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Karakaya, Seniye, E-mail: seniyek@ogu.edu.tr; Ozbas, Omer

    2015-02-15

    Highlights: • Nanostructure undoped and boron doped ZnO films were deposited by USP technique. • Influences of doping on the surface and optical properties of the ZnO films were investigated. • XRD spectra of the films exhibited a variation in crystalline quality depending on the B content. - Abstract: ZnO is an II–VI compound semiconductor with a wide direct band gap of 3.3 eV at room temperature. Doped with group III elements (B, Al or Ga), it becomes an attractive candidate to replace tin oxide (SnO{sub 2}) or indium tin oxide (ITO) as transparent conducting electrodes in solar cell devices and flat panel display due to competitive electrical and optical properties. In this work, ZnO and boron doped ZnO (ZnO:B) films have been deposited onto glass substrates at 350 ± 5 °C by a cost-efficient ultrasonic spray pyrolysis technique. The optical, structural, morphological and electrical properties of nanostructure undoped and ZnO:B films have been investigated. Electrical resistivity of films has been analyzed by four-probe technique. Optical properties and thicknesses of the films have been examined in the wavelength range 1200–1600 nm by using spectroscopic ellipsometry (SE) measurements. The optical constants (refractive index (n) and extinction coefficient (k)) and the thicknesses of the films have been fitted according to Cauchy model. The optical method has been used to determine the band gap value of the films. Transmission spectra have been taken by UV spectrophotometer. It is found that both ZnO and ZnO:B films have high average optical transmission (≥80%). X-ray diffraction (XRD) patterns indicate that the obtained ZnO has a hexagonal wurtzite type structure. The morphological properties of the films were studied by atomic force microscopy (AFM). The surface morphology of the nanostructure films is found to depend on the concentration of B. As a result, ZnO:B films are promising contender for their potential use as transparent window layer and

  18. DFT calculations on electronic properties of ZnO thin films deposited by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Cordeiro, J.M.; Reynoso, V.C.; Azevedo, D.H.M. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), SP (Brazil)

    2016-07-01

    Full text: Introduction - Thin films of Zinc oxide (ZnO) has a wide range of technological applications, as transparent conducting electrodes in solar cells, flat panel displays, and sensors, for example. More recently applications in optoelectronics, like light emitter diodes and laser diodes, due to its large band gap, are been explored. Studies of ZnO thin films are important for these applications. Methodology - In this study thin films of ZnO have been deposited by spray pyrolysis on glass substrate. The films were characterized by XRD and UV-VIS techniques and the electronic properties as a function of the film thickness have been investigated by DFT calculations with B3LYP hybrid potential implemented in the CRYSTAL09 code. Results - The diffractograms obtained for the ZnO thin films as a function of the thickness are shown. The films exhibit a hexagonal wurtzite structure with preferred c-axis orientation in (002) direction of ZnO crystal. A quantum mechanical approach based on the periodic Density Functional Theory (DFT), with B3LYP hybrid potential was used to investigate the electronic structure of the films as a function of the thickness. The CRYSTAL09 code has been used for the calculations on the wurtzite hexagonal structure of ZnO - spatial group P63mc. For optimizing the geometry of the pure ZnO crystal, the experimental lattice parameters were got as follows: a= 0.325 nm, b= 0.325 nm, c= 0.5207 nm with c/a= 1.602. Considering to the calculations of the band structure, it is suggested that the semiconducting properties of ZnO arises from the overlapping of the 4s orbital of the conducting band of Zn and the 2p orbital of the top of valence band of O. Conclusions - The structure of ZnO thin film deposited on glass substrate present preferential orientation in (002) direction. Variation in the optical properties as a function of the film thickness was observed. The band gap energy was determined from optical analysis to be ∼ 3.27 eV. The refractive

  19. Effect of copper concentration on the physical properties of copper doped NiO thin films deposited by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Mani Menaka, S., E-mail: manimenaka.phy@gmail.com [PG and Research Department of Physics, Government Arts College, Coimbatore, 641018, Tamilnadu (India); Umadevi, G. [PG and Research Department of Physics, Government Arts College, Coimbatore, 641018, Tamilnadu (India); Manickam, M. [SRMV College of Arts and Science, Coimbatore, 641020, Tamilnadu (India)

    2017-04-15

    The spray pyrolysis (SP) technique is an important and powerful method for the preparation of nickel oxide (NiO) and copper-doped nickel oxide thin films. The best films were obtained when the substrate temperature, T{sub s} = 450 °C on glass substrates. Copper (Cu) concentrations in the films were varied from 0 to 8%. The effect of Cu concentration on the structural, morphological, spectral, optical, and electrical properties of the thin films were studied by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transformed infrared spectroscopy (FTIR), UV–vis–NIR spectrophotometer, Hot probe and Hall system. The X-ray diffraction result shows the polycrystalline cubic structure of sprayed films with (200) preferred orientation. The variations of the structural parameters such as lattice parameters and grain sizes were investigated. The SEM image displays the surface morphology of the NiO and Cu:NiO thin films. The FTIR of the as-deposited films were associated with chemical identification. The optical transmittance and absorbance spectra of the films were measured by UV–vis–NIR spectrophotometer. The absorption coefficient and band gaps of the films were calculated using the optical method. All the NiO and Cu:NiO films were p-type. The resistivity of the above films decreases with the increase in copper concentration and so the conductivity of the films depend on the precursor concentration. - Highlights: • Pure and Cu:NiO films were deposited by Spray pyrolysis technique. • The XRD result shows the polycrystalline nature of pure and Cu:NiO films. • The formation of pure and Cu:NiO were confirmed by FTIR analysis. • Band gap values of pure and Cu:NiO decreases. • All the pure and Cu:NiO films were p-type.

  20. Effect of copper concentration on the physical properties of copper doped NiO thin films deposited by spray pyrolysis

    International Nuclear Information System (INIS)

    Mani Menaka, S.; Umadevi, G.; Manickam, M.

    2017-01-01

    The spray pyrolysis (SP) technique is an important and powerful method for the preparation of nickel oxide (NiO) and copper-doped nickel oxide thin films. The best films were obtained when the substrate temperature, T_s = 450 °C on glass substrates. Copper (Cu) concentrations in the films were varied from 0 to 8%. The effect of Cu concentration on the structural, morphological, spectral, optical, and electrical properties of the thin films were studied by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transformed infrared spectroscopy (FTIR), UV–vis–NIR spectrophotometer, Hot probe and Hall system. The X-ray diffraction result shows the polycrystalline cubic structure of sprayed films with (200) preferred orientation. The variations of the structural parameters such as lattice parameters and grain sizes were investigated. The SEM image displays the surface morphology of the NiO and Cu:NiO thin films. The FTIR of the as-deposited films were associated with chemical identification. The optical transmittance and absorbance spectra of the films were measured by UV–vis–NIR spectrophotometer. The absorption coefficient and band gaps of the films were calculated using the optical method. All the NiO and Cu:NiO films were p-type. The resistivity of the above films decreases with the increase in copper concentration and so the conductivity of the films depend on the precursor concentration. - Highlights: • Pure and Cu:NiO films were deposited by Spray pyrolysis technique. • The XRD result shows the polycrystalline nature of pure and Cu:NiO films. • The formation of pure and Cu:NiO were confirmed by FTIR analysis. • Band gap values of pure and Cu:NiO decreases. • All the pure and Cu:NiO films were p-type.

  1. Some physical parameters of CuInGaS{sub 2} thin films deposited by spray pyrolysis for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kotbi, Ahmed [Hassan II Casablanca University, MAC and PM Laboratory, ANEPMAER Group, FSTM, Mohammedia (Morocco); Hassan II Casablanca University, LIMAT Laboratory, Department of Physics, FSB, Casablanca (Morocco); Hartiti, Bouchaib; Fadili, Salah [Hassan II Casablanca University, MAC and PM Laboratory, ANEPMAER Group, FSTM, Mohammedia (Morocco); Ridah, Abderraouf [Hassan II Casablanca University, LIMAT Laboratory, Department of Physics, FSB, Casablanca (Morocco); Thevenin, Philippe [University of Lorraine, LMOPS Laboratory, Department of Physics, Metz (France)

    2017-05-15

    Copper-indium-gallium-disulphide (CuInGaS{sub 2}) is a promising absorber material for thin film photovoltaic. In this paper, CuInGaS{sub 2} (CIGS) thin films have been prepared by chemical spray pyrolysis method onto glass substrates at ambient atmosphere. Structural, morphological, optical and electrical properties of CuInGaS{sub 2} films were analysed by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), UV-Vis spectrophotometer and Hall Effect measurement, respectively. The films exhibited single phase chalcopyrite structure. The strain and dislocation density decreased with increase of spray time. The grain size of the films increased from 4.45 to 9.01 nm with increase of spray time. The Raman spectrum indicated the presence of the principal chalcopyrite peak at 295 cm{sup -1}. The optical properties of the synthesized films have been carried out through the measurement of the absorbance spectrum. The optical band gap was estimated by the absorption spectrum fitting (ASF) method. For each sample, the width of the band tail (E{sub Tail}) of CuInGaS{sub 2} thin films was determined. The resistivity (ρ), conductivity (σ), mobility (μ), carrier concentration and conduction type of the films were determined using Hall Effect measurements. The interesting optical properties of CuInGaS{sub 2} make them an attractive material for photovoltaic devices. (orig.)

  2. Some physical parameters of CuInGaS_2 thin films deposited by spray pyrolysis for solar cells

    International Nuclear Information System (INIS)

    Kotbi, Ahmed; Hartiti, Bouchaib; Fadili, Salah; Ridah, Abderraouf; Thevenin, Philippe

    2017-01-01

    Copper-indium-gallium-disulphide (CuInGaS_2) is a promising absorber material for thin film photovoltaic. In this paper, CuInGaS_2 (CIGS) thin films have been prepared by chemical spray pyrolysis method onto glass substrates at ambient atmosphere. Structural, morphological, optical and electrical properties of CuInGaS_2 films were analysed by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), UV-Vis spectrophotometer and Hall Effect measurement, respectively. The films exhibited single phase chalcopyrite structure. The strain and dislocation density decreased with increase of spray time. The grain size of the films increased from 4.45 to 9.01 nm with increase of spray time. The Raman spectrum indicated the presence of the principal chalcopyrite peak at 295 cm"-"1. The optical properties of the synthesized films have been carried out through the measurement of the absorbance spectrum. The optical band gap was estimated by the absorption spectrum fitting (ASF) method. For each sample, the width of the band tail (E_T_a_i_l) of CuInGaS_2 thin films was determined. The resistivity (ρ), conductivity (σ), mobility (μ), carrier concentration and conduction type of the films were determined using Hall Effect measurements. The interesting optical properties of CuInGaS_2 make them an attractive material for photovoltaic devices. (orig.)

  3. Effect of Solution Molarity, Substrate Temperature and Spray Time on The Structural and Optical Properties Of ZnO Thin Films Deposited By Spray Pyrolysis

    International Nuclear Information System (INIS)

    Ramadan, A.A.; Hashem, H. M.; El-Sayed, S. M.; Ashour, A.H.; Abdel-Haleem, S.M.

    2013-01-01

    Zinc oxide thin films were deposited on a glass substrate by spray pyrolysis technique using solution of zinc acetate and air as the carrier gas. Effects of solution molarity, substrate temperature and spray time on films properties were investigated. All films deposited were characterized using X-ray diffraction for structural characterization and UV-VIS transmission spectrophotometry for optical properties. According to the analytical method, the type of crystal lattice was found to be hexagonal and X-ray diffraction (XRD) patterns showed that the films deposited were polycrystalline with (002) plane as preferential orientation. The values of lattice constant, grain size, micro strain and dislocation density of all samples were calculated. In addition, Optical behaviors of film samples were analyzed by obtaining transmission spectra, in the wavelength range of 350-800 nm. The UV-VIS spectroscopy shows the high transparency of ZnO films in the UV region. An optimization of the films has been carried out to determine the best preparation conditions.

  4. Morphology-controllable of Sn doped ZnO nanorods prepared by spray pyrolysis for transparent electrode application

    Science.gov (United States)

    Hameed, M. Shahul; Princice, J. Joseph; Babu, N. Ramesh; Zahirullah, S. Syed; Deshmukh, Sampat G.; Arunachalam, A.

    2018-05-01

    Transparent conductive Sn doped ZnO nanorods have been deposited at various doping level by spray pyrolysis technique on glass substrate. The structural, surface morphological and optical properties of these films have been investigated with the help of X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscope (AFM) and UV-Vis spectrophotometer respectively. XRD patterns revealed a successful high quality growth of single crystal ZnO nanorods with hexagonal wurtzite structure having (002) preferred orientation. The scanning electron microscope (SEM) image of the prepared films exposed the uniform distribution of Sn doped ZnO nanorod shaped grains. All these films were highly transparent in the visible region with average transmittance of 90%.

  5. TiO2 anatase thin films deposited by spray pyrolysis of an aerosol of titanium diisopropoxide

    International Nuclear Information System (INIS)

    Conde-Gallardo, A.; Guerrero, M.; Castillo, N.; Soto, A.B.; Fragoso, R.; Cabanas-Moreno, J.G.

    2005-01-01

    Titanium dioxide thin films were deposited on crystalline silicon (100) and fused quartz substrates by spray pyrolysis (SP) of an aerosol, generated ultrasonically, of titanium diisopropoxide. The evolution of the crystallization, studied by X-ray diffraction (XRD), atomic force (AFM) and scanning electron microscopy (SEM), reflection and transmission spectroscopies, shows that the deposition process is nearly close to the classical chemical vapor deposition (CVD) technique, producing films with smooth surface and good crystalline properties. At deposition temperatures below 400 deg. C, the films grow in amorphous phase with a flat surface (roughness∼0.5 nm); while for equal or higher values to this temperature, the films develop a crystalline phase corresponding to the TiO 2 anatase phase and the surface roughness is increased. After annealing at 750 deg. C, the samples deposited on Si show a transition to the rutile phase oriented in (111) direction, while for those films deposited on fused quartz no phase transition is observed

  6. Structural, Optical and Electrical Properties of Transparent Conducting Oxide Based on Al Doped ZnO Prepared by Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    Abdeslam DOUAYAR

    2014-05-01

    Full Text Available Aluminum doped zinc oxide (AZO thin films were deposited on glass substrates at 350 °C by spray pyrolysis technique. X-ray diffraction patterns show that the undoped and AZO films exhibit the hexagonal wűrtzite crystal structure with a preferential orientation along 2 direction. AFM images showed that AZO film with 3 % of Al has a uniform grain sizes with a surface roughness of about 24 nm. All films present a high transmittance in the visible range. Both undoped and AZO films were n-type degenerate semiconductor and the best electrical resistivity value was around 8.0 ´ 10- 2 W.cm obtained for 3 % Al content.

  7. Nitrogen-doping effects on the growth, structure and electrical performance of carbon nanotubes obtained by spray pyrolysis method

    Energy Technology Data Exchange (ETDEWEB)

    Ionescu, Mihnea Ioan; Zhang Yong; Li Ruying [Department of Mechanical and Materials Engineering, University of Western Ontario, London, ON N6A 5B9 (Canada); Abou-Rachid, Hakima [Defense Research and Development Canada - Valcartier, 2459 Boulevard PieXI Nord, Quebec, QC G3J 1X5 (Canada); Sun Xueliang, E-mail: xsun@eng.uwo.ca [Department of Mechanical and Materials Engineering, University of Western Ontario, London, ON N6A 5B9 (Canada)

    2012-03-01

    Vertically aligned nitrogen-doped carbon nanotubes (CNTs) with modulated nitrogen content have been synthesized in a large scale by using spray pyrolysis chemical vapor deposition technique. The effects of nitrogen doping on the growth, structure and electrical performance of carbon nanotubes have been systematically examined. Field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Raman techniques have been employed to characterize the morphology, composition, and vibrational properties of nanotubes. The results indicate that the nitrogen incorporation significantly influences the growth rate, morphology, size and structure of nanotubes. Electrical measurement investigation of the nanotubes indicates that the change in electrical resistance increases with temperature and pressure as the nitrogen concentration increases inside the tubes. This work presents a versatile, safe, and easy way to scale up route of growing carbon nanotubes with controlled nitrogen content and modulated structure, and may provide an insight in developing various nitrogen-doped carbon-based nanodevices.

  8. Selectivity Enhancement by Using Double-Layer MOX-Based Gas Sensors Prepared by Flame Spray Pyrolysis (FSP

    Directory of Open Access Journals (Sweden)

    Julia Rebholz

    2016-09-01

    Full Text Available Here we present a novel concept for the selective recognition of different target gases with a multilayer semiconducting metal oxide (SMOX-based sensor device. Direct current (DC electrical resistance measurements were performed during exposure to CO and ethanol as single gases and mixtures of highly porous metal oxide double- and single-layer sensors obtained by flame spray pyrolysis. The results show that the calculated resistance ratios of the single- and double-layer sensors are a good indicator for the presence of specific gases in the atmosphere, and can constitute some building blocks for the development of chemical logic devices. Due to the inherent lack of selectivity of SMOX-based gas sensors, such devices could be especially relevant for domestic applications.

  9. Characterization and Gas Sensing Properties of Copper-doped Tin Oxide Thin Films Deposited by Ultrasonic Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    Zhaoxia ZHAI

    2016-05-01

    Full Text Available Tin oxide-based thin films are deposited by ultrasonic spray pyrolysis technology, in which Cu addition is introduced to enhance the gas sensing performance by H2S detection. The thin films are porous and comprise nano-sized crystallites. One of the Cu-containing thin film sensors demonstrates a fast and significant response to H2S gas. The values of power law exponent n are calculated to discuss the sensitivity of the sensors, which is significantly promoted by Cu additive. The sensitivity of Cu-doped SnO2 gas sensors is determined by two mechanisms. One is the normal gas sensing mechanism of SnO2 grains, and the other is the promoted mechanism caused by the transformation between CuO and CuS in the H2S detection. DOI: http://dx.doi.org/10.5755/j01.ms.22.2.12917

  10. Growth and characterization of V{sub 2}O{sub 5} nanorods deposited by spray pyrolysis at low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Abd-Alghafour, N. M., E-mail: na2013bil@gmail.com; Ahmed, Naser M., E-mail: nas-tiji@yahoo.com; Hassan, Zai. [Iraqi Ministry of Education, Anbar-Iraq (Iraq); Mohammad, Sabah M. [Nano-Optoelectronics Research and Technology Laboratory School of Physics, university sains Malaysia, 11800 Penang (Malaysia); Bououdina, M. [Nanotechnology Centre, University of Bahrain, PO Box 32038, Kingdom of Bahrain Department of Physics, College of Science, University of Bahrain, PO Box 32038, Kingdom of Bahrain, Iraqi Ministry of Education (Bahrain)

    2016-07-06

    Vanadium pentoxide (V{sub 2}O{sub 5}) nanorods were deposited by spray pyrolysis on preheated glass substrates at low temperatures. The influence of substrate temperature on the crystallization of V{sub 2}O{sub 5} has been investigated. X-ray diffraction analysis (XRD) revealed that the films deposited at T{sub sub} = 300°C were orthorhombic structures with preferential along (001) direction. Formation of nanorods from substrate surface which led to the formation of films with small-sized and rod-shaped nanostructure is observed by field scanning electron microscopy. Optical transmittance in the visible range increases to reach a maximum value of about 80% for a substrate temperature of 350°C. PL spectra reveal one main broad peak centered around 540 nm with high intensity.

  11. Effect of sample producing conditions on the thermoluminescence properties of ZnS thin films developed by spray pyrolysis method

    CERN Document Server

    Yazici, A N; Bedir, M

    2003-01-01

    In this work, the effect of thin film production conditions (substrate temperature and ratio of starting material) was studied on the intensity of thermoluminescence (TL) signal and TL emission spectrum of ZnS samples that were grown by spray pyrolysis method. It was observed that the intensity of TL signal increases with increasing the substrate temperature (T sub s) and reaches a maximum point at the substrate temperature of 500 deg. C with a high ratio of ZnCl sub 2 salt solutions. Secondly, it was observed that the energy level of trap present in ZnS samples is not single-level but instead has a distribution of energy levels. The type of the trap distribution is probably an exponential distribution. However, the distribution of energy levels approaches to single energy level with increasing substrate temperature.

  12. In vitro and in vivo antimicrobial properties of silver-containing hydroxyapatite prepared via ultrasonic spray pyrolysis route

    Energy Technology Data Exchange (ETDEWEB)

    Honda, Michiyo, E-mail: ap-honda@newkast.or.jp [Aizawa “Next-generation Bioceramics” Project, Kanagawa Academy of Science and Technology (KAST), 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa 213-0012 (Japan); Kawanobe, Yusuke [Department of Applied Chemistry, School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan); Ishii, Ken [Aizawa “Next-generation Bioceramics” Project, Kanagawa Academy of Science and Technology (KAST), 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa 213-0012 (Japan); Department of Orthopaedic Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); Konishi, Toshiisa [Aizawa “Next-generation Bioceramics” Project, Kanagawa Academy of Science and Technology (KAST), 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa 213-0012 (Japan); Department of Applied Chemistry, School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan); Mizumoto, Minori [Aizawa “Next-generation Bioceramics” Project, Kanagawa Academy of Science and Technology (KAST), 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa 213-0012 (Japan); Kanzawa, Nobuyuki [Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioicho, Chiyoda-ku, Tokyo 102-8554 (Japan); Matsumoto, Morio [Aizawa “Next-generation Bioceramics” Project, Kanagawa Academy of Science and Technology (KAST), 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa 213-0012 (Japan); Department of Orthopaedic Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); and others

    2013-12-01

    Hydroxyapatite (HAp), with its high biocompatibility and osteoconductivity, readily absorbs proteins, amino acids and other substances, which in turn favor the adsorption and colonization of bacteria. To prevent bacterial growth and biofilm formation on HAp discs, silver-containing (1–20 mol%) HAp (Ag-HAp) powders were synthesized using an ultrasonic spray pyrolysis (USSP) technique. The X-ray diffraction (XRD) peaks were very broad, indicating low crystallinity, and this induced the release of Ag{sup +} ions from Ag-HAp powders. In addition, a gradual increase in Ca{sup 2+} ion release was observed. These results suggest that dissolution of Ca{sup 2+} ion in Ag-HAp triggered the release of Ag{sup +} ions. The antimicrobial efficacy of Ag-HAp disc was tested against Staphylococcus aureus. Samples with Ag contents of more than 5 mol% were found to be highly effective against bacterial colonization and biofilm formation in vitro. In vivo antibacterial tests using bioluminescent strains also showed reductions in the viability of bacteria with Ag-HAp (5 mol%) discs. Biocompatibility tests using a modified Transwell® insert method showed that Ag-HAp (5 mol%) discs have negative effects on osteoblast proliferation. These results indicate that Ag-HAp (5 mol%) has effective antibacterial activity and good biocompatibility both in vitro and in vivo together with good biocompatibility, thus confirming its utility as a bactericidal material. - Highlights: • Ag-HAp powders were synthesized by an ultrasonic spray pyrolysis technique. • Ag-HAp powders with low crystallinity induced the release of Ag{sup +} ions. • Ag{sup +} ion was released from Ag-HAp powders over the course of 30 days. • Ag-HAp discs greatly affected antimicrobial activity in vitro and in vivo. • Optimal Ag content (5 mol%) did not affect osteoblastic cell proliferation.

  13. In vitro and in vivo antimicrobial properties of silver-containing hydroxyapatite prepared via ultrasonic spray pyrolysis route

    International Nuclear Information System (INIS)

    Honda, Michiyo; Kawanobe, Yusuke; Ishii, Ken; Konishi, Toshiisa; Mizumoto, Minori; Kanzawa, Nobuyuki; Matsumoto, Morio

    2013-01-01

    Hydroxyapatite (HAp), with its high biocompatibility and osteoconductivity, readily absorbs proteins, amino acids and other substances, which in turn favor the adsorption and colonization of bacteria. To prevent bacterial growth and biofilm formation on HAp discs, silver-containing (1–20 mol%) HAp (Ag-HAp) powders were synthesized using an ultrasonic spray pyrolysis (USSP) technique. The X-ray diffraction (XRD) peaks were very broad, indicating low crystallinity, and this induced the release of Ag + ions from Ag-HAp powders. In addition, a gradual increase in Ca 2+ ion release was observed. These results suggest that dissolution of Ca 2+ ion in Ag-HAp triggered the release of Ag + ions. The antimicrobial efficacy of Ag-HAp disc was tested against Staphylococcus aureus. Samples with Ag contents of more than 5 mol% were found to be highly effective against bacterial colonization and biofilm formation in vitro. In vivo antibacterial tests using bioluminescent strains also showed reductions in the viability of bacteria with Ag-HAp (5 mol%) discs. Biocompatibility tests using a modified Transwell® insert method showed that Ag-HAp (5 mol%) discs have negative effects on osteoblast proliferation. These results indicate that Ag-HAp (5 mol%) has effective antibacterial activity and good biocompatibility both in vitro and in vivo together with good biocompatibility, thus confirming its utility as a bactericidal material. - Highlights: • Ag-HAp powders were synthesized by an ultrasonic spray pyrolysis technique. • Ag-HAp powders with low crystallinity induced the release of Ag + ions. • Ag + ion was released from Ag-HAp powders over the course of 30 days. • Ag-HAp discs greatly affected antimicrobial activity in vitro and in vivo. • Optimal Ag content (5 mol%) did not affect osteoblastic cell proliferation

  14. A Review on the Preparation of Borazine-derived Boron Nitride Nanoparticles and Nanopolyhedrons by Spray-pyrolysis and Annealing Process

    Directory of Open Access Journals (Sweden)

    Vincent Salles

    2016-01-01

    Full Text Available Boron nitride (BN nanostructures (= nanoBN are struc‐ tural analogues of carbon nanostructures but display different materials chemistry and physics, leading to a wide variety of structural, thermal, electronic, and optical applications. Proper synthesis routes and advanced structural design are among the great challenges for preparing nanoBN with such properties. This review provides an insight into the preparation and characteriza‐ tion of zero dimensional (0D nanoBN including nanopar‐ ticles and nanopolyhedrons from borazine, an economically competitive and attractive (from a technical point of view molecule, beginning with a concise intro‐ duction to hexagonal BN, followed by an overview on the past and current state of research on nanoparticles. Thus, a review of the spray-pyrolysis of borazine to form BN nanoparticles is firstly presented. The use of BN nanopar‐ ticles as precursors of BN nanopolyhedrons is then de‐ tailed. Applications and research perspectives for these 0D nanoBN are discussed in the conclusion.

  15. Low-Temperature Preparation of Tungsten Oxide Anode Buffer Layer via Ultrasonic Spray Pyrolysis Method for Large-Area Organic Solar Cells

    Directory of Open Access Journals (Sweden)

    Ran Ji

    2017-07-01

    Full Text Available Tungsten oxide (WO3 is prepared by a low-temperature ultrasonic spray pyrolysis method in air atmosphere, and it is used as an anode buffer layer (ABL for organic solar cells (OSCs. The properties of the WO3 transition metal oxide material as well as the mechanism of ultrasonic spray pyrolysis processes are investigated. The results show that the ultrasonic spray pyrolysized WO3 ABL exhibits low roughness, matched energy level, and high conductivity, which results in high charge transport efficiency and suppressive recombination in OSCs. As a result, compared to the OSCs based on vacuum thermal evaporated WO3, a higher power conversion efficiency of 3.63% is reached with low-temperature ultrasonic spray pyrolysized WO3 ABL. Furthermore, the mostly spray-coated OSCs with large area was fabricated, which has a power conversion efficiency of ~1%. This work significantly enhances our understanding of the preparation and application of low temperature-processed WO3, and highlights the potential of large area, all spray coated OSCs for sustainable commercial fabrication.

  16. Low-Temperature Preparation of Tungsten Oxide Anode Buffer Layer via Ultrasonic Spray Pyrolysis Method for Large-Area Organic Solar Cells.

    Science.gov (United States)

    Ji, Ran; Zheng, Ding; Zhou, Chang; Cheng, Jiang; Yu, Junsheng; Li, Lu

    2017-07-18

    Tungsten oxide (WO₃) is prepared by a low-temperature ultrasonic spray pyrolysis method in air atmosphere, and it is used as an anode buffer layer (ABL) for organic solar cells (OSCs). The properties of the WO₃ transition metal oxide material as well as the mechanism of ultrasonic spray pyrolysis processes are investigated. The results show that the ultrasonic spray pyrolysized WO₃ ABL exhibits low roughness, matched energy level, and high conductivity, which results in high charge transport efficiency and suppressive recombination in OSCs. As a result, compared to the OSCs based on vacuum thermal evaporated WO₃, a higher power conversion efficiency of 3.63% is reached with low-temperature ultrasonic spray pyrolysized WO₃ ABL. Furthermore, the mostly spray-coated OSCs with large area was fabricated, which has a power conversion efficiency of ~1%. This work significantly enhances our understanding of the preparation and application of low temperature-processed WO₃, and highlights the potential of large area, all spray coated OSCs for sustainable commercial fabrication.

  17. Synthesis of tungsten oxide nano structures by laser pyrolysis

    CSIR Research Space (South Africa)

    Mwakikunga, BW

    2008-01-01

    Full Text Available Since the proposal to synthesise materials by laser assisted pyrolysis in the 1970s, and its practical realisation in 1982, a number of researchers have used this method in obtaining nano-powders from liquid droplets. This study revisits...

  18. Texture of high temperature superconductor thick films TI-1223 and TI-2223/LaAlO3 deposited by spray pyrolysis

    International Nuclear Information System (INIS)

    Nguyen Xuan, H.; Beauquis, S.; Galez, Ph.; Jorda, J.L.; Phok, S.; De-Barros, D.

    2004-01-01

    Superconducting TI-1223 and TI-2223 films have been prepared in a two steps process: deposition of Ba:Ca:Cu = 2:2:3 precursor by spray pyrolysis and ex-situ thallination. Pure textured TI-1223 films with good superconducting properties (T c =113 K and J c =0.7 MA/cm 2 at 77 K, 0T) have been obtained. Almost pure TI-2223 films have been obtained when precursor films have been thallinated with fluorinated sources. (orig.)

  19. Structural and optical properties of ZnO–SnO{sub 2} mixed thin films deposited by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Tharsika, T., E-mail: tharsika@siswa.um.edu.my; Haseeb, A.S.M.A., E-mail: haseeb@um.edu.my; Sabri, M.F.M., E-mail: faizul@um.edu.my

    2014-05-02

    Nanocrystalline ZnO–SnO{sub 2} mixed thin films were deposited by the spray pyrolysis technique at various substrate temperatures during deposition. The mixed films were prepared in the range of 20.9 at.% to 73.4 at.% by altering the Zn/(Sn + Zn) atomic ratio in the starting solution. Morphology, crystal structures, and optical properties of the films were characterized by field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and ultraviolet–visible and photoluminescence (PL) spectroscopy. XRD analysis reveals that the crystallinity of the Sn-rich mixed thin films increases with increasing substrate temperatures. FESEM images show that the grain size of mixed thin films is smaller compared to that of pure ZnO and SnO{sub 2} thin films. A drop in the thickness and optical bandgap of the film was observed for films fabricated at high temperatures, which coincided with the increased crystallinity of the films. The average optical transmission of mixed thin films increased from 70% to 95% within the visible range (400–800 nm) as the substrate temperature increases. Optical bandgap of the films was determined to be in the range of 3.21–3.96 eV. The blue shift in the PL spectra from the films was supported by the fact that grain size of the mixed thin films is much smaller than that of the pure ZnO and SnO{sub 2} thin films. Due to the improved transmission and reduced grain size, the ZnO–SnO{sub 2} mixed thin films can have potential use in photovoltaic and gas sensing applications. - Highlights: • ZnO–SnO{sub 2} mixed thin films were deposited on glass substrate by spray pyrolysis. • Crystallinity of the thin films increases with substrate temperature. • Grain size of the mixed thin films is smaller than that of the pure thin films. • Reduction of grain size depends on mixed atomic ratios of precursor solution. • Optical band gap of films could be engineered by changing substrate temperature.

  20. Corrosion resistance of zirconium oxynitride coatings deposited via DC unbalanced magnetron sputtering and spray pyrolysis-nitriding

    Energy Technology Data Exchange (ETDEWEB)

    Cubillos, G.I., E-mail: gcubillos@unal.edu.co [Department of Chemistry, Group of Materials and Chemical Processes, Universidad Nacional de Colombia, Av. Cra. 30 No 45-03, Bogotá (Colombia); Bethencourt, M., E-mail: manuel.bethencourt@uca.es [Department of Materials Science, Metallurgy Engineering and Inorganic Chemistry, International Campus of Excellence of the Sea - CEI-MAR, University of Cadiz, Avda. República Saharaui s/n, 11510 Puerto Real, Cádiz (Spain); Olaya, J.J., E-mail: jjolayaf@unal.edu.co [Faculty of Engineering, Group of Materials and Chemical Processes, Universidad Nacional de Colombia, Av. Cra. 30 No 45-03, Bogotá (Colombia)

    2015-02-01

    Highlights: • New ZrO{sub x}N{sub y} films were deposited on stainless steel 316L using PSY-N and UBMS. • ZrO{sub x}N{sub y} rhombohedral polycrystalline film grew with PSY-N. • Zr{sub 2}ON{sub 2} crystalline structures, mostly oriented along the (2 2 2) plane, grew with UBMS. • Layers improved corrosion behavior in NaCl media, especially those deposited by UBMS. - Abstract: ZrO{sub x}N{sub y}/ZrO{sub 2} thin films were deposited on stainless steel using two different methods: ultrasonic spray pyrolysis-nitriding (SPY-N) and the DC unbalanced magnetron sputtering technique (UBMS). Using the first method, ZrO{sub 2} was initially deposited and subsequently nitrided in an anhydrous ammonia atmosphere at 1023 K at atmospheric pressure. For UBMS, the film was deposited in an atmosphere of air/argon with a Φair/ΦAr flow ratio of 3.0. Structural analysis was carried out through X-ray diffraction (XRD), and morphological analysis was done through scanning electron microscopy (SEM) and atomic force microscopy (AFM). Chemical analysis was carried out using X-ray photoelectron spectroscopy (XPS). ZrO{sub x}N{sub y} rhombohedral polycrystalline film was produced with spray pyrolysis-nitriding, whereas using the UBMS technique, the oxynitride films grew with cubic Zr{sub 2}ON{sub 2} crystalline structures preferentially oriented along the (2 2 2) plane. Upon chemical analysis of the surface, the coatings exhibited spectral lines of Zr3d, O1s, and N1s, characteristic of zirconium oxynitride/zirconia. SEM analysis showed the homogeneity of the films, and AFM showed morphological differences according to the deposition technique of the coatings. Zirconium oxynitride films enhanced the stainless steel's resistance to corrosion using both techniques. The protective efficacy was evaluated using electrochemical techniques based on linear polarization (LP). The results indicated that the layers provide good resistance to corrosion when exposed to chloride

  1. Morphological differences in transparent conductive indium-doped zinc oxide thin films deposited by ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Jongthammanurak, Samerkhae; Cheawkul, Tinnaphob; Witana, Maetapa

    2014-01-01

    In-doped ZnO thin films were deposited on glass substrates by an ultrasonic spray pyrolysis technique, using indium chloride (InCl 3 ) as a dopant and zinc acetate solution as a precursor. Increasing the [at.% In]/[at.% Zn] ratio changed the crystal orientations of thin films, from the (100) preferred orientation in the undoped, to the (101) and (001) preferred orientations in the In-doped ZnO thin films with 4 at.% and 6–8 at.%, respectively. Undoped ZnO thin film shows relatively smooth surface whereas In-doped ZnO thin films with 4 at.% and 6–8 at.% show surface features of pyramidal forms and hexagonal columns, respectively. X-ray diffraction patterns of the In-doped ZnO thin films with [at.% In]/[at.% Zn] ratios of 6–8% presented an additional peak located at 2-theta of 32.95°, which possibly suggested that a metastable Zn 7 In 2 O 10 phase was present with the ZnO phase. ZnO thin films doped with 2 at.% In resulted in a sheet resistance of ∼ 645 Ω/sq, the lowest value among thin films with [at.% In]/[at.% Zn] ratio in a range of 0–8%. The precursor molarity was changed between 0.05 M and 0.20 M at an [at.% In]/[at.% Zn] ratio of 2%. Increasing the precursor molarity in a range of 0.10 M–0.20 M resulted in In-doped ZnO thin films with the (100) preferred orientation. An In-doped ZnO thin film deposited by 0.20 M precursor showed a sheet resistance of 25 Ω/sq, and an optical transmission of 75% at 550 nm wavelength. The optical band gap estimated from the transmission result was 3.292 eV. - Highlights: • Indium-doped ZnO thin films were grown on glass using ultrasonic spray pyrolysis. • Thin films' orientations depend on In doping and Zn molarity of precursor solution. • Highly c-axis or a-axis orientations were found in the In-doped ZnO thin films. • In doping of 6–8 at.% may have resulted in ZnO and a metastable Zn 7 In 2 O 10 phases. • Increasing precursor molarity reduced sheet resistance of In-doped ZnO thin films

  2. Dye-sensitized solar cell based on optically transparent TiO{sub 2} nanocrystalline electrode prepared by atomized spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Bandara, H.M.N., E-mail: hmnb@pdn.ac.l [Department of Chemistry, University of Peradeniya, Peradeniya (Sri Lanka); Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011 (Japan); Rajapakse, R.M.G. [Department of Chemistry, University of Peradeniya, Peradeniya (Sri Lanka); Murakami, K. [Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011 (Japan); Kumara, G.R.R.A.; Anuradha Sepalage, G. [Department of Chemistry, University of Peradeniya, Peradeniya (Sri Lanka)

    2011-10-30

    Highlights: > Transparent TiO{sub 2} films were prepared by the atomized spray pyrolysis method. > These films contain 3-5 nm discrete particles, interconnected to give a crack-free thin film structure. > Dye-absorption of the TiO{sub 2} film is 2.16 times higher than those used in conventional DSCs. > Conversion efficiency of 8.2% can be achieved with 1000 W m{sup -2} irradiation. - Abstract: Preparation of crack-free thin films of interconnected and non-agglomerated TiO{sub 2} nanoparticles on electronically conducting fluorine doped tin oxide surfaces is instrumental in designing and developing transparent dye-sensitized solar cells (DSCs). A novel technique called 'Atomized Spray Pyrolysis' (ASP) has been designed and developed to achieve such perfectly transparent thin films. Optical transmittance of TiO{sub 2} films produced on FTO surface by this ASP method has been compared with those obtained by doctor-blading and by hand spray methods and found that the atomized spray pyrolysis technique give films with high transparency. Dye adsorption per gram of TiO{sub 2} is 2.16 times higher in the sample produced by the ASP method when compared to the film produced by the hand spray method and is 1.60 times higher than that produced by the doctor-blading method using a commercially available TiO{sub 2} nanocrystalline paste. SEM studies show the presence of interconnected discrete particles in the film produced by the ASP method. The fill factor (ff) remains almost constant for the cells with thickness from 6 {mu}m to 13 {mu}m but the highest photovoltage and photocurrent were found in {approx}10 {mu}m film based DSC which gave 8.2% conversion efficiency at AM 1.5 irradiation for cells of 0.25 cm{sup 2} active area.

  3. Temperature dependent structural, luminescent and XPS studies of CdO:Ga thin films deposited by spray pyrolysis

    International Nuclear Information System (INIS)

    Moholkar, A.V.; Agawane, G.L.; Sim, Kyu-Ung; Kwon, Ye-bin; Choi, Doo Sun; Rajpure, K.Y.; Kim, J.H.

    2010-01-01

    Research highlights: → The CdO:Ga thin films seems an alternative to traditional TCO materials used in photovoltaic applications. This work deals the effect of deposition temperature on sprayed CdO:Ga films with respect to the structural, luminescent and XPS studies. → The crystalline quality of the GCO films improves with deposition temperature. → The oxygen vacancies are responsible for n-type conductivity and green emission. → The minimum resistivity, highest carrier concentration and mobility are 1.9 x 10 -4 Ω cm, 11.7 x 10 21 cm -3 and 27.64 cm 2 V -1 s -1 , respectively. - Abstract: The structural, compositional, photoluminescent and XPS properties of CdO:Ga thin films deposited at temperatures ranging from 275 to 350 o C, using spray pyrolysis are reported. X-ray diffraction characterization of as-deposited GCO thin films reveals that films are of cubic structure with a (2 0 0) preferred orientation. The crystalline quality of the GCO films improves and the grain size increases with deposition temperature. The EDS analyses confirm oxygen deficiency present in the film and are responsible for n-type conductivity. The photoluminescence spectra demonstrated that the green emission peaks of CdO thin films are centered at 482 nm. The relative intensity of these peaks is strongly dependent on the deposition temperature. Oxygen vacancies are dominant luminescent centers for green emission in CdO thin films. The XPS measurement shows the presence of Cd, Ga, O and C elements and confirms that CdO:Ga films are cadmium-rich.

  4. Characterization of dip-coated ITO films derived from nanoparticles synthesized by low-pressure spray pyrolysis

    International Nuclear Information System (INIS)

    Ogi, Takashi; Iskandar, Ferry; Itoh, Yoshifumi; Okuyama, Kikuo

    2006-01-01

    In 2 O 3 :Sn (Indium Tin Oxide; ITO) films were prepared from a sol solution with highly crystalline ITO nanoparticles (less than 20 nm in size with 10 at.% Sn) which had been prepared by low-pressure spray pyrolysis (LPSP) in a single step. The ITO sol solution was prepared by dispersing LPSP-prepared ITO nanoparticles into ultra pure water. The nanoparticle ITO film was deposited on a glass substrate using a dip-coating method and then annealed in air at various temperatures. The optical transmittances of the ITO films were measured by UV-Vis spectrometry, and the films were found to have a high transparency to visible light (in the case of a film thickness of 250 nm annealed at 400 deg. C, the transparency was in excess of 95% over the range λ=450-800 nm, with a maximum value near 100% at wavelengths above λ=700 nm). The optical transmittances of the films were influenced by the size of the ITO particle used, the film thickness and the annealing temperature. The ITO films showed a minimum resistivity of 9.5x10 -2 Ω cm, and their resistivity was affected by both the ITO particle size and the annealing temperature used

  5. An original way to obtain porous Zn(1–xMgxO thin films by spray pyrolysis technique

    Directory of Open Access Journals (Sweden)

    Abdelhakim Mahdjoub

    2017-04-01

    Full Text Available Zn(1–xMgxO thin films with various concentrations of magnesium were deposited using the spray pyrolysis method. The transmittance spectra recorded for all films exhibit maxima exceeding 90%. The band gap energy of the films with wurtzite structure increases from 3.22 up to 3.60 eV by incorporating Mg into ZnO. However, when the atomic ratio of Mg exceeded 0.4, a second crystalline phase (assigned to cubic MgO became discernable in XRD patterns, a compressive strain was observed in the wurtzite lattice, and crystallite sizes decreased significantly. In accordance with these observations, finer grains with a pronounced columnar growth were observed in 3D AFM representations and the surface roughness decreases significantly. Finally, selective etching in water yields to porous films with a great surface-to-volume ratio, a lower refractive index and a better light transmission. These porous films with tunable band gap seem to be excellent candidates to various interesting applications.

  6. Plasmonic metamaterial-based chemical converted graphene/TiO2/Ag thin films by a simple spray pyrolysis technique

    Science.gov (United States)

    Kumar, Promod; Swart, H. C.

    2018-04-01

    Graphene based hybrid nanostructures have received special attention in both the scientific and technological development due to their unique physicochemical behavior, which make them attractive in various applications such as, batteries, supercapacitors, fuel cells, solar cells, photovoltaic devices and bio-sensors. In the present study, the role of plasmonic metamaterials in light trapping photovoltaics for inorganic semiconducting materials by a simple and low cost spray pyrolysis technique has been studied. The plasmonic metamaterials thin film has been fabricated by depositing chemically converted graphene (CCG) onto TiO2-Ag nanoparticles which has a low resistivity and a low electron-hole recombination probability. The localized surface plasmon resonance at the metal-dielectric interface for the Ag nanoparticles has been observed at 403 nm after depositing chemical converted graphene (CCG) on the TiO2-Ag thin film. The results suggest that the stacking order of the CCG/TiO2/Ag plasmonic metamaterials samples did not change the band gap of TiO2 while it changed the conductivity of the film. Thus the diffusion of the noble metals in the glass and TiO2 matrices based thin films can trap the light of a particular wavelength by mean of plasmonic resonance and may be useful for superior photovoltaic and optoelectronic applications.

  7. Optical and electrical characterization of AgInS{sub 2} thin films deposited by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Calixto-Rodriguez, M., E-mail: manuela@fis.unam.mx [Instituto de Ciencias Fisicas-Universidad Nacional Autonoma de Mexico, Apartado Postal 48-3, 62210, Cuernavaca, Morelos (Mexico); Martinez, H. [Instituto de Ciencias Fisicas-Universidad Nacional Autonoma de Mexico, Apartado Postal 48-3, 62210, Cuernavaca, Morelos (Mexico); Calixto, M.E. [Instituto de Fisica, Benemerita Universidad Autonoma de Puebla, Apartado Postal J-48, 72570, Puebla, Puebla (Mexico); Pena, Y. [Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon, Pedro de Alba s/n, Ciudad Universitaria, 66451, San Nicolas de los Garza, Nuevo Leon (Mexico); Martinez-Escobar, Dalia [Centro de Investigacion en Energia-Universidad Nacional Autonoma de Mexico, 62580, Temixco, Morelos (Mexico); Tiburcio-Silver, A. [Instituto Tecnologico de Toluca-SEP, Apartado Postal 20, 52176, Metepec 3, Estado de Mexico (Mexico); Sanchez-Juarez, A. [Centro de Investigacion en Energia-Universidad Nacional Autonoma de Mexico, 62580, Temixco, Morelos (Mexico)

    2010-10-25

    Silver indium sulfide (AgInS{sub 2}) thin films have been prepared by spray pyrolysis (SP) technique using silver acetate, indium acetate, and N, N-dimethylthiourea as precursor compounds. Films were deposited onto glass substrates at different substrate temperatures (T{sub s}) and Ag:In:S ratios in the starting solutions. Optical transmission and reflection as well as electrical measurements were performed in order to study the effect of deposition parameters on the optical and electrical properties of AgInS{sub 2} thin films. X-ray diffraction measurements were used to identify the deposited compounds. It was found that different compounds such as AgInS{sub 2}, Ag{sub 2}S, In{sub 2}O{sub 3}, and In{sub 2}S{sub 3} can be grown only by changing the Ag:In:S ratio in the starting solution and T{sub s}. So that, by carefully selecting the deposition parameters, single phase AgInS{sub 2} thin films can be easily grown. Thin films obtained using a molar ratio of Ag:In:S = 1:1:2 and T{sub s} = 400 {sup o}C, have an optical band gap of 1.9 eV and n-type electrical conductivity with a value of 0.3 {Omega}{sup -1} cm{sup -1} in the dark.

  8. Effect of Annealing Temperature on Gas Sensing Performance of SnO2 Thin Films Prepared by Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    G. E. PATIL

    2010-12-01

    Full Text Available The effect of variation of annealing temperature on the gas sensing characteristics of SnO2 thin films, which have been prepared by spray pyrolysis on alumina substrate at 350 oC, is investigated systematically for various gases at different operating temperature. The XRD, UV-visible spectroscopy and SEM techniques were employed to establish the structural, optical and morphological characteristics of the materials, resp. The X-ray diffraction results showed an increase in the crystallinity at higher annealing temperature. A high value of sensitivity is obtained for H2S gas at an optimum temperature of 100 oC is improved considerably. A SnO2 gas sensor annealed at 950 oC with sensitivity as high as 24 %, 4 times higher than that of sensor annealed at 550oC, are obtained for 80 ppm of H2S. The degree of crystallinity and grain size calculated from the XRD patterns has been found increasing with annealing temp

  9. Compositional dependence of optical and electrical properties of indium doped zinc oxide (IZO) thin films deposited by chemical spray pyrolysis

    Science.gov (United States)

    Dintle, Lawrence K.; Luhanga, Pearson V. C.; Moditswe, Charles; Muiva, Cosmas M.

    2018-05-01

    The structural and optoelectronic properties of undoped and indium doped zinc oxide (IZO) thin films grown on glass substrates through a simple reproducible custom-made pneumatic chemical spray pyrolysis technique are presented. X-ray diffraction (XRD) results showed a polycrystalline structure of hexagonal wurtzite phase growing preferentially along the (002) plane for the undoped sample. Increase in dopant content modified the orientation leading to more pronounced (100) and (101) reflections. Optical transmission spectra showed high transmittance of 80-90% in the visible range for all thin films. The optical band gap energy (Eg) was evaluated on the basis of the derivative of transmittance (dT/dλ) versus wavelength (λ) model and Tauc's extrapolation method in the region where the absorption coefficient, α ≥ 104 cm-1. The observed values of Eg were found to decrease generally with increasing In dopant concentration. From the figure of merit calculations a sample with 4 at.% In dopant concentration showed better optoelectronic properties.

  10. Structural and Morphological Properties of Nanostructured ZnO Particles Grown by Ultrasonic Spray Pyrolysis Method with Horizontal Furnace

    Directory of Open Access Journals (Sweden)

    G. Flores-Carrasco

    2014-01-01

    Full Text Available ZnO nanoparticles were synthesized in a horizontal furnace at 500°C using different zinc nitrate hexahydrate concentrations (0.01 and 0.1 M as reactive solution by ultrasonic spray pyrolysis method. The physical-chemical properties of synthesized ZnO nanoparticles have been characterized by thermogravimetric analysis (TGA, X-ray diffraction (XRD, scanning electron microscopy (SEM, energy dispersive spectroscopy (EDS, and high resolution transmission electron microscopy (HRTEM. With the TGA is has optimized the temperature at which the initial reactive (Zn(NO32·6H2O, is decomposed completely to give way to its corresponding oxide, ZnO. SEM revealed secondary particles with a quasispherical shape that do not change significantly with the increasing of precursor solution concentration as well as some content of the broken spheres. Increasing the precursor solution concentration leads to the increase in the average size of ZnO secondary particles from 248±73 to 470±160 nm; XRD reveals the similar tendency for the crystallite size which changes from 23±4 to 45±4 nm. HRTEM implies that the secondary particles are with hierarchical structure composed of primary nanosized subunits. These results showed that the precursor concentration plays an important role in the evolution on the size, stoichiometry, and morphology of ZnO nanoparticles.

  11. Efficient acetone sensor based on Ni-doped ZnO nanostructures prepared by spray pyrolysis technique

    Science.gov (United States)

    Darunkar, Swapnil S.; Acharya, Smita A.

    2018-05-01

    Ni-doped ZnO thin film was prepared by home-built spray pyrolysis unit for the detection of acetone at 300°C. Scanning electron microscopic (SEM) images of as-developed thin film of undoped ZnO exhibits large quantity of spherical, non-agglomerated particles with uniform size while in Ni-doped ZnO, particles are quite non-uniform in nature. The particle size estimated by using image J are obtained to be around 20-200 nm. Ni-doping effect on band gaps are determined by UV-vis optical spectroscopy and band gap of Ni-doped ZnO is found to be 3.046 eV. Nickel doping exceptionally enhances the sensing response of ZnO as compared to undoped ZnO system. The major role of the Ni-doping is to create more active sites for chemisorbed oxygen on the surface of sensor and correspondingly, to improve the sensing response. The 6 at.% of Ni-doped ZnO exhibits the highest response (92%) for 100 ppm acetone at 300 °C.

  12. Structural and magnetic properties of Co-doped ZnO thin films grown by ultrasonic spray pyrolysis method

    Science.gov (United States)

    Baghdad, R.; Lemée, N.; Lamura, G.; Zeinert, A.; Hadj-Zoubir, N.; Bousmaha, M.; Bezzerrouk, M. A.; Bouyanfif, H.; Allouche, B.; Zellama, K.

    2017-04-01

    Cobalt-doped ZnO thin films with several different percentage of Co from 0 up to 15 at% were synthesized via a cheap, simple and versatile method i.e. ultrasonic spray pyrolysis at atmospheric pressure and a substrate temperature of 350 °C. The structure of the as-prepared samples was characterized by X-ray diffraction (XRD), Raman spectroscopy and FTIR. The Co-doping effect is revealed by the presence of three additional peaks around 235, 470 and 538 cm-1 respect to the Raman spectra of the unsubstituted film. Fourier transform infrared spectroscopy (FTIR) put in evidence the decrease of the bond force constant f with increasing Co-doping. By ultra-violet visible near infrared (UV-Vis-NIR) spectroscopy on Co-doped samples it was possible to show the presence of additional absorption bands at approximately 570, 620 and 660 nm suggesting that Co2+ ions do not change their oxidation when substituted to zinc and the ZnO lattice does not change its wurtzite structure as well. Finally, all our samples exhibit a paramagnetic behavior without any trace of intrinsic room temperature ferromagnetism.

  13. Influences of Pr and Ta doping concentration on the characteristic features of FTO thin film deposited by spray pyrolysis

    International Nuclear Information System (INIS)

    Turgut, Güven; Koçyiğit, Adem; Sönmez, Erdal

    2015-01-01

    The Pr and Ta separately doped FTO (10 at.% F incorporated SnO 2 ) films are fabricated via spray pyrolysis. The microstructural, topographic, optical, and electrical features of fluorine-doped TO (FTO) films are investigated as functions of Pr and Ta dopant concentrations. The x-ray diffraction (XRD) measurements reveal that all deposited films show polycrystalline tin oxide crystal property. FTO film has (200) preferential orientation, but this orientation changes to (211) direction with Pr and Ta doping ratio increasing. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) analyses show that all films have uniform and homogenous nanoparticle distributions. Furthermore, morphologies of the films depend on the ratio between Pr and Ta dopants. From ultraviolet-visible (UV-Vis) spectrophotometer measurements, it is shown that the transmittance value of FTO film decreases with Pr and Ta doping elements increasing. The band gap value of FTO film increases only at 1 at.% Ta doping level, it drops off with Pr and Ta doping ratio increasing at other doped FTO films. The electrical measurements indicate that the sheet resistance value of FTO film initially decreases with Pr and Ta doping ratio decreasing and then it increases with Pr and Ta doping ratio increasing. The highest value of figure of merit is obtained for 1 at.% Ta- and Pr-doped FTO film. These results suggest that Pr- and Ta-doped FTO films may be appealing candidates for TCO applications. (paper)

  14. Structure, optical and electrical properties of indium tin oxide ultra thin films prepared by jet nebulizer spray pyrolysis technique

    Directory of Open Access Journals (Sweden)

    M. Thirumoorthi

    2016-03-01

    Full Text Available Indium tin oxide (ITO thin films have been prepared by jet nebulizer spray pyrolysis technique for different Sn concentrations on glass substrates. X-ray diffraction patterns reveal that all the films are polycrystalline of cubic structure with preferentially oriented along (222 plane. SEM images show that films exhibit uniform surface morphology with well-defined spherical particles. The EDX spectrum confirms the presence of In, Sn and O elements in prepared films. AFM result indicates that the surface roughness of the films is reduced as Sn doping. The optical transmittance of ITO thin films is improved from 77% to 87% in visible region and optical band gap is increased from 3.59 to 4.07 eV. Photoluminescence spectra show mainly three emissions peaks (UV, blue and green and a shift observed in UV emission peak. The presence of functional groups and chemical bonding was analyzed by FTIR. Hall effect measurements show prepared films having n-type conductivity with low resistivity (3.9 × 10−4 Ω-cm and high carrier concentrations (6.1 × 1020 cm−3.

  15. Transparent nanostructured Fe-doped TiO2 thin films prepared by ultrasonic assisted spray pyrolysis technique

    Science.gov (United States)

    Rasoulnezhad, Hossein; Hosseinzadeh, Ghader; Ghasemian, Naser; Hosseinzadeh, Reza; Homayoun Keihan, Amir

    2018-05-01

    Nanostructured TiO2 and Fe-doped TiO2 thin films with high transparency were deposited on glass substrate through ultrasonic-assisted spray pyrolysis technique and were used in the visible light photocatalytic degradation of MB dye. The resulting thin films were characterized by scanning electron microscopy (SEM), Raman spectroscopy, photoluminescence spectroscopy, x-ray diffraction (XRD), and UV-visible absorption spectroscopy techniques. Based on Raman spectroscopy results, both of the TiO2 and Fe-doped TiO2 films have anatase crystal structure, however, because of the insertion of Fe in the structure of TiO2 some point defects and oxygen vacancies are formed in the Fe-doped TiO2 thin film. Presence of Fe in the structure of TiO2 decreases the band gap energy of TiO2 and also reduces the electron–hole recombination rate. Decreasing of the electron–hole recombination rate and band gap energy result in the enhancement of the visible light photocatalytic activity of the Fe-doped TiO2 thin film.

  16. Effect of Annealing on the Structural and Optical Properties of Nano Fiber ZnO Films Deposited by Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    M. R. Islam

    2011-11-01

    Full Text Available Nano fiber ZnO films have been deposited on to glass substrate at 200 °C by a simple spray pyrolysis technique under atmospheric pressure. The effect of annealing temperature on the structural and optical properties of the as grown films has been studied by Scanning Electron Microscopy (SEM attached with an EDX, powder X-ray diffraction and UV visible spectroscopy. The atomic weight % of Zinc and Oxygen were found to be 49.22 % and 49.62 % respectively. The SEM micrographs show nano fiber structure and uniform deposition on the substrate. Average grain size of ZnO thin film was found in the range of 21 to 27 nm. The lattice constant a and c of ZnO thin film are determined at different annealing temperatures and values are found slightly larger than those of JCPDS data and lower for the sample annealed at 600 °C. The lattice parameters a and c decrease with increasing temperature. It reveals that the samples are poly-crystalline and having with low densities. Band gap energy of ZnO was found in the range of 3.33 to 3.17 eV and decreases with the increase of the annealing temperature.

  17. Effect of Precursor Concentration on Structural Optical and Electrical Properties of NiO Thin Films Prepared by Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    Rafia Barir

    2017-01-01

    Full Text Available Undoped nickel oxide (NiO thin films were deposited on 500°C heated glass substrates using spray pyrolysis method at (0.015–0.1 M range of precursor. The latter was obtained by decomposition of nickel nitrate hexahydrate in double distilled water. Effect of precursor concentration on structural, optical, and electrical properties of NiO thin films was investigated. X-ray diffraction (XRD shows the formation of NiO under cubic structure with single diffraction peak along (111 plane at 2θ=37.24°. When precursor concentration reaches 0.1 M, an increment in NiO crystallite size over 37.04 nm was obtained indicating the product nano structure. SEM images reveal that beyond 0.04 M as precursor concentration the substrate becomes completely covered with NiO and thin films exhibit formation of nano agglomerations at the top of the sample surface. Ni-O bonds vibrations modes in the product of films were confirmed by FT-IR analysis. Transparency of the films ranged from 57 to 88% and band gap energy of the films decreases from 3.68 to 3.60 eV with increasing precursor concentration. Electrical properties of the elaborated NiO thin films were correlated to the precursor concentration.

  18. Ni-SiO2 Catalysts for the Carbon Dioxide Reforming of Methane: Varying Support Properties by Flame Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    Emma C. Lovell

    2015-03-01

    Full Text Available Silica particles were prepared by flame spray pyrolysis (FSP as a support for nickel catalysts. The impact of precursor feed rate (3, 5 and 7 mL/min during FSP on the silica characteristics and the ensuing effect on catalytic performance for the carbon dioxide, or dry, reforming of methane (DRM was probed. Increasing the precursor feed rate: (i progressively lowered the silica surface area from ≈340 m2/g to ≈240 m2/g; (ii altered the silanol groups on the silica surface; and (iii introduced residual carbon-based surface species to the sample at the highest feed rate. The variations in silica properties altered the (5 wt % nickel deposit characteristics which in turn impacted on the DRM reaction. As the silica surface area increased, the nickel dispersion increased which improved catalyst performance. The residual carbon-based species also appeared to improve nickel dispersion, and in turn catalyst activity, although not to the same extent as the change in silica surface area. The findings illustrate both the importance of silica support characteristics on the catalytic performance of nickel for the DRM reaction and the capacity for using FSP to control these characteristics.

  19. Probing the doping mechanisms and electrical properties of Al, Ga and In doped ZnO prepared by spray pyrolysis

    KAUST Repository

    Maller, Robert

    2016-05-24

    The measured structural, optical and electrical properties of Al, Ga and In doped ZnO films deposited using spray pyrolysis are reported over the doping range 0.1 - 3 atomic percent (at. %). Over the entire doping series highly transparent, polycrystalline thin films are prepared. Using the AC Hall effect we probe the electronic properties of our doped films separating the impact of doping on the measured charge carrier concentrations and Hall mobility, with an emphasis on the low doping, < 1 at. %, range. In this doping range highly resistive films are formed and we highlight AC Hall as a reliable and highly reproducible technique for analysing the doping mechanism. The implementation of a simple, post-deposition heat treatment of our AZO films creates typical films with charge carrier concentrations exceeding > 1019 cm-3 and electron mobilities over 10 cm2/Vs. We describe in detail the nature of the defect chemistry and the role of intrinsic defects, particularly traps, and show that despite significant variations in dopant species and grain boundary concentrations that the defect chemistry dominates the electrical characteristics.

  20. Double-layer indium doped zinc oxide for silicon thin-film solar cell prepared by ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Jiao Bao-Chen; Zhang Xiao-Dan; Wei Chang-Chun; Sun Jian; Ni Jian; Zhao Ying

    2011-01-01

    Indium doped zinc oxide (ZnO:In) thin films were prepared by ultrasonic spray pyrolysis on corning eagle 2000 glass substrate. 1 and 2 at.% indium doped single-layer ZnO:In thin films with different amounts of acetic acid added in the initial solution were fabricated. The 1 at.% indium doped single-layers have triangle grains. The 2 at.% indium doped single-layer with 0.18 acetic acid adding has the resistivity of 6.82×10 −3 Ω·cm and particle grains. The double-layers structure is designed to fabricate the ZnO:In thin film with low resistivity (2.58×10 −3 Ω·cm) and good surface morphology. It is found that the surface morphology of the double-layer ZnO:In film strongly depends on the substrate-layer, and the second-layer plays a large part in the resistivity of the double-layer ZnO:In thin film. Both total and direct transmittances of the double-layer ZnO:In film are above 80% in the visible light region. Single junction a-Si:H solar cell based on the double-layer ZnO:In as front electrode is also investigated. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  1. IBA of ZrO2:Yb/Si thin films produced by the spray pyrolysis method

    International Nuclear Information System (INIS)

    Andrade, E.; Ramirez, E.B.; Alonso, J.C.; Rocha, M.F.

    2008-01-01

    A spray pyrolysis method was used to produce thin films of ZrO 2 doped with different Yb concentrations on Si(1 0 0). The films of these ionic semiconductors have potential applications as solid electrolytes in modern ceramic fuel cells of second generation. The determination of the atomic composition of the films is very important because it strongly affects the chemical and thermal stability, as well as electrical properties of the films. A combination of two Ion Beam Analysis (IBA) methods was applied to obtain the atomic composition of the films. A nuclear reaction analysis (NRA) method using a low energy deuterium beam was applied to measure the oxygen content of the films. Heavy ion Rutherford backscattering (HI-RBS) method using a 12 C 3+ beam was applied to measure the Yb and Zr atomic profiles of the samples. X-ray diffraction (XRD) and ellipsometry were also employed to determine structural properties and refractive index of the films, respectively. The IBA, XRD and the ellipsometry supply a wide range of information about the film layers, which can be used for qualification as well as for feedback to the films production

  2. Probing the doping mechanisms and electrical properties of Al, Ga and In doped ZnO prepared by spray pyrolysis

    KAUST Repository

    Maller, Robert; Porte, Yoann; Alshareef, Husam N.; McLachlan, Martyn

    2016-01-01

    The measured structural, optical and electrical properties of Al, Ga and In doped ZnO films deposited using spray pyrolysis are reported over the doping range 0.1 - 3 atomic percent (at. %). Over the entire doping series highly transparent, polycrystalline thin films are prepared. Using the AC Hall effect we probe the electronic properties of our doped films separating the impact of doping on the measured charge carrier concentrations and Hall mobility, with an emphasis on the low doping, < 1 at. %, range. In this doping range highly resistive films are formed and we highlight AC Hall as a reliable and highly reproducible technique for analysing the doping mechanism. The implementation of a simple, post-deposition heat treatment of our AZO films creates typical films with charge carrier concentrations exceeding > 1019 cm-3 and electron mobilities over 10 cm2/Vs. We describe in detail the nature of the defect chemistry and the role of intrinsic defects, particularly traps, and show that despite significant variations in dopant species and grain boundary concentrations that the defect chemistry dominates the electrical characteristics.

  3. Use of low-temperature nanostructured CuO thin films deposited by spray-pyrolysis in lithium cells

    International Nuclear Information System (INIS)

    Morales, J.; Sanchez, L.; Martin, F.; Ramos-Barrado, J.R.; Sanchez, M.

    2005-01-01

    Nanostructured CuO thin films were prepared by spray pyrolysis of aqueous copper acetate solutions at temperatures over 200-300 deg C range. The textural and structural properties of the films were determined by scanning electron microscopy, atomic force microscopy, X-ray diffraction spectroscopy and X-ray photoelectron spectroscopy (XPS). Although the sole crystalline phase detected in the film was CuO, XPS spectra revealed a more complex surface structure due to the presence of undecomposed copper acetate that can be easily removed by Ar + ion sputtering. The heating temperature was found to have little limited effect on the particle size and thickness of the films, which, however, increased significantly increasing deposition time. The film with the smallest grain size exhibited an excellent electrochemical response in Li battery electrodes and was capable of supplying sustained specific capacity as high as 625 A h kg -1 (50% greater than that delivered by bulk CuO and close to the theoretical capacity for the CuO Cu reaction) upon extensive cycling

  4. Surface modification of submicronic TiO{sub 2} particles prepared by ultrasonic spray pyrolysis for visible light absorption

    Energy Technology Data Exchange (ETDEWEB)

    Dugandzic, Ivan M. [Institute of Technical Sciences of SASA (Serbia); Jovanovic, Dragana J. [University of Belgrade, Vinca Institute of Nuclear Sciences (Serbia); Mancic, Lidija T. [Institute of Technical Sciences of SASA (Serbia); Zheng, Nan; Ahrenkiel, Scott P. [South Dakota School of Mines and Technology (United States); Milosevic, Olivera B. [Institute of Technical Sciences of SASA (Serbia); Saponjic, Zoran V.; Nedeljkovic, Jovan M., E-mail: jovned@vinca.rs [University of Belgrade, Vinca Institute of Nuclear Sciences (Serbia)

    2012-10-15

    Spherical, submicronic TiO{sub 2} assemblage with high specific surface area and controllable phase composition was prepared in the process of ultrasonic spray drying/pyrolysis in a wide temperature range (150-800 Degree-Sign C) by using as a precursor aqueous colloidal solution consisting of TiO{sub 2} nanoparticles (4.5 nm). Submicronic, soft and grained spherical TiO{sub 2} particles (d = 370-500 nm) comprising clustered nanocrystals (<10 nm) were obtained at low processing temperature, while particle densification, intensive growth of the clustered primary units and anatase-to-rutile transformation ({approx}30 wt%) were observed at the higher temperatures. Detailed structural and morphological characterisation were performed by X-ray powder diffraction, scanning and field emission electron microscopy, transmission electron microscopy, and laser particle size analysis. Moreover, the surface modification of TiO{sub 2} particles through the formation of charge-transfer (CT) complex was achieved with different ligands: ascorbic acid, dopamine, catechol, 2,3-dihydroxynaphthalene, and anthrarobin. Optical properties of the surface-modified TiO{sub 2} particles were studied by using diffuse reflection spectroscopy. The binding structure between the surface titanium atoms and different ligands was determined by using Fourier transform infrared spectroscopy. The formation of CT complexes induced significant red shift of optical absorption in comparison to unmodified TiO{sub 2} particles.

  5. Structural, optical and thermal properties of {beta}-SnS{sub 2} thin films prepared by the spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Khelia, C.; Ben Nasrallah, T.; Amlouk, M.; Belgacem, S. [Faculte des Sciences, Tunis (Tunisia). Lab. de Physique de la Matiere Condensee; Maiz, F. [Equipe de Photothermique de Nabeul, Inst. Preparatoire aux Etudes d' Ingenieur de Nabeul (Tunisia); Mnari, M. [Lab. de Chimie Analytique, Campus Univ., Tunis (Tunisia)

    2000-03-01

    Tin disulfide {beta}-SnS{sub 2} thin films have been prepared on pyrex substrates by the spray pyrolysis technique using tin tetrachloride and thiourea as starting materials. The depositions were carried out in the range of substrate temperatures from 240 to 400 C. Highly c-axis oriented {beta}-SnS{sub 2} films, having a strong (001) X-ray diffraction line are obtained at temperature 280 C and using concentration ratio in solution R = [S]/[Sn] = 2.5. Films surfaces were analyzed by contact atomic force microscopy (AFM) and by scanning electron microscopy (SEM) in order to understand the effect of the deposited temperature on the surface structure. On the other hand, from transmission and reflection spectra, the band gap energy determined is about 2.71 eV. Finally using the photodeflection spectroscopy technique, the thermal conductivity K{sub c} and diffusivity D{sub c} were obtained. Their values are 10 Wm{sup -1}K{sup -1} and 10{sup -5} m{sup 2}s{sup -1} respectively. (orig.)

  6. High-capacity cathodes for lithium-ion batteries from nanostructured LiFePO4 synthesized by highly-flexible and scalable flame spray pyrolysis

    Science.gov (United States)

    Hamid, N. A.; Wennig, S.; Hardt, S.; Heinzel, A.; Schulz, C.; Wiggers, H.

    2012-10-01

    Olivine, LiFePO4 is a promising cathode material for lithium-ion batteries due to its low cost, environmental acceptability and high stability. Its low electric conductivity prevented it for a long time from being used in large-scale applications. Decreasing its particle size along with carbon coating significantly improves electronic conductivity and lithium diffusion. With respect to the controlled formation of very small particles with large specific surface, gas-phase synthesis opens an economic and flexible route towards high-quality battery materials. Amorphous FePO4 was synthesized as precursor material for LiFePO4 by flame spray pyrolysis of a solution of iron acetylacetonate and tributyl phosphate in toluene. The pristine FePO4 with a specific surface from 126-218 m2 g-1 was post-processed to LiFePO4/C composite material via a solid-state reaction using Li2CO3 and glucose. The final olivine LiFePO4/C particles still showed a large specific surface of 24 m2 g-1 and were characterized using X-ray diffraction (XRD), electron microscopy, X-ray photoelectron spectrocopy (XPS) and elemental analysis. Electrochemical investigations of the final LiFePO4/C composites show reversible capacities of more than 145 mAh g-1 (about 115 mAh g-1 with respect to the total coating mass). The material supports high drain rates at 16 C while delivering 40 mAh g-1 and causes excellent cycle stability.

  7. Copper indium diselenide films deposited by spray-pyrolysis; Filmes de disseleneto de cobre e indio depositados por spray-pirolise

    Energy Technology Data Exchange (ETDEWEB)

    Manhanini, C. S.; Paes Junior, H.R., E-mail: carlamanhanini@gmail.com, E-mail: hervalpaes@gmail.com [Universidade Estadual do Norte Fluminense, (CCT/UENF), Campos dos Goytacazes, RJ (Brazil). Lab. de Materiais Avancados

    2017-04-15

    Cu{sub 1-x}In{sub x} Se{sub 2} (0.45≤ x ≤0.80) films were deposited on glass substrate by spray pyrolysis technique, for use as absorbing layer of photovoltaic cells. The structural, morphological, optical and electrical properties of the films were analyzed according to the variation of the stoichiometry used. The analysis by X-ray diffraction showed that the most intense peaks were of orientation (204/220) and the films have the phases CuSe, CuSe{sub 2} and CuInSe{sub 2}. The films showed uniform surface without cracks independently of the stoichiometry used. In the electrical characterization, the deposited films showed activation energy of the electrical conduction process with average value of 0.74 eV and typical behavior for semiconductors. The optical characterization was performed at the wavelength gap of 350 to 1100 nm, and the films showed absorption coefficient on the order of 10{sup 3} cm{sup -1} in the wavelength of 550 nm and optical band gap of 1.4 eV. The results indicated that the most suitable condition for deposition of films for their application as absorbing layer had as substrate temperature 400 °C, a solution flow rate of 1 mL/min, deposition time of 10 min and stoichiometry of Cu{sub 0.2}In{sub 0.8}Se{sub 2}, thus obtaining films without cracks, with large absorption coefficient of 6.8x10{sup 3} cm{sup -1} for the wavelength of 550 nm, thickness of approximately 2.5 μm and electrical resistivity of 0.13 kΩ.m at room temperature. (author)

  8. Spectroscopic ellipsometry studies of index profile of indium tin oxide films prepared by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    El Rhaleb, H.; Benamar, E.; Rami, M.; Roger, J.P.; Hakam, A.; Ennaoui, A

    2002-11-30

    Spectroscopic ellipsometry (SE) has proven to be a very powerful diagnostic for thin film characterisation. It was used to determine thin film parameters such as film thickness and optical functions of polycrystalline tin-doped indium oxide (ITO) films deposited by spray pyrol onto Pyrex substrates. Dielectric ITO films often present microstructures which give rise to a variation of the refractive index with the distance from substrate. In this work, it was found that the fit between ellipsometric data and optical models results could be significantly improved when it was assumed that the refractive index of ITO films varied across the upper 60 nm near the film surface. Also, the surface roughness was modelled and compared with that given by the atomic force microscope (AFM)

  9. Process Design for Size-Controlled Flame Spray Synthesis of Li4Ti5O12 and Electrochemical Performance

    Directory of Open Access Journals (Sweden)

    Waser Oliver

    2017-03-01

    Full Text Available Inexpensive synthesis of electroceramic materials is required for efficient energy storage. Here the design of a scalable process, flame spray pyrolysis (FSP, for synthesis of size-controlled nanomaterials is investigated focusing on understanding the role of air entrainment (AE during their aerosol synthesis with emphasis on battery materials. The AE into the enclosed FSP reactor is analysed quantitatively by computational fluid dynamics (CFD and calculated temperatures are verified by Fourier transform infrared spectroscopy (FTIR. Various Li4Ti5O12 (LTO particle compositions are made and characterized by N2 adsorption, electron microscopy and X-ray diffraction while the electrochemical performance of LTO is tested at various charging rates. Increasing AE decreases recirculation in the enclosing tube leading to lower reactor temperatures and particle concentrations by air dilution as well as shorter and narrower residence time distributions. As a result, particle growth by coagulation - coalescence decreases leading to smaller primary particles that are mostly pure LTO exhibiting high C-rate performance with more than 120 mAh/g galvanostatic specific charge at 40C, outperforming commercial LTO. The effect of AE on FSP-made particle characteristics is demonstrated also in combustion synthesis of LiFePO4 and ZrO2.

  10. Synthesis and Characterization of Calcium Phosphate Powders for Biomedical Applications by Plasma Spray Coating

    OpenAIRE

    Sasidharan Pillai, Rahul

    2015-01-01

    This PhD work mainly focus on the synthesis and characterization of calcium phosphate powders for plasma spray coating. The preparation of high temperature phase stabilized βTCP and HA/βTCP powders for plasma spray coating applications has been the topic of investigation. Nowadays plasma sprayed coatings are widely used for biomedical applications especially in the dental and orthopaedic implantation field. Previously Ti based alloys were widely used for the orthopaedic and dental implant ap...

  11. The synthesis and pyrolysis of polycyclic organic sulphites

    International Nuclear Information System (INIS)

    Venter, H.J.

    1988-01-01

    The syntheses and thermolyses of model sulphite substrates were investigated: Lithium aluminium hidride reductions via the formation of a cyclic transition state lead to the formation of an endo-endo-diol as the main product. In contrast with the above, sodium borohidride reductions proceded via the formation of an acyclic transition state, which gave rise to different end products. The influence of specific reaction mechanisms on the product distribution of hidride reductions is discussed. The pinacoles required for the syntheses of certain substrates were obtained by means of the Clemmensen reductions. An unusual alcohol was formed during one of Clemmensen reductions. A mechanisms for ring cleavage and pinacole formation is presented, while a modified mechanism is proposed for the Clemmensen reduction of ketones. Treatment of some of the pinacoles with thionyl chloride lead to the formation of specific sulphites. A cyclic sulphite was derived from a diol obtained via a lithium aluminium hidride reduction reaction. In contrast a specific diketone was converted to a specific hemiketal when treated with zinc and acetic acid. Attempts to convert the diketone to the corresponding diol were unsuccessful. The pyrolytic behaviour of some sulphites as well as some of the diols were investigated. The pyrolysis of γ-diols and the corresponding sulphites proceded similarly. Various structures were derived from extensive comparative 1 H- and 13 C- studies

  12. Preparation of NaTaO3 by Spray Pyrolysis and Evaluation of Apparent Photocatalytic Activity for Hydrogen Production from Water

    Directory of Open Access Journals (Sweden)

    Hyun Woo Kang

    2008-01-01

    Full Text Available NaTaO3 photocatalyst was prepared by spray pyrolysis process and tested as photocatalyst for water splitting under UV light. Precursor solution was prepared from NaNO3 and Ta(OC2H55 in nitric acid solution and spray-pyrolyzed in air at between 973 and 1273 K. Considerable enhancement of photocatalytic activity was achieved by loading 0.05∼0.2 wt% of NiO on the surface of NaTaO3. The NiO loading was more effective on the NaTaO3 synthesized by spray pyrolysis in comparison with that synthesized by solid-state reaction. The quantum yield (QY of NiO/NaTaO3 photocatalyst was measured by chemical actinometry using potassium ferrioxalate and compared with the apparent photocatalytic activities (APA which would be more useful for the purpose of photocatalytic reactor design than the quantum yield. The apparent photocatalytic activity (APA was defined by the rate of hydrogen production divided by weight of catalyst, volume of reactant mixture, duration of irradiation, and power of UV lamp. The validity of the apparent photocatalytic activity (APA was discussed based on our results and reported activities of NaTaO3 photocatalyst loaded with or without NiO.

  13. Influence of solution deposition rate on properties of V{sub 2}O{sub 5} thin films deposited by spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Abd–Alghafour, N. M., E-mail: na2013bil@gmail.com [Iraqi Ministry of Education, Anbar (Iraq); Ahmed, Naser M.; Hassan, Zai; Mohammad, Sabah M. [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, University Sains Malaysia,11800 Penang (Malaysia)

    2016-07-19

    Vanadium oxide (V{sub 2}O{sub 5}) thin films were deposited on glass substrates by using a cost-efficient spray pyrolysis technique. The films were grown at 350° through thermal decomposition of VCl{sub 3} in deionized water with different solution spray rates. The high resolution X-ray diffraction results revealed the formation of nanocrystalline films having orthorhombic structures with preferential orientation along (101) direction. The spray rate influenced the surface morphology and crystallite size of the films. The crystallite size was found to increase whereas the micro-strain was decreased by increasing the spray deposition rates. The increase in crystallite size and decrease in the macrostrain resulted in an improvement in the films’ crystallinity. The UV-Visible spectroscopy analysis indicated that the average transmittance of all films lies in the range 75-80 %. The band gap of V{sub 2}O{sub 5} film was decreased from 2.65 to 2.46 eV with increase of the spray deposition rate from 5 ml/min to 10 ml/min. first, second, and third level headings (first level heading).

  14. Synthesis of carbon nanotubes by pyrolysis of solid Ni(dmg)2

    International Nuclear Information System (INIS)

    Kordatos, K.; Vlasopoulos, A.D.; Strikos, S.; Ntziouni, A.; Gavela, S.; Trasobares, S.; Kasselouri-Rigopoulou, V.

    2009-01-01

    We describe the high yield synthesis of multi-walled carbon nanotubes (MWCNTs) and the determination of the optimum production conditions. The method involves the catalytic pyrolysis of solid Ni(dmg) 2 under an Ar atmosphere. The obtained materials were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Raman spectroscopy and thermogravimetry analysis (TGA). The data revealed the formation of MWCNTs surrounded by a varying quantity of byproducts such as amorphous carbon and metallic particles, depending mainly on the reaction temperature. Pyrolysis of Ni(dmg) 2 at 900 deg. C results in the production of nanotube material with the highest degree of crystallinity

  15. Growth of tin oxide thin films composed of nanoparticles on hydrophilic and hydrophobic glass substrates by spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Paloly, Abdul Rasheed; Satheesh, M. [Nano Functional Materials Lab, Department of Physics, Cochin University of Science and Technology, Kochi 682022, Kerala (India); Martínez-Tomás, M. Carmen; Muñoz-Sanjosé, Vicente [Departamento de Física Aplicada y Electromagnetismo, Universitat de Valencia, c/Dr Moliner 50, Burjassot, Valencia 46100 (Spain); Rajappan Achary, Sreekumar [Nano Functional Materials Lab, Department of Physics, Cochin University of Science and Technology, Kochi 682022, Kerala (India); Bushiri, M. Junaid, E-mail: junaidbushiri@gmail.com [Nano Functional Materials Lab, Department of Physics, Cochin University of Science and Technology, Kochi 682022, Kerala (India)

    2015-12-01

    Highlights: • SnO{sub 2} thin films were grown on hydrophilic and hydrophobic glass substrates. • Samples on hydrophobic substrates are having comparatively larger lattice volume. • Films on hydrophobic substrates have larger particles and low density distribution. • Substrate dependent photoluminescence emission is observed and studied. • SnO{sub 2} thin films grown over hydrophobic substrates may find potential applications. - Abstract: In this paper, we have demonstrated the growth of tin oxide (SnO{sub 2}) thin films composed of nanoparticles on hydrophobic (siliconized) and hydrophilic (non-siliconized) glass substrates by using the spray pyrolysis technique. X-ray diffraction (XRD) analysis confirmed the formation of SnO{sub 2} thin films with tetragonal rutile-phase structure. Average particle size of nanoparticles was determined to be in the range of 3–4 nm measured from the front view images obtained by a field emission gun scanning electron microscope (FESEM), while the size of nanoparticle clusters, when present, were in the range of 11–20 nm. Surface morphology of SnO{sub 2} films grown over hydrophobic substrates revealed larger isolated particles which are less crowded compared to the highly crowded and agglomerated smaller particles in films on hydrophilic substrates. Blue shift in the band gap is observed in samples in which the average particle size is slightly larger than the exciton Bohr radius. Photoluminescence (PL) analysis of samples grown over hydrophobic substrates exhibited an intense defect level emission and a weak near band edge emission. The enhanced visible emission from these SnO{sub 2} thin films is attributed to lattice defects formed during the film growth due to the mismatch between the film and the hydrophobic substrate surface.

  16. Influence of precursor concentration on physical properties of CdO thin films prepared by spray pyrolysis technique using nebulizer

    Energy Technology Data Exchange (ETDEWEB)

    Anitha, M.; Amalraj, L.; Anitha, N. [Virudhunagar Hindu Nadar' s Senthikumara Nadar College (Autonomous), Department of Physics, Virudhunagar, Tamilnadu (India)

    2017-12-15

    Cadmium oxide (CdO) thin films were prepared with different concentrations of precursor solution (0.05, 0.1, 0.15, 0.2 and 0.25 M, respectively) at the optimized temperature (200 C) using the nebulized spray pyrolysis technique to obtain better crystallinity in polycrystalline thin films on amorphous glass substrates. The XRD characterization of those samples revealed a preferential orientation along the (111) plane having a cubic structure. The scanning electron microscopy (SEM) analysis displayed that all the as-deposited thin films have spherical shaped grains. The transmittance of the as-deposited CdO thin films had decreased from 88 to 71% for longer wavelength regions (600-900 nm) as the precursor concentration had increased and then increased for higher precursor concentration. The optical band gap was found to lie between 2.45 and 2.40 eV belonging to direct transition for those thin films. The presence of Cd-O bond (540 cm{sup -1}) was confirmed by FTIR spectrum. The emission properties of CdO thin films were studied by luminescence spectrum recorded at room temperature. A maximum carrier concentration and minimum resistivity values of 4.743 x 10{sup 19} cm{sup -3} and 1.06 x 10{sup -3} Ω-cm, respectively, were obtained for 0.2 M precursor concentration. These CdO thin films have high optical transmittance and high room temperature conductivity, which can be used as the TCO and Solar cell (window layer) material. (orig.)

  17. Characterization of luminescent praseodymium-doped ZrO{sub 2} coatings deposited by ultrasonic spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Ramos-Brito, F [Laboratorio de Materiales Optoelectronicos, DiDe, Centro de Ciencias de Sinaloa, Av. De las Americas No. 2771 Nte. Col. Villa Universidad, C.P. 80010 Culiacan, Sinaloa (Mexico); Garcia-Hipolito, M [Departamento de Materiales Metalicos y Ceramicos, Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, AP 70-360 Coyoacan 04510 DF (Mexico); Alejo-Armenta, C [Laboratorio de Materiales Optoelectronicos, DiDe, Centro de Ciencias de Sinaloa, Av. De las Americas No. 2771 Nte. Col. Villa Universidad, C.P. 80010 Culiacan, Sinaloa (Mexico); Alvarez-Fragoso, O [Departamento de Materiales Metalicos y Ceramicos, Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, AP 70-360 Coyoacan 04510 DF (Mexico); Falcony, C [Departamento de Fisica, CINVESTAV-IPN, Apdo. Postal 14-740, 07000 DF (Mexico)

    2007-11-07

    ZrO{sub 2} : Pr films were synthesized by the ultrasonic spray pyrolysis process. X-ray diffraction studies, as a function of the deposition temperature, indicate a tetragonal crystal structure of zirconia as the substrate temperature was increased. Luminescence (photo- and cathodoluminescence) properties of the films were studied as a function of growth parameters such as the substrate temperature and the praseodymium concentration. For an excitation wavelength of 290 nm, all the photoluminescent emission spectra show peaks located at 490, 510, 566, 615, 642, 695, 718, 740 and 833 nm, associated with the electronic transitions {sup 3} P{sub 0} {yields} {sup 3}H{sub 4}, {sup 3}P{sub 0} {yields} {sup 3} H{sub 4}, {sup 3}P{sub 1} + {sup 1}I{sub 6} {yields} {sup 3}H{sub 5}, {sup 1}D{sub 2} {yields} {sup 3}H{sub 4}, {sup 3} P{sub 0} {yields} {sup 3}H{sub 6}, {sup 1}D{sub 2} {yields} {sup 3} H{sub 5}, {sup 1}D{sub 2} {yields} {sup 3}H{sub 5}, {sup 3} P{sub 0} {yields} {sup 3}F{sub 3,4} and {sup 1}D{sub 2} {yields} {sup 3} F{sub 2} of the Pr{sup 3+} ion. As the deposition temperature is increased, an increasing intensity of the luminescence emission is observed. Also, quenching of the luminescence, with increasing doping concentration, is observed. The chemical composition of the films as determined by energy dispersive spectroscopy is reported as well. In addition, the surface morphology characteristics of the films, as a function of the deposition temperature, are presented.

  18. Zr-doped SnO2 thin films synthesized by spray pyrolysis technique for barrier layers in solar cells

    Science.gov (United States)

    Reddy, N. Nanda Kumar; Akkera, Harish Sharma; Sekhar, M. Chandra; Park, Si-Hyun

    2017-12-01

    In the present work, we investigated the effect of Zr doping (0-6 at%) on the structural, electrical, and optical properties of tin oxide (SnO2) thin films deposited onto glass substrates using a spray pyrolysis technique. The room-temperature X-ray diffraction pattern shows that all deposited films exhibit polycrystalline tetragonal structure. The pure SnO2 film is grown along a preferred (200) direction, whereas Zr-doped SnO2 (Zr:SnO2) films started growing along the (220) orientation along with a high intensity peak of (200). Scanning electron microscope (SEM) and atomic force microscope (AFM) images showed that the grains of the films are spherical in structure, and the grain size decreased with increasing of Zr concentration. The optical transmission spectra of deposited films as a function of wavelength confirm that the average optical transmittance is > 85% for Zr:SnO2 films. The value of the optical bandgap is significantly decreased from 3.94 to 3.68 eV with increasing Zr concentration. Furthermore, the electrical measurements found that the sheet resistance ( R sh) and resistivity ( ρ) values are decreased with increasing of Zr doping. The lowest values of R sh = 6.82 Ω and ρ = 0.4 × 10- 3 Ω cm are found in 6-at% Zr-doped SnO2 film. In addition, a good efficiency value of the figure of merit ( ɸ = 3.35 × 10- 3 Ω-1) is observed in 6-at% Zr-doped SnO2 film. These outstanding properties of Zr-doped SnO2 films make them useful for several optoelectronic device applications.

  19. Influences of alcoholic solvents on spray pyrolysis deposition of TiO{sub 2} blocking layer films for solid-state dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Changyun, E-mail: jiangc@imre.a-star.edu.sg [Institute of Materials Research and Engineering, A-STAR, 3 Research Link, 117602 Singapore (Singapore); Koh, Wei Lin; Leung, Man Yin [Institute of Materials Research and Engineering, A-STAR, 3 Research Link, 117602 Singapore (Singapore); Hong, Wei [Department of Chemical Engineering and Waterloo Institute for Nanotechnology (WIN), University of Waterloo, 200 University Ave West ON, Waterloo, Canada N2L 3G1 (Canada); Li, Yuning, E-mail: yuning.li@uwaterloo.ca [Institute of Materials Research and Engineering, A-STAR, 3 Research Link, 117602 Singapore (Singapore); Department of Chemical Engineering and Waterloo Institute for Nanotechnology (WIN), University of Waterloo, 200 University Ave West ON, Waterloo, Canada N2L 3G1 (Canada); Zhang, Jie [Institute of Materials Research and Engineering, A-STAR, 3 Research Link, 117602 Singapore (Singapore)

    2013-02-15

    Influences of alcoholic solvents for titanium diisopropoxide bis(acetylacetonate) (TPA) precursor solutions on the spray pyrolysis deposited TiO{sub 2} films and the photovoltaic performance of the solid-state dye-sensitized solar cells (SDSCs) using these TiO{sub 2} films as the blocking layers were investigated. Smooth TiO{sub 2} films were obtained by spray pyrolysis deposition of a TPA solution in isopropanol (IPA) at a relatively low temperature of 260 Degree-Sign C. On the other hand, when ethanol was used as solvent, the TiO{sub 2} films fabricated at the same temperature showed much rougher surfaces with many pinholes. Our results showed that ethanol reacts with TPA to form titanium diethoxide bis(acetylacetonate) (TEA), which requires a higher thermal decomposition temperature than that of TPA. SDSCs with TiO{sub 2} blocking layer films fabricated using a TPA solution in IPA showed higher power conversion efficiencies with smaller variations. - Graphical abstract: Alcoholic solvents used for the TiO{sub 2} precursor play a critical role in determining the surface morphology of blocking layers and thus the photovoltaic performance of the SDSCs. Highlights: Black-Right-Pointing-Pointer Solvent influences morphology of spray pyrolysis deposited TiO{sub 2} blocking layer. Black-Right-Pointing-Pointer Ethanol reacts with TPA, resulting poor quality of blocking layer. Black-Right-Pointing-Pointer Isopropanol is better than ethanol for obtaining smooth blocking layer. Black-Right-Pointing-Pointer SDSC with blocking layer made with isopropanol showed better performance.

  20. Facile synthesis of antimony-doped tin oxide nanoparticles by a polymer-pyrolysis method

    International Nuclear Information System (INIS)

    Li, Yuan-Qing; Wang, Jian-Lei; Fu, Shao-Yun; Mei, Shi-Gang; Zhang, Jian-Min; Yong, Kang

    2010-01-01

    In this article, antimony-doped tin oxide (ATO) nanoparticles was synthesized by a facile polymer-pyrolysis method. The pyrolysis behaviors of the polymer precursors prepared via in situ polymerization of metal salts and acrylic acid were analyzed by simultaneous thermogravimetric and differential scanning calorimetry (TG-DSC). The structural and morphological characteristics of the products were studied by powder X-ray diffraction (XRD) and transmission electron microscope (TEM). The results reveal that the ATO nanoparticles calcined at 600 o C show good crystallinity with the cassiterite structure and cubic-spherical like morphology. The average particle size of ATO decreases from 200 to 15 nm as the Sb doping content increases from 5 mol% to 15 mol%. Electrical resistivity measurement shows that the resistivity for the 10-13 mol% Sb-doped SnO 2 nanoparticles is reduced by more than three orders compared with the pure SnO 2 nanoparticles. In addition, due to its versatility this polymer-pyrolysis method can be extended to facile synthesis of other doped n-type semiconductor, such as In, Ga, Al doped ZnO, Sn doped In 2 O 3 .

  1. Synthesis of carbon nanostructures by the pyrolysis of wood sawdust in a tubular reactor

    Directory of Open Access Journals (Sweden)

    Maria G. Sebag Bernd

    2017-04-01

    Full Text Available Carbon nanostructures were produced by wood sawdust pyrolysis. The results obtained revealed that the thermodynamic simulations (FactSage were successful to predict the best reaction conditions for the synthesis of carbon, and potentially carbon fibers and nanotubes production. Graphite formation was indicated by XRD study, and by thermal analysis which presented the carbon oxidation range. The morphology of the samples (SEM/TEM analysis showed carbon nanotubes/nanofibers varying in size and thickness, with defects and flaws. The tubular reactor was considered to be an economic and environmental correct way to nanomaterials growing, with the simultaneous generation of hydrogen and lower pollutant gas emissions.

  2. Synthesis of niobium nitride by pyrolysis of niobium pentachloride ammines

    International Nuclear Information System (INIS)

    Grebtsova, O.M.; Shulga, Y.M.; Troitskii, V.N.

    1986-01-01

    This paper investigates the conditions for the preparation of niobium nitride in the thermal decomposition of niobium nitride in the thermal decomposition of niobium pentachloride ammines. The synthesis of the ammines was accomplished by the reaction of powdered NbC1 5 with dry ammonia at 210 K. Thermography and x-ray diffraction, spectral, and chemical analyses were used to identify the ammonolysis products. It was established that the products of ammonolysis of NbC1 5 are a mixture of the x-ray-amorphous complex Nb (NH 2 ) /SUB 5-x/ - (NG 3 ) 3 CL 3 (x≅) and 2 moles of NH 4 C1. The steps in the thermal decomposition of this mixture were studied. The phase transition that is observed in the case of further vacuum heat treatment at 1100-1300 K is presented

  3. Fabrication and performance of Li4Ti5O12/C Li-ion battery electrodes using combined double flame spray pyrolysis and pressure-based lamination technique

    Science.gov (United States)

    Gockeln, Michael; Pokhrel, Suman; Meierhofer, Florian; Glenneberg, Jens; Schowalter, Marco; Rosenauer, Andreas; Fritsching, Udo; Busse, Matthias; Mädler, Lutz; Kun, Robert

    2018-01-01

    Reduction of lithium-ion battery (LIB) production costs is inevitable to make the use of LIB technology more viable for applications such as electric vehicles or stationary storage. To meet the requirements in today's LIB cost efficiency, our current research focuses on an alternative electrode fabrication method, characterized by a combination of double flame spray pyrolysis and lamination technique (DFSP/lamination). In-situ carbon coated nano-Li4Ti5O12 (LTO/C) was synthesized using versatile DFSP. The as-prepared composite powder was then directly laminated onto a conductive substrate avoiding the use of any solvent or binder for electrode preparation. The influence of lamination pressures on the microstructure and electrochemical performance of the electrodes was also investigated. Enhancements in intrinsic electrical conductivity were found for higher lamination pressures. Capacity retention of highest pressurized DFSP/lamination-prepared electrode was 87.4% after 200 dis-/charge cycles at 1C (vs. Li). In addition, LTO/C material prepared from the double flame spray pyrolysis was also used for fabricating electrodes via doctor blading technique. Laminated electrodes obtained higher specific discharge capacities compared to calendered and non-calendered blade-casted electrodes due to superior microstructural properties. Such a fast and industrially compelling integrative DFSP/lamination tool could be a prosperous, next generation technology for low-cost LIB electrode fabrication.

  4. Microstructural and electrical characterizations of tungsten-doped La2Mo2O9 prepared by spray pyrolysis

    DEFF Research Database (Denmark)

    Baqué, Laura; Vega-Castillo, Jesús; Georges, Samuel

    2013-01-01

    La2Mo2 − xWxO9 (x=0, 0.5, 1.0, and 1.3) nanocrystalline powders were synthesized by spray pyrolysis (SP) assisted by an ultrasonic atomizer. Microstructure, sinterability and thermal stability of the prepared powders were investigated. Spherical particles of 430 to 530 nm in diameter and crystall......La2Mo2 − xWxO9 (x=0, 0.5, 1.0, and 1.3) nanocrystalline powders were synthesized by spray pyrolysis (SP) assisted by an ultrasonic atomizer. Microstructure, sinterability and thermal stability of the prepared powders were investigated. Spherical particles of 430 to 530 nm in diameter...... by applying different sintering programs starting from La2Mo2 − xWxO9 powders (x=0 and 1.3) obtained by SP and SSR processes. The electrical properties of these ionic conductors were analyzed by Electrochemical Impedance Spectroscopy (EIS) and correlated with microstructural observations. No significant...... variation of the electrical properties of these ionic conductors was found as compared to conventional ceramics with remarkable microstructural differences....

  5. Improved performance of low cost CuInS2 superstrate-type solar cells using Zinc assisted spray pyrolysis processing

    Science.gov (United States)

    Cheshme Khavar, Amir Hossein; Mahjoub, Ali Reza; Taghavinia, Nima

    2017-12-01

    Superstrate configuration CuInS2 (CIS) solar cells are fabricated using a spray pyrolysis method. We avoided selenization process, cyanide etching and CdS buffer layer, to keep the process ‘green’. CIS layers are formed by spray pyrolysis of an aqueous precursor ink containing metal chloride salts and thiourea at 350 °C. We investigated the effect of intentional Zn doping on structural, morphological and photovoltaic response of the fabricated CIS films by dissolving ZnCl2 in aqueous precursor solution. At a zinc doping level ranging between 0.25 and 1.00 mol%, Zn doping is found to improve the CIS crystal growth and surface morphology of CIS films. Compared with the performance of the non-doped CIS cell, the Zn-doped CIS solar cell displayed a remarkable efficiency enhancement of 58-97% and the maximum enhancement was obtained at a Zn content of 0.5 mol%. The device structure consists of    and show promising PCE of 4.29 % without any anti-reflection coating. Over the course of 300 d under ambient condition, the fabricated device showed only 1% loss in efficiency.

  6. Substrate Temperature Effect on Charge Transport Performance of ZnO Electron Transport Layer Prepared by a Facile Ultrasonic Spray Pyrolysis in Polymer Solar Cells

    Directory of Open Access Journals (Sweden)

    Jiang Cheng

    2015-01-01

    Full Text Available A novel ultrasonic spray pyrolysis for high-quality ZnO films based on zinc-ammonia solution was achieved in air. To investigate the structural and optical properties as well as the performance of polymer solar cells (PSCs, ZnO films at different substrate temperatures and thicknesses were prepared. The performance of poly(3-hexylthiophene:[6,6]-phenyl C61-butyric acid methyl ester (P3HT:PCBM based PSC was found to be improved due to the ZnO films. The crystal structure and roughness of the ZnO films fabricated at different temperatures were found to affect the performance of PSCs. The optimized power conversion efficiency was found to be maximum for PSCs with ZnO films prepared at 200°C. The growth process of these ZnO films is very simple, cost-effective, and compatible for larger-scale PSC preparation. The precursor used for spray pyrolysis is environmentally friendly and helps to achieve ZnO film preparation at a relative low temperature.

  7. The effect of strontium doping on structural and morphological properties of ZnO nanofilms synthesized by ultrasonic spray pyrolysis method

    Directory of Open Access Journals (Sweden)

    A. Ouhaibi

    2018-03-01

    Full Text Available Pristine and strontium doped ZnO nanometric films were successfully synthesized on heated glass substrates by the ultrasonic spray pyrolysis technique. The samples were characterized by means of X-ray diffraction (XRD, Atomic Force Microscope (AFM, UV–visible spectroscopy and photoluminescence (PL. X-ray diffraction patterns confirmed the hexagonal (wurtzite structure, where the most pronounced (002 peak indicates the preferential orientation along the c-axis perpendicular to the sample surface. The intensity of this peak was increased rapidly from the first doping of 1% and its position was shifted toward higher angles under Sr-doping effect. For the used doping range of 1–5%, the Sr-doping at 3% attracted an especial attention. At this concentration, the particular transformation in the surface morphology of doped ZnO films was observed. The surface became granular and rough by expanding the crystallites' size. From optical measurements, transmittance and PL spectra were found to be sensitive to Sr-doping, where two different behaviors were observed before and after 3% of Sr-doping. Keywords: Ultrasonic spray pyrolysis, Sr-doped ZnO, Morphology study, Optical properties

  8. Transparent conducting properties of Ni doped zinc oxide thin films prepared by a facile spray pyrolysis technique using perfume atomizer

    Energy Technology Data Exchange (ETDEWEB)

    Bouaoud, A.; Rmili, A.; Ouachtari, F.; Louardi, A.; Chtouki, T. [Laboratoire des Hautes Energies, Sciences de l' Ingenierie et Reacteurs (LHESIR), Equipe Ingenierie et Materiaux (INMA), Departement de Physique, Faculte des Sciences, Kenitra (Morocco); Elidrissi, B., E-mail: e.bachir@mailcity.com [Laboratoire des Hautes Energies, Sciences de l' Ingenierie et Reacteurs (LHESIR), Equipe Ingenierie et Materiaux (INMA), Departement de Physique, Faculte des Sciences, Kenitra (Morocco); Erguig, H. [Laboratoire des Hautes Energies, Sciences de l' Ingenierie et Reacteurs (LHESIR), Equipe Ingenierie et Materiaux (INMA), Departement de Physique, Faculte des Sciences, Kenitra (Morocco); Ecole Nationale des Sciences Appliquees de Kenitra (ENSAK) (Morocco)

    2013-01-15

    Undoped and Ni doped zinc oxide (Ni-ZnO) thin films were prepared by a facile spray pyrolysis technique using perfume atomizer from aqueous solution of anhydrous zinc acetate (Zn(CH{sub 3}COOH){sub 2} and hexahydrated nickel chloride (NiCl{sub 2}{center_dot}6H{sub 2}O) as sources of zinc and nickel, respectively. The films were deposited onto the amorphous glass substrates kept at (450 Degree-Sign C). The effect of the [Ni]/[Zn] ratio on the structural, morphological, optical and electrical properties of Ni doped ZnO thin film was studied. It was found from X-ray diffraction (XRD) analysis that both the undoped and Ni doped ZnO films were crystallized in the hexagonal structure with a preferred orientation of the crystallites along the [002] direction perpendicular to the substrate. The scanning electron microscopy (SEM) images showed a relatively dense surface structure composed of crystallites in the spherical form whose average size decreases when the [Ni]/[Zn] ratio increases. The optical study showed that all the films were highly transparent. The optical transmittance in the visible region varied between 75 and 85%, depending on the dopant concentrations. The variation of the band gap versus the [Ni]/[Zn] ratio showed that the energy gap decreases from 2.95 to 2.72 eV as the [Ni]/[Zn] ratio increases from 0 to 0.02 and then increases to reach 3.22 eV for [Ni]/[Zn] = 0.04. The films obtained with the [Ni]/[Zn] ratio = 0.02 showed minimum resistivity of 2 Multiplication-Sign 10{sup -3} {Omega} cm at room temperature. -- Highlights: Black-Right-Pointing-Pointer The optical transmittance of Ni doped ZnO varies between 75 and 85%. Black-Right-Pointing-Pointer The energy gap of these films decreases from 2.95 to 2.72 eV as the [Ni]/[Zn] ratio increases from 0 to 0.02. Black-Right-Pointing-Pointer The energy gap increases to reach 3.22 eV for [Ni]/[Zn] = 0.04. Black-Right-Pointing-Pointer The films obtained with [Ni]/[Zn] ratio = 0.02 show minimum resistivity of 2

  9. The effect of oxidation time on the parameters of ITO/Si solar cell prepared by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Kandil, S. A; Afifi, H. H; El-hefnawi, S. H; Eliwa, A.Y [Electronic Research Institute, Dokki, Cairo (Egypt)

    2000-07-01

    The indium tin oxide (ITO/N-Si) solar cells have been fabricated by spray pyrolysis technique. The silicon wafers are heated at 500 Celsius degrees with different oxidation time (2-20 min). The best values obtained for ITO/Si solar cell output parameters; open circuit voltage V{sub o}c, short circuit current density J{sub s}c, fill factor FF and efficiency {eta} are 0.48 V, 15 mA/cm{sup 2}, 0.7 and 10.1% respectively. The preceding results were obtained under conditions of 5 minutes oxidation time and the surface area equal to 8 mm{sup 2} when the light intensity is 50 MW/ cm{sup 2}. The values of V{sub o}c, J{sub s}c, FF and {eta} are affected strongly by the varying the oxidation time. This paper is devoted to explain the effect of the interfacial layer SiO{sub 2} thickness on the ITO/Si solar cell parameters as deduced from the I-V and C-V measurements. [Spanish] Mediante tecnicas de pirolisis de dispersion se han fabricado celdas solares de oxido de Indio estanado ITO/N-Si. Las obleas de silicon se calientan a 500 con diferentes tiempos de oxidacion (2-20 min.) Los mejores valores obtenidos para los parametros de produccion de las celdas solares ITO-Si de voltaje en circuito abierto V{sub o}c densidad de corriente de corto circuito J{sub s}c factor de llenado FF y eficiencia {eta} son de 0.48 V, 15 mA/cm{sup 2}, 0.7% y 10.1% respectivamente los resultados precedentes se obtuvieron bajo condiciones de 5 minutos de tiempo de oxidacion y la superficie del area=8 mm{sup 2} cuando la intensidad de la luz es de 50mW/Cm{sup 2}. Los valores de V{sub o}c, J{sub s}c, FF y {eta} se afectan fuertemente por la variacion del tiempo de oxidacion. Este articulo esta dedicado a explicar el efecto del espesor de la capa interfacial de SiO{sub 2} en los parametros de la celda solar ITO-Si como se deduce de las mediciones I-V y C-V.

  10. Electrical characteristics and preparation of (Ba0.5Sr0.5)TiO3 films by spray pyrolysis and rapid thermal annealing

    International Nuclear Information System (INIS)

    Koo, Horngshow; Ku, Hongkou; Kawai, Tomoji; Chen Mi

    2007-01-01

    Functional films of (Ba 0.5 Sr 0.5 )TiO 3 on Pt (1000 A)/Ti (100 A)/SiO 2 (2000 A)/Si substrates are prepared by spray pyrolysis and subsequently rapid thermal annealing. Barium nitrate, strontium nitrate and titanium isopropoxide are used as starting materials with ethylene glycol as solvent. For (Ba 0.5 Sr 0.5 )TiO 3 functional thin film, thermal characteristics of the precursor powder scratched from as-sprayed films show a remarkable peak around 300-400degC and 57.7% weight loss up to 1000degC. The as-sprayed precursor film with coffee-like color and amorphous-like phase is transformed into the resultant film with white, crystalline perovskite phase and characteristic peaks (110) and (100). The resultant films show correspondent increases of dielectric constant, leakage current and dissipation factor with increasing annealing temperatures. The dielectric constant is 264 and tangent loss is 0.21 in the resultant films annealed at 750degC for 5 min while leakage current density is 1.5x10 -6 A/cm 2 in the film annealed at 550degC for 5 min. (author)

  11. Flash pyrolysis at high temperature of ligno-cellulosic biomass and its components - production of synthesis gas

    International Nuclear Information System (INIS)

    Couhert, C.

    2007-11-01

    Pyrolysis is the first stage of any thermal treatment of biomass and governs the formation of synthesis gas for the production of electricity, hydrogen or liquid fuels. The objective of this work is to establish a link between the composition of a biomass and its pyrolysis gas. We study experimental flash pyrolysis and fix the conditions in which quantities of gas are maximal, while aiming at a regime without heat and mass transfer limitations (particles about 100 μm): temperature of 950 C and residence time of about 2 s. Then we try to predict gas yields of any biomass according to its composition, applicable in this situation where thermodynamic equilibrium is not reached. We show that an additivity law does not allow correlating gas yields of a biomass with fractions of cellulose, hemi-cellulose and lignin contained in this biomass. Several explanations are suggested and examined: difference of pyrolytic behaviour of the same compound according to the biomass from which it is extracted, interactions between compounds and influence of mineral matter. With the aim of industrial application, we study pyrolysis of millimetric and centimetric size particles, and make a numerical simulation of the reactions of pyrolysis gases reforming. This simulation shows that the choice of biomass affects the quantities of synthesis gas obtained. (author)

  12. Fabricate heterojunction diode by using the modified spray pyrolysis method to deposit nickel-lithium oxide on indium tin oxide substrate.

    Science.gov (United States)

    Wu, Chia-Ching; Yang, Cheng-Fu

    2013-06-12

    P-type lithium-doped nickel oxide (p-LNiO) thin films were deposited on an n-type indium tin oxide (ITO) glass substrate using the modified spray pyrolysis method (SPM), to fabricate a transparent p-n heterojunction diode. The structural, optical, and electrical properties of the p-LNiO and ITO thin films and the p-LNiO/n-ITO heterojunction diode were characterized by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), UV-visible spectroscopy, Hall effect measurement, and current-voltage (I-V) measurements. The nonlinear and rectifying I-V properties confirmed that a heterojunction diode characteristic was successfully formed in the p-LNiO/n-ITO (p-n) structure. The I-V characteristic was dominated by space-charge-limited current (SCLC), and the Anderson model demonstrated that band alignment existed in the p-LNiO/n-ITO heterojunction diode.

  13. Comparison of carrier transport mechanism under UV/Vis illumination in an AZO photodetector and an AZO/p-Si heterojunction photodiode produced by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Shasti, M.; Mortezaali, A., E-mail: mortezaali@alzahra.ac.ir; Dariani, R. S. [Department of Physics, Alzahra University, Tehran 1993893973 (Iran, Islamic Republic of)

    2015-01-14

    In this study, Aluminum doped Zinc Oxide (AZO) layer is deposited on p-type silicon (p-Si) by spray pyrolysis method to fabricate ultraviolet-visible (UV/Vis) photodetector as Al doping process can have positive effect on the photodetector performance. Morphology, crystalline structure, and Al concentration of AZO layer are investigated by SEM, XRD, and EDX. The goal of this study is to analyze the mechanism of carrier transport by means of current-voltage characteristics under UV/Vis illumination in two cases: (a) electrodes connected to the surface of AZO layer and (b) electrodes connected to cross section of heterojunction (AZO/p-Si). Measurements indicate that the AZO/p-Si photodiode exhibits a higher photocurrent and lower photoresponse time under visible illumination with respect to AZO photodetector; while under UV illumination, the above result is inversed. Besides, the internal junction field of AZO/p-Si heterojunction plays an important role on this mechanism.

  14. Comparison of carrier transport mechanism under UV/Vis illumination in an AZO photodetector and an AZO/p-Si heterojunction photodiode produced by spray pyrolysis

    International Nuclear Information System (INIS)

    Shasti, M.; Mortezaali, A.; Dariani, R. S.

    2015-01-01

    In this study, Aluminum doped Zinc Oxide (AZO) layer is deposited on p-type silicon (p-Si) by spray pyrolysis method to fabricate ultraviolet-visible (UV/Vis) photodetector as Al doping process can have positive effect on the photodetector performance. Morphology, crystalline structure, and Al concentration of AZO layer are investigated by SEM, XRD, and EDX. The goal of this study is to analyze the mechanism of carrier transport by means of current-voltage characteristics under UV/Vis illumination in two cases: (a) electrodes connected to the surface of AZO layer and (b) electrodes connected to cross section of heterojunction (AZO/p-Si). Measurements indicate that the AZO/p-Si photodiode exhibits a higher photocurrent and lower photoresponse time under visible illumination with respect to AZO photodetector; while under UV illumination, the above result is inversed. Besides, the internal junction field of AZO/p-Si heterojunction plays an important role on this mechanism

  15. Morphology and microstructure of textured SnO2 thin films obtained by spray pyrolysis and their effect on electrical and optical properties

    International Nuclear Information System (INIS)

    Paraguay-Delgado, F.; Miki-Yoshida, M.; Antunez, W.; Gonzalez-Hernandez, J.; Vorobiev, Y.V.; Prokhorov, E.

    2008-01-01

    Tin dioxide thin films on glass substrate with different Zn doping levels were obtained by spray pyrolysis. Their microstructure, preferred crystallographic orientation, electrical and optical properties were extensively studied. The characterization techniques employed were scanning electron microscopy, transmission electron microscopy, atomic force microscopy, X-ray diffraction, electrical conductivity and optical transmission measurements. It was found that the material obtained has a nano-scale texture which characteristic size and orientation strongly depend on the Zn doping level. Doping-induced variations in texture and structure modify both the electrical and optical properties of films (namely, refractive index and transparency). The results obtained are relevant for potential applications of the studied films in gas sensing and photoconductive devices

  16. Fabrication of 10%Gd-doped ceria (GDC)/NiO-GDC half cell for low or intermediate temperature solid oxide fuel cells using spray pyrolysis

    DEFF Research Database (Denmark)

    Chourashiya, M. G.; Bhardwaj, S. R.; Jadhav, L. D.

    2010-01-01

    temperature SOFCs. Additionally, if GDC is employed in thin film form, rather higher ionic conductivity at further lower temperatures can be obtained and thereby allowing its use in low temperature SOFC. In the present investigation, the preparative parameters of spray pyrolysis technique (SPT) were optimized...... SEM observations of post heat-treated (at 1,000 °C) GDC/NiO-GDC structure revealed that GDC films were uniform in thickness with improved adherence to substrate. The relative density of post heat-treated films was of the order of 96%, which was attributed to the presence of nano-granules in the thin...... to deposit dense and adherent films of GDC on ceramic substrate. NiO-GDC was used as ceramic substrate, which also acts as a precursor composite anode for GDC-based SOFCs. Prepared half cells (GDC/NiO-GDC) were characterized using XRD, SEM, and electrochemical impedance spectroscopy. The surface and fractal...

  17. LETTER TO THE EDITOR: Green emission and bandgap narrowing due to two-photon excitation in thin film CdS formed by spray pyrolysis

    Science.gov (United States)

    Ullrich, B.; Schroeder, R.

    2001-08-01

    Thin (10 µm) film CdS on Pyrex® formed by spray pyrolysis is excited below the gap at 804 nm with 200 fs laser pulses at room temperature. Excitation intensities up to 250 GW cm-2 evoke green bandgap emission due to two-photon transitions. This two-photon photoluminescence does not show a red emission contribution in contrast to the single-photon excited emission, which is dominated by broad emission in the red spectral range. It is demonstrated that two-photon excitation causes photo-induced bandgap narrowing due to Debye screening. At 250 GW cm-2 bandgap narrowing of 47 meV is observed, which corresponds to an excited electron density of 1.6×1018 cm-3.

  18. Pyrolysis-GCMS Analysis of Solid Organic Products from Catalytic Fischer-Tropsch Synthesis Experiments

    Science.gov (United States)

    Locke, Darren R.; Yazzie, Cyriah A.; Burton, Aaron S.; Niles, Paul B.; Johnson, Natasha M.

    2015-01-01

    Abiotic synthesis of complex organic compounds in the early solar nebula that formed our solar system is hypothesized to occur via a Fischer-Tropsch type (FTT) synthesis involving the reaction of hydrogen and carbon monoxide gases over metal and metal oxide catalysts. In general, at low temperatures (less than 200 C), FTT synthesis is expected to form abundant alkane compounds while at higher temperatures (greater than 200 C) it is expected to product lesser amounts of n-alkanes and greater amounts of alkene, alcohol, and polycyclic aromatic hydrocarbons (PAHs). Experiments utilizing a closed-gas circulation system to study the effects of FTT reaction temperature, catalysts, and number of experimental cycles on the resulting solid insoluble organic products are being performed in the laboratory at NASA Goddard Space Flight Center. These experiments aim to determine whether or not FTT reactions on grain surfaces in the protosolar nebula could be the source of the insoluble organic matter observed in meteorites. The resulting solid organic products are being analyzed at NASA Johnson Space Center by pyrolysis gas chromatography mass spectrometry (PY-GCMS). PY-GCMS yields the types and distribution of organic compounds released from the insoluble organic matter generated from the FTT reactions. Previously, exploratory work utilizing PY-GCMS to characterize the deposited organic materials from these reactions has been reported. Presented here are new organic analyses using magnetite catalyst to produce solid insoluble organic FTT products with varying reaction temperatures and number of experimental cycles.

  19. Effect of the substrate temperature on the physical properties of molybdenum tri-oxide thin films obtained through the spray pyrolysis technique

    International Nuclear Information System (INIS)

    Martínez, H.M.; Torres, J.; López Carreño, L.D.; Rodríguez-García, M.E.

    2013-01-01

    Polycrystalline molybdenum tri-oxide thin films were prepared using the spray pyrolysis technique; a 0.1 M solution of ammonium molybdate tetra-hydrated was used as a precursor. The samples were prepared on Corning glass substrates maintained at temperatures ranging between 423 and 673 K. The samples were characterized through micro Raman, X-ray diffraction, optical transmittance and DC electrical conductivity. The species MoO 3 (H 2 O) 2 was found in the sample prepared at a substrate temperature of 423 K. As the substrate temperature rises, the water disappears and the samples crystallize into α-MoO 3 . The optical gap diminishes as the substrate temperature rises. Two electrical transport mechanisms were found: hopping under 200 K and intrinsic conduction over 200 K. The MoO 3 films' sensitivity was analyzed for CO and H 2 O in the temperature range 160 to 360 K; the results indicate that CO and H 2 O have a reduction character. In all cases, it was found that the sensitivity to CO is lower than that to H 2 O. - Highlights: ► A low cost technique is used which produces good material. ► Thin films are prepared using ammonium molybdate tetra hydrated. ► The control of the physical properties of the samples could be done. ► A calculation method is proposed to determine the material optical properties. ► The MoO 3 thin films prepared by spray pyrolysis could be used as gas sensor.

  20. Influence of the spray pyrolysis seeding and growth parameters on the structure and optical properties of ZnO nanorod arrays

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez, Juan, E-mail: jrodriguez@uni.edu.pe [Facultad de Ciencias, Universidad Nacional de Ingeniería, P.O. Box 31-139, Lima 31 (Peru); Feuillet, Guy [CEA Grenoble/LETI, 17 rue des Martyrs, F-38054 Grenoble Cedex 9 (France); Donatini, Fabrice [Univ. Grenoble Alpes, Inst NEEL, F-38000 Grenoble (France); CNRS, Inst NEEL, F-38042 Grenoble (France); Onna, Diego [DQIAQF-INQUIMAE, FCEyN-Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, 1428 Buenos Aires (Argentina); Sanchez, Luis [Facultad de Ciencias, Universidad Nacional de Ingeniería, P.O. Box 31-139, Lima 31 (Peru); Candal, Roberto [DQIAQF-INQUIMAE, FCEyN-Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, 1428 Buenos Aires (Argentina); ECyT, 3iA, Universidad Nacional de San Martín, Martín de Irigoyen N° 3100 (1650), San Martín, Pcia de Buenos Aires (Argentina); Marchi, M. Claudia [DQIAQF-INQUIMAE, FCEyN-Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, 1428 Buenos Aires (Argentina); CMA, FCEyN-Universidad de Buenos Aires, Ciudad Universitaria, Pab. I, 1428 Buenos Aires (Argentina); Bilmes, Sara A. [DQIAQF-INQUIMAE, FCEyN-Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, 1428 Buenos Aires (Argentina); Chandezon, Frédéric [University Grenoble Alpes, INAC-SPRAM, F-38000 Grenoble (France); CNRS, INAC-SPRAM, F-38000 Grenoble (France); CEA, INAC-SPRAM, F-38000 Grenoble (France)

    2015-02-01

    ZnO nanorods (NRs) were grown on fluorine doped tin oxide (FTO) substrates at low temperatures (90 °C) from Zn{sup 2+} precursors in alkaline media previously seeded with ZnO nanoparticles. These were deposited onto the FTO substrate heated at 350 °C by spray pyrolysis of a Zn acetate solution in a water ethanol mixture. The structure of seeds was tuned by the ethanol to water ratio, Γ, which controls the solvent evaporation rate of drops impinging the substrate. From a detailed characterization using a combination of scanning electron microscopy, X-ray diffraction, UV–visible absorption and cathodoluminescence spectroscopies, the dependence of the morphology and optical properties of the ZnO NRs on the seeding conditions was demonstrated. NRs grown on seeds deposited from solutions with Γ in the 0.03–0.06 range – i.e. when the surface excess of ethanol in the water–ethanol mixture has a maximum – show thinner average diameters and stacking faults due to the presence of zinc blende domains embedded into an overall wurtzite NR. They furthermore exhibit blue-shifted near band edge emission peak and a high deep level emission in cathodoluminescence. All these findings support the use of spray pyrolysis as a simple and reproducible way to control the seeds deposition, influencing the growth, the structure and the optical properties of the final ZnO NRs. - Highlights: • ZnO pyrolytic seeds tuned by the rate of solvent evaporation. • ZnO NRs grown from tuned pyrolytic seed's structure shows diameter dependence. • ZnO NRs show stacking faults due to the presence of zinc blende domains.

  1. Semi-automatic spray pyrolysis deposition of thin, transparent, titania films as blocking layers for dye-sensitized and perovskite solar cells.

    Science.gov (United States)

    Krýsová, Hana; Krýsa, Josef; Kavan, Ladislav

    2018-01-01

    For proper function of the negative electrode of dye-sensitized and perovskite solar cells, the deposition of a nonporous blocking film is required on the surface of F-doped SnO 2 (FTO) glass substrates. Such a blocking film can minimise undesirable parasitic processes, for example, the back reaction of photoinjected electrons with the oxidized form of the redox mediator or with the hole-transporting medium can be avoided. In the present work, thin, transparent, blocking TiO 2 films are prepared by semi-automatic spray pyrolysis of precursors consisting of titanium diisopropoxide bis(acetylacetonate) as the main component. The variation in the layer thickness of the sprayed films is achieved by varying the number of spray cycles. The parameters investigated in this work were deposition temperature (150, 300 and 450 °C), number of spray cycles (20-200), precursor composition (with/without deliberately added acetylacetone), concentration (0.05 and 0.2 M) and subsequent post-calcination at 500 °C. The photo-electrochemical properties were evaluated in aqueous electrolyte solution under UV irradiation. The blocking properties were tested by cyclic voltammetry with a model redox probe with a simple one-electron-transfer reaction. Semi-automatic spraying resulted in the formation of transparent, homogeneous, TiO 2 films, and the technique allows for easy upscaling to large electrode areas. The deposition temperature of 450 °C was necessary for the fabrication of highly photoactive TiO 2 films. The blocking properties of the as-deposited TiO 2 films (at 450 °C) were impaired by post-calcination at 500 °C, but this problem could be addressed by increasing the number of spray cycles. The modification of the precursor by adding acetylacetone resulted in the fabrication of TiO 2 films exhibiting perfect blocking properties that were not influenced by post-calcination. These results will surely find use in the fabrication of large-scale dye-sensitized and perovskite solar

  2. Co-pyrolysis of coal with hydrogen-rich gases. 1. Coal pyrolysis under coke-oven gas and synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Liao, H.; Li, B.; Zhang, B. [Chinese Academy of Sciences, Taiyuan (China). State Key Lab. of Coal Conversion

    1998-06-01

    To improve the economics of the hydropyrolysis process, it has been suggested that cheaper hydrogen-rich gases (such as coke oven gas, synthesis gas) could be used instead of pure hydrogen. Pyrolysis of Chinese Xianfeng lignite was carried out with coke oven gas (COG) and synthesis gas (SG) as reactive gases at 0.1-5 MPa and at a final temperature up to 650{degree}C with a heating rate of 5-25{degree}C min{sup -1} in a 10 g fixed-bed reactor. The results indicate that it is possible to use COG and SG instead of pure hydrogen in hydropyrolysis, but that the experimental conditions must be adjusted to optimize the yields of the valuable chemicals. 14 refs., 3 figs., 6 tabs.

  3. Obtention of zirconia films stabilized with Yttria via pyrolysis spray: study of the solvent influence; Obtencao de filmes de zirconia estabilizada com itria via spray pirolise: estudo da influencia do solvente

    Energy Technology Data Exchange (ETDEWEB)

    Halmenschlager, Cibele Melo; Vieira, Ramaugusto da Porciuncula; Takimi, Antonio Shigueaki; Bergmann, Carlos Perez; Silva, Aline Lima da; Malfatti, Celia de Fraga [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia de Minas, Metalurgica e de Materiais (PPGEM). Lab. de Materiais Ceramicos (LACER)]. E-mail: cibelemh@yahoo.com.br

    2008-07-01

    Yttria-stabilized-zirconia (YSZ) has been object of many studies, due to its great chemical stability and excellent ionic conduction in high temperature. This material has been studies with an intention of to be used with electrolyte of oxide solid fuel cells, which work in high temperature. The aim of the present work was to evaluate the influence of the solvent on the elaboration of crystalline films of YSZ via spray pyrolysis. The film was prepared by spray pyrolysis with zirconium acetylacetonate (Zr(C{sub 6}H{sub 7}O{sub 2}){sub 4}) and yttrium chloride (YCl{sub 3}.6H{sub 2}O), dissolved in different solvents: ethanol (C{sub 2}H{sub 6}O), ethanol (C{sub 2}H{sub 6}O) + propyleneglycol (C{sub 3}H{sub 8}O{sub 2}) with volume ratio (1:1) and ethanol (C{sub 2}H{sub 6}O) + diethylene glycol butyl ether (C{sub 8}H{sub 18}O{sub 3}) with volume ratio of 1:1. A disk of steel 316L was used as substrate. The amorphous film was deposited in the substrate heated at 280 deg C {+-} 50 deg C. After deposition from thermal treatment at 700 deg C the amorphous film was changed into Yttria-stabilized-zirconia film. The thermal behavior of the films has been studied by both (DTA/TGA) thermogravimetric and mass spectroscopy analyses. The morphology and crystalline phase of the films was investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The YSZ film obtained after heat treatment was dense and crystalline, however, the analyses indicate a significant influence of the solvent and of the substrate temperature during the deposition process on the film morphology.(author)

  4. Chemical Synthesis Accelerated by Paper Spray: The Haloform Reaction

    Science.gov (United States)

    Bain, Ryan M.; Pulliam, Christopher J.; Raab, Shannon A.; Cooks, R. Graham

    2016-01-01

    In this laboratory, students perform a synthetic reaction in two ways: (i) by traditional bulk-phase reaction and (ii) in the course of reactive paper spray ionization. Mass spectrometry (MS) is used both as an analytical method and a means of accelerating organic syntheses. The main focus of this laboratory exercise is that the same ionization…

  5. OPTICAL PROPERTIES OF Al:ZnO THIN FILM DEPOSITED BY DIFFERENT SOL-GEL TECHNIQUES: ULTRASONIC SPRAY PYROLYSIS AND DIP-COATING

    Directory of Open Access Journals (Sweden)

    Ebru Gungor

    2016-08-01

    Full Text Available Undoped and Al-doped ZnO polycrystalline thin films have been fabricated on glass substrates by using a computer-controlled dip coating (DC and ultrasonic spray pyrolysis (USP systems. The film deposition parameters of DC process were optimized for the samples. In this technique, the substrate was exposed to temperature gradient using a tube furnace. In the study, the other solvent-based technique was conventional USP. The zinc salt and Al salt concentrations in the solution were kept constant as 0.1 M and 2% of Zn salt’s molarity, respectively. The optical properties were compared for the films deposited two different techniques. The optical transmission of Al:ZnO/Glass/Al:ZnO sample dip coated and  the optical transmission of Al:ZnO/Glass sample ultrasonically sprayed were determined higher than 80% in the visible and near infrared region. Experimental optical transmittance spectra of the films in the forms of FilmA/Glass/FilmA and FilmA/glass were used to determine the optical constants. It was observed that the optical band gaps of Al doped ZnO films onto glass substrate were increases with increase of Al content and the absorption edge shifted to the shorter wavelength (blue shift compared with the undoped ZnO thin film.

  6. Nanocrystalline LiMn2O4 thin film cathode material prepared by polymer spray pyrolysis method for Li-ion battery

    International Nuclear Information System (INIS)

    Karthick, S.N.; Richard Prabhu Gnanakan, S.; Subramania, A.; Kim, Hee-Je

    2010-01-01

    Nanocrystalline cubic spinel lithium manganese oxide thin film was prepared by a polymer spray pyrolysis method using lithium acetate and manganese acetate precursor solution and polyethylene glycol-4000 as a polymeric binder. The substrate temperature was selected from the thermogravimetric analysis by finding the complete crystallization temperature of LiMn 2 O 4 precursor sample. The deposited LiMn 2 O 4 thin films were annealed at 450, 500 and 600 o C for 30 min. The thin film annealed at 600 o C was found to be the sufficient temperature to form high phase pure nanocrystalline LiMn 2 O 4 thin film. The formation of cubic spinel thin film was confirmed by X-ray diffraction study. Scanning electron microscopy and atomic force microscopy analysis revealed that the thin film annealed at 600 o C was found to be nanocrystalline in nature and the surface of the films were uniform without any crack. The electrochemical charge/discharge studies of the prepared LiMn 2 O 4 film was found to be better compared to the conventional spray pyrolysed thin film material.

  7. Structural, optical and electrical properties of Cu{sub 2}FeSnX{sub 4} (X = S, Se) thin films prepared by chemical spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Khadka, Dhruba B.; Kim, JunHo, E-mail: jhk@inu.ac.kr

    2015-07-25

    Highlights: • CFTS(Se) thin films have been synthesized by low-cost spray-based deposition. • The fabricated films were found to be of stannite structure and p-type conductivity. • Band gaps of CFTS and CFTSe thin films are 1.37 and 1.11 eV, respectively. - Abstract: We report on fabrication of polycrystalline Cu{sub 2}FeSnX{sub 4} (X = S, Se) thin films by chemical spray pyrolysis subsequent with post-sulfurization and selenization. The post-annealing of as-sprayed Cu{sub 2}FeSnS{sub 4} (CFTS) films in sulfur and selenium ambient demonstrated drastically improved surface texture as well as crystallinity. The crystal lattice parameters calculated from X-ray diffraction patterns for post-annealed films were found to be consistent with stannite structure. The fabricated Cu{sub 2}FeSnS{sub 4} (CFTS) and Cu{sub 2}FeSnSe{sub 4} (CFTSe) films showed p-type conductivity with carrier concentration in the range of 10{sup 21} cm{sup −3} and mobility ∼1–5 cm{sup 2} V{sup −1} s{sup −1}. The band gap energies of post-sulfurized CFTS and post-selenized CFTSe films were estimated to be ∼1.37 eV and ∼1.11 eV with an error of ±0.02 eV by UV–Vis absorption, respectively, which are promising for photovoltaic application.

  8. An Investigation of Structural and Electrical Properties of Nano Crystalline SnO2:Cu Thin Films Deposited by Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    J. Podder

    2011-11-01

    Full Text Available Pure tin oxide (SnO2 and Cu doped SnO2 thin films have been deposited onto glass substrates by a simple spray pyrolysis technique under atmospheric pressure at temperature 350 °C. The doping concentration of Cu was varied from 1 to 8 wt. % while all other deposition parameters such as spray rate, carrier air gas pressure, deposition time, and distance between spray nozzle to substrate were kept constant. Surface morphology of the as-deposited thin films has been studied by Scanning Electron Microscopy (SEM. The SEM micrograph of the films shows uniform deposition. The structural properties of the as-deposited and annealed thin films have been studied by XRD and the electrical characterization was performed by Van-der Pauw method. The as-deposited films are found polycrystalline in nature with tetragonal crystal structure. Average grain sizes of pure and Cu doped SnO2 thin film have been obtained in the range of 7.2445 Å to 6.0699 Å, which indicates the nanometric size of SnO2 grains developed in the film. The resistivity of SnO2 films was found to decrease initially from 4.5095×10−4 Ωm to 1.1395× 10−4 Ωm for concentration of Cu up to 4 % but it was increased further with increasing of Cu concentrations. The experimental results depict the suitability of this material for using as transparent and conducting window materials in solar cells and gas sensors.

  9. CuS p-type thin film characterization deposited on Ti, ITO and glass substrates using spray pyrolysis deposition (SPD) for light emitting diode (LED) application

    Energy Technology Data Exchange (ETDEWEB)

    Sabah, Fayroz A., E-mail: fayroz-arif@yahoo.com [Institue of Nano-Optoelectronics Research and Technology (INOR), School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Department of Electrical Engineering, College of Engineering, Al-Mustansiriya University, Baghdad (Iraq); Ahmed, Naser M., E-mail: naser@usm.my; Hassan, Z., E-mail: zai@usm.my; Azzez, Shrook A. [Institue of Nano-Optoelectronics Research and Technology (INOR), School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Rasheed, Hiba S., E-mail: hibasaad1980@yahoo.com [Institue of Nano-Optoelectronics Research and Technology (INOR), School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Department of Physics, College of Education, Al-Mustansiriya University, Baghdad (Iraq); Al-Hazim, Nabeel Z., E-mail: nabeelnano333@gmail.com [Institue of Nano-Optoelectronics Research and Technology (INOR), School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Ministry of Education, the General Directorate for Educational Anbar (Iraq)

    2016-07-06

    The copper sulphide (CuS) thin films were grown with good adhesion by spray pyrolysis deposition (SPD) on Ti, ITO and glass substrates at 200 °C. The distance between nozzle and substrate is 30 cm. The composition was prepared by mixing copper chloride CuCl{sub 2}.2H{sub 2}O as a source of Cu{sup 2+} and sodium thiosulfate Na{sub 2}S{sub 2}O{sub 3}.5H{sub 2}O as a source of and S{sup 2−}. Two concentrations (0.2 and 0.4 M) were used for each CuCl{sub 2} and Na{sub 2}S{sub 2}O{sub 3} to be prepared and then sprayed (20 ml). The process was started by spraying the solution for 3 seconds and after 10 seconds the cycle was repeated until the solution was sprayed completely on the hot substrates. The structural characteristics were studied using X-ray diffraction; they showed covellite CuS hexagonal crystal structure for 0.2 M concentration, and covellite CuS hexagonal crystal structure with two small peaks of chalcocite Cu{sub 2}S hexagonal crystal structure for 0.4 M concentration. Also the surface and electrical characteristics were investigated using Field Emission Scanning Electron Microscopy (FESEM) and current source device, respectively. The surface study for the CuS thin films showed nanorods to be established for 0.2 M concentration and mix of nanorods and nanoplates for 0.4 M concentration. The electrical study showed ohmic behavior and low resistivity for these films. Hall Effect was measured for these thin films, it showed that all samples of CuS are p- type thin films and ensured that the resistivity for thin films of 0.2 M concentration was lower than that of 0.4 M concentration; and for the two concentrations CuS thin film deposited on ITO had the lowest resistivity. This leads to the result that the conductivity was high for CuS thin film deposited on ITO substrate, and the conductivity of the three thin films of 0.2 M concentration was higher than that of 0.4 M concentration.

  10. Deposition and characterization of graded Cu(In{sub 1-x}Ga{sub x})Se{sub 2} thin films by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Babu, B.J. [Department of Electrical Engineering-SEES, CINVESTAV-IPN, Avenida IPN 2508, San Pedro Zacatenco, D.F. C.P 07360 (Mexico); Institute of Molecules and Materials, UMR-CNRS 6283, Université du Maine, Avenue O. Messiaen, F-72085 Le Mans (France); Velumani, S., E-mail: velu@cinvestav.mx [Department of Electrical Engineering-SEES, CINVESTAV-IPN, Avenida IPN 2508, San Pedro Zacatenco, D.F. C.P 07360 (Mexico); College of Information and Communication Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kassiba, A. [Institute of Molecules and Materials, UMR-CNRS 6283, Université du Maine, Avenue O. Messiaen, F-72085 Le Mans (France); Asomoza, R. [Department of Electrical Engineering-SEES, CINVESTAV-IPN, Avenida IPN 2508, San Pedro Zacatenco, D.F. C.P 07360 (Mexico); Chavez-Carvayar, J.A. [Instituto Investigaciones en Materiales-UNAM, Ciudad Universitario, D.F.Mexico (Mexico); Yi, Junsin, E-mail: yi@yurim.skku.ac.kr [College of Information and Communication Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2015-07-15

    Cu(In{sub 1-x}Ga{sub x})Se{sub 2} (CIGS) thin films and their graded (x = 1 to 0) layer were grown on soda lime glass substrates using chemical spray pyrolysis (CSP) at different substrate temperatures (T{sub s}). After optimization of T{sub s}, depositions were carried out at different gallium composition (x) at optimized temperature of 350 °C. All the films deposited at T{sub s} ≥ 350 °C were polycrystalline chalcopyrite structure, with a preferential orientation of (112), including the graded layer. With increase in x, lattice parameters a and c were observed to decrease. Line scan of the CIGS layer showed intersection of gallium and indium concentrations, revealing the graded nature of the film. Composition dependence of Raman peak for CuInSe{sub 2} (CIS) deposited by CSP was analyzed. Optical transmittance at a wavelength of 800 nm of the film with x = 0 (CIS) (30%) was found lower than that of the film grown with x = 0.82 (CIGS) (50%). Cusp-shape of the resistivity was observed with an increase of x leading to steep rise in resistivity of the films (1.61–71.68 Ω-cm) till x = 0.42 and then decreased to 4.78 Ω-cm at x = 0.82. Carrier concentrations of the films were evaluated in the order of 10{sup 16}–10{sup 19} cm{sup −3} with p-type conductivity. These results indicate that graded CIGS thin films with modulated gallium composition can be prepared by CSP. - Graphical abstract: Display Omitted - Highlights: • Optimization of the spray deposition system for device grade chalcopyrite CIGS films. • Optimized substrate temperature to obtain single-phase CIGS by spray deposition. • Detailed report on compositional dependence of CuInSe{sub 2} (CIS) thin films. • Systematic analysis of the influence of Ga in CIS by spray deposition. • Bowing parameter is extracted from the experiment values.

  11. Characterization of silica and titania nanoparticles synthesized in a spray flame reactor

    Energy Technology Data Exchange (ETDEWEB)

    Cignoli, F.; Maffi, S.; Bellomunno, C.; De Iuliis, S.; Zizak, G. [CNR-IENI, Milano (Italy)

    2009-07-01

    Nanostructured materials represent nowadays a wide and largely unexplored field of potential applications. This is a research topic in high and rapid development, both at a basic level and under the point of view of potential practical applications, leaving large space for a thorough scientific analysis, which requires a significant amount of time for ultimate conclusions. This paper dealt with the preliminary work performed in the field of frame spray pyrolysis synthesis for nanoparticles, using an external mixing gas assisted nozzle. An experimental apparatus was designed, realized, and characterized for the synthesis of nanoparticles by the flame spray pyrolysis method. The presentation discussed the advantages of the flame spray pyrolysis technique and the experimental set-up including an image of the water spray and discussion of phase doppler anemometry and visualizations to investigate the flow field and the dimensional distribution of the droplets generated by the atomizer. The presentation also discussed the selection of precursor and dispersion fuel for nanoparticles synthesis through flame spray pyrolysis and transmission electron microscopy for dimensional analysis of nanoparticles. It was concluded that the apparatus demonstrated good stability and reproducibility of the reaction flame and, therefore, of the material produced. figs.

  12. Room temperature synthesis of glycerol carbonate catalyzed by spray dried sodium aluminate microspheres

    OpenAIRE

    Sreerangappa, Ramesh; Debecker, Damien P.; 13th European Congress on Catalysis – EuropaCat 2017

    2017-01-01

    Nanostructured NaAlO2 microspheres are produced by one-pot spray dried route, and are characterized by various physico-chemical methods. The obtained solids are composed of spherical aggregates of sodium aluminate with small crystallite size and strong surface basicity. This makes them highly active catalysts in the base-catalyzed synthesis of glycerol carbonate from glycerol and dimethyl carbonate. The catalyst does not leach and showed good reusability up to three cycles.

  13. Effect of tin doping on the optical properties of indium oxide films by a spray pyrolysis method

    International Nuclear Information System (INIS)

    Ibrahim Abu Talib; Muhammad Mat Salleh; Muhammad Yahya; Mod Noor Bader Sher

    1993-01-01

    Thin films of stannum doped indium oxide were deposited on glass by a X-ray pyrolysis method. The substrate temperature and the rate of flow of the carrier gas were fixed at 450 0 C and 2.5 litre/minute respectively during deposition. The dependence of the optical properties of the films on the doping concentration was studied. It is found that the transmission of the visible wavelengths (300 to 800 nm) through the films increases around 5% from 74.9% as the film was doped with 10% stannum. It is also found that the optical energy bandgap increases 0.2 eV from 3.16 to 3.36 eV by doping the film with 10% stannum. The increase is attributed to the Bernstein-Moss (1) and self-energy (2) effects

  14. Plasma-spray synthesis and characterization of ti-based nitride and oxide nanogranules

    Energy Technology Data Exchange (ETDEWEB)

    Antipas, Georgios S.E., E-mail: gantipas@metal.ntua.gr [School of Mining Engineering and Metallurgy, National Technical University of Athens, Athens (Greece)

    2014-09-15

    The synthesis of nanosized Ti-based nanogranules via plasma spraying is reported. The synthesis route involved use of both nitrogen and oxygen gases with varying results. In the case of nitrogen, a mixture of titanium nitrides were produced, yielding both the Ti2N and the sub-stoichiometric TiN0.61 compounds. In the case of oxygen, both the stoichiometric rutile and TiO ceramic phases were indexed. Based on EDS analysis, even fractional oxygen concentrations caused tungsten impurities which originated from the cathode electrode. The method yielded particle mass median sizes of the order of 15nm and the smallest particles detected were 5nm. (author)

  15. Properties of CuInS₂ Nano-Particles on TiO₂ by Spray Pyrolysis for CuInS₂/TiO₂ Composite Solar Cell.

    Science.gov (United States)

    Park, Gye-Choon; Li, Zhen-Yu; Yang, O-Bong

    2017-04-01

    In this letter, for the absorption layer of a CuInS₂/TiO₂ composite solar cell, I–III–VI2 chalcopyrite semiconductor CuInS₂ nano-particles were deposited by using spray pyrolysis method on TiO2 porous film. Their material characteristics including structural and optical properties of CuInS₂ nano-particles on TiO₂ nanorods were analyzed as a function of its composition ratios of Cu:In:S. Crystalline structure, surface morphology and crystalline size were also investigated by X-ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), and High-Resolution TEM (HRTEM), respectively. On the other hand, optical property was characterized by an UV-Visible Spectrophotometer. As a result, it was found that the size of CuInS₂ nano-particles, which was formed at 300±5 °C, was smaller than 16 nm from HRTEM analyses, and it was identified that the CuInS₂ particle size was increased as increasing the heat-treatment temperature and time. However, as the size of CuInS₂ nano-particle becomes smaller, optical absorption edge of ternary compound film tends to move to the blue wavelength band. It turns out that the optical energy-band gap of the compound films was ranging from 1.48 eV to 1.53 eV.

  16. Effect of fuel rate and annealing process of LiFePO{sub 4} cathode material for Li-ion batteries synthesized by flame spray pyrolysis method

    Energy Technology Data Exchange (ETDEWEB)

    Halim, Abdul; Setyawan, Heru; Machmudah, Siti; Nurtono, Tantular; Winardi, Sugeng [Chemical Engineering, Sepuluh Nopember Institute of Technology, Kampus Sukolilo Surabaya Indonesia 60111 (Indonesia)

    2014-02-24

    In this study the effect of fuel rate and annealing on particle formation of LiFePO{sub 4} as battery cathode using flame spray pyrolysis method was investigated numerically and experimentally. Numerical study was done using ANSYS FLUENT program. In experimentally, LiFePO{sub 4} was synthesized from inorganic aqueous solution followed by annealing. LPG was used as fuel and air was used as oxidizer and carrier gas. Annealing process attempted in inert atmosphere at 700°C for 240 min. Numerical result showed that the increase of fuel rate caused the increase of flame temperature. Microscopic observation using Scanning Electron Microscopy (SEM) revealed that all particles have sphere and polydisperse. Increasing fuel rate caused decreasing particle size and increasing particles crystallinity. This phenomenon attributed to the flame temperature. However, all produced particles still have more amorphous phase. Therefore, annealing needed to increase particles crystallinity. Fourier Transform Infrared (FTIR) analysis showed that all particles have PO4 function group. Increasing fuel rate led to the increase of infrared spectrum absorption corresponding to the increase of particles crystallinity. This result indicated that phosphate group vibrated easily in crystalline phase. From Electrochemical Impedance Spectroscopy (EIS) analysis, annealing can cause the increase of Li{sup +} diffusivity. The diffusivity coefficient of without and with annealing particles were 6.84399×10{sup −10} and 8.59888×10{sup −10} cm{sup 2} s{sup −1}, respectively.

  17. Production and characterization of submicron hematite (α−Fe{sub 2}O{sub 3}) particles by ultrasonic spray pyrolysis method

    Energy Technology Data Exchange (ETDEWEB)

    Kırcı, Burak; Ebin, Burçak; Gürmen, Sebahattin [Department of Metallurgical and Materials Engineering, Istanbul Technical University Istanbul (Turkey)

    2013-12-16

    The ultrasonic spray pyrolysis (USP) method has been used to prepare submicron hematite (α−Fe{sub 2}O{sub 3}) particles using two different industrial pickling solutions of iron chloride (41 g/L FeCl{sub 2} and 54 g/L FeCl{sub 3}) Particles were obtained by thermal decomposition of generated aerosols from precursor solutions using 1.7 MHz ultrasonic atomizer. Reaction temperature was set up at 800 °C and aerosol droplets were carried into the heated zone by 0.7 L/min air flow rate. X-Ray Diffraction (XRD) studies were used to determine the crystal structure and crystallite size of the particles. Results indicate that patterns correspond to hematite phase with rhombohedral crystal structure (space group: R3c). The crystallite sizes of particles prepared from FeCl{sub 2} and FeCl{sub 3} solutions that were calculated from Scherrer equation are 59 and 33 nm, respectively. Scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) investigations give detailed information about particle size, morphology and composition. SEM micrographs show that hematite nanoparticles aggregate and formed spherical secondary particles in submicron range.

  18. Effects of ultraviolet light on B-doped CdS thin films prepared by spray pyrolysis method using perfume atomizer

    Energy Technology Data Exchange (ETDEWEB)

    Novruzov, V.D. [Department of Physics, Recep Tayyip Erdogan University, Rize (Turkey); Keskenler, E.F., E-mail: keskenler@gmail.com [Department of Nanotechnology Engineering, Recep Tayyip Erdogan University, Rize (Turkey); Tomakin, M. [Department of Physics, Recep Tayyip Erdogan University, Rize (Turkey); Kahraman, S. [Department of Physics, Mustafa Kemal University, Hatay (Turkey); Gorur, O. [Department of Physics, Abant Izzet Baysal University, Bolu (Turkey)

    2013-09-01

    Boron doped CdS thin films were deposited by spray pyrolysis method using perfume atomizer. The effects of ultraviolet light on the structural, optical and electrical properties of B-doped CdS thin films were investigated as a function of dopant concentration (B/Cd). X-ray diffraction studies showed that all samples were polycrystalline nature with hexagonal structure. It was determined that the preferred orientation of non-illuminated samples changes from (1 0 1) to (0 0 2) with B concentration. The c lattice constant of films decreases from 6.810 Å to 6.661 Å with boron doping. The XRD peak intensity increased with the illumination for almost all the samples. The lattice parameters of B-doped samples remained nearly constant after illumination. It was found that the optical transmittance, photoluminescence spectra, resistivity and carrier concentration of the B-doped samples are stable after the illumination with UV light. Also the effects of UV light on B-doped CdS/Cu{sub 2}S solar cell were investigated and it was determined that photoelectrical parameters of B-doped solar cell were more durable against the UV light.

  19. Investigations on structural, vibrational, morphological and optical properties of CdS and CdS/Co films by ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Aksay, S.; Polat, M.; Ozer, T.; Koese, S.; Guerbuez, G.

    2011-01-01

    CdS and CdS/Co films have been deposited on glass substrates by an ultrasonic spray pyrolysis method. The effects of Co incorporation on the structural, optical, morphological, elemental and vibrational properties of these films were investigated. XRD analysis confirmed the hexagonal wurtzite structure of all films and had no impurity phase. While CdS film has (0 0 2) as the preferred orientation, CdS/Co films have (1 1 0) as the preferred orientation. The direct optical band gap was found to decrease from 2.42 to 2.39 eV by Co incorporation. The decrease of the direct energy gaps by increasing Co contents is mainly due to the sp-d exchange interaction between the localized d-electrons of Co 2+ ions and band electrons of CdS. After the optical investigations, it was seen that the transmittance of CdS films decreased by Co content. The Raman measurements revealed two peaks corresponding to the 1LO and 2LO modes of hexagonal CdS. The vibrational modes of Cd-S were obtained in the wavenumber range (590-715 cm -1 ) using Fourier transform infrared spectroscopy (FTIR). The elemental analysis of the film was done by energy dispersive X-ray spectrometry.

  20. Investigations on structural, vibrational, morphological and optical properties of CdS and CdS/Co films by ultrasonic spray pyrolysis

    Science.gov (United States)

    Aksay, S.; Polat, M.; Özer, T.; Köse, S.; Gürbüz, G.

    2011-09-01

    CdS and CdS/Co films have been deposited on glass substrates by an ultrasonic spray pyrolysis method. The effects of Co incorporation on the structural, optical, morphological, elemental and vibrational properties of these films were investigated. XRD analysis confirmed the hexagonal wurtzite structure of all films and had no impurity phase. While CdS film has (0 0 2) as the preferred orientation, CdS/Co films have (1 1 0) as the preferred orientation. The direct optical band gap was found to decrease from 2.42 to 2.39 eV by Co incorporation. The decrease of the direct energy gaps by increasing Co contents is mainly due to the sp-d exchange interaction between the localized d-electrons of Co2+ ions and band electrons of CdS. After the optical investigations, it was seen that the transmittance of CdS films decreased by Co content. The Raman measurements revealed two peaks corresponding to the 1LO and 2LO modes of hexagonal CdS. The vibrational modes of Cd-S were obtained in the wavenumber range (590-715 cm-1) using Fourier transform infrared spectroscopy (FTIR). The elemental analysis of the film was done by energy dispersive X-ray spectrometry.

  1. Effects of ultraviolet light on B-doped CdS thin films prepared by spray pyrolysis method using perfume atomizer

    Science.gov (United States)

    Novruzov, V. D.; Keskenler, E. F.; Tomakin, M.; Kahraman, S.; Gorur, O.

    2013-09-01

    Boron doped CdS thin films were deposited by spray pyrolysis method using perfume atomizer. The effects of ultraviolet light on the structural, optical and electrical properties of B-doped CdS thin films were investigated as a function of dopant concentration (B/Cd). X-ray diffraction studies showed that all samples were polycrystalline nature with hexagonal structure. It was determined that the preferred orientation of non-illuminated samples changes from (1 0 1) to (0 0 2) with B concentration. The c lattice constant of films decreases from 6.810 Å to 6.661 Å with boron doping. The XRD peak intensity increased with the illumination for almost all the samples. The lattice parameters of B-doped samples remained nearly constant after illumination. It was found that the optical transmittance, photoluminescence spectra, resistivity and carrier concentration of the B-doped samples are stable after the illumination with UV light. Also the effects of UV light on B-doped CdS/Cu2S solar cell were investigated and it was determined that photoelectrical parameters of B-doped solar cell were more durable against the UV light.

  2. Nanostructured CuO thin film electrodes prepared by spray pyrolysis: a simple method for enhancing the electrochemical performance of CuO in lithium cells

    International Nuclear Information System (INIS)

    Morales, Julian; Sanchez, Luis; Martin, Francisco; Ramos-Barrado, Jose R.; Sanchez, Miguel

    2004-01-01

    Nanostructured CuO thin films were prepared by using a spray pyrolysis method, copper acetate as precursor and stainless steel as substrate. The textural and structural properties of the films were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The SEM images revealed thorough coating of the substrate and thickness of 450-1250 nm; the average particle size as determined from the AFM images ranged from 30 to 160 nm. The XRD patterns revealed the formation of CuO alone and the XPS spectra confirmed the presence of Cu 2+ as the main oxidation state on the surface. The films were tested as electrodes in lithium cells and their electrochemical properties evaluated from galvanostatic and step potential electrochemical spectroscopy (SPES) measurements. The discharge STEP curves exhibited various peaks consistent with the processes CuO Cu 2 O Cu and with decomposition of the electrolyte, a reversible process in the light of the AFM images. The best electrode exhibited capacity values of 625 Ah kg -1 over more than 100 cycles. This value, which involves a CuO Cu reversible global reaction, is ca. 50% higher than that reported for bulk CuO. The nanosize of the particles and the good adherence of the active material to the substrate are thought to be the key factors accounting for the enhanced electrochemical activity found

  3. Structural and photoluminescence characterization of SnO{sub 2}: F thin films deposited by advanced spray pyrolysis technique at low substrate temperature

    Energy Technology Data Exchange (ETDEWEB)

    Shewale, P.S. [Thin Film Physics Laboratory, Department of Electronics, Shivaji University, Kolhapur 416004 (India); Ung Sim, Kyu; Kim, Ye-bin; Kim, J.H. [Department of Materials Science and Engineering, Chonnam National University, 300 Yongbong-Dong, Buk-Gu, Gwangju 500757 (Korea, Republic of); Moholkar, A.V. [Department of Physics, Shivaji University, Kolhapur 416004 (India); Uplane, M.D., E-mail: mdu_eln@unishivaji.ac.in [Thin Film Physics Laboratory, Department of Electronics, Shivaji University, Kolhapur 416004 (India)

    2013-07-15

    Fluorine doped tin oxide (FTO) thin films were deposited on glass substrates, at different substrate temperatures using advanced spray pyrolysis technique. X-ray diffraction studies showed that the crystallinity of the thin films increased with increasing substrate temperature. FESEM and AFM studies support the conclusions drawn from X-ray diffraction studies. X-ray photoelectron studies confirm oxygen deficiency in formation of the FTO nanocrystallites. The photoluminescence of the FTO films were investigated. It was found that, room temperature photoluminescence spectra are dominated by oxygen vacancies and exhibit a rich violet photoluminescence band about ∼404 nm with an extensively feeble red emission about 700 nm. The Photoluminescence intensity varies with the substrate temperature. The photoemission position is observed to be independent of substrate temperature. -- Highlights: ► Photoluminescent FTO thin films were deposited at low substrate temperatures. ► Influence of substrate temperature on the PL characteristics was studied. ► The samples are polycrystalline with a cassiterite tetragonal crystal structure. ► The room temperature UV/violet PL emission was dominated by the oxygen vacancies. ► PL efficiency is optimum at 613 K substrate temperature.

  4. Preparation and characterizations of electroluminescent p-ZnO : N/n-ZnO : Ga/ITO thin films by spray pyrolysis method

    Directory of Open Access Journals (Sweden)

    C. Panatarani

    2016-02-01

    Full Text Available ZnO thin films were fabricated by spray pyrolysis (SP method with p-ZnO : N/n-ZnO:Ga/ITO structure. The X-ray results show that the deposited films have hexagonal wurtzite structure. The EDS results observed that the composition of Ga in ZnO:Ga and N in ZnO:N was 3.73% and 27.73% respectively. The photoluminescence (PL with excitation wave length of 260 nm shows that ZnO:Ga and ZnO:N films emitted UV emission at ∼393 and ∼388 nm, respectively and the films resistivity was 7.12 and 12.80 Ohm-cm respectively. The electroluminescence of the p-ZnO : N/n-ZnO:Ga/ITO structure was obtained by applying forward bias of 5 volt with 30 mA current, resulting in a 3.35 volt threshold bias with the peak electroluminescence in UV-blue range.

  5. Indium-Nitrogen Codoped Zinc Oxide Thin Film Deposited by Ultrasonic Spray Pyrolysis on n-(111 Si Substrate: The Effect of Film Thickness

    Directory of Open Access Journals (Sweden)

    Cheng-Chang Yu

    2014-01-01

    Full Text Available Indium-nitrogen codoped zinc oxide (INZO thin films were fabricated by spray pyrolysis deposition technique on n-(111 Si substrate with different film thicknesses at 450°C using a precursor containing zinc acetate, ammonium acetate, and indium nitrate with 1 : 3 : 0.05 at.% concentration. The morphology and structure studies were carried out by scanning electron microscopy (SEM and X-ray diffraction (XRD. The grain size of the films increased when increasing the film thickness. From XRD spectra, polycrystalline ZnO structure can be observed and the preferred orientation behavior varied from (002 to (101 as the film thickness increased. The concentration and mobility were investigated by Hall effect measurement. the p-type films with a hole mobility around 3 cm2V−1s−1 and hole concentration around 3×1019 cm−3 can be achieved with film thickness less than 385 nm. The n-type conduction with concentration 1×1020 cm−3 is observed for film with thickness 1089 nm. The defect states were characterized by photoluminescence. With temperature-dependent conductivity analysis, acceptor state with activation energy 0.139 eV dominate the p type conduction for thin INZO film. And the Zn-related shallow donors with activation energy 0.029 eV dominate the n-type conduction for the thick INZO film.

  6. High power density cell using nanostructured Sr-doped SmCoO3 and Sm-doped CeO2 composite powder synthesized by spray pyrolysis

    Science.gov (United States)

    Shimada, Hiroyuki; Yamaguchi, Toshiaki; Suzuki, Toshio; Sumi, Hirofumi; Hamamoto, Koichi; Fujishiro, Yoshinobu

    2016-01-01

    High power density solid oxide electrochemical cells were developed using nanostructure-controlled composite powder consisting of Sr-doped SmCoO3 (SSC) and Sm-doped CeO2 (SDC) for electrode material. The SSC-SDC nano-composite powder, which was synthesized by spray pyrolysis, had a narrow particle size distribution (D10, D50, and D90 of 0.59, 0.71, and 0.94 μm, respectively), and individual particles were spherical, composing of nano-size SSC and SDC fragments (approximately 10-15 nm). The application of the powder to a cathode for an anode-supported solid oxide fuel cell (SOFC) realized extremely fine cathode microstructure and excellent cell performance. The anode-supported SOFC with the SSC-SDC cathode achieved maximum power density of 3.65, 2.44, 1.43, and 0.76 W cm-2 at 800, 750, 700, and 650 °C, respectively, using humidified H2 as fuel and air as oxidant. This result could be explained by the extended electrochemically active region in the cathode induced by controlling the structure of the starting powder at the nano-order level.

  7. Mass Production of LiFePO4/C Powders by Large Type Spray Pyrolysis Apparatus and Its Application to Cathode for Lithium Ion Battery

    Directory of Open Access Journals (Sweden)

    Shinsuke Akao

    2010-01-01

    Full Text Available Spherical LiFePO4/C powders were successfully produced at a rate of 100 g/h using a large type spray pyrolysis apparatus. Organic compounds such as citric acid and sucrose were used as carbon sources. Scanning electron microscopy observation showed that they had a spherical morphology with nonaggregation. X-ray diffraction analysis revealed that the olivine phase was obtained by heating at 600∘C under argon (95%/hydrogen (5% atmosphere. The chemical composition of LiFePO4/C powders was in good agreement with that of the starting solution. Electrochemical measurement revealed that the use of citric acid was most effective in ensuring a high rechargeable capacity and cycle stability. The rechargeable capacity of the LiFePO4/C cathode obtained using citric acid was 155 mAh/g at a discharge rate of 1 C. Because of the good discharge capacity of the LiFePO4/C cathode, it exhibited excellent cycle stability after 100 cycles at each discharge rate. Moreover, this high cycle stability of the LiFePO4/C cathode was maintained even at 50∘C.

  8. Development of SnS (FTO/CdS/SnS) thin films by nebulizer spray pyrolysis (NSP) for solar cell applications

    Science.gov (United States)

    Arulanantham, A. M. S.; Valanarasu, S.; Jeyadheepan, K.; Ganesh, V.; Shkir, Mohd

    2018-01-01

    Herein we report a well-organized analysis on various key-properties of SnS thin films for solar cell fabricated by nebulizer spray pyrolysis technique. X-ray diffraction study reveals the polycrystalline nature of deposited films with orthorhombic crystal structure. The crystallite size was calculated and observed to be in the range of 8-28 nm with increasing molarity of precursor solution. The stoichiometry composition of SnS was confirmed by EDX study. SEM/AFM studies divulge the well-covered deposited surface with spherical grains and the size of grains is increasing with concentration and so the roughness. A remarkable decrease in band gap from 2.6 eV to 1.6 eV was noticed by raising the molar concentration from 0.025 M up to 0.075 M. A single strong emission peak at about 825 nm is observed in PL spectra with enhanced intensity which may be attributed to near band edge emission. From the Hall effect measurement, it was found that the SnS thin film exhibits p-type conductivity. The calculated values of resistivity and carrier concentration are 0.729 Ω cm and 3.67 × 1018/cm3 respectively. Furthermore, to study the photovoltaic properties of SnS thin films a heterojunction solar cell, FTO/n-CdS/p-SnS was produced and the conversion efficiency was recorded about 0.01%.

  9. Structural, optical and electrical properties of CuInS{sub 2} thin films prepared by chemical spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Terasako, Tomoaki; Uno, Yuji; Inoue, Seiki; Shirakata, Sho [Faculty of Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama 780-8577 (Japan); Kariya, Tetsuya [Faculty of Science, Kochi University, Akebono-cho, Kochi, 780-8072 (Japan)

    2006-09-15

    Polycrystalline CuInS{sub 2} thin films were prepared by chemical spray pyrolisis (CSP) on glass substrate from the ethanol aqueous solution containing CuCl{sub 2}, InCl{sub 3} and thiourea. Structural, electrical and optical properties were systematically studied in terms of substrate temperature, pH and the ion ratio (Cu/In) of the spray solution. Although the In-rich films were composed of CuInS{sub 2} and In{sub 2}S{sub 3}, the In{sub 2}S{sub 3} content in the film decreased with Cu/In ratio. Appearance of Raman peaks at 288 and 298 cm{sup -1} indicated that the films contained CuInS{sub 2} with chalcopyrite and CuAu phases. Typical grain size in the Cu-rich films was 200 nm. Optical gap energies were approximately 0.1-0.2eV smaller than the bandgap energy of the CuInS{sub 2} bulk crystal. Resistivity of the Cu-rich films without In{sub 2}S{sub 3} secondary phase was 0.2-5 {omega}cm. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Synthesis of nano-carbon (nanotubes, nanofibres, graphene ...

    Indian Academy of Sciences (India)

    In the present study, we report the synthesis of carbon nanotubes (CNTs) using a new natural precursor: castor oil. The CNTs were synthesized by spray pyrolysis of castor oil–ferrocene solution at 850°C under an Ar atmosphere. We also report the synthesis of carbon nitrogen (C–N) nanotubes using castor ...

  11. Synthesis and Deposition of TiC-Fe Coatings by Oxygen-acetylene Flame Spraying

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A simpler and more convenient method for producing wear-resistant, TiC-reinforced coatings were investigated in this study. It consists of the simultaneous synthesis and deposition of TiC-Fe materials by oxyacetylene flame spraying.Solid reagents bound together to form a single particle are injected into the flame stream where an in-situ reaction occurs. The reaction products are propelled onto a substrate to form a coating. Microstructural analyses reveal that TiC and Fe are the dominant phases in the coatings. The reaction between Ti and C happens step by step along with the reactive spray powder flight, and TiC-Fe materials were mainly synthesized where the spray distance is 125~170 mm. The TiC-Fe coatings are composed of alternate TiC-rich and TiC-poor lamellae with different microhardness of 11.9~13.7 and 3.0~6.0 Gpa, respectively. Submicron and round TiC particles are dispersed within a ductile metal matrix. The peculiar microstructure is thought to be responsible for its good wear resistance, which is better nearly five times than WC-reinforced cermet coatings obtained by traditional oxyacetylene flame spray.

  12. Characterization of the SnO{sub 2}:F/CdS:In structures prepared by the spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Ikhmayies, Shadia J.; Ahmad-Bitar, Riyad N. [University of Jordan, Faculty of Science, Physics Department, Queen Rania Street, Amman 11942 (Jordan)

    2010-05-15

    SnO{sub 2}:F/CdS:In bilayers were spray-deposited on glass substrates. The structures were characterized by recording and investigating their transmittance curves, I-V plots, X-ray diffractograms (XRD) and by observing their scanning electron microscope (SEM) images. From the I-V plots it was found that the SnO{sub 2}:F forms an ohmic or quasi-ohmic contact with CdS:In. XRD patterns show the polycrystalline nature of the films and show that there is a small shift in the position of the (2 0 0) line of SnO{sub 2}:F without the appearance of new peaks. The morphology of the structures are compared with those of SnO{sub 2}:F alone and CdS:In alone on glass substrates. (author)

  13. Spray pyrolysis deposition of Cu-ZnO and Zn-SnO{sub 2} solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Khelfane, A.; Tarzalt, H.; Sebboua, B.; Zerrouki, H.; Kesri, N., E-mail: kesri5n@gmail.com [Faculty of Physics, University of Science and Technology of Houari Boumediene, Algiers (Algeria)

    2015-12-31

    Large-gap metal oxides, such as titanium, tin, and zinc oxides, have attracted great interest because of their remarkable potential in dye-sensitized solar cells (DSSC) and their low cost and simple preparation procedure. In this work, we investigated several Zn-SnO{sub 2} and Cu-ZnO thin films that were sprayed under different experimental conditions. We varied [Zn/[Sn] and [Cu/[Zn] ratios, calculated on atomic percent in the starting solution. We report some structural results of the films using X-ray diffraction. Optical reflection and transmission spectra investigated by an UV/VIS/NIR spectrophotometer permit the determination of optical constants. The direct band gap was deduced from the photon energy dependence of the absorption coefficient.

  14. Structural and fluorescence properties of Ni:MgO-SiO2 particles synthesized by flame spray pyrolysis

    International Nuclear Information System (INIS)

    Suzuki, Takenobu; Ohishi, Yasutake; Tani, Takao

    2006-01-01

    Structural and fluorescence properties of flame spray-synthesized Ni 1 mol%-doped MgO-SiO 2 nano-particles (MgO:SiO 2 = 100:0, 50:50, 25:75 and 0:100 in mol%) were investigated as a first step to prepare transparent materials containing Ni:MgO for optical gain media. Polyhedral aggregates of primary particles with diameters of 8-19 nm were obtained for all compositions. The 100MgO particles were single crystalline and showed the fluorescences (centered at 1260 and 1320 nm) and lifetime (3.8 ms) similar to those of solid state-synthesized Ni:MgO polycrystalline powder under laser excitation at 976 nm, suggesting Ni ions incorporated in MgO

  15. Carbon Isotope Characterization of Organic Intermediaries in Hydrothermal Hydrocarbon Synthesis by Pyrolysis-GC-MS-C-IRMS

    Science.gov (United States)

    Socki, Richard A.; Fu, Qi; Niles, Paul B.

    2010-01-01

    We report results of experiments designed to characterize the carbon isotope composition of intermediate organic compounds produced as a result of mineral surface catalyzed reactions. The impetus for this work stems from recently reported detection of methane in the Martian atmosphere coupled with evidence showing extensive water-rock interaction during Martian history. Abiotic formation by Fischer-Tropsch-type (FTT) synthesis during serpentinization reactions may be one possible process responsible for methane generation on Mars, and measurement of carbon and hydrogen isotopes of intermediary organic compounds can help constrain the origin of this methane. Of particular interest within the context of this work is the isotopic composition of organic intermediaries produced on the surfaces of mineral catalysts (i.e. magnetite) during hydrothermal experiments, and the ability to make meaningful and reproducible isotope measurements. Our isotope measurements utilize a unique analytical technique combining Pyrolysis-Gas Chromatograph-Mass Spectrometry-Combustion-Isotope Ratio Mass Specrometry (Py-GC-MS-C-IRMS). Others have conducted similar pyrolysis-IRMS experiments on low molecular weight organic acids (Dias, et al, Organic Geochemistry, 33 [2002]). Our technique differs in that it carries a split of the pyrolyzed GC-separated product to a Thermo DSQ-II quadrupole mass spectrometer as a means of making qualitative and semi-quantitative compositional measurements of the organic compounds. A sample of carboxylic acid (mixture of C1 through C6) was pyrolyzed at 100 XC and passed through the GC-MS-C-IRMS (combusted at 940 XC). In order to test the reliability of our technique we compared the _13C composition of different molecular weight organic acids (from C1 through C6) extracted individually by the traditional sealed-tube cupric oxide combustion (940 XC) method with the _13C produced by our pyrolysis technique. Our data indicate that an average 4.3. +/-0.5. (V

  16. SnO2 thin-films prepared by a spray-gel pyrolysis: Influence of sol properties on film morphologies

    International Nuclear Information System (INIS)

    Luyo, Clemente; Fabregas, Ismael; Reyes, L.; Solis, Jose L.; Rodriguez, Juan; Estrada, Walter; Candal, Roberto J.

    2007-01-01

    Nanostructured tin oxide films were prepared by depositing different sols using the so-called spray-gel pyrolysis process. SnO 2 suspensions (sols) were obtained from tin (IV) tert-amyloxide (Sn(t-OAm) 4 ) or tin (IV) chloride pentahydrate (SnCl 4 .5H 2 O) precursors, and stabilized with ammonia or tetraethylammonium hydroxide (TEA-OH). Xerogels from the different sols were obtained by solvent evaporation under controlled humidity. The Relative Gelling Volumes (RGV) of these sols strongly depended on the type of precursor. Xerogels obtained from inorganic salts gelled faster, while, as determined by thermal gravimetric analysis, occluding a significant amount of volatile compounds. Infrared spectroscopic analysis was performed on raw and annealed xerogels (300, 500 deg. C, 1 h). Annealing removed water and ammonium or alkyl ammonium chloride, increasing the number of Sn-O-Sn bonds. SnO 2 films were prepared by spraying the sols for 60 min onto glass and alumina substrates at 130 deg. C. The films obtained from all the sols were amorphous or displayed a very small grain size, and crystallized after annealing at 400 deg. C or 500 deg. C in air for 2 h. X-ray diffraction analysis showed the presence of the cassiterite structure and line broadening indicated a polycrystalline material with a grain size in the nanometer range. Results obtained from Scanning Electron Microscopy analysis demonstrated a strong dependence of the film morphology on the RGV of the sols. Films obtained from Sn(t-OAm) 4 showed a highly textured morphology based on fiber-shape bridges, whereas the films obtained from SnCl 4 .5H 2 O had a smoother surface formed by 'O-ring' shaped domains. Lastly, the performance of these films as gas sensor devices was tested. The conductance (sensor) response for ethanol as a target analyte was of the same order of magnitude for the three kinds of films. However, the response of the highly textured films was more stable with shorter response times

  17. Process development for synthesis and plasma spray deposition of LaPO4 and YPO4 for nuclear applications

    International Nuclear Information System (INIS)

    Chakravarthy, Y.; Sreekumar, K.P.; Jayakumar, S.; Thiyagarajan, T.K.; Ananthapadmanabhan, P.V.; Das, A.K.; Gantayet, L.M.; Krishnan, K.

    2009-01-01

    Rare earth phosphates are geologically very stable and considered as potential matrix material for nuclear waste disposal and also for many high temperature thermal barrier and corrosion barrier applications involving molten metals. This paper focuses on developmental studies related to synthesis, thermal stability and plasma spray deposition of LaPO 4 and YPO 4 . The rare earth phosphates were synthesized by chemical method from their respective oxide materials using ortho phosphoric acid. The as-precipitated powders were converted to thermal spray grade powder by compaction, sintering and crushing. Thermal stability of these phosphates up to their melting point was determined by arc plasma melting, followed by X-ray diffraction. Results indicate that LaPO 4 and YPO 4 melt congruently without decomposition. Plasma spray deposition was carried out using the in-house 40 kW atmospheric plasma spray system. Adherent coatings could be deposited on various substrates by optimizing the plasma spray parameters. (author)

  18. The electrical, optical, structural and thermoelectrical characterization of n- and p-type cobalt-doped SnO 2 transparent semiconducting films prepared by spray pyrolysis technique

    Science.gov (United States)

    Bagheri-Mohagheghi, Mohammad-Mehdi; Shokooh-Saremi, Mehrdad

    2010-10-01

    The electrical, optical and structural properties of Cobalt (Co) doped SnO 2 transparent semiconducting thin films, deposited by the spray pyrolysis technique, have been studied. The SnO 2:Co films, with different Co-content, were deposited on glass substrates using an aqueous-ethanol solution consisting of tin and cobalt chlorides. X-ray diffraction studies showed that the SnO 2:Co films were polycrystalline only with tin oxide phases and preferential orientations along (1 1 0) and (2 1 1) planes and grain sizes in the range 19-82 nm. Optical transmittance spectra of the films showed high transparency ∼75-90% in the visible region, decreasing with increase in Co-doping. The optical absorption edge for undoped SnO 2 films was found to be 3.76 eV, while for higher Co-doped films shifted toward higher energies (shorter wavelengths) in the range 3.76-4.04 eV and then slowly decreased again to 4.03 eV. A change in sign of the Hall voltage and Seebeck coefficient was observed for a specific acceptor dopant level ∼11.4 at% in film and interpreted as a conversion from n-type to p-type conductivity. The thermoelectric electro-motive force (e.m.f.) of the films was measured in the temperature range 300-500 K and Seebeck coefficients were found in the range from -62 to +499 μVK -1 for various Co-doped SnO 2 films.

  19. The electrical, optical, structural and thermoelectrical characterization of n- and p-type cobalt-doped SnO2 transparent semiconducting films prepared by spray pyrolysis technique

    International Nuclear Information System (INIS)

    Bagheri-Mohagheghi, Mohammad-Mehdi; Shokooh-Saremi, Mehrdad

    2010-01-01

    The electrical, optical and structural properties of Cobalt (Co) doped SnO 2 transparent semiconducting thin films, deposited by the spray pyrolysis technique, have been studied. The SnO 2 :Co films, with different Co-content, were deposited on glass substrates using an aqueous-ethanol solution consisting of tin and cobalt chlorides. X-ray diffraction studies showed that the SnO 2 :Co films were polycrystalline only with tin oxide phases and preferential orientations along (1 1 0) and (2 1 1) planes and grain sizes in the range 19-82 nm. Optical transmittance spectra of the films showed high transparency ∼75-90% in the visible region, decreasing with increase in Co-doping. The optical absorption edge for undoped SnO 2 films was found to be 3.76 eV, while for higher Co-doped films shifted toward higher energies (shorter wavelengths) in the range 3.76-4.04 eV and then slowly decreased again to 4.03 eV. A change in sign of the Hall voltage and Seebeck coefficient was observed for a specific acceptor dopant level ∼11.4 at% in film and interpreted as a conversion from n-type to p-type conductivity. The thermoelectric electro-motive force (e.m.f.) of the films was measured in the temperature range 300-500 K and Seebeck coefficients were found in the range from -62 to +499 μVK -1 for various Co-doped SnO 2 films.

  20. Improvement of Transparent Conducting Performance on Oxygen-Activated Fluorine-Doped Tin Oxide Electrodes Formed by Horizontal Ultrasonic Spray Pyrolysis Deposition.

    Science.gov (United States)

    Koo, Bon-Ryul; Oh, Dong-Hyeun; Riu, Doh-Hyung; Ahn, Hyo-Jin

    2017-12-27

    In this study, highly transparent conducting fluorine-doped tin oxide (FTO) electrodes were fabricated using the horizontal ultrasonic spray pyrolysis deposition. In order to improve their transparent conducting performances, we carried out oxygen activation by adjusting the ratio of O 2 /(O 2 +N 2 ) in the carrier gas (0%, 20%, and 50%) used during the deposition process. The oxygen activation on the FTO electrodes accelerated the substitution concentration of F (F O • ) into the oxygen sites in the FTO electrode while the oxygen vacancy (V O • • ) concentration was reduced. In addition, due to growth of pyramid-shaped crystallites with (200) preferred orientations, this oxygen activation caused the formation of a uniform surface structure. As a result, compared to others, the FTO electrode prepared at 50% O 2 showed excellent electrical and optical properties (sheet resistance of ∼4.0 ± 0.14 Ω/□, optical transmittance of ∼85.3%, and figure of merit of ∼5.09 ± 0.19 × 10 -2 Ω -1 ). This led to a superb photoconversion efficiency (∼7.03 ± 0.20%) as a result of the improved short-circuit current density. The photovoltaic performance improvement can be defined by the decreased sheet resistance of FTO used as a transparent conducting electrode in dye-sensitized solar cells (DSSCs), which is due to the combined effect of the high carrier concentration by the improved F O • concentration on the FTO electrodes and the fasted Hall mobility by the formation of a uniform FTO surface structure and distortion relaxation on the FTO lattices resulting from the reduced V O • • • concentration.

  1. Investigations of AlGaN/GaN MOS-HEMT with Al2O3 deposition by ultrasonic spray pyrolysis method

    International Nuclear Information System (INIS)

    Chou, Bo-Yi; Hsu, Wei-Chou; Liu, Han-Yin; Wu, Yu-Sheng; Lee, Ching-Sung; Sun, Wen-Ching; Wei, Sung-Yen; Yu, Sheng-Min; Chiang, Meng-Hsueh

    2015-01-01

    This work investigates Al 2 O 3 /AlGaN/GaN metal-oxide-semiconductor high electron mobility transistors (MOS-HEMTs) grown on SiC substrate by using the non-vacuum ultrasonic spray pyrolysis deposition (USPD) method. The Al 2 O 3 was deposited as gate dielectric and surface passivation simultaneously to effectively suppress gate leakage current, enhance output current density, reduce RF drain current collapse, and improve temperature-dependent stabilities performance. The present MOS-HEMT design has shown improved device performances with respect to a Schottky-gate HEMT, including drain-source saturation current density at zero gate bias (I DSS : 337.6 mA mm −1  → 462.9 mA mm −1 ), gate-voltage swing (GVS: 1.55 V → 2.92 V), two-terminal gate-drain breakdown voltage (BV GD : −103.8 V → −183.5 V), unity-gain cut-off frequency (f T : 11.3 GHz → 17.7 GHz), maximum oscillation frequency (f max : 14.2 GHz → 19.1 GHz), and power added effective (P.A.E.: 25.1% → 43.6%). The bias conditions for measuring f T and f max of the studied MOS-HEMT (Schottky-gate HEMT) are V GS  = −2.5 (−2) V and V DS  = 7 V. The corresponding V GS and V DS biases are −2.5 (−2) V and 15 V for measuring the P.A.E. characteristic. Moreover, small capacitance-voltage (C–V) hysteresis is obtained in the Al 2 O 3 -MOS structure by using USPD. Temperature-dependent characteristics of the present designs at 300–480 K are also studied. (paper)

  2. Investigations on MgO-dielectric GaN/AlGaN/GaN MOS-HEMTs by using an ultrasonic spray pyrolysis deposition technique

    International Nuclear Information System (INIS)

    Lee, Ching-Sung; Liu, Han-Yin; Wu, Ting-Ting; Hsu, Wei-Chou; Sun, Wen-Ching; Wei, Sung-Yen; Yu, Sheng-Min

    2016-01-01

    This work investigates GaN/Al 0.24 Ga 0.76 N/GaN metal-oxide-semiconductor high electron mobility transistors (MOS-HEMTs) grown on a Si substrate with MgO gate dielectric by using the non-vacuum ultrasonic spray pyrolysis deposition (USPD) technique. The oxide layer thickness is tuned to be 30 nm with the dielectric constant of 8.8. Electron spectroscopy for chemical analysis (ESCA), secondary ion mass spectrometry (SIMS), atomic force microscopy (AFM), transmission electron microscopy (TEM), C–V, low-frequency noise spectra, and pulsed I–V measurements are performed to characterize the interface and oxide quality for the MOS-gate structure. Improved device performances have been successfully achieved for the present MOS-HEMT (Schottky-gate HEMT) design, consisting of a maximum drain-source current density (I DS, max ) of 681 (500) mA/mm at V GS  = 4 (2) V, I DS at V GS  = 0 V (I DSS0 ) of 329 (289) mA/mm, gate-voltage swing (GVS) of 2.2 (1.6) V, two-terminal gate-drain breakdown voltage (BV GD ) of −123 (−104) V, turn-on voltage (V on ) of 1.7 (0.8) V, three-terminal off-state drain-source breakdown voltage (BV DS ) of 119 (96) V, and on/off current ratio (I on /I off ) of 2.5 × 10 8 (1.2 × 10 3 ) at 300 K. Improved high-frequency and power performances are also achieved in the present MOS-HEMT design. (paper)

  3. Effects of growth temperatures on the physical properties of Cu2ZnSnS4 thin films deposited through spray pyrolysis for solar cell applications

    Science.gov (United States)

    Fadavieslam, M. R.; Keshavarz, S.

    2018-02-01

    This paper reports the effects of substrate temperature on the structural, optical, and electrical properties of Cu2ZnSnS4 (CZTS) thin films deposited on soda lime glass through spray pyrolysis without sulfurization. Substrate temperatures ranged from 250 to 500 °C at a step of 50 °C, and a precursor solution was prepared by dissolving copper chloride, zinc acetate, zinc chloride, and thiourea in ethanol and di-ionized water. The films were characterized through X-ray diffraction (XRD), field emission scanning electron microscopy, ultraviolet-visible spectroscopy, and electrical resistance and Hall effect measurements, respectively, obtained by two-point probe and van der Pauw techniques. XRD revealed the formation of polycrystalline CZTS thin films and the appearance of relatively intense and sharp diffraction peaks at (112), (200), (220), and (312) of a kesterite phase with (112) preferential orientation, in which the crystalline degree increased as substrate temperature increased. Surface morphological analysis demonstrated the formation of a smooth, compact, and uniform CZTS surface. When substrate temperature increased from 250 to 500 °C, single-crystal grains increased from 6.38 to 28 nm, carrier concentration increased from 3.4 × 1017 to 2.36 × 1019 cm-3, Hall mobility increased from 30.96 to 68.52 cm2/V.S, optical band gap decreased from 1.74 to 1.14 eV, and resistivity decreased from 0.59 to 3.87 × 10-3 Ωcm. Hall effect analysis indicated that the films exhibited p-type conductivity.

  4. Study of sensing properties of SnO2 prepared by spray-pyrolysis deposition towards ethanol gas

    Science.gov (United States)

    Saadaldin, Nasser M.; Hussain, Nabiha; AlZouabi, Abla

    2018-05-01

    Ethanol is widely used in all kinds of products with direct exposure to the human skin (e.g. medicinal products like hand disinfectants in occupational settings, cosmetics like hairsprays or mouthwashes, in this study, thin films of (SnO2) were deposited by using the thermal spray method (SPD) on quartz at 450°C substrate temperature using tin chloride SnCl2.2H2O, (1.0M). A gas sensor was constructed with the prepared SnO2, used to detect ethanol gas and some other gases. The films were characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM). The grain size was calculated the results showed nanostructure polycrystalline and crystallize in a tetragonal, S.G:P42/m nm, reaching grain Size approximately 27nm. The sensing properties of the films were studied towards ethanol at different concentrations ranging within (1-200 ppm,) the results showed that the sensitivity of the film increases with the concentration of ethanol, the best operating temperature reached about 300 °C, We studied the sensing properties of the films towards Ethanol alcohol gas, The first and foremost concerns of topical ethanol applications for public health are its carcinogenic effects, high selectivity and sensitivity of the film towards ethanol gas was found compared to other tested toxic gases such as methanol gas, acetone and methylbenzene. Yet an upto-date risk assessment of ethanol application on the skin and inside the oral cavity is currently lacking.

  5. Room temperature synthesis of glycerol carbonate catalyzed by spray dried sodium aluminate microspheres

    OpenAIRE

    Sreerangappa, Ramesh; Debecker, Damien P.

    2017-01-01

    Nanostructured NaAlO2 microspheres are produced from an aqueous solution, by a one-pot spray drying route. The obtained solids are composed of spherical aggregates of sodium aluminate with small crystallite size and strong surface basicity. This makes them highly active catalysts in the base-catalyzed synthesis of glycerol carbonate from glycerol and dimethyl carbonate. The new catalyst does not leach and is recyclable. NaAlO2 microspheres outcompete commercially available NaAlO2 as well as o...

  6. Oxidation Behavior of Titanium Carbonitride Coating Deposited by Atmospheric Plasma Spray Synthesis

    Science.gov (United States)

    Zhu, Lin; He, Jining; Yan, Dianran; Liao, Hanlin; Zhang, Nannan

    2017-10-01

    As a high-hardness and anti-frictional material, titanium carbonitride (TiCN) thick coatings or thin films are increasingly being used in many industrial fields. In the present study, TiCN coatings were obtained by atmospheric plasma spray synthesis or reactive plasma spray. In order to promote the reaction between the Ti particles and reactive gases, a home-made gas tunnel was mounted on a conventional plasma gun to perform the spray process. The oxidation behavior of the TiCN coatings under different temperatures in static air was carefully investigated. As a result, when the temperature was over 700 °C, the coatings suffered from serious oxidation, and finally they were entirely oxidized to the TiO2 phase at 1100 °C. The principal oxidation mechanism was clarified, indicating that the oxygen can permeate into the defects and react with TiCN at high temperatures. In addition, concerning the use of a TiCN coating in high-temperature conditions, the microhardness of the oxidized coatings at different treatment temperatures was also evaluated.

  7. Synthesis and characterization of spray deposited CZTS thin films for photo-electrochemical application

    Science.gov (United States)

    Chavda, Arvind; Patel, Biren; Mukhopadhyay, Priyanka Marathey Indrajit; Ray, Abhijit

    2018-05-01

    Cu2ZnSnS4 (CZTS) is one of the most promising light absorber materials for photovoltaic and photo-electrochemical applications. We synthesized CZTS thin films on a F:SnO2 and soda lime glass substrates by very simple, cost effective and highly scalable spray pyrolysis technique. The films were post treated by rapid thermal processing route of sulfurization to enhance the stoichiometry and crystallinity of the film. The structural, morphological, optical and electrical properties of RTP sulfurized films were studied. The X-ray diffraction (XRD) pattern revealed the formation of tetragonal CZTS phase, which confirmed by Raman analysis with a major peak at 336 cm-1 without the presence of the principle vibration mode of any other secondary phases, such as Cu2SnS3, CuxS(x=1.8,2) etc. The sulfurized film exhibited increased crystallinity and better stoichiometry. The optical and electrical data reveal the direct optical band gap, bulk carrier concentration and resistivity of 1.5 eV, 2.28×1018 cm-3 and 1.21 Ω/cm2, respectively. Finally the photoactivity of CZTS thin films was tested by forming photoelectrochemical cell in 0.1M Na2S2O3 electrolyte (pH=7.72), showing a cathodic photocurrent of nearly 20 µA/cm2 at 0V RHE.

  8. Natural rubber, a potential alternative source for the synthesis of renewable fuels via Hydrous Pyrolysis

    Science.gov (United States)

    Ahmad, N.; Dayana, S. A. S.; Abnisa, F.; Mohd, W. A. W. D.

    2018-03-01

    Natural rubber is a humid agricultural harvest, which mostly contains hydrocarbon cis-1, 4-Poly isoprene. Through depolymerisation technology, the natural rubber can be changed into liquid product, and then it can be subsequently utilized as a fuel or chemical feedstock. This article aims to provide an outlook on the natural rubber and its sources, which are available globally. Numerous depolymerisation processes, which include pyrolysis, gasification, chemical degradation, catalytic cracking and hydrogenation, were introduced in this paper, while the focus of discussion was emphasized on the hydrous pyrolysis process. Many studies have shown that the use of hydrous pyrolysis able to improve the depolymerisation process, e.g. the raw material can be feed without drying, the process can be carried out at lower temperature, only the water is used as the reaction medium, and it is easy to separate the water from oil product. The effect of operating parameters such as temperature, water to rubber mass ratio, reaction time and type of gases on the product yield and composition were reviewed in this paper. In addition, this paper also highlighted the eco-friendly and economic viability of the hydrous pyrolysis process.

  9. Synthesis of single-walled carbon nanotubes by the pyrolysis of a ...

    Indian Academy of Sciences (India)

    by the increase in the D:G ratio from 0.56 to 0.87 in the Raman spectra and the observation of an average of one carboxylic acid ... Arc-discharge,1,2 laser ablation,4 pyrolysis of iron (II) ... trols diameter size.21 In the current work, Ar gas was.

  10. Synthesis of carbon nanotubes and porous carbons from printed circuit board waste pyrolysis oil

    International Nuclear Information System (INIS)

    Quan Cui; Li Aimin; Gao Ningbo

    2010-01-01

    The possibility and feasibility of using pyrolysis oil from printed circuit board (PCB) waste as a precursor for advanced carbonaceous materials is presented. The PCB waste was first pyrolyzed in a laboratory scale fixed bed reactor at 600 deg. C to prepare pyrolysis oil. The analysis of pyrolysis oil by gas chromatography-mass spectroscopy indicated that it contained a very high proportion of phenol and phenol derivatives. It was then polymerized in formaldehyde solution to synthesize pyrolysis oil-based resin which was used as a precursor to prepare carbon nanotubes (CNTs) and porous carbons. Scanning electron microscopy and transmission microscopy investigation showed that the resulting CNTs had hollow cores with outer diameter of ∼338 nm and wall thickness of ∼86 nm and most of them were filled with metal nanoparticles or nanorods. X-ray diffraction reveals that CNTs have an amorphous structure. Nitrogen adsorption isotherm analysis indicated the prepared porous carbons had a Brunauer-Emmett-Teller surface area of 1214 m 2 /g. The mechanism of the formation of the CNTs and porous carbons was discussed.

  11. Effect of La{sub 0.8}Sr{sub 0.2}MnO{sub 3} powder addition in the precursor solution on the properties of cathode films deposited by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Caio Luis Santos; Rangel, Maria do Carmo, E-mail: clssilva@ufba.br, E-mail: mcarmov@ufba.br [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Grupo de Estudo em Cinetica e Catalise; Gama, Leonardo Marques; Paes Junior, Herval Ramos, E-mail: leonardo.m.gama@gmail.com, E-mail: herval@uenf.br [Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ (Brazil). Laboratorio de Materiais Avancados; Santos, Jacqueline Amanda Figueiredo dos; Domingues, Rosana Zacarias, E-mail: jac.amanda28@gmail.com, E-mail: rosanazd@ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Laboratorio de Materiais e Pilhas a Combustivel

    2017-01-15

    Films of lanthanum strontium manganite, LSM (La{sub 0.8}Sr{sub 0.2}MnO{sub 3}) were deposited on yttria stabilized zirconia (YSZ) substrates by different methods aiming to establish the most suitable route to prepare cathodes for solid oxide fuel cells (SOFC). Samples were obtained by using a solution of lanthanum, strontium and manganese nitrates or a dispersion of the LSM powder in this solution. Both commercial and synthesized LSM powders were used, the last one obtained by amorphous citrate method. The films were deposited by spray pyrolysis on YSZ substrates prepared by uniaxial and isostatic pressing. Samples were characterized by scanning electron microscopy, confocal laser scanning microscopy, X-ray diffraction and two-probe conductivity measurements. The area specific resistance and relaxation to cathodic activation were measured by electrochemical impedance spectroscopy. The substrate obtained by uniaxial pressing and the commercial LSM produced films with the highest amount of surface cracks. The film obtained from the suspension showed area specific resistance and activation energy lower than the other produced from the solution. For both samples, the cathodic activation process resulted in an initial reduction of the total resistance of around 20%, the sample produced from the suspension being more resistant to relaxation. Therefore, the LSM suspension is more suitable than the salts solution for preparing films by spray pyrolysis on YSZ substrates to obtain efficient cathodes for SOFC. (author)

  12. Shape matters: Cr(VI) removal using iron nanoparticle impregnated 1-D vs 2-D carbon nanohybrids prepared by ultrasonic spray pyrolysis

    Science.gov (United States)

    Masud, Arvid; Cui, Yanbin; Atkinson, John D.; Aich, Nirupam

    2018-03-01

    Iron nanoparticles (Fe NPs) are used for treating water contaminated with metals or organic compounds. One-dimensional (1-D) carbon nanotubes (CNTs) and two-dimensional (2-D) graphenes act as useful nanocarbon (NC) supports for Fe NPs by resisting aggregation and enhancing adsorption and redox activity. However, no study showed how shape difference between tubular CNT and planar graphene structures dictates the physicochemical properties and pollutant removal potential of their iron-based nanohybrids. In this work, ultrasonic spray pyrolysis was used to continuously prepare Fe-CNT and Fe-rGO nanohybrids. Both NC shape and Fe/NC ratio influenced Fe NP size, loading, and oxidation states. High Fe content (precursor Fe/NC mass ratio = 2) resulted Fe NPs with diameters of 30.97 ± 7.00 and 24.11 ± 4.42 nm for Fe-CNT and Fe-rGO, respectively; however, low Fe content (Fe/NC = 0.2) provided more uniformly dispersed Fe NPs of 15.65 ± 3.06 and 9.67 ± 1.49 nm, respectively, while unsupported Fe NPs were 285.71 ± 132.42 nm. The USP-derived nanohybrids, for the first time, were used for removal of pollutant, i.e., chromium (Cr(VI)) from aqueous media. Both CNT and rGO provided synergistic effects to significantly enhance Fe NPs' ability to remove Cr(VI); the effect was more pronounced in Fe-rGO than Fe-CNT and also for low Fe content in both cases. Fe-rGO with low Fe/NC ratio and smallest Fe NPs provided the highest Cr(VI) removal capacity (25 mg/g), which was a multifold improvement over bare Fe NPs and other synthesized nanohybrids (range 7-14 mg/g). Overall, 2-D rGO improved contaminant removal capacity of the nanohybrids more than 1-D CNT indicating towards shape effect of NC supports. [Figure not available: see fulltext.

  13. Pt-doped In{sub 2}O{sub 3} nanoparticles prepared by flame spray pyrolysis for NO{sub 2} sensing

    Energy Technology Data Exchange (ETDEWEB)

    Inyawilert, K. [Chiang Mai University, Department of Physics and Materials Science, Faculty of Science (Thailand); Channei, D. [Naresuan University, Department of Chemistry, Faculty of Science (Thailand); Tamaekong, N. [Maejo University, Program in Materials Science, Faculty of Science (Thailand); Liewhiran, C. [Chiang Mai University, Department of Physics and Materials Science, Faculty of Science (Thailand); Wisitsoraat, A.; Tuantranont, A. [National Electronics and Computer Technology Center (NECTEC), Nanoelectronics and MEMS Laboratory (Thailand); Phanichphant, S., E-mail: sphanichphant@gmail.com [Chiang Mai University, Faculty of Science, Materials Science Research Center (Thailand)

    2016-02-15

    Undoped In{sub 2}O{sub 3} and 0.25–1.00 wt% M (M=Pt, Nb, and Ru)-doped/loaded In{sub 2}O{sub 3} nanoparticles were successfully synthesized in a single-step flame spray pyrolysis technique using indium nitrate, platinum (II) acetylacetonate, niobium ethoxide, and ruthenium (III) acetylacetonate precursors. The undoped In{sub 2}O{sub 3} and M-doped In{sub 2}O{sub 3} nanoparticles were characterized by Brunauer–Emmett–Teller (BET) analysis, X-ray diffraction (XRD), and scanning and transmission electron microscopy (SEM & TEM). The BET average diameter of spherical nanoparticles was found to be in the range of 10.2–15.2 nm under 5/5 (precursor/oxygen) flame conditions. All XRD peaks were confirmed to correspond to the cubic structure of In{sub 2}O{sub 3}. TEM images showed that there is no Pt nanoparticle loaded on In{sub 2}O{sub 3} surface, suggesting that Pt should form solid solution with the In{sub 2}O{sub 3} lattice. Gas sensing studies showed that 0.5 wt% Pt doping in In{sub 2}O{sub 3} nanoparticles gave a significant enhancement of NO{sub 2} sensing performances in terms of sensor response and selectivity. 0.5 wt% Pt/In{sub 2}O{sub 3} exhibited a high NO{sub 2} response of ∼1904 to 5 ppm NO{sub 2} at 250 °C and good NO{sub 2} selectivity against NO, H{sub 2}S, H{sub 2}, and C{sub 2}H{sub 5}OH. In contrast, Nb and Ru loading resulted in deteriorated NO{sub 2} response. Therefore, Pt is demonstrated to be an effective additive to enhance NO{sub 2} sensing performances of In{sub 2}O{sub 3}-based sensors.

  14. Cathode materials produced by spray flame synthesis for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Hamid, NoorAshrina Binti A.

    2013-07-03

    Lithium ion batteries are one of the most enthralling rechargeable energy storage systems for portable application due to their high energy density. Nevertheless, with respect to electromobility innovation towards better electrochemical properties such as higher energy and power density is required. Altering the cathode material used in Li-ion batteries is favorable since the mass- and volume performance is closely related to the cathode electrode mass. Instead of using LiCoO{sub 2} as cathode electrode, LiFePO{sub 4} has gained serious attention as this material owns a high theoretical capacity of 170 mAh g{sup -1}. It is non-toxic, cheap and consists of abundant materials but suffers from low electronic and ionic conductivity. Utilization of nanotechnology methods in combination with composite formation is known to cure this problem effectively. In this work, a new combination of techniques using highly scalable gas-phase synthesis namely spray-flame synthesis and subsequent solid-state reaction has been used to synthesize nanocomposite LiFePO{sub 4}/C. At first this work deals with the formation and characterization of nanosize FePO{sub 4} from a solution of iron(III)acetylacetonate and tributyl phosphate in toluene using spray-flame synthesis. It was shown that a subsequent solid state reaction with Li{sub 2}CO{sub 3} and glucose yielded a LiFePO{sub 4}/C nanocomposite with very promising electrochemical properties. Based on these initial findings the influence of two synthesis parameter - carbon content and annealing temperature - was investigated towards the physicochemical properties of LiFePO{sub 4}/C. It was shown that an annealing temperature of 700 C leads to high purity composite materials consisting of crystalline LiFePO{sub 4} with crystallite sizes well below 100 nm and amorphous carbon consisting of disordered and graphite-like carbon. Variation of glucose amount between 10 and 30 wt% resulted in carbon contents between 2.1 and 7.3 wt%. In parallel

  15. Cathode materials produced by spray flame synthesis for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Hamid, NoorAshrina Binti A.

    2013-07-03

    Lithium ion batteries are one of the most enthralling rechargeable energy storage systems for portable application due to their high energy density. Nevertheless, with respect to electromobility innovation towards better electrochemical properties such as higher energy and power density is required. Altering the cathode material used in Li-ion batteries is favorable since the mass- and volume performance is closely related to the cathode electrode mass. Instead of using LiCoO{sub 2} as cathode electrode, LiFePO{sub 4} has gained serious attention as this material owns a high theoretical capacity of 170 mAh g{sup -1}. It is non-toxic, cheap and consists of abundant materials but suffers from low electronic and ionic conductivity. Utilization of nanotechnology methods in combination with composite formation is known to cure this problem effectively. In this work, a new combination of techniques using highly scalable gas-phase synthesis namely spray-flame synthesis and subsequent solid-state reaction has been used to synthesize nanocomposite LiFePO{sub 4}/C. At first this work deals with the formation and characterization of nanosize FePO{sub 4} from a solution of iron(III)acetylacetonate and tributyl phosphate in toluene using spray-flame synthesis. It was shown that a subsequent solid state reaction with Li{sub 2}CO{sub 3} and glucose yielded a LiFePO{sub 4}/C nanocomposite with very promising electrochemical properties. Based on these initial findings the influence of two synthesis parameter - carbon content and annealing temperature - was investigated towards the physicochemical properties of LiFePO{sub 4}/C. It was shown that an annealing temperature of 700 C leads to high purity composite materials consisting of crystalline LiFePO{sub 4} with crystallite sizes well below 100 nm and amorphous carbon consisting of disordered and graphite-like carbon. Variation of glucose amount between 10 and 30 wt% resulted in carbon contents between 2.1 and 7.3 wt%. In parallel

  16. Characteristics of CuIn{sub 1−x}Ga{sub x}S{sub 2} thin films synthesized by chemical spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Ajili, Mejda, E-mail: ajili.mejda@yahoo.fr [Laboratoire de Physique de la Matière Condensée, Faculté des Sciences de Tunis, Tunis El Manar 2092 (Tunisia); Castagné, Michel [Institut d’Electronique du Sud, Université de Montpellier II, Sciences et Techniques du Languedoc, case courrier 083. Place Eugène BATAILLON, 34 095 Montpellier cedex 05 (France); Kamoun Turki, Najoua [Laboratoire de Physique de la Matière Condensée, Faculté des Sciences de Tunis, Tunis El Manar 2092 (Tunisia)

    2014-06-01

    CuIn{sub 1−x}Ga{sub x}S{sub 2} multi-component semiconductors thin films were prepared by chemical spray pyrolysis on glass substrates using different concentrations of gallium in the spray solutions (y=([Ga{sup 3+}]/[In{sup 3+}]) varying from 0 to 20 at% by a step of 5 at%). Samples were characterized using X-ray diffraction, Raman spectroscopy, Atomic Force Microscopy, photoluminescence spectroscopy, spectrophotometric and Hall effect measurements. The X-ray spectra reveal that the CuIn{sub 1−x}Ga{sub x}S{sub 2} thin films are of chalcopyrite crystalline phase with a highly (1 1 2) preferential orientation. The best crystallinity is obtained for 10 at% Ga incorporation since the maximum (1 1 2) peak intensity and grain size are obtained at this Ga incorporation rate. The level of the residual microstrain and dislocation network seems to be reduced respectively to the values 0.09% and 4×10{sup 8} lines mm{sup −2} for an optimum y=10 at% for which the crystallinity of CuIn{sub 1−x}Ga{sub x}S{sub 2} thin layers is the best one. Raman spectra indicate that the sprayed thin films are grown only with CH-ordering. Optical analysis by means of transmission T(λ) and reflection R(λ) measurements allow us to determine the direct band gap energy value which increases by increasing the Ga content and it is in the range 1.39–1.53 eV, indicating that CuIn{sub 1−x}Ga{sub x}S{sub 2} compound has an absorbing property favorable for applications in solar cell devices. Photoluminescence measurements are performed on CuIn{sub 1−x}Ga{sub x}S{sub 2} crystals and the analysis reveals that the emission is mainly due to donor–acceptor pair transitions. The film resistivity (ρ) and Hall mobility (μ) are strongly affected by Ga incorporation rate. The lowest resistivity (ρ=0.1 Ω cm) and maximum value of Hall mobility (μ=0.5 cm{sup 2} V{sup −1} s{sup −1}) are also obtained for the thin layers prepared with y=10 at%. Finally, we reported two new structures for Cu

  17. Spray-combustion synthesis: efficient solution route to high-performance oxide transistors.

    Science.gov (United States)

    Yu, Xinge; Smith, Jeremy; Zhou, Nanjia; Zeng, Li; Guo, Peijun; Xia, Yu; Alvarez, Ana; Aghion, Stefano; Lin, Hui; Yu, Junsheng; Chang, Robert P H; Bedzyk, Michael J; Ferragut, Rafael; Marks, Tobin J; Facchetti, Antonio

    2015-03-17

    Metal-oxide (MO) semiconductors have emerged as enabling materials for next generation thin-film electronics owing to their high carrier mobilities, even in the amorphous state, large-area uniformity, low cost, and optical transparency, which are applicable to flat-panel displays, flexible circuitry, and photovoltaic cells. Impressive progress in solution-processed MO electronics has been achieved using methodologies such as sol gel, deep-UV irradiation, preformed nanostructures, and combustion synthesis. Nevertheless, because of incomplete lattice condensation and film densification, high-quality solution-processed MO films having technologically relevant thicknesses achievable in a single step have yet to be shown. Here, we report a low-temperature, thickness-controlled coating process to create high-performance, solution-processed MO electronics: spray-combustion synthesis (SCS). We also report for the first time, to our knowledge, indium-gallium-zinc-oxide (IGZO) transistors having densification, nanoporosity, electron mobility, trap densities, bias stability, and film transport approaching those of sputtered films and compatible with conventional fabrication (FAB) operations.

  18. Synthesis Characterization and Decomposition Studies of tris[N-N-dibenzyidithocarbaso)Indium (III) Chemical Spray Deposition of Polycrystalline CuInS2 on Copper Films

    Science.gov (United States)

    Hehemann, David G.; Lau, J. Eva; Harris, Jerry D.; Hoops, Michael D.; Duffy, Norman V.

    2005-01-01

    This paper presents the results of the synthesis characterization and decomposition studies of tris[N-N-dibenzyidithocarbaso)Indium (III) with chemical spray deposition of polycrystalline CuInS2 on Copper Films.

  19. Dual Layer Monolith ATR of Pyrolysis Oil for Distributed Synthesis Gas Production

    Energy Technology Data Exchange (ETDEWEB)

    Lawal, Adeniyi [Stevens Institute of Technology, Castle Point Hoboken NJ 07030

    2012-09-29

    We have successfully demonstrated a novel reactor technology, based on BASF dual layer monolith catalyst, for miniaturizing the autothermal reforming of pyrolysis oil to syngas, the second and most critical of the three steps for thermochemically converting biomass waste to liquid transportation fuel. The technology was applied to aged as well as fresh samples of pyrolysis oil derived from five different biomass feedstocks, namely switch-grass, sawdust, hardwood/softwood, golden rod and maple. Optimization of process conditions in conjunction with innovative reactor system design enabled the minimization of carbon deposit and control of the H2/CO ratio of the product gas. A comprehensive techno-economic analysis of the integrated process using in part, experimental data from the project, indicates (1) net energy recovery of 49% accounting for all losses and external energy input, (2) weight of diesel oil produced as a percent of the biomass to be ~14%, and (3) for a demonstration size biomass to Fischer-Tropsch liquid plant of ~ 2000 daily barrels of diesel, the price of the diesel produced is ~$3.30 per gallon, ex. tax. However, the extension of catalyst life is critical to the realization of the projected economics. Catalyst deactivation was observed and the modes of deactivation, both reversible and irreversible were identified. An effective catalyst regeneration strategy was successfully demonstrated for reversible catalyst deactivation while a catalyst preservation strategy was proposed for preventing irreversible catalyst deactivation. Future work should therefore be focused on extending the catalyst life, and a successful demonstration of an extended (> 500 on-stream hours) catalyst life would affirm the commercial viability of the process.

  20. Structural properties of In2Se3 precursor layers deposited by spray pyrolysis and physical vapor deposition for CuInSe2 thin-film solar cell applications

    International Nuclear Information System (INIS)

    Reyes-Figueroa, P.; Painchaud, T.; Lepetit, T.; Harel, S.; Arzel, L.; Yi, Junsin; Barreau, N.; Velumani, S.

    2015-01-01

    The structural properties of In 2 Se 3 precursor thin films grown by chemical spray pyrolysis (CSP) and physical vapor deposition (PVD) methods were compared. This is to investigate the feasibility to substitute PVD process of CuInSe 2 (CISe) films by CSP films as precursor layer, thus decreasing the production cost by increasing material-utilization efficiency. Both films of 1 μm thickness were deposited at the same substrate temperature of 380 °C. X-ray diffraction and Raman spectra confirm the formation of γ-In 2 Se 3 crystalline phase for both films. The PVD and CSP films exhibited (110) and (006) preferred orientations, respectively. The PVD films showed a smaller full width at half maximum value (0.09°) compared with CSP layers (0.1°). Films with the same crystalline phase but with different orientations are normally used in the preparation of high quality CISe films by 3-stage process. Scanning electron microscope cross-section images showed an important difference in grain size with well-defined larger grains of size 1–2 μm in the PVD films as compared to CSP layers (600 nm). Another important characteristic that differentiates the two precursor films is the oxygen contamination. X-ray photoelectron spectroscopy showed the presence of oxygen in CSP films. The oxygen atoms could be bonded to indium by replacing Se vacancies, which are formed during CSP deposition. Taking account of the obtained results, such CSP films can be used as precursor layer in a PVD process in order to produce CISe absorber films. - Highlights: • To find the intricacies involved in spray pyrolysis (CSP) and physical vapor (PVD) deposition. • Comparison of CSP and PVD film formations — especially in structural properties. • Feasibility to substitute CSP (cheaper) films for PVD in the manufacturing process. • Decreasing the global production cost of Cu(In,Ga)Se 2 devices in the 3-stage process

  1. Flame spray synthesis under a non-oxidizing atmosphere: Preparation of metallic bismuth nanoparticles and nanocrystalline bulk bismuth metal

    Energy Technology Data Exchange (ETDEWEB)

    Grass, Robert N.; Stark, Wendelin J. [Institute for Chemical and Bioengineering, ETH Zuerich (Switzerland)], E-mail: wendelin.stark@chem.ethz.ch

    2006-10-15

    Metallic bismuth nanoparticles of over 98% purity were prepared by a modified flame spray synthesis method in an inert atmosphere by oxygen-deficient combustion of a bismuth-carboxylate based precursor. The samples were characterized by X-ray diffraction, thermal analysis and scanning electron microscopy confirming the formation of pure, crystalline metallic bismuth nanoparticles. Compression of the as-prepared powder resulted in highly dense, nanocrystalline pills with strong electrical conductivity and bright metallic gloss.

  2. Quantum-dot-sensitized solar cells fabricated by the combined process of the direct attachment of colloidal CdSe quantum dots having a ZnS glue layer and spray pyrolysis deposition.

    Science.gov (United States)

    Im, Sang Hyuk; Lee, Yong Hui; Seok, Sang Il; Kim, Sung Woo; Kim, Sang-Wook

    2010-12-07

    We were able to attach CdSe quantum dots (QDs) having a ZnS inorganic glue layer directly to a mesoporous TiO(2) (mp-TiO(2)) surface by spray coating and thermal annealing. Quantum-dot-sensitized solar cells based on CdSe QDs having ZnS as the inorganic glue layer could easily transport generated charge carriers because of the intimate bonding between CdSe and mp-TiO(2). The application of spray pyrolysis deposition (SPD) to obtain additional CdSe layers improved the performance characteristics to V(oc) = 0.45 V, J(sc) = 10.7 mA/cm(2), fill factor = 35.8%, and power conversion efficiency = 1.7%. Furthermore, ZnS post-treatment improved the device performance to V(oc) = 0.57 V, J(sc) = 11.2 mA/cm(2), fill factor = 35.4%, and power conversion efficiency = 2.2%.

  3. Synthesis, microstructure and mechanical properties of ceria stabilized tetragonal zirconia prepared by spray drying technique

    International Nuclear Information System (INIS)

    Sharma, S.C.; Gokhale, N.M.; Dayal, Rajiv; Lazl, Ramji

    2002-01-01

    Ceria stabilized zirconia powders with ceria concentration varying from 6 to 16 mol% were synthesized using spray drying technique. Powders were characterized for their particle size distribution and specific surface area. The dense sintered ceramics fabricated using these powders were characterized for their microstructure, crystallite size and phase composition. The flexural strength, fracture toughness and micro-hardness of sintered ceramics were measured. High fracture toughness and flexural strength were obtained for sintered bodies with 12 mol% of CeO 2 . Flexural strength and fracture toughness were dependent on CeO 2 concentration, crystallite size and phase composition of sintered bodies. Correlation of data has indicated that the transformable tetragonal phase is the key factor in controlling the fracture toughness and strength of ceramics. It has been demonstrated that the synthesis method is effective to prepare nanocrystalline tetragonal ceria stabilized zirconia powders with improved mechanical properties. Ce-ZrO 2 with 20 wt% alumina was also prepared with flexural strength, 1200 MPa and fracture toughness 9.2 MPa√m. (author)

  4. Synthesis, characterization and gas sensing performance of SnO2 ...

    Indian Academy of Sciences (India)

    Synthesis, characterization and gas sensing performance of SnO2 thin films prepared by spray pyrolysis. GANESH E PATIL, D D KAJALE, D N CHAVAN†, N K PAWAR††, P T AHIRE, S D SHINDE#,. V B GAIKWAD# and G H JAIN. ∗. Materials Research Laboratory, Arts, Commerce and Science College, Nandgaon 423 106, ...

  5. Characterization of Lanthanum Ferric Cobaltite doped with Strontium (LSCF) films deposited by spray-pyrolysis for application as cathode in PaCOS-TI; Caracterizacao de filmes de CFLE depositados por spray-pirolise para utilizacao como catodo em PaCOS-TI

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, L.S.; Guimaraes, V.F.; Paes Junior, H.R. [Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ (Brazil). Lab. de Materiais Avancados], Emails: laryssadsa@yahoo.com.br, valtencyguimaraes@yahoo.com.br, herval@uenf.br

    2010-07-01

    The lanthanum ferric cobaltite doped with strontium (LSCF) is a ceramic material with the perovskite structure that stands out in the field of research for its use as cathode in solid oxide fuel cells at intermediate temperatures (IT-SOFC). The films were synthesized by spray-pyrolysis technique on 8% mol Yttria stabilized zirconia (YSZ) substrates. It was studied the influence of heat treatment temperatures (600-1000 deg C) on the properties of the films under the conditions of treatment during four hours. Samples were tested electrically by measuring the variation of electrical conductivity with temperature, structurally by X-ray diffraction (XRD) and morphologically by scanning electron microscopy (SEM). The films heat treated at 700 deg C for 4 hours showed better performance for application as cathode. (author)

  6. Large-scale synthesis of high-purity well-aligned carbon nanotubes using pyrolysis of iron(II) phthalocyanine and acetylene

    Science.gov (United States)

    Liu, B. C.; Lee, T. J.; Lee, S. H.; Park, C. Y.; Lee, C. J.

    2003-08-01

    Well-aligned carbon nanotubes (CNTs) with high purity have been produced by pyrolysis of iron(II) phthalocyanine and acetylene at 800 °C. The synthesized CNTs have a length of 75 μm and diameters ranging from 20 to 60 nm. The CNTs have a bamboo-like structure and exhibit good crystallinity of graphite sheets. The growth rate of the CNTs was rapidly increased with adding C 2H 2. Our results demonstrate that the proposed growth method is suitable to large-scale synthesis of high-purity well-aligned CNTs on various substrates.

  7. Investigations of structural, morphological and optical properties of Cu:ZnO/TiO2/ZnO and Cu:TiO2/ZnO/TiO2 thin films prepared by spray pyrolysis technique

    Directory of Open Access Journals (Sweden)

    M.I. Khan

    Full Text Available The aim of this research work is presented a comparison study of Cu:ZnO/TiO2/ZnO (Cu:ZTZ and Cu:TiO2/ZnO/TiO2 (Cu:TZT thin films deposited by spray pyrolysis technique on FTO substrates. After deposition, these films are annealed at 500 °C. XRD confirms the anatase phase of TiO2 and Hexagonal wurtzite phase of ZnO. SEM shows that Cu:TZT has more porous surface than Cu:ZTZ and also the root mean square (RMS roughness of Cu:TZT film is 48.96 and Cu:ZTZ film is 32.69. The calculated optical band gaps of Cu:TZT and Cu:ZTZ thin films are 2.65 eV and 2.6 eV respectively, measured by UV–Vis spectrophotometer. This work provides an environment friendly and low cost use of an abundant material for highly efficient dye sensitized solar cells (DSSCs. Keywords: Multilayer films, ZnO, TiO2, Cu

  8. Nanostructured thin film La{sub 0.6}Sr{sub 0.4}CoO{sub 3-δ} synthesized via salt-assisted spray pyrolysis for micro-SOFC application

    Energy Technology Data Exchange (ETDEWEB)

    Benel, Cahit; Darbandi, Azad J. [Institute for Nanotechnology, Karlsruhe Institute of Technology (Germany); Joint Research Laboratory Nanomaterials/Technische Universitaet Darmstadt and Karlsruhe Institute of Technology (Germany); Center for Functional Nanostructures, Karlsruhe Institute of Technology (Germany); Evans, Anna; Toelke, Rene [Nonmetallic Inorganic Materials, Department of Materials, ETH Zurich (Switzerland); Hahn, Horst [Institute for Nanotechnology, Karlsruhe Institute of Technology (Germany); Joint Research Laboratory Nanomaterials/Technische Universitaet Darmstadt and Karlsruhe Institute of Technology (Germany)

    2012-07-01

    Micro-solid oxide fuel cells (micro-SOFCs) are anticipated for battery replacement due to their increased energy capacity for applications such as portable electronic devices, mobile phones and laptops. In this work, nanocrystalline La{sub 0.6}Sr{sub 0.4}CoO{sub 3-δ} (LSC) powder with ultrafine microstructure and high specific surface area was synthesized via salt-assisted spray pyrolysis method. XRD results show the formation of a nanocrystalline single phase perovskite structure. Agglomerate-free LSC nanoparticles were stabilized in water-based dispersion without the need of ultrasonic energy application. Nanoparticulate cathode thin films of LSC with thickness between 150 and 500 nm were prepared via single step spin coating on yttria stabilized zirconia (YSZ) substrates. Gadolinium doped ceria (GDC) film was applied to YSZ substrate to avoid the chemical reaction between cathode and electrolyte. The performance of the thin film cathodes was evaluated by high temperature impedance spectroscopy on symmetrical samples.

  9. Effects of the precursor concentration and different annealing ambients on the structural, optical, and electrical properties of nanostructured V2O5 thin films deposited by spray pyrolysis technique

    Science.gov (United States)

    Irani, Rowshanak; Rozati, Seyed Mohammad; Beke, Szabolcs

    2018-04-01

    V2O5 thin films were deposited with different precursor concentrations of 0.01, 0.05, and 0.1 M on glass substrates by spray pyrolysis technique, then the optimized films were annealed in different ambients (air, oxygen, and vacuum). The results showed that by increasing the concentration, the films grew along the (001) direction with an orthorhombic structure. Field emission scanning electron microscopy showed that nanorods were formed when depositing 0.05 molar of VCl3. We conclude that with the precursor concentration, the surface nanostructure can be well-controlled. Annealing improved the crystallinity under all ambients, but the best crystallinity was achieved in vacuum. It was revealed that the as-deposited films had the highest transmission, whereas the films annealed in air had the lowest. When annealed in air, the optical band gap decreased from 2.45 to 2.32 eV. The sheet resistance, resistivity, mobility, conductivity, and carrier concentration were measured for all the prepared V2O5 films.

  10. Extremely fine structured cathode for solid oxide fuel cells using Sr-doped LaMnO3 and Y2O3-stabilized ZrO2 nano-composite powder synthesized by spray pyrolysis

    Science.gov (United States)

    Shimada, Hiroyuki; Yamaguchi, Toshiaki; Sumi, Hirofumi; Nomura, Katsuhiro; Yamaguchi, Yuki; Fujishiro, Yoshinobu

    2017-02-01

    A solid oxide fuel cell (SOFC) for high power density operation was developed with a microstructure-controlled cathode using a nano-composite powder of Sr-doped LaMnO3 (LSM) and Y2O3-stabilized ZrO2 (YSZ) synthesized by spray pyrolysis. The individual LSM-YSZ nano-composite particles, formed by crystalline and amorphous nano-size LSM and YSZ particles, showed spherical morphology with uniform particle size. The use of this powder for cathode material led to an extremely fine microstructure, in which all the LSM and YSZ grains (approximately 100-200 nm) were highly dispersed and formed their own network structures. This microstructure was due to the two phase electrode structure control using the powder, namely, nano-order level in each particle and micro-order level between particles. An anode-supported SOFC with the LSM-YSZ cathode using humidified H2 as fuel and ambient air as oxidant exhibited high power densities, such as 1.29 W cm-2 under a voltage of 0.75 V and a maximum power density of 2.65 W cm-2 at 800 °C. Also, the SOFC could be stably operated for 250 h with no degradation, even at a high temperature of 800 °C.

  11. Effect of Al-doped on physical properties of ZnO Thin films grown by spray pyrolysis on SnO2: F/glass

    Directory of Open Access Journals (Sweden)

    Castagné M.

    2012-06-01

    Full Text Available Transparent conducting thin films of aluminum-doped zinc oxide (ZnO:Al have been deposited on SnO2:F/glass by the chemical spray technique, starting from zinc acetate (CH3CO22Zn.2H2O and aluminum chloride AlCl3. The effect of changing the aluminum-to-zinc ratio y from 0 to 3 at.%, has been thoroughly investigated. It was found that the optical and electrical properties of Al doped ZnO films improved with the addition of aluminum in the spray solution until y=2%. At this Al doping percentage, the thin layers have a resistivity equal to 4.1 × 10−4 Ω.cm and a transmittance of about 90 % in the region [600-1000] nm. XRD patterns confirm that the films have polycristalline nature and a wurtzite (hexagonal structure which characterized with (100, (002 and (101 principal orientations. The undoped films have (002 as the preferred orientation but Al doped ones have (101 as the preferred orientation. Beyond y= 1%, peak intensities decrease considerably.

  12. Roughness-based monitoring of transparency and conductivity in boron-doped ZnO thin films prepared by spray pyrolysis

    International Nuclear Information System (INIS)

    Gaikwad, Rajendra S.; Bhande, Sambhaji S.; Mane, Rajaram S.; Pawar, Bhagwat N.; Gaikwad, Sanjay L.; Han, Sung-Hwan; Joo, Oh-Shim

    2012-01-01

    Graphical abstract: Display Omitted Highlights: ► We report surface roughness dependent transparency and conductivity in ZnO films. ► The surface roughness with respected to boron doping concentrations is studied. ► Boron doped and pristine Zinc oxide thin films have showed ≥95% transmittance. ► Increased carrier concentration of 9.21 × 10 21 cm −3 revealed from Hall measurement. -- Abstract: Sprayed polycrystalline ZnO and boron-doped ZnO thin films composed of spherical grains of 25–32 nm in diameters are used in roughness measurement and further correlated with the transparency and the conductivity characteristics. The surface roughness is increased up to Zn 0.98 B 0.02 O and then declined at higher boron concentrations. The sprayed ZnO films revealed ≥95% transmittance in the visible wavelength range, 1.956 × 10 −4 Ω cm electrical resistivity, 46 cm 2 /V s Hall mobility and 9.21 × 10 21 cm −3 charge carrier concentration. The X-ray photoelectron spectroscopy study has confirmed 0.15 eV binding energy change for Zn 2p 3/2 when 2 at% boron content is mixed without altering electro-optical properties substantially. Finally, using soft modeling importance of these textured ZnO over non-textured films for enhancing the solar cells performance is explored.

  13. Plasma-spraying synthesis of high-performance photocatalytic TiO2 coatings

    International Nuclear Information System (INIS)

    Takahashi, Yasuo; Maeda, Masakatsu; Ohmori, Akira; Shibata, Yoshitaka; Miyano, Yasuyuki; Murai, Kensuke

    2014-01-01

    Anatase (A-) TiO 2 is a photocatalytic material that can decompose air-pollutants, acetaldehyde, bacteria, and so on. In this study, three kinds of powder (A-TiO 2 without HAp, TiO 2 + 10mass%HAp, and TiO 2 +30mass%HAp, where HAp is hydroxyapatite and PBS is polybutylene succinate) were plasma sprayed on biodegradable PBS substrates. HAp powder was mixed with A-TiO 2 powder by spray granulation in order to facilitate adsorption of acetaldehyde and bacteria. The crystal structure was almost completely maintained during the plasma spray process. HAp enhanced the decomposition of acetaldehyde and bacteria by promoting adsorption. A 10mass% HAp content was the most effective for decomposing acetaldehyde when plasma preheating of the PBS was not carried out before the plasma spraying. The plasma preheating of PBS increased the yield rate of the spray process and facilitated the decomposition of acetaldehyde by A-TiO 2 coatings without HAp. HAp addition improved photocatalytic sterilization when plasma preheating of the PBS was performed

  14. Direct Synthesis of Fe3C-Functionalized Graphene by High Temperature Autoclave Pyrolysis for Oxygen Reduction

    DEFF Research Database (Denmark)

    Hu, Yang; Jensen, Jens Oluf; Zhang, Wei

    2014-01-01

    We present a novel approach to direct fabrication of few-layer graphene sheets with encapsulated Fe3C nanoparticles from pyrolysis of volatile non-graphitic precursors without any substrate. This one-step autoclave approach is facile and potentially scalable for production. Tested as an electroca...

  15. Flash pyrolysis at high temperature of ligno-cellulosic biomass and its components - production of synthesis gas; Pyrolyse flash a haute temperature de la biomasse ligno-cellulosique et de ses composes - production de gaz de synthese

    Energy Technology Data Exchange (ETDEWEB)

    Couhert, C

    2007-11-15

    Pyrolysis is the first stage of any thermal treatment of biomass and governs the formation of synthesis gas for the production of electricity, hydrogen or liquid fuels. The objective of this work is to establish a link between the composition of a biomass and its pyrolysis gas. We study experimental flash pyrolysis and fix the conditions in which quantities of gas are maximal, while aiming at a regime without heat and mass transfer limitations (particles about 100 {mu}m): temperature of 950 C and residence time of about 2 s. Then we try to predict gas yields of any biomass according to its composition, applicable in this situation where thermodynamic equilibrium is not reached. We show that an additivity law does not allow correlating gas yields of a biomass with fractions of cellulose, hemi-cellulose and lignin contained in this biomass. Several explanations are suggested and examined: difference of pyrolytic behaviour of the same compound according to the biomass from which it is extracted, interactions between compounds and influence of mineral matter. With the aim of industrial application, we study pyrolysis of millimetric and centimetric size particles, and make a numerical simulation of the reactions of pyrolysis gases reforming. This simulation shows that the choice of biomass affects the quantities of synthesis gas obtained. (author)

  16. Organic Analysis of Catalytic Fischer-Tropsch Synthesis Products and Ordinary Chondrite Meteorites by Stepwise Pyrolysis-GCMS: Organics in the Early Solar Nebula

    Science.gov (United States)

    Locke, Darren R.; Yazzie, Cyriah A.; Burton, Aaron S.; Niles, Paul B.; Johnson, Natasha M.

    2014-01-01

    Abiotic generation of complex organic compounds, in the early solar nebula that formed our solar system, is hypothesized by some to occur via Fischer-Tropsch (FT) synthesis. In its simplest form, FT synthesis involves the low temperature (300degC) produces FT products that include lesser amounts of n-alkanes and greater alkene, alcohol, and polycyclic aromatic hydrocarbon (PAH) compounds. We have begun to experimentally investigate FT synthesis in the context of abiotic generation of organic compounds in the early solar nebula. It is generally thought that the early solar nebula included abundant hydrogen and carbon monoxide gases and nano-particulate matter such as iron and metal silicates that could have catalyzed the FT reaction. The effect of FT reaction temperature, catalyst type, and experiment duration on the resulting products is being investigated. These solid organic products are analyzed by thermal-stepwise pyrolysis-GCMS and yield the types and distribution of hydrocarbon compounds released as a function of temperature. We show how the FT products vary by reaction temperature, catalyst type, and experimental duration and compare these products to organic compounds found to be indigenous to ordinary chondrite meteorites. We hypothesize that the origin of organics in some chondritic meteorites, that represent an aggregation of materials from the early solar system, may at least in part be from FT synthesis that occurred in the early solar nebula.

  17. Prikaz knjige Srećka Stopića: Sinteza nanočestica metala ultrazvučnim raspršivanjem u uslovima pirolize / Review of a book by Srećko Stopić: Synthesis of metallic nanosized particles by ultrasonic spray pyrolysis / Обзор книги Сречка Стопича «Синтез наночастиц металлов ультразвуковым распылительным пиролизом»

    Directory of Open Access Journals (Sweden)

    Milena D. Stopić

    2015-10-01

    Full Text Available Nanotechnology belongs to the key innovative technologies for powder production. Ultrasonic spray pyrolysis is a versatile method for the formation of nanosized particles of metals, oxides and composites. This work deals with Ag, Cu and Au nanoparticles formed by ultrasonic spray pyrolysis using the horizontal and vertical reactor. Furthermore, a direct synthesis of Ru-TiO2 and RuO2-TiO2 nanoparticles with the core and shell structure was investigated. The molar fractions of precursors, solvent type, and the process temperature play the crucial role in the formation of core and shell structures. Moreover, the influence of the reaction parameters (temperature, residence time, solution concentration and ultrasonic frequency on the morphological characteristics of the prepared nanoparticles was studied. A decrease in the solution concentration decreases the final nanoparticle size. An increase in temperature from 150°C to 1000°C leads from an irregular form to a more spherical one. Subsequently, a model of metallic nanoparticle formation from an aerosol droplet could be proposed. Using ultrasonic spray pyrolysis, ideal spherical metallic particles were obtained at temperatures above the melting point. A scanning mobility particle sizer (SMPS was used for the on-line determination of nanoparticle size distribution. The collection of nanosized particles was performed in an electrostatic field. The scale up of the ultrasonic spray pyrolysis method was successfully applied for the synthesis of silver powder from a water solution of silver nitrate. / Нанотехнология является ключевой иновационной технологией в производстве порошковых изделий. Распыление порошков ультразвуковым пиролизом имеет широкое применение в сфере образования частиц нанопорошковых металлов,

  18. α-MoO3 thin films prepared by spray pyrolysis Películas delgadas de α-MoO3 preparadas por atomización pirolítica

    Directory of Open Access Journals (Sweden)

    L D López-Carreño

    2011-12-01

    Full Text Available MoO3 thin films have been deposited on clean glass slides using the spray pyrolysis technique. The samples were grown with different thicknesses by spraying on common glass substrates a solution of(ammoniummolybdatetetrahydrate ((NH36Mo7O244H2O. The samples were characterized by X-ray diffraction (XRD, infrared spectroscopy, scanning electron microscopy (SEM and electrically through electrical resistivity measurements as a function of temperature. It was found that samples present crystalline structure associated with the alpha phase of MoO3 grown with preferential direction of growth along the planes (0k0. As result of increasing the volume of precursor solution sample surface becomes porous. The change in electrical resistance of MoO3 films by exposure to carbon monoxide (CO at room temperature, makes the films obtained by this technique could be promising in its use in gas sensing devices at room temperature.En este trabajo se prepararon películas delgadas de trióxido de molibdeno (MoO3 por la técnica de atomización pirolítica. Las películas fueron depositadas sobre sustratos de vidrio y obtenidas a partir de una solución precursora de Heptamolibdato de Amonio Tetrahidratado ((NH36Mo7O24.4H2O 0.1 M. La temperatura del sustrato se mantuvo constante en 400 oC y se varío el volumen de la solución precursora. Las muestras se caracterizaron por difracción de Rayos X (XRD, espectroscopía infrarroja, Microscopía Electrónica de Barrido (SEM y eléctricamente a través de medidas de resistividad eléctrica en función de la temperatura. Las muestras crecen con estructura cristalina correspondiente a la fase alfa del MoO3 con dirección preferencial de crecimiento a lo largo de los planos (0k0. Al aumentar el volumen de la solución precursora la superficie de las muestras se vuelve porosa. La resistividad en estas muestras cambia en un orden de magnitud cuando son expuestas a la atmosfera de CO.

  19. Effect of Zn/Sn molar ratio on the microstructural and optical properties of Cu2Zn1-xSnxS4 thin films prepared by spray pyrolysis technique

    Science.gov (United States)

    Thiruvenkadam, S.; Prabhakaran, S.; Sujay Chakravarty; Ganesan, V.; Vasant Sathe; Santhosh Kumar, M. C.; Leo Rajesh, A.

    2018-03-01

    Quaternary kesterite Cu2ZnSnS4 (CZTS) compound is one of the most promising semiconductor materials consisting of abundant and eco-friendly elements for absorption layer in thin film solar cells. The effect of Zn/Sn ratio on Cu2Zn1-xSnxS4 (0 ≤ x ≤ 1) thin films were studied by deposited by varying molar volumes in the precursor solution of zinc and tin was carried out in proportion of (1-x) and x respectively onto soda lime glass substrates kept at 573 K by using chemical spray pyrolysis technique. The GIXRD pattern revealed that the films having composites of Cu2ZnSnS4, Cu2SnS3, Sn2S3, CuS and ZnS phases. The crystallinity and grain size were found to increase by increasing the x value and the preferential orientation along (103), (112), (108) and (111) direction corresponding to CZTS, Cu2SnS3, CuS, and ZnS phases respectively. Micro-Raman spectra exposed a prominent peak at 332 cm-1 corresponding to the CZTS phase. Atomic force microscopy was employed to study the grain size and roughness of the deposited thin films. The optical band gap was found to lie between 1.45 and 2.25 eV and average optical absorption coefficient was found to be greater than 105 cm-1. Hall measurements exhibited that all the deposited Cu2Zn1-xSnxS4 films were p type and the resistivity lies between 10.9 ×10-2Ωcm and 149.6 × 10-2Ωcm .

  20. Synthesis of complex oxides with garnet structure by spray drying of an aqueous salt solution

    Science.gov (United States)

    Makeenko, A. V.; Larionova, T. V.; Klimova-Korsmik, O. G.; Starykh, R. V.; Galkin, V. V.; Tolochko, O. V.

    2017-04-01

    The use of spray drying to obtain powders of complex oxides with a garnet structure has demonstrated. The processes occurring during heating of the synthesized oxide-salt product, leading to the formation of a material with a garnet structure, have been investigated using DTA, TGA, XPS, and XRD. It has been shown that a single-phase garnet structure of system (Y x Gd(3- x))3Al5O12 can be synthesized over the entire range of compositions.

  1. Solution synthesis of mixed-metal chalcogenide nanoparticles and spray deposition of precursor films

    Science.gov (United States)

    Schulz, Douglas L.; Curtis, Calvin J.; Ginley, David S.

    2000-01-01

    A colloidal suspension comprising metal chalcogenide nanoparticles and a volatile capping agent. The colloidal suspension is made by reacting a metal salt with a chalcogenide salt in an organic solvent to precipitate a metal chalcogenide, recovering the metal chalcogenide, and admixing the metal chalcogenide with a volatile capping agent. The colloidal suspension is spray deposited onto a substrate to produce a semiconductor precursor film which is substantially free of impurities.

  2. Synthesis of Cr-doped CaTiSiO5 ceramic pigments by spray drying

    International Nuclear Information System (INIS)

    Lyubenova, T. Stoyanova; Matteucci, F.; Costa, A.L.; Dondi, M.; Ocana, M.; Carda, J.

    2009-01-01

    Cr-doped CaTiSiO 5 was synthesized by spray drying and conventional ceramic method in order to assess its potential as ceramic pigment. The evolution of the phase composition with thermal treatment was investigated by X-ray powder diffraction (XRPD) and thermal analyses (DTA-TGA-EGA). Powder morphology and particle size distribution were analyzed by scanning electron microscopy (SEM) and laser diffraction, respectively. The color efficiency of pigments was evaluated by optical spectroscopy (UV-vis-NIR) and colorimetric analysis (CIE Lab). Results proved that spray drying is an efficient procedure to prepare highly reactive pigment precursors. The spray-dried powders consist of hollow spherical particles with aggregate size in the 1-10 μm range, developing a brown coloration. Optical spectra reveal the occurrence of Cr(III) and Cr(IV), both responsible for the brown color of this pigment. The former occupies the octahedral site of titanite, in substitution of Ti(IV), while the latter is located at the tetrahedral site, where replaces Si(IV)

  3. Scalable synthesis of mesoporous titania microspheres via spray-drying method.

    Science.gov (United States)

    Pal, Manas; Wan, Li; Zhu, Yongheng; Liu, Yupu; Liu, Yang; Gao, Wenjun; Li, Yuhui; Zheng, Gengfeng; Elzatahry, Ahmed A; Alghamdi, Abdulaziz; Deng, Yonghui; Zhao, Dongyuan

    2016-10-01

    Mesoporous TiO2 has several potential applications due to its unique electronic and optical properties, although its structures and morphologies are typically difficult to tune because of its uncontrollable and fast sol-gel reaction. In this study we have coupled the template-directed-sol-gel-chemistry with the low-cost, scalable, and environmentally benign aerosol (spray-drying) one-pot preparation technique for the fabrication of hierarchically mesoporous TiO2 microspheres and Fe3O4@mesoporous TiO2-x microspheres in a large scale. Parameters during the pre-hydrolysis and spray-drying treatment were varied to successfully control the bead diameter, morphology, monodispersity, surface area and pore size for improving their effectiveness for better application. Unlike to the previous aerosol synthetic approaches, where mainly quite a high temperature gradient with the strict control of spray-drying precursor concentration is implied, our strategy is lying on comparatively low drying temperature with an additional post-ultrasonication (further hydrolysis and condensation) route of the pre-calcined TiO2 samples. As-synthesized mesoporous microspheres have a size distribution from 500nm to 5μm, specific surface areas ranging from 150 to 162m(2)g(-1) and mean pore sizes of several nanometers (4-6nm). Further Fe3O4@mesoporous TiO2-x microspheres were observed to show remarkable selective phosphopeptide-enrichment activity which might have significant importance in disease diagnosis and other biomedical applications. Copyright © 2016. Published by Elsevier Inc.

  4. Iron Oxide Doped Alumina-Zirconia Nanoparticle Synthesis by Liquid Flame Spray from Metal Organic Precursors

    OpenAIRE

    Juha-Pekka Nikkanen; Helmi Keskinen; Mikko Aromaa; Mikael Järn; Tomi Kanerva; Erkki Levänen; Jyrki M. Mäkelä; Tapio Mäntylä

    2008-01-01

    The liquid flame spray (LFS) method was used to make iron oxide doped alumina-zirconia nanoparticles. Nanoparticles were generated using a turbulent, high-temperature (Tmax⁡∼3000 K) H2-O2 flame. The precursors were aluminium-isopropoxide, zirconium-n-propoxide, and ferrocene in xylene solution. The solution was atomized into micron-sized droplets by high velocity H2 flow and introduced into the flame where nanoparticles were formed. The particle morphology, size, phase, and chemical compositi...

  5. Direct synthesis of Fe3 C-functionalized graphene by high temperature autoclave pyrolysis for oxygen reduction.

    Science.gov (United States)

    Hu, Yang; Jensen, Jens Oluf; Zhang, Wei; Huang, Yunjie; Cleemann, Lars N; Xing, Wei; Bjerrum, Niels J; Li, Qingfeng

    2014-08-01

    We present a novel approach to direct fabrication of few-layer graphene sheets with encapsulated Fe3 C nanoparticles from pyrolysis of volatile non-graphitic precursors without any substrate. This one-step autoclave approach is facile and potentially scalable for production. Tested as an electrocatalyst, the graphene-based composite exhibited excellent catalytic activity towards the oxygen reduction reaction in alkaline solution with an onset potential of ca. 1.05 V (vs. the reversible hydrogen electrode) and a half-wave potential of 0.83 V, which is comparable to the commercial Pt/C catalyst. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Synthesis and tribological studies of nanoparticle additives for pyrolysis bio-oil formulated as a diesel fuel

    International Nuclear Information System (INIS)

    Xu, Yufu; Peng, Yubin; Zheng, Xiaojing; Dearn, Karl D.; Xu, Hongming; Hu, Xianguo

    2015-01-01

    The tribological behaviour of pyrolysis bio-oil with a synthesized nano-Lanthanum oxide (La 2 O 3 ) additive was evaluated using a point contact four ball tribometer under different frictional conditions. Results were compared against a micro (μ)-La 2 O 3 additive and an un-additised bio-oil as a control. The results show that nano-La 2 O 3 impregnated bio-oil had better tribological properties than the control groups. Under the operating loads, the optimum nanoparticle concentration within the bio-oil was investigated. At these levels, the combined action of adsorbed bio-oil films on the worn surfaces and the bearing effects of the nano-La 2 O 3 minimized friction and wear. The tribo-mechanisms were ascribed to adhesive wear as a result of lubrication starvation under high loads, and abrasive wear at high rotational speeds as a result of combined deformation and aggregation of the nano-La 2 O 3 particles. - Highlights: • The tribological properties of pyrolysis bio-oil with (μ & n) La 2 O 3 were assessed. • Nano-La 2 O 3 was synthesized with diameters of approximately 20–1000 nm. • Bio-oil w. 1% nano-La 2 O 3 was the optimum additive & concentration for tribological properties. • 1% nano-La 2 O 3 reduced corrosive wear with stable lubrication film for test conditions. • Wear mechanisms were predominately adhesive for higher loads and abrasive for higher speeds

  7. Iron Oxide Doped Alumina-Zirconia Nanoparticle Synthesis by Liquid Flame Spray from Metal Organic Precursors

    Directory of Open Access Journals (Sweden)

    Juha-Pekka Nikkanen

    2008-01-01

    Full Text Available The liquid flame spray (LFS method was used to make iron oxide doped alumina-zirconia nanoparticles. Nanoparticles were generated using a turbulent, high-temperature (Tmax⁡∼3000 K H2-O2 flame. The precursors were aluminium-isopropoxide, zirconium-n-propoxide, and ferrocene in xylene solution. The solution was atomized into micron-sized droplets by high velocity H2 flow and introduced into the flame where nanoparticles were formed. The particle morphology, size, phase, and chemical composition were determined by TEM, XRD, XPS, and N2-adsorption measurements. The collected particulate material consists of micron-sized aggregates with nanosized primary particles. In both doped and undoped samples, tetragonal phase of zirconia was detected in room temperature while alumina was found to be noncrystalline. In the doped powder, Fe was oxidized to Fe2O3. The primary particle size of collected sample was approximately from 6 nm to 40 nm. Doping was observed to increase the specific surface area of the powder from 39 m2/g to 47 m2/g.

  8. Bitumen pyrolysis

    International Nuclear Information System (INIS)

    Braehler, G.; Noll, T.

    2014-01-01

    In the past bitumen was a preferred matrix for the embedding of low and intermediate level radioactive waste: its geological history promised long term stability in final repositories. A great variety of waste has been embedded: technological waste, spent ion exchange resins, concrete, rubble, etc. Liquid waste like evaporator concentrates can be dried and embedded simultaneously in extruders, allowing simple processes and equipment. Unfortunately, during long term intermediate storage the bituminized waste drums proved out being not as stable as expected: a significant number turned out to be no longer acceptable for final disposal, and some of them even needed repacking to enable further intermediate storage. A method to rework such drums with bituminized radioactive waste seems to be urgently needed. Pyrolysis and pyro-hydrolysis (= pyrolysis with water steam added) have a long history for the treatment of organic waste: spent solvent (TBP), spent ion exchange resins, alpha waste (predominantly PVC), etc. Due to its low process temperature and the endothermic character, such processes offer significant safety advantages, as compared to incineration or dissolving in organic solvents. Results of lab-scale investigations and concepts for facilities are presented. (authors)

  9. Synthesis of nanosized metal particles from an aerosol

    Directory of Open Access Journals (Sweden)

    Srećko R. Stopić

    2013-10-01

    Full Text Available The synthesis of metallic nanoparticles from the precursor solution of salts using the ultrasonic spray pyrolysis method was considered in this work. During the control of process parameters (surface tension and density, the concentration of solution, residence time of aerosol in the reactor, presence of additives, gas flow rate, decomposition temperature of aerosol, type of precursor and working atmosphere it is possible to guide the process in order to obtain powders with such a morphology which satisfies more complex requirements for the desired properties of advanced engineering materials.  Significant advance in the improvement of powder characteristics (lower particles sizes, better spheroidity, higher surface area was obtained by the application of the ultrasonic generator for the preparation of aerosols. Ultrasonic spray pyrolysis is performed by the action of a powerful source of ultrasound on the corresponding precursor solution forming the aerosol with a constant droplet size, which depends on the characteristics of liquid and the frequency of ultrasound. The produced aerosols were transported into the hot reactor, which enables the reaction to occur in a very small volume of a particle and formation of  nanosized powder. Spherical, nanosized particles of metals (Cu, Ag, Au, Co were produced with new and improved physical and chemical characteristics at the IME, RWTH Aachen University. The high costs associated with small quantities of produced nanosized particles represent a limitation of the USP-method. Therefore, scale up of the ultrasonic spray pyrolysis was performed as a final target in the synthesis of nanosized powder.

  10. Microstructure and performance of La0.58Sr0.4Co0.2Fe0.8O3−δ cathodes deposited on BaCe0.2Zr0.7Y0.1O3−δ by infiltration and spray pyrolysis

    DEFF Research Database (Denmark)

    Ricote, Sandrine; Bonanos, Nikolaos; Rørvik, Per Martin

    2012-01-01

    . The area specific resistances obtained are 0.61Ωcm2 and 0.89Ωcm2 at 600°C for the spray-pyrolyzed LSCF cell in dry and humidified air, respectively; the corresponding resistances are 0.63Ωcm2 and 0.98Ωcm2 for the 12 times infiltrated LSCF cell. These resistances are the lowest reported for LSCF cathodes...... from a solution, infiltrated into a screen-printed BZCY27 porous backbone (4 and 12 infiltrations), and one prepared by spray pyrolysis onto a polished electrolyte. In all three cases, LSCF is obtained after annealing at 700°C for 2h. Analysis of the electrochemical impedance spectra between 450°C...... and 600°C in air, with varying p(H2O), reveals that the charge transfer contribution is the lowest for the backbone-infiltrated cathode while the oxygen dissociation/adsorption contribution is the lowest for the spray-pyrolyzed cathode. The area specific resistances increase with the water vapor pressure...

  11. Application of the laser pyrolysis to the synthesis of SiC, TiC and ZrC pre-ceramics nano-powders

    International Nuclear Information System (INIS)

    Leconte, Y.; Maskrot, H.; Combemale, L.; Herlin-Boime, N.; Reynaud, C.

    2007-01-01

    Refractory carbide nano-structured ceramics appear to be promising materials for high temperature applications requiring hard materials such as nuclear energy industry. Such carbide materials are usually obtained with micrometric sizes from the high temperature carbo-reduction of an oxide phase in a raw mixture of C black and titania or zirconia. TiC and ZrC nano-powders were produced from an intimate mixture of oxide nano-grains with free C synthesized by laser pyrolysis from the decomposition of a liquid precursor. The temperature and the duration of the thermal treatment leading to the carburization were decreased, allowing the preservation of the nano-scaled size of the starting grains. A solution of titanium iso-prop-oxide was laser-pyrolyzed with ethylene as sensitizer in order to synthesize Ti/C/O powders. These powders were composed of crystalline TiO 2 nano-grains mixed with C. Annealing under argon enabled the formation of TiC through the carburization of TiO 2 by free C. The final TiC mean grain size was about 80 nm. Zr/O/C powders were prepared from a solution of zirconium butoxide and were composed of ZrO 2 crystalline nano-grains and free C. The same thermal treatment as for TiC, but at higher temperature, showed the formation of crystalline ZrC with a final mean grain size of about 40 nm. These two liquid routes of nano-particles synthesis are also compared to the very efficient gaseous route of SiC nano-powders synthesis from a mixture of silane and acetylene. (authors)

  12. Synthesis of mullite-based coatings from alumina and zircon powder mixtures by plasma spraying and laser remelting

    International Nuclear Information System (INIS)

    Hazra, S.; Das, J.; Bandyopadhyay, P.P.

    2015-01-01

    A mechanical mixture of alumina and pulverized zircon sand in 3:2 M ratio has been plasma sprayed to obtain mullite coating. Thereafter, the top layer of the coating has been remelted using laser. The presence of a mullite phase in the as-sprayed and laser remelted coatings has been confirmed qualitatively using X-ray diffraction. Both as-sprayed and laser remelted coatings have been characterized for their microstructure, hardness and porosity. The ultrafine grain structure of the coating produced by rapid quenching has been analyzed using transmission electron microscope. Presence of a mullite phase in the coatings has also been confirmed using small angle electron diffraction. Laser remelting has resulted in an appreciable reduction in porosity and increase in hardness in the coatings. - Highlights: • Mullite has been produced by plasma spraying of alumina–zircon powder mixture. • As sprayed coating shows good integrity. • Laser remelting reduced porosity and increased coating hardness

  13. Synthesis of mullite-based coatings from alumina and zircon powder mixtures by plasma spraying and laser remelting

    Energy Technology Data Exchange (ETDEWEB)

    Hazra, S. [Integrated Test Range, Chandipur, Balasore, Odisha 756025 (India); Das, J. [Department of Metallurgical and Materials Engineering, IIT Kharagpur, 721302 (India); Bandyopadhyay, P.P., E-mail: ppb@mech.iitkgp.ernet.in [Department of Mechanical Engineering, IIT Kharagpur, 721302 (India)

    2015-03-15

    A mechanical mixture of alumina and pulverized zircon sand in 3:2 M ratio has been plasma sprayed to obtain mullite coating. Thereafter, the top layer of the coating has been remelted using laser. The presence of a mullite phase in the as-sprayed and laser remelted coatings has been confirmed qualitatively using X-ray diffraction. Both as-sprayed and laser remelted coatings have been characterized for their microstructure, hardness and porosity. The ultrafine grain structure of the coating produced by rapid quenching has been analyzed using transmission electron microscope. Presence of a mullite phase in the coatings has also been confirmed using small angle electron diffraction. Laser remelting has resulted in an appreciable reduction in porosity and increase in hardness in the coatings. - Highlights: • Mullite has been produced by plasma spraying of alumina–zircon powder mixture. • As sprayed coating shows good integrity. • Laser remelting reduced porosity and increased coating hardness.

  14. SPRAY CASTING

    OpenAIRE

    SALAMCI, Elmas

    2010-01-01

    ABSTRACT This paper is designed to provide a basic review of spray casting. A brief overview of the historical development of spray  casting and the description of plant and equipment have been given. Following metallurgical characteristics of spray formed alloys, process parameters and solidification mechanism of spray deposition have been discussed in detail. Finally, microstructure and mechanical properties of the selected spray cast Al-Zn-Mg-Cu alloys have been presented and comp...

  15. Synthesis and characterization of in situ TiC–TiB2 composite coatings by reactive plasma spraying on a magnesium alloy

    International Nuclear Information System (INIS)

    Zou Binglin; Tao Shunyan; Huang Wenzhi; Khan, Zuhair S.; Fan Xizhi; Gu Lijian; Wang Ying; Xu Jiaying; Cai Xiaolong; Ma Hongmei; Cao Xueqiang

    2013-01-01

    Highlights: ► TiC–TiB 2 composites coatings were produced on Mg alloy by reactive plasma spraying. ► Phase composition, microstructure and wear resistance of the coatings were studied. ► The resultant product in the coatings was composed of TiC and TiB 2 . ► The produced coatings displayed porous and dense microstructures. ► The synthesized coatings exhibited good wear resistance for Mg alloy substrate. - Abstract: TiC–TiB 2 composite coatings were successfully synthesized using the technique of reactive plasma spraying (RPS) on a magnesium alloy. Phase composition, microstructure and wear resistance of the coatings were characterized by using X-ray diffraction, scanning electron microscopy and pin-on-disk wear test, respectively. The results showed that the resultant product in the RPS coatings was composed of TiC and TiB 2 . Depending on the ignition of self-propagating high-temperature synthesis reaction in the agglomerate particles, the RPS coatings displayed porous and dense microstructures. The porosity of the RPS coatings, to some extent, decreased when the feed powders were plasma sprayed with Ni powders. The RPS coatings provided good wear resistance for the substrate under various loads. For high loads (e.g., ≥15 N), the wear resistance could be significantly improved by the proper addition of Ni into the RPS coatings.

  16. Laser induced pyrolysis techniques

    International Nuclear Information System (INIS)

    Vanderborgh, N.E.

    1976-01-01

    The application of laser pyrolysis techniques to the problems of chemical analysis is discussed. The processes occurring during laser pyrolysis are first briefly reviewed. The problems encountered in laser pyrolysis gas chromatography are discussed using the analysis of phenanthrene and binary hydrocarbons. The application of this technique to the characterization of naturally occurring carbonaceous material such as oil shales and coal is illustrated

  17. Synthesis of carbon quantum dots and zinc oxide nanosheets by pyrolysis of novel metal–organic framework compounds

    International Nuclear Information System (INIS)

    Ma, Qiliang; Zhang, Zhaochun; Yu, Zhenwei

    2015-01-01

    Highlights: • Thermodynamic and kinetic analysis of porous MOFs. • One step synthesis of CQDs and ZnO nanosheets. • The coexistence of CQDs and ZnO nanosheets show strong ultraviolet emission. - Abstract: Here, the carbon quantum dots and zinc oxide nanosheets with novel superstructures are successfully synthesized simultaneously from a hydrothermal preparation and thermal decomposition of a porous precursor of metal–organic frameworks. Porous metal–organic frameworks are prepared by the hydrothermal process by using zinc nitrate hexahydrate, 4,4′-oxybisbenzoic acid and 4,4′-bipyridine as the starting materials. Fluorescence spectrophotometer, X-ray powder diffraction, transmission electron microscopy and high-resolution transmission electron microscopy were used to characterize the structure and property. The results show the coexistence of carbon quantum dots and zinc oxide nanosheets. The carbon quantum dots size is about 4 nm. Particularly, zinc oxide nanosheets show a new triangular sheet structure that has almost the same size. Strong ultraviolet emission of this coexistence system should be useful in developing visible light-emitting and nanophotonic devices

  18. Synthesis of carbon quantum dots and zinc oxide nanosheets by pyrolysis of novel metal–organic framework compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Qiliang; Zhang, Zhaochun, E-mail: zhangzhaochun@shu.edu.cn; Yu, Zhenwei

    2015-09-05

    Highlights: • Thermodynamic and kinetic analysis of porous MOFs. • One step synthesis of CQDs and ZnO nanosheets. • The coexistence of CQDs and ZnO nanosheets show strong ultraviolet emission. - Abstract: Here, the carbon quantum dots and zinc oxide nanosheets with novel superstructures are successfully synthesized simultaneously from a hydrothermal preparation and thermal decomposition of a porous precursor of metal–organic frameworks. Porous metal–organic frameworks are prepared by the hydrothermal process by using zinc nitrate hexahydrate, 4,4′-oxybisbenzoic acid and 4,4′-bipyridine as the starting materials. Fluorescence spectrophotometer, X-ray powder diffraction, transmission electron microscopy and high-resolution transmission electron microscopy were used to characterize the structure and property. The results show the coexistence of carbon quantum dots and zinc oxide nanosheets. The carbon quantum dots size is about 4 nm. Particularly, zinc oxide nanosheets show a new triangular sheet structure that has almost the same size. Strong ultraviolet emission of this coexistence system should be useful in developing visible light-emitting and nanophotonic devices.

  19. Characteristics of spray flames and the effect of group combustion on the morphology of flame-made nanoparticles

    Science.gov (United States)

    Eslamian, Morteza; Heine, Martin C.

    2008-01-01

    Characteristics of burning and non-burning sprays generated by a coaxial air-assist nozzle, previously used for the synthesis of ceramic nanoparticles by flame spray pyrolysis (FSP), are studied using phase Doppler anemometry. Also, the effect of droplet interaction on the overall combustion behavior of the spray (group combustion) and, consequently, on the characteristics of flame-made ceramic particles is investigated. A physical model is proposed which correlates the formation of inhomogeneous mixtures of micron-sized hollow particles and solid nanoparticles to the combustion mode: the precursor droplets which entirely evaporate in the hot flame are responsible for the formation of nanoparticles. The vapor species react, forming intermediate and product molecules and clusters that quickly grow to nanosized ceramic particles. On the other hand, under certain conditions, a small number of the droplets, particularly with large initial sizes, escape from the spray boundaries and become extinguished, producing large hollow ceramic particles. It is also possible that some of the large droplets, which lie within the spray core, do not entirely evaporate. These surviving droplets then form large particles which are usually hollow but can collapse to solid particles at sufficiently high temperatures. Also, a criterion for the formation of homogeneous ceramic nanoparticles is presented.

  20. Characteristics of spray flames and the effect of group combustion on the morphology of flame-made nanoparticles

    International Nuclear Information System (INIS)

    Eslamian, Morteza; Heine, Martin C

    2008-01-01

    Characteristics of burning and non-burning sprays generated by a coaxial air-assist nozzle, previously used for the synthesis of ceramic nanoparticles by flame spray pyrolysis (FSP), are studied using phase Doppler anemometry. Also, the effect of droplet interaction on the overall combustion behavior of the spray (group combustion) and, consequently, on the characteristics of flame-made ceramic particles is investigated. A physical model is proposed which correlates the formation of inhomogeneous mixtures of micron-sized hollow particles and solid nanoparticles to the combustion mode: the precursor droplets which entirely evaporate in the hot flame are responsible for the formation of nanoparticles. The vapor species react, forming intermediate and product molecules and clusters that quickly grow to nanosized ceramic particles. On the other hand, under certain conditions, a small number of the droplets, particularly with large initial sizes, escape from the spray boundaries and become extinguished, producing large hollow ceramic particles. It is also possible that some of the large droplets, which lie within the spray core, do not entirely evaporate. These surviving droplets then form large particles which are usually hollow but can collapse to solid particles at sufficiently high temperatures. Also, a criterion for the formation of homogeneous ceramic nanoparticles is presented

  1. Device for removing pyrolysis residues from a pyrolysis plant. Vorrichtung zum Austragen von Verschwelungsrueckstaenden aus einer Pyrolyseanlage

    Energy Technology Data Exchange (ETDEWEB)

    Eisenmann, A

    1985-03-28

    The purpose of the invention is a device for removing the hot solid pyrolysis residues of heterogeneous composition from an hermetically sealed pyrolysis plant, especially one for pyrolysing refuse and other materials. In order to achieve continuous permanent operation with hermetic sealing of the system to the atmosphere, the device according to the invention has a lock on the funnel-shaped floor of a shaft, which has a worm conveyor after it. There is a spray device in an hermetically sealed chamber of the lock, through which the hot pyrolysis residues are sprayed, in order to bind the dust particles and simultaneously to reduce the temperature. A sludge pump is connected to the worm conveyor, which removes the material to silos.

  2. Pyrolysis mechanism of microalgae Nannochloropsis sp. based on model compounds and their interaction

    International Nuclear Information System (INIS)

    Wang, Xin; Tang, Xiaohan; Yang, Xiaoyi

    2017-01-01

    Highlights: • Pyrolysis experiments were conducted by model compounds of algal components. • Interaction affected little bio-crude yield of model compounds co-pyrolysis. • Some interaction pathways between microalgae components were recommended. • N-heterocyclic compounds were further pyrolysis products of Maillard reaction products. • Surfactant synthesis (lipid-amino acids and lipid-glucose) between algal components. - Abstract: Pyrolysis is one of important pathways to convert microalgae to liquid biofuels and key components of microalgae have different chemical composition and structure, which provides a barrier for large-scale microalgae-based liquid biofuel application. Microalgae component pyrolysis mechanism should be researched to optimal pyrolysis process parameters. In this study, single pyrolysis and co-pyrolysis of microalgal components (model compounds castor oil, soybean protein and glucose) were conducted to reveal interaction between them by thermogrametric analysis and bio-crude evaluation. Castor oil (model compound of lipid) has higher pyrolysis temperature than other model compounds and has the maximum contribution to bio-crude formation. Bio-crude from soybean protein has higher N-heterocyclic compounds as well as phenols, which could be important aromatic hydrocarbon source during biorefineries and alternative aviation biofuel production. Potential interaction pathways based on model compounds are recommended including further decomposition of Maillard reaction products (MRPs) and surfactant synthesis, which indicate that glucose played an important role on pyrolysis of microalgal protein and lipid components. The results should provide necessary information for microalgae pyrolysis process optimization and large-scale pyrolysis reactor design.

  3. Solution synthesis of telluride-based nano-barbell structures coated with PEDOT:PSS for spray-printed thermoelectric generators

    Science.gov (United States)

    Bae, Eun Jin; Kang, Young Hun; Jang, Kwang-Suk; Lee, Changjin; Cho, Song Yun

    2016-05-01

    Solution-processable telluride-based heterostructures coated with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (Te-Bi2Te3/PEDOT:PSS) were synthesized through a solution-phase reaction at low temperatures. The water-based synthesis yielded PEDOT:PSS-coated Te-Bi2Te3 nano-barbell structures with a high Seebeck coefficient that can be stably dispersed in water. These hybrid solutions were deposited onto a substrate by the spray-printing method to prepare thermoelectric generators. The thermoelectric properties of the Te-Bi2Te3/PEDOT:PSS hybrid films were significantly enhanced by a simple acid treatment due to the increased electrical conductivity, and the power factor of those materials can be effectively tuned over a wide range depending on the acid concentration of the treatment. The power factors of the synthesized Te-Bi2Te3/PEDOT:PSS hybrids were optimized to 60.05 μW m-1 K-2 with a Seebeck coefficient of 93.63 μV K-1 and an electrical conductivity of 69.99 S cm-1. The flexible thermoelectric generator fabricated by spray-printing Te-Bi2Te3/PEDOT:PSS hybrid solutions showed an open-circuit voltage of 1.54 mV with six legs at ΔT = 10 °C. This approach presents the potential for realizing printing-processable hybrid thermoelectric materials for application in flexible thermoelectric generators.Solution-processable telluride-based heterostructures coated with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (Te-Bi2Te3/PEDOT:PSS) were synthesized through a solution-phase reaction at low temperatures. The water-based synthesis yielded PEDOT:PSS-coated Te-Bi2Te3 nano-barbell structures with a high Seebeck coefficient that can be stably dispersed in water. These hybrid solutions were deposited onto a substrate by the spray-printing method to prepare thermoelectric generators. The thermoelectric properties of the Te-Bi2Te3/PEDOT:PSS hybrid films were significantly enhanced by a simple acid treatment due to the increased electrical conductivity, and

  4. Modelling of biomass pyrolysis

    International Nuclear Information System (INIS)

    Kazakova, Nadezhda; Petkov, Venko; Mihailov, Emil

    2015-01-01

    Pyrolysis is an essential preliminary step in a gasifier. The first step in modelling the pyrolysis process of biomass is creating a model for the chemical processes taking place. This model should describe the used fuel, the reactions taking place and the products created in the process. The numerous different polymers present in the organic fraction of the fuel are generally divided in three main groups. So, the multistep kinetic model of biomass pyrolysis is based on conventional multistep devolatilization models of the three main biomass components - cellulose, hemicelluloses, and lignin. Numerical simulations have been conducted in order to estimate the influence of the heating rate and the temperature of pyrolysis on the content of the virgin biomass, active biomass, liquid, solid and gaseous phases at any moment. Keywords: kinetic models, pyrolysis, biomass pyrolysis.

  5. Synthesis of free-standing carbon nanohybrid by directly growing carbon nanotubes on air-sprayed graphene oxide paper and its application in supercapacitor

    International Nuclear Information System (INIS)

    Wei, Li; Jiang, Wenchao; Yuan, Yang; Goh, Kunli; Yu, Dingshan; Wang, Liang; Chen, Yuan

    2015-01-01

    We report the synthesis of a free-standing two dimensional carbon nanotube (CNT)-reduced graphene oxide (rGO) hybrid by directly growing CNTs on air-sprayed GO paper. As a result of the good integration between CNTs and thermally reduced GO film during chemical vapor deposition, excellent electrical conductivity (2.6×10 4 S/m), mechanical flexibility (electrical resistance only increases 1.1% after bent to 90° for 500 times) and a relatively large surface area (335.3 m 2 /g) are achieved. Two-electrode supercapacitor assembled using the CNT–rGO hybrids in ionic liquid electrolyte (1-ethyl-3-methylimidazolium tetrafluoroborate) shows excellent stability upon 500 bending cycles with the gravimetric energy density measuring 23.7 Wh/kg and a power density of 2.0 kW/kg. Furthermore, it shows an impedance phase angle of −64.4° at a frequency of 120 Hz, suggesting good potentials for 120 Hz alternating current line filtering applications. - Graphical abstract: Flexible and highly conductive carbon nanotube-reduced graphene oxide nanohybrid. - Highlights: • Direct growth of carbon nanotubes by chemical vapor deposition on air-sprayed graphene oxide paper. • Two-dimensional carbon nanohybrid with excellent conductivity and mechanical flexibility. • Supercapacitor with excellent performance stability upon mechanical deformation for flexible electronics applications. • Supercapacitor with high impedance phase angle for 120 Hz alternating current line filtering applications

  6. Spray cooling

    International Nuclear Information System (INIS)

    Rollin, Philippe.

    1975-01-01

    Spray cooling - using water spraying in air - is surveyed as a possible system for make-up (peak clipping in open circuit) or major cooling (in closed circuit) of the cooling water of the condensers in thermal power plants. Indications are given on the experiments made in France and the systems recently developed in USA, questions relating to performance, cost and environmental effects of spray devices are then dealt with [fr

  7. Rapid in situ synthesis of spherical microflower Pt/C catalyst via spray-drying for high performance fuel cell application

    Energy Technology Data Exchange (ETDEWEB)

    Balgis, R.; Ogi, T.; Okuyama, K. [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, Higashi Hiroshima, Hiroshima (Japan); Anilkumar, G.M.; Sago, S. [Research and Development Centre, Noritake Co., Ltd., Higashiyama, Miyoshi, Aichi (Japan)

    2012-08-15

    A facile route for the rapid in situ synthesis of platinum nanoparticles on spherical microflower carbon has been developed. An aqueous precursor slurry containing carbon black, polystyrene latex (PSL), polyvinyl alcohol, and platinum salt was spray-dried, followed by calcination to simultaneously reduce platinum salt and to decompose PSL particles. Prepared Pt/C catalyst showed high-performance electrocatalytic activity with excellent durability. The mass activity and specific activity values were 132.26 mA mg{sup -1} Pt and 207.62 {mu}A cm{sup -2} Pt, respectively. This work presents a future direction for the production of high-performance Pt/C catalyst in an industrial scale. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Synthesis and electrochemical characteristics of spinel LiMn2O4 via a precipitation spray-drying process

    International Nuclear Information System (INIS)

    Wu, H.M.; Tu, J.P.; Yuan, Y.F.; Li, Y.; Zhao, X.B.; Cao, G.S.

    2005-01-01

    Spinel LiMn 2 O 4 has been successfully synthesized using a precipitation spray-drying process. After the precursor was annealed at 750 deg. C for 10 h, the synthesized material was well-crystallized spinel particle, and exhibited uniform particle size distribution. From cyclic voltammetry results, there is an anomalous redox peaks (3.75/3.26 V). In the charge/discharge potential (versus Li) ranging from 3.2 to 4.5 V, it delivered a high initial discharge capacity of 123 mAh/g at a discharge rate of 60 μA/cm 2 (1/4 C rate). At a high discharge rate of 2.4 mA/cm 2 (10 C rate), the obtainable reversible capacity was 79 mAh/g. The simple procedure of precipitation spray-drying process is time and energy saving, and thus is promising for commercial application

  9. Coal pyrolysis under hydrogen-rich gases

    Energy Technology Data Exchange (ETDEWEB)

    Liao, H.; Sun, C.; Li, B.; Liu, Z. [Chinese Academy of Sciences, Taiyuan (China). State Key Laboratory of Coal Conversion, Institute of Coal Chemistry

    1998-04-01

    To improve the economy of the pyrolysis process by reducing the hydrogen cost, it is suggested to use cheaper hydrogen-rich gases such as coke-oven gas (COG) or synthesis gas (SG) instead of pure hydrogen. The pyrolysis of Chinese Xianfeng lignite which was carried out with real COG and SG at 3-5 MPa, a final temperature of 650{degree}C and a heating rate of 5{degree}C/min in a 10g fixed-bed reactor is compared with coal pyrolysis with pure hydrogen and nitrogen under the same conditions. The results indicate that compared with hydropyrolysis at the same total pressure, the total conversion and tar yields from coal pyrolysis with COG and SG decreases while the unwanted water increases. However, at the same H{sub 2} partial pressure, the tar yields and yields of BBTX, PCX and naphthalene from the pyrolysis of coal with COG and SG are all significantly higher than those of hydropyrolysis. Therefore, it is possible to use COG and SG instead of pure hydrogen. 8 refs., 3 figs., 6 tabs.

  10. Synthesis of high-performance Li2FeSiO4/C composite powder by spray-freezing/freeze-drying a solution with two carbon sources

    Science.gov (United States)

    Fujita, Yukiko; Iwase, Hiroaki; Shida, Kenji; Liao, Jinsun; Fukui, Takehisa; Matsuda, Motohide

    2017-09-01

    Li2FeSiO4 is a promising cathode active material for lithium-ion batteries due to its high theoretical capacity. Spray-freezing/freeze-drying, a practical process reported for the synthesis of various ceramic powders, is applied to the synthesis of Li2FeSiO4/C composite powders and high-performance Li2FeSiO4/C composite powders are successfully synthesized by using starting solutions containing both Indian ink and glucose as carbon sources followed by heating. The synthesized composite powders have a unique structure, composed of Li2FeSiO4 nanoparticles coated with a thin carbon layer formed by the carbonization of glucose and carbon nanoparticles from Indian ink. The carbon layer enhances the electrochemical reactivity of the Li2FeSiO4, and the carbon nanoparticles play a role in the formation of electron-conducting paths in the cathode. The composite powders deliver an initial discharge capacity of 195 and 137 mAh g-1 at 0.1 C and 1 C, respectively, without further addition of conductive additive. The discharge capacity at 1 C is 72 mAh g-1 after the 100th cycle, corresponding to approximately 75% of the capacity at the 2nd cycle.

  11. Modeling of biomass pyrolysis

    International Nuclear Information System (INIS)

    Samo, S.R.; Memon, A.S.; Akhund, M.A.

    1995-01-01

    The fuels used in industry and power sector for the last two decades have become expensive. As a result renewable energy source have been emerging increasingly important, of these, biomass appears to be the most applicable in the near future. The pyrolysis of biomass plays a key role amongst the three major and important process generally encountered in a gas producer, namely, pyrolysis, combustion and reduction of combustion products. Each biomass has its own pyrolysis characteristics and this important parameters must be known for the proper design and efficient operation of a gasification system. Thermogravimetric analysis has been widely used to study the devolatilization of solid fuels, such as biomass. It provides the weight loss history of a sample heated at a predetermined rate as a function of time and temperature. This paper presents the experimental results of modelling the weight loss curves of the main biomass components i.e. cellulose, hemicellulose and lignin. Thermogravimetric analysis of main components of biomass showed that pyrolysis is first order reaction. Furthermore pyrolysis of cellulose and hemicelluloe can be regarded as taking place in two stages, for while lignin pyrolysis is a single stage process. This paper also describes the Thermogravimetric Analysis (TGA) technique to predict the weight retained during pyrolysis at any temperature, for number of biomass species, such as cotton stalk, bagasse ad graoundnut shell. (author)

  12. Gram-scale synthesis of catalytic Co9S8 nanocrystal ink as a cathode material for spray-deposited, large-area dye-sensitized solar cells.

    Science.gov (United States)

    Chang, Shu-Hao; Lu, Ming-De; Tung, Yung-Liang; Tuan, Hsing-Yu

    2013-10-22

    We report the development of Co9S8 nanocrystals as a cost-effective cathode material that can be readily combined with spraying techniques to fabricate large-area dye-sensitized solar cell (DSSC) devices and can be further connected with series or parallel cell architectures to obtain a relatively high output voltage or current. A gram-scale synthesis of Co9S8 nanocrystal is carried out via a noninjection reaction by mixing anhydrous CoCl2 with trioctylphosphine (TOP), dodecanethiol and oleylamine (OLA) at 250 °C. The Co9S8 nanocrystals possess excellent catalytic ability with respect to I(-)/I3(-) redox reactions. The Co9S8 nanocrystals are prepared as nanoinks to fabricate uniform, crack-free Co9S8 thin films on different substrates by using a spray deposition technique. These Co9S8 films are used as counter electrodes assembled with dye-adsorbed TiO2 photoanodes to fabricate DSSC devices having a working area of 2 cm(2) and an average power conversion efficiency (PCE) of 7.02 ± 0.18% under AM 1.5 solar illumination, which is comparable with the PCE of 7.2 ± 0.12% obtained using a Pt cathode. Furthermore, six 2 cm(2)-sized DSSC devices connected in series output an open-circuit voltage of 4.2 V that can power a wide range of electronic devices such as LED arrays and can charge commercial lithium ion batteries.

  13. Catalytic biomass pyrolysis process

    Science.gov (United States)

    Dayton, David C.; Gupta, Raghubir P.; Turk, Brian S.; Kataria, Atish; Shen, Jian-Ping

    2018-04-17

    Described herein are processes for converting a biomass starting material (such as lignocellulosic materials) into a low oxygen containing, stable liquid intermediate that can be refined to make liquid hydrocarbon fuels. More specifically, the process can be a catalytic biomass pyrolysis process wherein an oxygen removing catalyst is employed in the reactor while the biomass is subjected to pyrolysis conditions. The stream exiting the pyrolysis reactor comprises bio-oil having a low oxygen content, and such stream may be subjected to further steps, such as separation and/or condensation to isolate the bio-oil.

  14. Self-templating synthesis of hollow spheres of zeolite ZSM-5 from spray-dried aluminosilicate precursor

    Czech Academy of Sciences Publication Activity Database

    Pashková, Veronika; Tokarová, V.; Brabec, Libor; Dědeček, Jiří

    2016-01-01

    Roč. 228, JUL 2016 (2016), s. 59-63 ISSN 1387-1811 R&D Projects: GA ČR GA15-13876S; GA MŠk LM2015073 Institutional support: RVO:61388955 Keywords : MFI * zeolite shells * template free synthesis Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.615, year: 2016

  15. Laser oxidative pyrolysis synthesis and annealing of TiO{sub 2} nanoparticles embedded in carbon–silica shells/matrix

    Energy Technology Data Exchange (ETDEWEB)

    Fleaca, C.T. [National Institute for Plasma, Laser and Radiation Physics (NILPRP), Atomistilor 409, P.O. Box MG 36, R-077125 Magurele, Bucharest (Romania); “Politehnica” University of Bucharest, Physics Department, Independentei 313, Bucharest (Romania); Scarisoreanu, M., E-mail: monica.scarisoreanu@inflpr.ro [National Institute for Plasma, Laser and Radiation Physics (NILPRP), Atomistilor 409, P.O. Box MG 36, R-077125 Magurele, Bucharest (Romania); Morjan, I.; Luculescu, C.; Niculescu, A.-M.; Badoi, A. [National Institute for Plasma, Laser and Radiation Physics (NILPRP), Atomistilor 409, P.O. Box MG 36, R-077125 Magurele, Bucharest (Romania); Vasile, E. [“Politehnica” University of Bucharest, Faculty of Applied Chemistry and Materials Science, Department of Oxide Materials and Nanomaterials, Gh. Polizu 1-7, Bucharest (Romania); Kovacs, G. [“Babes-Boyai” University, Faculty of Chemistry and Chemical Engineering, Arany Janos 11, Cluj-Napoca (Romania)

    2015-05-01

    Highlights: • TiO{sub 2}-based nanocomposites were obtained by one-step laser oxidative pyrolysis. • Titania particles are surrounded by/embedded in carbon/silica shells/matrix. • They contain an anatase/rutile mixture with mean crystalline diameters up to 24 nm. • Their carbon content decreased with the increasing of introduced air coflow. • Their bandgap energy decreased due to the carbon incorporation. - Abstract: Titania nanoparticles containing a mixture of anatase and rutile phases (with mean crystalline sizes up to 24 nm) covered with/embedded in carbon/silica thin layers or matrix were obtained in a single step using laser oxidative pyrolysis. Titanium tetrachloride and hexamethyldisiloxane (HMDSO) vapors were separately introduced into the reaction zone – both together with the laser-absorbing agent (sensitizer) ethylene – which acts also as carbon source – and the oxidant (air) – through the inner and the concentric nozzle, respectively. By increasing the air flow through the annular nozzle, while keeping constant the TiC{sub 4}, inner air, HMDSO and C{sub 2}H{sub 4} flows, the atomic carbon concentration as well as the rutile to anatase ratio in the resulted nanopowders decrease. A much brighter and extended flame was observed for the experiment involving the greatest air flow. The Ti/Si atomic ratio in the resulted nanocomposites was higher than that from the introduced precursors (1.8), indicating a partial siloxane conversion to silica. The annealed powders (at 450 °C to further carbon content reducing) exhibit a lower bandgap energy than those of the reference sample without silica (and also lower than the commercial Degussa P25 nano-TiO{sub 2})

  16. Refining fast pyrolysis of biomass

    NARCIS (Netherlands)

    Westerhof, Roel Johannes Maria

    2011-01-01

    Pyrolysis oil produced from biomass is a promising renewable alternative to crude oil. Such pyrolysis oil has transportation, storage, and processing benefits, none of which are offered by the bulky, inhomogeneous solid biomass from which it originates. However, pyrolysis oil has both a different

  17. Pyrolysis synthesis of Zn{sub 2}SiO{sub 4}:Mn{sup 2+} phosphors – effect of fuel, flux and co-dopants

    Energy Technology Data Exchange (ETDEWEB)

    Sivakumar, V.; Lakshmanan, Arunachalam, E-mail: arunachalamlakshmanan@yahoo.com

    2014-01-15

    Green emitting α-Zn{sub 2}SiO{sub 4}:Mn{sup 2+} phosphors were made by pyrolysis route at 600 °C followed by sintering at a moderate temperature of 1000 °C for 1 h duration. The effects of different fuels (urea, citric acid, polyethylene glycol and glycine), flux materials (H{sub 3}BO{sub 3}, NH{sub 4}Cl, NH{sub 4}F, NH{sub 4}Br, BaCl{sub 2}, BaBr{sub 2}, CaF{sub 2} and BaF{sub 2}), divalant co-dopants (Ca{sup 2+}, Ba{sup 2+}, Mg{sup 2+} and Sr{sup 2+}), trivalent co-dopants (Al{sup 3+}, Y{sup 3+} and Gd{sup 3+}) and sintering temperature (800–1000 °C) on the photoluminescence (PL) efficiency of Zn{sub 2}SiO{sub 4}:Mn{sup 2+} were studied. Among the fuels, urea and among the flux, H{sub 3}BO{sub 3} gave a maximum broad band green PL emission peak at 525 nm on excitation at 254 nm. Divalent co-dopants improved the PL intensity much more than the trivalent co-dopants used. Highest PL efficiency was observed with Sr{sup 2+} co-doped Zn{sub 2}SiO{sub 4}:Mn{sup 2+} sintered at 1000 °C in reducing atmosphere which was 20% higher than that of the commercial Zn{sub 2}SiO{sub 4}:Mn{sup 2+}. The formation of a single crystalline phase of willemite structure in the α-Zn{sub 2}SiO{sub 4}:Mn{sup 2+} samples synthesized was confirmed by powder XRD measurements. -- Highlights: • Zn{sub 2}SiO{sub 4}:Mn{sup 2+} green phosphors were made by pyrolysis route. • Effect of fuel, flux and co dopant on PL intensity. • Enhancement in luminescence with divalent co-dopants, notably Sr. • PL efficiency 20% higher than that of the commercial phosphor. • XRD confirm single phase willemite structure of Zn{sub 2}SiO{sub 4}:Mn{sup 2+}.

  18. Catalytic pyrolysis of hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Vail' eva, N A; Buyanov, R A

    1979-01-01

    Catalytic pyrolysis of petroleum fractions (undecane) was performed with the object of clarifying such questions as the mechanism of action of the catalyst, the concepts of activity and selectivity of the catalyst, the role of transport processes, the temperature ranges and limitations of the catalytic process, the effect of the catalyst on secondary processes, and others. Catalysts such as quartz, MgO, Al/sub 2/O/sub 3/, were used. Analysis of the experimental findings and the fact that the distribution of products is independent of the nature of the surface, demonstrate that the pyrolysis of hydrocarbons in the presence of catalysts is based on the heterogeneous-homogeneous radical-chain mechanism of action, and that the role of the catalysts reduces to increasing the concentration of free radicals. The concept of selectivity cannot be applied to catalysts here, since they do not affect the mechanism of the unfolding of the process of pyrolysis and their role consists solely in initiating the process. In catalytic pyrolysis the concepts of kinetic and diffusive domains of unfolding of the catalytic reaction do not apply, and only the outer surface of the catalyst is engaged, whereas the inner surface merely promotes deletorious secondary processes reducing the selectivity of the process and the activity of the catalyst. 6 references, 2 figures.

  19. Pyrolysis of Pine Wood

    DEFF Research Database (Denmark)

    Fjellerup, Jan Søren; Ahrenfeldt, Jesper; Henriksen, Ulrik Birk

    2005-01-01

    In this study, pinewood has been pyrolyzed using a fixed heating rate with a variable end-temperature. The pyrolysis process has been simulated using a mechanism with three parallel reactions for the formation of char, gas and tar. First order irreversible kinetics is assumed. This kind of model ...

  20. Spray pyrolytic deposition of α-MoO3 film and its use in dye-sensitized solar cell

    Science.gov (United States)

    Tamboli, Parvin S.; Jagtap, Chaitali V.; Kadam, Vishal S.; Ingle, Ravi V.; Vhatkar, Rajiv S.; Mahajan, Smita S.; Pathan, Habib M.

    2018-04-01

    Thermal decomposition of ammonium para molybdate tetrahydrate precursor has been studied to determine degradation temperatures in air atmosphere. Current work explores the synthesis of α-MoO3 films by an economical spray pyrolysis technique using ammonium para molybdate tetrahydrate precursor in the presence of compressed air. A variety of characterization techniques such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV-visible spectroscopy, Fourier transform infrared, and Raman spectroscopy were carried out, and the studies have confirmed that orthorhombic phase formation of MoO3 takes place with spongy mesh-type structure. The study of electro-catalytic activity of α-MoO3 in titania-based dye-sensitized solar cell is also carried out by cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel curves to evaluate its performance as a counter electrode.

  1. Biomass pyrolysis for chemicals

    Energy Technology Data Exchange (ETDEWEB)

    De Wild, P.

    2011-07-15

    The problems associated with the use of fossil fuels demand a transition to renewable sources (sun, wind, water, geothermal, biomass) for materials and energy where biomass provides the only renewable source for chemicals. In a biorefinery, biomass is converted via different technologies into heat, power and various products. Here, pyrolysis (thermal degradation without added oxygen) of lignocellulosic biomass can play an important role, because it leads to an array of useful chemicals. Examples are furfural and acetic acid from hemicellulose, levoglucosan from cellulose and phenols and biochar from lignin. Since the three major biomass polymers hemicellulose, cellulose and lignin possess dissimilar thermal stabilities and reactivities, type and amount of degradation products are tunable by proper selection of the pyrolysis conditions. To determine if step-wise pyrolysis would be suitable for the production of chemicals, staged degasification of lignocellulosic biomass was studied. Due to limited yields, a hot pressurized water pre-treatment (aquathermolysis) followed by pyrolysis was subsequently developed as an improved version of a staged approach to produce furfural and levoglucosan from the carbohydrate fraction of the biomass. Lignin is the only renewable source for aromatic chemicals. Lignocellulosic biorefineries for bio-ethanol produce lignin as major by-product. The pyrolysis of side-streams into valuable chemicals is of prime importance for a profitable biorefinery. To determine the added-value of lignin side-streams other than their use as fuel for power, application research including techno-economic analysis is required. In this thesis, the pyrolytic valorisation of lignin into phenols and biochar was investigated and proven possible.

  2. 'Beautiful' unconventional synthesis and processing technologies of superconductors and some other materials

    Directory of Open Access Journals (Sweden)

    Petre Badica, Adrian Crisan, Gheorghe Aldica, Kazuhiro Endo, Hanna Borodianska, Kazumasa Togano, Satoshi Awaji, Kazuo Watanabe, Yoshio Sakka and Oleg Vasylkiv

    2011-01-01

    Full Text Available Superconducting materials have contributed significantly to the development of modern materials science and engineering. Specific technological solutions for their synthesis and processing helped in understanding the principles and approaches to the design, fabrication and application of many other materials. In this review, we explore the bidirectional relationship between the general and particular synthesis concepts. The analysis is mostly based on our studies where some unconventional technologies were applied to different superconductors and some other materials. These technologies include spray-frozen freeze-drying, fast pyrolysis, field-assisted sintering (or spark plasma sintering, nanoblasting, processing in high magnetic fields, methods of control of supersaturation and migration during film growth, and mechanical treatments of composite wires. The analysis provides future research directions and some key elements to define the concept of 'beautiful' technology in materials science. It also reconfirms the key position and importance of superconductors in the development of new materials and unconventional synthesis approaches.

  3. Pyrolysis and Gasification

    DEFF Research Database (Denmark)

    Astrup, Thomas; Bilitewski, B.

    2011-01-01

    a waste management perspective, pyrolysis and gasification are of relatively little importance as an overall management option. Today, gasification is primarily used on specific waste fractions as opposed to mixed household wastes. The main commercial activity so far has been in Japan, with only limited....... Today gasification is used within a range of applications, the most important of which are conversion of coal into syngas for use as chemical feedstock or energy production; but also gasification of biomass and waste is gaining significant interest as emerging technologies for sustainable energy. From...... success in Europe and North America (Klein et al., 2004). However, pyrolysis and gasification of waste are generally expected to become more widely used in the future. A main reason for this is that public perceptions of waste incineration in some countries is a major obstacle for installing new...

  4. Pyrolysis process and apparatus

    Science.gov (United States)

    Lee, Chang-Kuei

    1983-01-01

    This invention discloses a process and apparatus for pyrolyzing particulate coal by heating with a particulate solid heating media in a transport reactor. The invention tends to dampen fluctuations in the flow of heating media upstream of the pyrolysis zone, and by so doing forms a substantially continuous and substantially uniform annular column of heating media flowing downwardly along the inside diameter of the reactor. The invention is particularly useful for bituminous or agglomerative type coals.

  5. Controlled air pyrolysis incinerator

    International Nuclear Information System (INIS)

    Dufrane, K.H.; Wilke, M.

    1982-01-01

    An advanced controlled air pyrolysis incinerator has been researched, developed and placed into commercial operation for both radioactive and other combustible wastes. Engineering efforts cocentrated on providing an incinerator which emitted a clean, easily treatable off-gas and which produced a minimum amount of secondary waste. Feed material is continuously fed by gravity into the system's pyrolysis chamber without sorting, shredding, or other such pretreatment. Metal objects, liquids such as oil and gasoline, or solid products such as resins, blocks of plastic, tire, animal carcasses, or compacted trash may be included along with normal processed waste. The temperature of the waste is very gradually increased in a reduced oxygen atmosphere. Volatile pyrolysis gases are produced, tar-like substances are cracked and the resulting product, a relatively uniform, easily burnable material, is introduced into the combustion chamber. Steady burning is thus accomplished under easily controlled excess air conditions with the off-gasthen passing through a simple dry clean-up system. Gas temperatures are then reduced by air dilution before passing through final HEPA filters. Both commercial and nuclear installations have been operated with the most recent application being the central incinerator to service West Germany's nuclear reactors

  6. Performance of rotary kiln reactor for the elephant grass pyrolysis.

    Science.gov (United States)

    De Conto, D; Silvestre, W P; Baldasso, C; Godinho, M

    2016-10-01

    The influence of process conditions (rotary speed/temperature) on the performance of a rotary kiln reactor for non-catalytic pyrolysis of a perennial grass (elephant grass) was investigated. The product yields, the production of non-condensable gases as well as the biochar properties were evaluated. The maximum H2 yield was close to that observed for catalytic pyrolysis processes, while the bio-oil yield was higher than reported for pyrolysis of other biomass in rotary kiln reactors. A H2/CO ratio suitable for Fischer-Tropsch synthesis (FTS) was obtained. The biochars presented an alkaline pH (above 10) and interesting contents of nutrients, as well as low electrical conductivity, indicating a high potential as soil amendment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Comparative studies of spray pyrolysis deposited copper sulfide ...

    Indian Academy of Sciences (India)

    X-ray diffraction analysis showed that while the layer/glass sample has an individual CuS (covellite) ... that all these materials have a relatively high absorption coefficient (∼5 × .... and S2 that were deposited on glass substrates, had the co-.

  8. Pyrolysis characteristics of typical biomass thermoplastic composites

    Directory of Open Access Journals (Sweden)

    Hongzhen Cai

    Full Text Available The biomass thermoplastic composites were prepared by extrusion molding method with poplar flour, rice husk, cotton stalk and corn stalk. The thermo gravimetric analyzer (TGA has also been used for evaluating the pyrolysis process of the composites. The results showed that the pyrolysis process mainly consists of two stages: biomass pyrolysis and the plastic pyrolysis. The increase of biomass content in the composite raised the first stage pyrolysis peak temperature. However, the carbon residue was reduced and the pyrolysis efficiency was better because of synergistic effect of biomass and plastic. The composite with different kinds of biomass have similar pyrolysis process, and the pyrolysis efficiency of the composite with corn stalk was best. The calcium carbonate could inhibit pyrolysis process and increase the first stage pyrolysis peak temperature and carbon residue as a filling material of the composite. Keywords: Biomass thermoplastic composite, Calcium carbonate, Pyrolysis characteristic

  9. Pyrolysis oil as diesel fuel

    Energy Technology Data Exchange (ETDEWEB)

    Gros, S [Wartsila Diesel International Ltd., Vaasa (Finland). Diesel Technology

    1997-12-31

    Wood waste pyrolysis oil is an attractive fuel alternative for diesel engine operation. The main benefit is the sustainability of the fuel. No fossil reserves are consumed. The fact that wood waste pyrolysis oil does not contribute to CO{sub 2} emissions is of utmost importance. This means that power plants utilising pyrolysis oil do not cause additional global warming. Equally important is the reduced sulphur emissions that this fuel alternative implies. The sulphur content of pyrolysis oil is extremely low. The high water content and low heating value are also expected to result in very low NO{sub x} emissions. Utilisation of wood waste pyrolysis oil in diesel engines, however, involves a lot of challenges and problems to be solved. The low heating value requires a new injection system with high capacity. The corrosive characteristics of the fluid also underline the need for new injection equipment materials. Wood waste pyrolysis oil contains solid particles which can clog filters and cause abrasive wear. Wood waste pyrolysis oil has proven to have extremely bad ignition properties. The development of a reliable injection system which is able to cope with such a fuel involves a lot of optimisation tests, redesign and innovative solutions. Successful single-cylinder tests have already been performed and they have verified that diesel operation on wood pyrolysis oil is technically possible. (orig.)

  10. Time resolved pyrolysis of char

    DEFF Research Database (Denmark)

    Egsgaard, H.; Ahrenfeldt, J.; Henriksen, U.B.

    pyrolysis, and slow heating in direct combination with mass spectrometry, gas chromatography/mass spectrometry and flame ionization detection, respectively. Characteristic ions derived from the flash pyrolysis-gas chromatography/mass spectrometry data enable the release of volatiles to be time and, hence...

  11. Pyrolysis oil as diesel fuel

    Energy Technology Data Exchange (ETDEWEB)

    Gros, S. [Wartsila Diesel International Ltd., Vaasa (Finland). Diesel Technology

    1996-12-31

    Wood waste pyrolysis oil is an attractive fuel alternative for diesel engine operation. The main benefit is the sustainability of the fuel. No fossil reserves are consumed. The fact that wood waste pyrolysis oil does not contribute to CO{sub 2} emissions is of utmost importance. This means that power plants utilising pyrolysis oil do not cause additional global warming. Equally important is the reduced sulphur emissions that this fuel alternative implies. The sulphur content of pyrolysis oil is extremely low. The high water content and low heating value are also expected to result in very low NO{sub x} emissions. Utilisation of wood waste pyrolysis oil in diesel engines, however, involves a lot of challenges and problems to be solved. The low heating value requires a new injection system with high capacity. The corrosive characteristics of the fluid also underline the need for new injection equipment materials. Wood waste pyrolysis oil contains solid particles which can clog filters and cause abrasive wear. Wood waste pyrolysis oil has proven to have extremely bad ignition properties. The development of a reliable injection system which is able to cope with such a fuel involves a lot of optimisation tests, redesign and innovative solutions. Successful single-cylinder tests have already been performed and they have verified that diesel operation on wood pyrolysis oil is technically possible. (orig.)

  12. Integrated biomass pyrolysis with organic Rankine cycle for power generation

    Science.gov (United States)

    Nur, T. B.; Syahputra, A. W.

    2018-02-01

    The growing interest on Organic Rankine Cycle (ORC) application to produce electricity by utilizing biomass energy sources are increasingly due to its successfully used to generate power from waste heat available in industrial processes. Biomass pyrolysis is one of the thermochemical technologies for converting biomass into energy and chemical products consisting of liquid bio-oil, solid biochar, and pyrolytic gas. In the application, biomass pyrolysis can be divided into three main categories; slow, fast and flash pyrolysis mainly aiming at maximizing the products of bio-oil or biochar. The temperature of synthesis gas generated during processes can be used for Organic Rankine Cycle to generate power. The heat from synthesis gas during pyrolysis processes was transfer by thermal oil heater to evaporate ORC working fluid in the evaporator unit. In this study, the potential of the palm oil empty fruit bunch, palm oil shell, and tree bark have been used as fuel from biomass to generate electricity by integrated with ORC. The Syltherm-XLT thermal oil was used as the heat carrier from combustion burner, while R245fa was used as the working fluid for ORC system. Through Aspen Plus, this study analyses the influences on performance of main thermodynamic parameters, showing the possibilities of reaching an optimum performance for different working conditions that are characteristics of different design parameters.

  13. Admittance spectroscopy of spray-pyrolyzed ZnO film

    International Nuclear Information System (INIS)

    Kavasoglu, Nese; Kavasoglu, A. Sertap

    2008-01-01

    A ZnO film was deposited using the spray pyrolysis method. The admittance spectroscopy method was used to establish the contributions to electrical behavior from grains, grain boundaries, and electrodes of film. Proper equivalent electrical circuit of a ZnO film composed of a single parallel resistor, capacitor, and inductor network connected with a series resistance was proposed. Moreover, we displayed metal-semiconductor transition (MST) in the ZnO film via admittance spectroscopy

  14. Pyrolysis characteristics of typical biomass thermoplastic composites

    Science.gov (United States)

    Cai, Hongzhen; Ba, Ziyu; Yang, Keyan; Zhang, Qingfa; Zhao, Kunpeng; Gu, Shiyan

    The biomass thermoplastic composites were prepared by extrusion molding method with poplar flour, rice husk, cotton stalk and corn stalk. The thermo gravimetric analyzer (TGA) has also been used for evaluating the pyrolysis process of the composites. The results showed that the pyrolysis process mainly consists of two stages: biomass pyrolysis and the plastic pyrolysis. The increase of biomass content in the composite raised the first stage pyrolysis peak temperature. However, the carbon residue was reduced and the pyrolysis efficiency was better because of synergistic effect of biomass and plastic. The composite with different kinds of biomass have similar pyrolysis process, and the pyrolysis efficiency of the composite with corn stalk was best. The calcium carbonate could inhibit pyrolysis process and increase the first stage pyrolysis peak temperature and carbon residue as a filling material of the composite.

  15. Synthesis and characterization of Yb and Er based monosilicate powders and durability of plasma sprayed Yb2SiO5 coatings on C/C–SiC composites

    International Nuclear Information System (INIS)

    Khan, Zuhair S.; Zou Binglin; Huang Wenzhi; Fan Xizhi; Gu Lijian; Chen Xiaolong; Zeng Shuibing; Wang Chunjie; Cao Xueqiang

    2012-01-01

    Highlights: ► Ultra-pure rare-earth monosilicate powders based on Er and Yb have been fabricated by solid-state reaction. ► Spray-drying treatment results in powders with free flowing characteristics and rounded surface morphologies. ► CTEs are found to be 7.1 ppm/°C for Yb 2 SiO 5 and 7.5 ppm/°C for Er 2 SiO 5 . ► Plasma spraying has been used to deposit Yb 2 SiO 5 coatings on C/C–SiC substrate. ► Coatings remain strongly intact with the substrate on thermal cycling between ∼400 °C and 1500 °C in gas burner rig experiment. - Abstract: Rare-earth silicates such as Yb 2 SiO 5 and Er 2 SiO 5 are promising environmental barrier coating materials for ceramic matrix composites. In this work, Yb 2 SiO 5 and Er 2 SiO 5 ceramic powders have been synthesized by solid-state reaction using Yb 2 O 3 , Er 2 O 3 and SiO 2 as starting materials. The fabricated powders were subjected to spray drying treatment for subsequent synthesis of coatings by plasma spraying. The spray drying resulted in well-dispersed and spherical powder particles with good flowability. Analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry and differential scanning calorimetry (TGA/DSC) and dilatometry were applied to study the microstructural and thermal characteristics of the powders. Ultra-high purity monosilicate powders formed as a result of heating treatments at 1400 °C in a box furnace for 20 h. TG/DSC revealed the genesis temperatures of the silicate formation (low temperature polymorphs) and also showed that the solid-state reactions to form Yb and Er based monosilicates proceeded without any weight-loss in the tested temperature range. The values of coefficients of thermal expansion (CTE) of the fabricated compounds are found to be 7.1 ppm/°C for Yb 2 SiO 5 and 7.5 ppm/°C for Er 2 SiO 5 by dilatometric measurements. Besides these studies, coating formation by plasma spraying of spray-dried Yb 2 SiO 5 powders on the ceramic

  16. Pyrolysis and oxidative pyrolysis experiments with organization exchange resin

    International Nuclear Information System (INIS)

    Chun, Ung Kyung

    1997-01-01

    Pyrolysis may be an important pretreatment step before vitrification in a cold crucible melter (CCM). During vitrification of organic resin the carbon or other remaining residues may harm the performance of the cold crucible melter of the eventual stability of the final glass product. Hence, it is important to reduce or prevent such harmful waste from entry into the cold crucible melter. Pretreatment with pyrolysis will generally provide volume reduction resulting in less amount of solid waste that needs to be handled by the CCM; in addition, the pyrolytic processes may breakdown much of the complex organics causing release through volatilization resulting in less carbon and other harmful substances. Hence, KEPRI has undertaken studies on the pyrolysis and oxidative pyrolysis of organic ion exchange resin. Pyrolysis and oxidative pyrolysis were examined with TGA and a tube furnace. TGA results for pyrolysis with the flow of nitrogen indicate that even after pyrolyzing from room temperature to about 900 deg C, a significant mass fraction of the original cationic resin remains, approximately 46 %. The anionic resin when pyrolytically heated in a flow of nitrogen only, from room temperature to about 900 deg C, produced a final residue mass fraction of about 8 percent. Oxidation at a ratio of air to nitrogen, 1:2, reduced the cationic resin to 5.3% when heated at 5 C/min. Oxidation of anionic resin at the same ratio and same heating rate left almost no solid residue. Pyrolysis (e.g. nitrogen-only environment) in the tube furnace of larger samples relative to the TGA produced very similar results to the TGA. The differences may be attributed to the scale effects such as surface area exposure to the gas stream, temperature distributions throughout the resin, etc. (author) 7 refs., 7 figs

  17. Pyrolysis and oxidative pyrolysis experiments with organization exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Ung Kyung [Korea Electric Power Research Insititute, Taejon (Korea, Republic of)

    1997-12-31

    Pyrolysis may be an important pretreatment step before vitrification in a cold crucible melter (CCM). During vitrification of organic resin the carbon or other remaining residues may harm the performance of the cold crucible melter of the eventual stability of the final glass product. Hence, it is important to reduce or prevent such harmful waste from entry into the cold crucible melter. Pretreatment with pyrolysis will generally provide volume reduction resulting in less amount of solid waste that needs to be handled by the CCM; in addition, the pyrolytic processes may breakdown much of the complex organics causing release through volatilization resulting in less carbon and other harmful substances. Hence, KEPRI has undertaken studies on the pyrolysis and oxidative pyrolysis of organic ion exchange resin. Pyrolysis and oxidative pyrolysis were examined with TGA and a tube furnace. TGA results for pyrolysis with the flow of nitrogen indicate that even after pyrolyzing from room temperature to about 900 deg C, a significant mass fraction of the original cationic resin remains, approximately 46 %. The anionic resin when pyrolytically heated in a flow of nitrogen only, from room temperature to about 900 deg C, produced a final residue mass fraction of about 8 percent. Oxidation at a ratio of air to nitrogen, 1:2, reduced the cationic resin to 5.3% when heated at 5 C/min. Oxidation of anionic resin at the same ratio and same heating rate left almost no solid residue. Pyrolysis (e.g. nitrogen-only environment) in the tube furnace of larger samples relative to the TGA produced very similar results to the TGA. The differences may be attributed to the scale effects such as surface area exposure to the gas stream, temperature distributions throughout the resin, etc. (author) 7 refs., 7 figs.

  18. Optical fuel spray measurements

    Energy Technology Data Exchange (ETDEWEB)

    Hillamo, H.

    2011-07-01

    Diesel fuel sprays, including fuel/air mixing and the physics of two-phase jet formation, are discussed in the thesis. The fuel/air mixing strongly affects emissions formation in spray combustion processes where the local combustion conditions dictate the emission formation. This study comprises optical measurements both in pressurized spray test rigs and in a running engine.The studied fuel injection was arranged with a common rail injection system and the injectors were operated with a solenoid-based injection valve. Both marine and heavy-duty diesel engine injectors were used in the study. Optical fuel spray measurements were carried out with a laser-based double-framing camera system. This kind of equipments is usually used for flow field measurements with Particle Image Velocimetry technique (PIV) as well as for backlight imaging. Fundamental fuel spray properties and spray formation were studied in spray test rigs. These measurements involved studies of mixing, atomization, and the flow field. Test rig measurements were used to study the effect of individual injection parameters and component designs. Measurements of the fuel spray flow field, spray penetration, spray tip velocity, spray angle, spray structure, droplet accumulation, and droplet size estimates are shown. Measurement campaign in a running optically accessible large-bore medium-speed engine was also carried out. The results from engine tests were compared with equivalent test rig measurements, as well as computational results, to evaluate the level of understanding of sprays. It was shown that transient spray has an acceleration and a deceleration phase. Successive flow field measurements (PIV) in optically dense diesel spray resulted in local and average velocity data of diesel sprays. Processing fuel spray generates a flow field to surrounding gas and entrainment of surrounding gas into fuel jet was also seen at the sides of the spray. Laser sheet imaging revealed the inner structure of diesel

  19. Detection of H2S gas at lower operating temperature using sprayed ...

    Indian Academy of Sciences (India)

    Nanostructured In2O3; thin films; spray pyrolysis; H2S gas sensor; low temperature. 1. Introduction ... nozzle to and fro frequency (16 cycles/min), nozzle to sub- ... were confirmed by measuring the thermoelectric power of the thin film samples.

  20. Synthesis of nickel oxide nanospheres by a facile spray drying method and their application as anode materials for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Anguo, E-mail: hixiaoanguo@126.com; Zhou, Shibiao; Zuo, Chenggang; Zhuan, Yongbing; Ding, Xiang

    2015-10-15

    Graphical abstract: NiO nanospheres prepared by a facile spray drying method show high lithium ion storage performance as anode of lithium ion battery. - Highlights: • NiO nanospheres are prepared by a spray drying method. • NiO nanospheres are composed of interconnected nanoparticles. • NiO nanospheres show good lithium ion storage properties. - Abstract: Fabrication of advanced anode materials is indispensable for construction of high-performance lithium ion batteries. In this work, nickel oxide (NiO) nanospheres are fabricated by a facial one-step spray drying method. The as-prepared NiO nanospheres show diameters ranging from 100 to 600 nm and are composed of nanoparticles of 30–50 nm. As an anode for lithium ion batteries, the electrochemical properties of the NiO nanospheres are investigated by cyclic voltammetry (CV) and galvanostatic charge/discharge tests. The specific reversible capacity of NiO nanospheres is 656 mA h g{sup −1} at 0.1 C, and 476 mA h g{sup −1} at 1 C. The improvement of electrochemical properties is attributed to nanosphere structure with large surface area and short ion/electron transfer path.

  1. Synthesis of nickel oxide nanospheres by a facile spray drying method and their application as anode materials for lithium ion batteries

    International Nuclear Information System (INIS)

    Xiao, Anguo; Zhou, Shibiao; Zuo, Chenggang; Zhuan, Yongbing; Ding, Xiang

    2015-01-01

    Graphical abstract: NiO nanospheres prepared by a facile spray drying method show high lithium ion storage performance as anode of lithium ion battery. - Highlights: • NiO nanospheres are prepared by a spray drying method. • NiO nanospheres are composed of interconnected nanoparticles. • NiO nanospheres show good lithium ion storage properties. - Abstract: Fabrication of advanced anode materials is indispensable for construction of high-performance lithium ion batteries. In this work, nickel oxide (NiO) nanospheres are fabricated by a facial one-step spray drying method. The as-prepared NiO nanospheres show diameters ranging from 100 to 600 nm and are composed of nanoparticles of 30–50 nm. As an anode for lithium ion batteries, the electrochemical properties of the NiO nanospheres are investigated by cyclic voltammetry (CV) and galvanostatic charge/discharge tests. The specific reversible capacity of NiO nanospheres is 656 mA h g −1 at 0.1 C, and 476 mA h g −1 at 1 C. The improvement of electrochemical properties is attributed to nanosphere structure with large surface area and short ion/electron transfer path

  2. Fixed automated spray technology.

    Science.gov (United States)

    2011-04-19

    This research project evaluated the construction and performance of Boschungs Fixed Automated : Spray Technology (FAST) system. The FAST system automatically sprays de-icing material on : the bridge when icing conditions are about to occur. The FA...

  3. Hair spray poisoning

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002705.htm Hair spray poisoning To use the sharing features on this page, please enable JavaScript. Hair spray poisoning occurs when someone breathes in (inhales) ...

  4. Remotely controlled spray gun

    Science.gov (United States)

    Cunningham, William C. (Inventor)

    1987-01-01

    A remotely controlled spray gun is described in which a nozzle and orifice plate are held in precise axial alignment by an alignment member, which in turn is held in alignment with the general outlet of the spray gun by insert. By this arrangement, the precise repeatability of spray patterns is insured.

  5. Gas-phase synthesis of magnetic metal/polymer nanocomposites

    Science.gov (United States)

    Starsich, Fabian H. L.; Hirt, Ann M.; Stark, Wendelin J.; Grass, Robert N.

    2014-12-01

    Highly magnetic metal Co nanoparticles were produced via reducing flame spray pyrolysis, and directly coated with an epoxy polymer in flight. The polymer content in the samples varied between 14 and 56 wt% of nominal content. A homogenous dispersion of Co nanoparticles in the resulting nanocomposites was visualized by electron microscopy. The size and crystallinity of the metallic fillers was not affected by the polymer, as shown by XRD and magnetic hysteresis measurements. The good control of the polymer content in the product nanocomposite was shown by elemental analysis. Further, the successful polymerization in the gas phase was demonstrated by electron microscopy and size measurements. The presented effective, dry and scalable one-step synthesis method for highly magnetic metal nanoparticle/polymer composites presented here may drastically decrease production costs and increase industrial yields.

  6. Extent of pyrolysis impacts on fast pyrolysis biochar properties.

    Science.gov (United States)

    Brewer, Catherine E; Hu, Yan-Yan; Schmidt-Rohr, Klaus; Loynachan, Thomas E; Laird, David A; Brown, Robert C

    2012-01-01

    A potential concern about the use of fast pyrolysis rather than slow pyrolysis biochars as soil amendments is that they may contain high levels of bioavailable C due to short particle residence times in the reactors, which could reduce the stability of biochar C and cause nutrient immobilization in soils. To investigate this concern, three corn ( L.) stover fast pyrolysis biochars prepared using different reactor conditions were chemically and physically characterized to determine their extent of pyrolysis. These biochars were also incubated in soil to assess their impact on soil CO emissions, nutrient availability, microorganism population growth, and water retention capacity. Elemental analysis and quantitative solid-state C nuclear magnetic resonance spectroscopy showed variation in O functional groups (associated primarily with carbohydrates) and aromatic C, which could be used to define extent of pyrolysis. A 24-wk incubation performed using a sandy soil amended with 0.5 wt% of corn stover biochar showed a small but significant decrease in soil CO emissions and a decrease in the bacteria:fungi ratios with extent of pyrolysis. Relative to the control soil, biochar-amended soils had small increases in CO emissions and extractable nutrients, but similar microorganism populations, extractable NO levels, and water retention capacities. Corn stover amendments, by contrast, significantly increased soil CO emissions and microbial populations, and reduced extractable NO. These results indicate that C in fast pyrolysis biochar is stable in soil environments and will not appreciably contribute to nutrient immobilization. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  7. Bulk synthesis by spray forming of Al–Cu–Fe and Al–Cu–Fe–Sn alloys containing a quasicrystalline phase

    International Nuclear Information System (INIS)

    Srivastava, V.C.; Huttunen-Saarivirta, E.; Cui, C.; Uhlenwinkel, V.; Schulz, A.; Mukhopadhyay, N.K.

    2014-01-01

    Highlights: • 40 kg Bulk material spray formed based on Al–Cu–Fe and Al–Cu–Fe + Sn. • Deposited Al–Cu–Fe alloy showed single phase bulk quasicrystals(QC). • DSC, XRD and microscopic analyses were done to ascertain the QC nature. • Sn does not help in single phase quasicrystal formation in the deposit. • The possible structural evolution mechanisms have been discussed in detail. - Abstract: In this study, Al–Cu–Fe alloys without and with the addition of Sn and containing a quasicrystalline phase were spray deposited. The spray-deposited bulk materials were characterized in terms of microstructure and hardness. The results showed that the Al 62.5 Cu 25 Fe 12.5 alloy contains the icosahedral quasicrystalline phase (i-phase) along with the minor λ-Al 13 Fe 4 phase, whereas the Al 62.5 Cu 25 Fe 12.5 + Sn alloy contains five phases: the major i-phase and the crystalline phases of Sn, θ-Al 2 Cu, λ-Al 13 Fe 4 and β-AlFe(Cu) phases. These results have been corroborated by X-ray diffraction (XRD), scanning and transmission electron microscopies (SEM and TEM) and differential scanning calorimetry (DSC). The hardness value of the Al–Cu–Fe alloy reached 10.5 GPa at 50 g load and then decreased steadily with increase in the applied load, while that for Al–Cu–Fe–Sn alloy it was originally somewhat lower, then decreased dramatically with slight increase in the applied load but stayed constant with further load increase. The hardness indentations in Al–Cu–Fe alloy introduced cracking in the material, whereas in the case of Al–Cu–Fe–Sn alloy the Sn-rich areas inhibited the crack growth. The present study provides an insight into the mechanism of phase and microstructural evolutions during spray forming of the studied alloys. Furthermore, the role of Sn in terms of microstructure and properties is highlighted

  8. Fast Pyrolysis of Lignin Using a Pyrolysis Centrifuge Reactor

    DEFF Research Database (Denmark)

    Trinh, Ngoc Trung; Jensen, Peter Arendt; Sárossy, Zsuzsa

    2013-01-01

    Fast pyrolysis of lignin from an ethanol plant was investigated on a lab scale pyrolysis centrifuge reactor (PCR) with respect to pyrolysis temperature, reactor gas residence time, and feed rate. A maximal organic oil yield of 34 wt % dry basis (db) (bio-oil yield of 43 wt % db) is obtained...... at temperatures of 500−550 °C, reactor gas residence time of 0.8 s, and feed rate of 5.6 g/min. Gas chromatography mass spectrometry and size-exclusion chromatography were used to characterize the Chemical properties of the lignin oils. Acetic acid, levoglucosan, guaiacol, syringols, and p-vinylguaiacol are found...... components and molecular mass distribution of the lignin oils. The obtained lignin oil has a very different components composition when compared to a beech wood oil....

  9. Fuels Combustion Research: Supercritical Fuel Pyrolysis

    National Research Council Canada - National Science Library

    Glassman, Irvin

    2001-01-01

    .... The focus during the subject period was directed to understanding the pyrolysis and combustion of endothermic fuels under subcritical conditions and the pyrolysis of these fuels under supercritical conditions...

  10. Fuels Combustion Research: Supercritical Fuel Pyrolysis

    National Research Council Canada - National Science Library

    Glassman, Irvin

    2000-01-01

    .... The focus during the subject period was directed to understanding the pyrolysis and combustion of endothermic fuels under subcritical conditions and the pyrolysis of these fuels under supercritical conditions...

  11. Pyrolysis of Coconut Shell: An Experimental Investigation

    Directory of Open Access Journals (Sweden)

    E. Ganapathy Sundaram

    2009-12-01

    Full Text Available Fixed-bed slow pyrolysis experiments of coconut shell have been conducted to determine the effect of pyrolysis temperature, heating rate and particle size on the pyrolysis product yields. The effect of vapour residence time on the pyrolysis yield was also investigated by varying the reactor length. Pyrolysis experiments were performed at pyrolysis temperature between 400 and 600°C with a constant heating rate of 60°C/min and particle sizes of 1.18-1.80 mm. The optimum process conditions for maximizing the liquid yield from the coconut shell pyrolysis in a fixed bed reactor were also identified. The highest liquid yield was obtained at a pyrolysis temperature of 550 °C, particle size of 1.18-1.80 mm, with a heating rate of 60 °C/min in a 200 mm length reactor. The yield of obtained char, liquid and gas was 22-31 wt%, 38-44 wt% and 30-33 wt% respectively at different pyrolysis conditions. The results indicate that the effects of pyrolysis temperature and particle size on the pyrolysis yield are more significant than that of heating rate and residence time. The various characteristics of pyrolysis oil obtained under the optimum conditions for maximum liquid yield were identified on the basis of standard test methods.

  12. Exploratory studies on fast pyrolysis oil upgrading

    NARCIS (Netherlands)

    Mahfud, Farchad Husein

    2007-01-01

    Pyrolysis oil is a dark brown liquid which can be produced in high yield from different kind of biomass sources by means of fast pyrolysis. Pyrolysis oil is considered as a promising second generation energy carrier and may play an important role in the future of "biobased economies". The energy

  13. Fractional condensation of biomass pyrolysis vapors

    NARCIS (Netherlands)

    Westerhof, Roel Johannes Maria; Brilman, Derk Willem Frederik; Garcia Perez, M.; Wang, Zhouhong; Oudenhoven, Stijn; van Swaaij, Willibrordus Petrus Maria; Kersten, Sascha R.A.

    2011-01-01

    In this paper, we have investigated the possibilities to steer the composition and, thus, the quality of pyrolysis liquids by the reactor temperature and the pyrolysis vapor condenser temperature. Pine wood was pyrolyzed in a 1 kg/h fluidized-bed pyrolysis reactor operated at 330 or 480 °C. The

  14. Synthesis, characterization and decomposition studies of tris(N,N-dibenzyldithiocarbamato)indium(III): chemical spray deposition of polycrystalline CuInS2 on copper films

    International Nuclear Information System (INIS)

    Hehemann, David G.; Lau, J. Eva; Harris, Jerry D.; Hoops, Michael D.; Duffy, Norman V.; Fanwick, Philip E.; Khan, Osman; Jin, Michael H.-C.; Hepp, Aloysius F.

    2005-01-01

    Tris(bis(phenylmethyl)carbamodithioato-S,S'), commonly referred to as tris(N,N-dibenzyldithiocarbamato)indium(III), In(S 2 CNBz 2 ) 3 , was synthesized and characterized by single crystal X-ray crystallography. The compound crystallizes in the triclinic space group P1-bar with two molecules per unit cell. The material was further characterized using a novel analytical system employing the combined powers of thermogravimetric analysis, gas chromatography/mass spectrometry, and Fourier transform infrared (FT-IR) spectroscopy to investigate its potential use as a precursor for the chemical vapor deposition (CVD) of thin film materials for photovoltaic applications. Upon heating, the material thermally decomposes to release CS 2 and benzyl moieties in to the gas phase, resulting in bulk In 2 S 3 . Preliminary spray CVD experiments indicate that In(S 2 CNBz 2 ) 3 decomposed on a Cu substrate reacts to produce stoichiometric CuInS 2 films

  15. Synthesis, Characterization and Decomposition Studies of Tris(N,N-dibenzyldithiocarbamato) Indium(III): Chemical Spray Deposition of Polycrystalline CuInS2 on Copper Films

    Science.gov (United States)

    Hehemann, David G.; Lau, J. Eva; Harris, Jerry D.; Hoops, Michael D.; Duffy, Norman V.; Fanwick, Philip E.; Khan, Osman; Jin, Michael H.-C.; Hepp, Aloysius F.

    2005-01-01

    Tris(bis(phenylmethyl)carbamodithioato-S,S ), commonly referred to as tris(N,Ndibenzyldithiocarbamato) indium(III), In(S2CNBz2)3, was synthesized and characterized by single crystal X-ray crystallography. The compound crystallizes in the triclinic space group P1 bar with two molecules per unit cell. The material was further characterized using a novel analytical system employing the combined powers of thermogravimetric analysis, gas chromatography/mass spectrometry and Fourier-Transform infrared spectroscopy to investigate its potential use as a precursor for the chemical vapor deposition (CVD) of thin film materials for photovoltaic applications. Upon heating, the material thermally decomposes to release CS2 and benzyl moieties in to the gas phase, resulting in bulk In2S3. Preliminary spray CVD experiments indicate that In(S2CNBz2)3 decomposed on a Cu substrate reacts to produce stoichiometric CuInS2 films.

  16. Production, properties and utilisation of pyrolysis oil

    Energy Technology Data Exchange (ETDEWEB)

    Sipilae, K; Oasmaa, A; Arpiainen, V; Solantausta, Y; Leppaemaeki, E; Kuoppala, E; Levander, J; Kleemola, J; Saarimaeki, P [VTT Energy, Jyvaeskylae (Finland). Energy Production Technologies

    1997-12-01

    In this project VTT Energy co-ordinates the EU JOULE Project `Biofuel oil for power plants and boilers` supporting the development projects of Finnish enterprises, and participates in the Pyrolysis Project of IEA Bioenergy Agreement. Presently two pyrolysis devices with capacities of 150 g/h and 1 kg/h are used for the project. Hot gas filtering tests by using one ceramic candle equipment have been carried out with the 1 kg/h device for pyrolysis oil. The solids and alkali contents of the product oil were reduced clearly. Suitable conditions are being defined for continuous hot gas filtering. A PDU device of 20 kg/h is being commissioned. The main aim of the chemical characterisation of pyrolysis oil was to develop as simple a method as possible for differentiating pyrolysis oils and for finding correlations between the characteristics and behaviour of pyrolysis oils. Pyrolysis oils produced from various raw materials (hardwood, pine, straw) were analysed and compared with each other. VTT Energy participates in the pyrolysis network (EU/PYNE) of EU, the aim of which is to collect and disseminate research results of pyrolysis studies, i.e., through a journal with a wide circulation. VTT also participates in the pyrolysis activity of IEA (PYRA), the other partners being Great Britain, EU, Canada and the United States. I.e., quality criteria and improvement, occupational safety and pyrolysis kinetics are discussed in IEA/PYRA

  17. Cold spray nozzle design

    Science.gov (United States)

    Haynes, Jeffrey D [Stuart, FL; Sanders, Stuart A [Palm Beach Gardens, FL

    2009-06-09

    A nozzle for use in a cold spray technique is described. The nozzle has a passageway for spraying a powder material, the passageway having a converging section and a diverging section, and at least the diverging section being formed from polybenzimidazole. In one embodiment of the nozzle, the converging section is also formed from polybenzimidazole.

  18. Characterization of ultrasonic spray pyrolysed ruthenium oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Patil, P.S.; Ennaoui, E.A.; Lokhande, C.D.; Mueller, M.; Giersig, M.; Diesner, K.; Tributsch, H. [Hahn-Meitner-Institut Berlin GmbH (Germany). Bereich Physikalische Chemie

    1997-11-21

    The ultrasonic spray pyrolysis (USP) technique was employed to deposit ruthenium oxide thin films. The films were prepared at 190 C substrate temperature and further annealed at 350 C for 30 min in air. The films were 0.22 {mu} thick and black grey in color. The structural, compositional and optical properties of ruthenium oxide thin films are reported. Contactless transient photoconductivity measurement was carried out to calculate the decay time of excess charge carriers in ruthenium oxide thin films. (orig.) 28 refs.

  19. Pyrolysis of rubber gloves in integral pyrolysis test plant

    International Nuclear Information System (INIS)

    Norasalwa Zakaria; Mohd Noor Muhd Yunus; Mohd Annuar Assadat Husain; Farid Nasir Ani

    2010-01-01

    Previously, pyrolysis of rubber gloves in laboratory study was described. In order to visualize the practical application of rubber gloves pyrolysis in terms of treating rubber gloves in medical waste, a new test plant was designed and constructed. The semi-continuous test plant was designed to accommodate rubber gloves that were not cut or shredded. The test plant has a capacity of 2kg/ hr and employed auxiliary fuel instead of the conventional electrical power for heating. The concept was based on moving bed reactor, but additional feature of sand jacket feature was also introduced in the design. Pyrolysis of the gloves was conducted at three temperatures, namely 350 degree Celsius, 400 degree Celsius and 450 degree Celsius. Oxygen presents inside of the reactor due to the combined effect of imperfect sealing and suction effect. This study addresses the performance of this test plant covering the time temperature profile, gas evolution profile and product yield. Comparison between the yield of the liquid, gas and char pyrolyzate was made against the laboratory study. It was found that the oil yield was less than the one obtained from bench scale study. Water formation was more pronounced. The presence of the oxygen also altered the tail gas composition but eliminate the sticky nature of solid residue, making it easier to handle. The chemical composition of the oil was determined and the main compounds in the oil were esters and phtalic acid. (author)

  20. Electrostatically atomised hydrocarbon sprays

    Energy Technology Data Exchange (ETDEWEB)

    Yule, A.J.; Shrimpton, J.S.; Watkins, A.P.; Balachandran, W.; Hu, D. [UMIST, Manchester (United Kingdom). Thermofluids Division, Dept. of Mechanical Engineering

    1995-07-01

    A burner using an electrostatic method to produce and control a fuel spray is investigated for non-burning sprays. The burner has a charge injection nozzle and the liquid flow rate and charge injection rate are varied using hydrocarbon liquids of differing viscosities, surface tensions and electrical conductivities (kerosene, white spirit and diesel oil). Droplet size distributions are measured and it is shown how the dropsize, spray pattern, breakup mechanism and breakup length depend on the above variables, and in particular on the specific charge achieved in the spray. The data are valuable for validating two computer models under development. One predicts the electric field and flow field inside the nozzle as a function of emitter potential, geometry and flow rate. The other predicts the effect of charge on spray dispersion, with a view to optimizing spray combustion. It is shown that electrostatic disruptive forces can be used to atomize oils at flow rates commensurate with practical combustion systems and that the charge injection technique is particularly suitable for highly resistive liquids. Possible limitations requiring further research include the need to control the wide spray angle, which may provide fuel-air mixtures too lean near the nozzle, and the need to design for maximum charge injection rate, which is thought to be limited by corona breakdown in the gas near the nozzle orifice. 30 refs., 15 figs., 1 tab.

  1. Thermal Arc Spray Overview

    Science.gov (United States)

    Hafiz Abd Malek, Muhamad; Hayati Saad, Nor; Kiyai Abas, Sunhaji; Mohd Shah, Noriyati

    2013-06-01

    Usage of protective coating for corrosion protection was on highly demand during the past decade; and thermal spray coating played a major part during that time. In recent years, the thermal arc spray coating becomes a popular coating. Many big players in oil and gas such as PETRONAS, EXXON MOBIL and SHELL in Malaysia tend to use the coating on steel structure as a corrosion protection. Further developments in coating processes, the devices, and raw materials have led to expansion of functional coatings and applications scope from conventional coating to specialized industries. It is widely used because of its ability to withstand high process temperature, offer advantages in efficiency, lower cost and acts as a corrosion protection. Previous research also indicated that the thermal arc spray offers better coating properties compared to other methods of spray. This paper reviews some critical area of thermal spray coating by discussing the process/parameter of thermal arc spray technology and quality control of coating. Coating performance against corrosion, wear and special characteristic of coating are also described. The field application of arc spray technology are demonstrated and reviewed.

  2. Thermal Arc Spray Overview

    International Nuclear Information System (INIS)

    Malek, Muhamad Hafiz Abd; Saad, Nor Hayati; Abas, Sunhaji Kiyai; Shah, Noriyati Mohd

    2013-01-01

    Usage of protective coating for corrosion protection was on highly demand during the past decade; and thermal spray coating played a major part during that time. In recent years, the thermal arc spray coating becomes a popular coating. Many big players in oil and gas such as PETRONAS, EXXON MOBIL and SHELL in Malaysia tend to use the coating on steel structure as a corrosion protection. Further developments in coating processes, the devices, and raw materials have led to expansion of functional coatings and applications scope from conventional coating to specialized industries. It is widely used because of its ability to withstand high process temperature, offer advantages in efficiency, lower cost and acts as a corrosion protection. Previous research also indicated that the thermal arc spray offers better coating properties compared to other methods of spray. This paper reviews some critical area of thermal spray coating by discussing the process/parameter of thermal arc spray technology and quality control of coating. Coating performance against corrosion, wear and special characteristic of coating are also described. The field application of arc spray technology are demonstrated and reviewed.

  3. Reactor container spray device

    International Nuclear Information System (INIS)

    Yanai, Ryoichi.

    1980-01-01

    Purpose: To enable decrease in the heat and the concentration of radioactive iodine released from the reactor vessel into the reactor container in the spray device of BWR type reactors. Constitution: A plurality of water receiving trays are disposed below the spray nozzle in the dry well and communicated to a pressure suppression chamber by way of drain pipeways passing through a diaphragm floor. When the recycling system is ruptured and coolants in the reactor vessel and radioactive iodine in the reactor core are released into the dry well, spray water is discharged from the spray nozzle to eliminate the heat and the radioactive iodine in the dry well. In this case, the receiving trays collect the portions of spray water whose absorption power for the heat and radioactive iodine is nearly saturated and falls them into the pool water of the pressure suppression chamber. Consequently, other portions of the spray water that still possess absorption power can be jetted with no hindrance, to increase the efficiency for the removal of the heat and iodine of the spray droplets. (Horiuchi, T.)

  4. Slow pyrolysis of pistachio shell

    Energy Technology Data Exchange (ETDEWEB)

    Apaydin-Varol, Esin; Putun, Ersan; Putun, Ayse E [Anadolu University, Eskisehir (Turkey). Department of Chemical Engineering

    2007-08-15

    In this study, pistachio shell is taken as the biomass sample to investigate the effects of pyrolysis temperature on the product yields and composition when slow pyrolysis is applied in a fixed-bed reactor at atmospheric pressure to the temperatures of 300, 400, 500, 550, 700{sup o}C. The maximum liquid yield was attained at about 500-550{sup o}C with a yield of 20.5%. The liquid product obtained under this optimum temperature and solid products obtained at all temperatures were characterized. As well as proximate and elemental analysis for the products were the basic steps for characterization, column chromatography, FT-IR, GC/MS and SEM were used for further characterization. The results showed that liquid and solid products from pistachio shells show similarities with high value conventional fuels. 31 refs., 9 figs., 1 tab.

  5. Catalytic Fast Pyrolysis: A Review

    Directory of Open Access Journals (Sweden)

    Theodore Dickerson

    2013-01-01

    Full Text Available Catalytic pyrolysis is a promising thermochemical conversion route for lignocellulosic biomass that produces chemicals and fuels compatible with current, petrochemical infrastructure. Catalytic modifications to pyrolysis bio-oils are geared towards the elimination and substitution of oxygen and oxygen-containing functionalities in addition to increasing the hydrogen to carbon ratio of the final products. Recent progress has focused on both hydrodeoxygenation and hydrogenation of bio-oil using a variety of metal catalysts and the production of aromatics from bio-oil using cracking zeolites. Research is currently focused on developing multi-functional catalysts used in situ that benefit from the advantages of both hydrodeoxygenation and zeolite cracking. Development of robust, highly selective catalysts will help achieve the goal of producing drop-in fuels and petrochemical commodities from wood and other lignocellulosic biomass streams. The current paper will examine these developments by means of a review of existing literature.

  6. Desulfurized gas production from vertical kiln pyrolysis

    Science.gov (United States)

    Harris, Harry A.; Jones, Jr., John B.

    1978-05-30

    A gas, formed as a product of a pyrolysis of oil shale, is passed through hot, retorted shale (containing at least partially decomposed calcium or magnesium carbonate) to essentially eliminate sulfur contaminants in the gas. Specifically, a single chambered pyrolysis vessel, having a pyrolysis zone and a retorted shale gas into the bottom of the retorted shale zone and cleaned product gas is withdrawn as hot product gas near the top of such zone.

  7. Catalytic partial oxidation of pyrolysis oils

    Science.gov (United States)

    Rennard, David Carl

    2009-12-01

    details the catalytic partial oxidation of glycerol without preheat: droplets of glycerol are sprayed directly onto the top of the catalyst bed, where they react autothermally with contact times on the order of tau ≈ 30 ms. The reactive flash volatilization of glycerol results in equilibrium syngas production over Rh-Ce catalysts. In addition, water can be added to the liquid glycerol, resulting in true autothermal reforming. This highly efficient process can increase H2 yields and alter the H2 to CO ratio, allowing for flexibility in syngas quality depending on the purpose. Chapter 5 details the results of a time on stream experiment, in which optimal syngas conditions are chosen. Although conversion is 100% for 450 hours, these experiments demonstrate the deactivation of the catalyst over time. Deactivation is exhibited by decreases in H2 and CO 2 production accompanied by a steady increase in CO and temperature. These results are explained as a loss of water-gas shift equilibration. SEM images suggest catalyst sintering may play a role; EDS indicates the presence of impurities on the catalyst. In addition, the instability of quartz in the reactor is demonstrated by etching, resulting in a hole in the reactor tube at the end of the experiment. These results suggest prevaporization may be desirable in this application, and that quartz is not a suitable material for the reactive flash volatilization of oxygenated fuels. In Chapter 6, pyrolysis oil samples from three sources - poplar, pine, and hardwoods - are explored in the context of catalytic partial oxidation. Lessons derived from the tests with model compounds are applied to reactor design, resulting in the reactive flash vaporization of bio oils. Syngas is successfully produced, though deactivation due to coke and ash deposition keeps H2 below equlibrium. Coke formation is observed on the reactor walls, but is avoided between the fuel injection site and catalyst by increasing the proximity of these in the reactor

  8. Modelling solid-convective flash pyrolysis of straw and wood in the Pyrolysis Centrifuge Reactor

    DEFF Research Database (Denmark)

    Bech, Niels; Larsen, Morten Boberg; Jensen, Peter Arendt

    2009-01-01

    in the Pyrolysis Centrifuge Reactor, a novel solid-convective flash pyrolysis reactor. The model relies on the original concept for ablative pyrolysis of particles being pyrolysed through the formation of an intermediate liquid compound which is further degraded to form liquid organics, char, and gas. To describe...

  9. Spray deposited gallium doped tin oxide thinfilm for acetone sensor application

    Science.gov (United States)

    Preethi, M. S.; Bharath, S. P.; Bangera, Kasturi V.

    2018-04-01

    Undoped and gallium doped (1 at.%, 2 at.% and 3 at.%) tin oxide thin films were prepared using spray pyrolysis technique by optimising the deposition conditions such as precursor concentration, substrate temperature and spraying rate. X-ray diffraction analysis revealed formation of tetragonally structured polycrystalline films. The SEM micrographs of Ga doped films showed microstructures. The electrical resistivity of the doped films was found to be more than that of the undoped films. The Ga-doped tin oxide thin films were characterised for gas sensors. 1 at.% Ga doped thin films were found to be better acetone gas sensor, showed 68% sensitivity at 350°C temperature.

  10. Thermal and catalytic pyrolysis of plastic waste

    Directory of Open Access Journals (Sweden)

    Débora Almeida

    2016-02-01

    Full Text Available Abstract The amount of plastic waste is growing every year and with that comes an environmental concern regarding this problem. Pyrolysis as a tertiary recycling process is presented as a solution. Pyrolysis can be thermal or catalytical and can be performed under different experimental conditions. These conditions affect the type and amount of product obtained. With the pyrolysis process, products can be obtained with high added value, such as fuel oils and feedstock for new products. Zeolites can be used as catalysts in catalytic pyrolysis and influence the final products obtained.

  11. Understanding the fast pyrolysis of lignin.

    Science.gov (United States)

    Patwardhan, Pushkaraj R; Brown, Robert C; Shanks, Brent H

    2011-11-18

    In the present study, pyrolysis of corn stover lignin was investigated by using a micro-pyrolyzer coupled with a GC-MS/FID (FID=flame ionization detector). The system has pyrolysis-vapor residence times of 15-20 ms, thus providing a regime of minimal secondary reactions. The primary pyrolysis product distribution obtained from lignin is reported. Over 84 % mass balance and almost complete closure on carbon balance is achieved. In another set of experiments, the pyrolysis vapors emerging from the micro-pyrolyzer are condensed to obtain lignin-derived bio-oil. The chemical composition of the bio-oil is analyzed by using GC-MS and gel permeation chromatography techniques. The comparison between results of two sets of experiments indicates that monomeric compounds are the primary pyrolysis products of lignin, which recombine after primary pyrolysis to produce oligomeric compounds. Further, the effect of minerals (NaCl, KCl, MgCl(2), and CaCl(2)) and temperature on the primary pyrolysis product distribution is investigated. The study provides insights into the fundamental mechanisms of lignin pyrolysis and a basis for developing more descriptive models of biomass pyrolysis. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Dynamics of flare sprays

    International Nuclear Information System (INIS)

    Tandberg-Hanssen, E.; Hansen, R.T.

    1980-01-01

    During solar cycle No. 20 new insight into the flare-spray phenomenon has been attained due to several innovations in solar optical-observing techniques (higher spatial resolution cinema-photography, tunable pass-band filters, multi-slit spectroscopy and extended angular field coronographs). From combined analysis of 13 well-observed sprays which occured between 1969-1974 we conclude that (i) the spray material originates from a preexisting active region filament which undergoes increased absorption some tens of minutes prior to the abrupt chromospheric brightening at the 'flare-start', and (ii) the spray material is confined within a steadily expanding, loop-shaped (presumably magnetically controlled) envelope with part of the material draining back down along one or both legs of the loop. (orig.)

  13. Triamcinolone Nasal Spray

    Science.gov (United States)

    ... class of medications called corticosteroids. It works by blocking the release of certain natural substances that cause ... 5 sprays into the air away from the face. If you have not used it for 2 ...

  14. Beclomethasone Nasal Spray

    Science.gov (United States)

    ... class of medications called corticosteroids. It works by blocking the release of certain natural substances that cause ... your thumb. Point the applicator away from your face. If you are using the spray for the ...

  15. Flunisolide Nasal Spray

    Science.gov (United States)

    ... class of medications called corticosteroids. It works by blocking the release of certain natural substances that cause ... your thumb. Point the applicator away from your face. If you are using the spray for the ...

  16. ROTARY SPRAY DUSTER

    Directory of Open Access Journals (Sweden)

    E. S. Nechaeva

    2013-01-01

    Full Text Available Results of researches of hydraulic resistance, ablation of splashes and efficiency of dedusting in the rotor spray dust collector are given. Influence of frequency of rotation of the spray, the specified speed of gas and diameter of spattering holes on hydraulic resistance, size ablation of splashes and efficiency of a dedusting the device by diameter 0,25 m is investigated. As model liquid water is used. Results of mathematical processing are presented.

  17. Thermal conditions for stopping pyrolysis of forest combustible material and applications to firefighting

    Directory of Open Access Journals (Sweden)

    Zhdanova Alena O.

    2017-01-01

    Full Text Available Five models describing heat transfer during evaporation of the water sprayed over the forest to stop fires and to cool down the pyrolysis of the bio- top layer are established and investigated by a parametric approach. It aims to improve the understanding of the behaviour and the properties of the forest combustible material. A mathematical description of forest combustible material surfaces (needles of pine and fir-tree, leaves of birch is established. The characteristic time, td, to cool down the forest combustible material layer below the temperature of the onset of the pyrolysis is the important parameter investigated in the present work. The effective conditions were determined allowing to reach the shortest td and the lowest consumption of e. g. water to be dropped.

  18. Spray deposited CeO2–TiO2 counter electrode for electrochromic ...

    Indian Academy of Sciences (India)

    Abstract. Optically passive thin films of CeO2–TiO2 mixed oxides with molar ratio of Ce/Ti of 0.05 were deposited by the spray pyrolysis technique (SPT) on a glass and fluorine-doped tin oxide (FTO)-coated glass substrates. Precur- sor solution containing cerium nitrate hexahydrate (Ce(NO3)2·6H2O) and titanium ...

  19. Rotor for a pyrolysis centrifuge reactor

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a rotor for a pyrolysis centrifuge reactor, said rotor comprising a rotor body having a longitudinal centre axis, and at least one pivotally mounted blade being adapted to pivot around a pivot axis under rotation of the rotor body around the longitudinal centre axis....... Moreover, the present invention relates to a pyrolysis centrifuge reactor applying such a rotor....

  20. Toxicity of pyrolysis gases from polyether sulfone

    Science.gov (United States)

    Hilado, C. J.; Olcomendy, E. M.

    1979-01-01

    A sample of polyether sulfone was evaluated for toxicity of pyrolysis gases, using the toxicity screening test method developed at the University of San Francisco. Animal response times were relatively short at pyrolysis temperatures of 600 to 800 C, with death occurring within 6 min. The principal toxicant appeared to be a compound other than carbon monoxide.

  1. Historical Developments of Pyrolysis Reactors : A Review

    NARCIS (Netherlands)

    Garcia-Nunez, J. A.; Pelaez-Samaniego, M.R.; Garcia-Perez, M. E.; Fonts, I.; Abrego, J.; Westerhof, R. J.M.; Garcia Perez, M.

    2017-01-01

    This paper provides a review of pyrolysis technologies, focusing on reactor designs and companies commercializing these technologies. The renewed interest in pyrolysis is driven by the potential to convert lignocellulosic materials into bio-oil and biochar and the use of these intermediates for the

  2. Flame spray technology method for production of nanopowders

    CERN Document Server

    Trommer, Rafael M

    2015-01-01

    This books presents a complete and updated overview of Flame Spray process, from its History to the Apparatus necessary for the synthesis of nanostructures. It addresses not only the materials produced by this technique, but also their properties, such as crystallinity and crystallite size, specific surface area, particle size and morphology. Also, the principles of nanoparticle formation are described. It is a useful read to all those interested in low cost synthesis of nanostructured powders and coatings.

  3. Spray boom for selectively spraying a herbicidal composition onto dicots

    DEFF Research Database (Denmark)

    2012-01-01

    There is provided a method and spray boom for discriminating cereal crop (monocot) and weeds (dicots). The spray boom includes means for digitally recording an image of a selected area to be treated by a nozzle on the spray boom, whereby a plant material is identified based on a segmentation proc...

  4. Droplets and sprays

    CERN Document Server

    Sazhin, Sergei

    2014-01-01

    Providing a clear and systematic description of droplets and spray dynamic models, this book maximises reader insight into the underlying physics of the processes involved, outlines the development of new physical and mathematical models, and broadens understanding of interactions between the complex physical processes which take place in sprays. Complementing approaches based on the direct application of computational fluid dynamics (CFD), Droplets and Sprays treats both theoretical and practical aspects of internal combustion engine process such as the direct injection of liquid fuel, subcritical heating and evaporation. Includes case studies that illustrate the approaches relevance to automotive applications,  it is also anticipated that the described models can find use in other areas such as in medicine and environmental science.

  5. Sprayed concrete linings

    Energy Technology Data Exchange (ETDEWEB)

    Hindle, D.

    1999-12-01

    Sprayed concrete, or shotcrete, was invented in the 1920s for preserving dinosaur skeletons and was used underground initially in coalmines for the preservation and fine proofing of timber supports. Its use as a support lining in rock tunnelling was developed in the 1950s and 60s. The article surveys equipment available from major manufacturers and suppliers of concrete spraying equipment (Aliva, Cifa, GIA, Industri, Ingersoll Rand, etc.), specialist cement and additive manufacturers (Castle, Cement, Moria Carbotech). manufacturers of lattice girders and fibre reinforcement, and manufacturers of instrumentation for tunnel linings. 5 tabs., 9 photos.

  6. SPRAY code user's report

    International Nuclear Information System (INIS)

    Shire, P.R.

    1977-03-01

    The SPRAY computer code has been developed to model the effects of postulated sodium spray release from LMFBR piping within containment chambers. The calculation method utilizes gas convection, heat transfer and droplet combustion theory to calculate the pressure and temperature effects within the enclosure. The applicable range is 0-21 mol percent oxygen and .02-.30 inch droplets with or without humidity. Droplet motion and large sodium surface area combine to produce rapid heat release and pressure rise within the enclosed volume

  7. Pyrolysis of spent ion-exchanger resins

    International Nuclear Information System (INIS)

    Slametschka, Rainer; Braehler, Georg

    2012-01-01

    Initial tests have shown that ion exchangers (IEX) can be decomposed by pyrolysis with very good results, yielding an inert and chemically resistant product. No additives are necessary. The main constituent of the product, the pyrolysis residues or ash, is carbon. It has been discovered that the entire radioactive inventory remains in the pyrolysis residues during pyrolysis of the IEX. This is achieved by relatively low process temperatures that prevent highly volatile nuclides such as the caesium nuclides from passing into the gaseous phase. Sintered metal filters in pyrolysis plant ensure that even the radioactivity bonded to the dust remains in the pyrolysis residues. In addition to the radionuclides, the main constituents of the residue are carbon from the original polystyrene matrix and sulphur from the functional groups. The pyrolysis residues form a flowable solid material and not a melt. It is thus easy to handle and can be compacted or cemented, depending on the requirements for interim and permanent storage. Any further constituents such as inorganic filter materials or even other organic materials do not interfere with the process, they are dried, calcined or also pyrolysed. (orig.)

  8. Effect of post annealing treatment on electrochromic properties of spray deposited niobium oxide thin films

    International Nuclear Information System (INIS)

    Mujawar, S.H.; Inamdar, A.I.; Betty, C.A.; Ganesan, V.; Patil, P.S.

    2007-01-01

    Niobium oxide thin films were deposited on the glass and fluorine doped tin oxide (FTO) coated glass substrates using simple and inexpensive spray pyrolysis technique. During deposition of the films various process parameters like nozzle to substrate distance, spray rate, concentration of sprayed solution were optimized to obtain well adherent and transparent films. The films prepared were further annealed and effect of post annealing on the structural, morphological, optical and electrochromic properties was studied. Structural and morphological characterizations of the films were carried out using scanning electron microscopy, atomic force microscopy and X-ray diffraction techniques. Electrochemical properties of the niobium oxide thin films were studied by using cyclic-voltammetry, chronoamperometry and chronocoulometry

  9. Thermal spray for commercial shipbuilding

    Science.gov (United States)

    Rogers, F. S.

    1997-09-01

    Thermal spraying of steel with aluminum to protect it from corrosion is a technology that has been proven to work in the marine environment. The thermal spray coating system includes a paint sealer that is applied over the thermally sprayed aluminum. This extends the service life of the coating and provides color to the end product. The thermal spray system protects steel both through the principle of isolation (as in painting) and galvanizing. With this dual protection mechanism, steel is protected from corrosion even when the coating is damaged. The thermal- sprayed aluminum coating system has proved the most cost- effective corrosion protection system for the marine environment. Until recently, however, the initial cost of application has limited its use for general application. Arc spray technology has reduced the application cost of thermal spraying of aluminum to below that of painting. Commercial shipbuilders could use this technology to enhance their market position in the marine industry.

  10. Fabrication of Semiconducting Methylammonium Lead Halide Perovskite Particles by Spray Technology

    Science.gov (United States)

    Ahmadian-Yazdi, Mohammad-Reza; Eslamian, Morteza

    2018-01-01

    In this "nano idea" paper, three concepts for the preparation of methylammonium lead halide perovskite particles are proposed, discussed, and tested. The first idea is based on the wet chemistry preparation of the perovskite particles, through the addition of the perovskite precursor solution to an anti-solvent to facilitate the precipitation of the perovskite particles in the solution. The second idea is based on the milling of a blend of the perovskite precursors in the dry form, in order to allow for the conversion of the precursors to the perovskite particles. The third idea is based on the atomization of the perovskite solution by a spray nozzle, introducing the spray droplets into a hot wall reactor, so as to prepare perovskite particles, using the droplet-to-particle spray approach (spray pyrolysis). Preliminary results show that the spray technology is the most successful method for the preparation of impurity-free perovskite particles and perovskite paste to deposit perovskite thin films. As a proof of concept, a perovskite solar cell with the paste prepared by the sprayed perovskite powder was successfully fabricated.

  11. Fabrication of Semiconducting Methylammonium Lead Halide Perovskite Particles by Spray Technology.

    Science.gov (United States)

    Ahmadian-Yazdi, Mohammad-Reza; Eslamian, Morteza

    2018-01-10

    In this "nano idea" paper, three concepts for the preparation of methylammonium lead halide perovskite particles are proposed, discussed, and tested. The first idea is based on the wet chemistry preparation of the perovskite particles, through the addition of the perovskite precursor solution to an anti-solvent to facilitate the precipitation of the perovskite particles in the solution. The second idea is based on the milling of a blend of the perovskite precursors in the dry form, in order to allow for the conversion of the precursors to the perovskite particles. The third idea is based on the atomization of the perovskite solution by a spray nozzle, introducing the spray droplets into a hot wall reactor, so as to prepare perovskite particles, using the droplet-to-particle spray approach (spray pyrolysis). Preliminary results show that the spray technology is the most successful method for the preparation of impurity-free perovskite particles and perovskite paste to deposit perovskite thin films. As a proof of concept, a perovskite solar cell with the paste prepared by the sprayed perovskite powder was successfully fabricated.

  12. Pyrolysis - gas chromatography - mass spectrometry of lignins

    Energy Technology Data Exchange (ETDEWEB)

    Martin, F; Saiz-Jimenez, C; Gonzalez-Vila, F J

    1979-01-01

    Milled wood lignins from spruce, beech and bamboo were pyrolysed. The high-boiling products of pyrolysis were studied by GLC and mass spectrometry. The forty-three products identified provide information on the structural units of lignin.

  13. Production of Lunar Oxygen Through Vacuum Pyrolysis

    National Research Council Canada - National Science Library

    Matchett, John

    2006-01-01

    .... The vacuum pyrolysis method of oxygen production from lunar regolith presents a viable option for in situ propellant production because of its simple operation involving limited resources from earth...

  14. Growth and physical investigations of sprayed ZnMoO4 thin films along with wettability tests

    Science.gov (United States)

    Askri, Besma; Mhamdi, Ammar; Mahdhi, Noureddine; Amlouk, Mosbah

    2018-06-01

    Ternary oxides based on zinc and molybdenum elements have known as semiconductor oxides with large band gap energies. With the focus mainly on their synthesis by cost-effective process as thin films, the aspect of their stability and reactivity as transparent layers against both UV radiation and oxidation under wet medium due to their oxygen deficiency has so far not been investigated. This work covers the synthesis as well as the structural, electrical and the wettability properties of ZnMoO4 thin films which have been prepared by the spray pyrolysis method on glass substrates at 460 °C. First, X-ray diffraction analysis shows that this oxide crystallizes in triclinic structure with the space group P-1. The thickness value of ZnMoO4 thin film of about 1.5 μm was estimated by spectroscopic ellipsometry (SE). Moreover, a special emphasis has been focused on the photoluminescence properties of such films to reach possible presence of defaults and oxygen vacancy. Second, the electrical conductivity, conduction mechanism, relaxation model of these films were indeed studied using impedance spectroscopy technique in the frequency range 10-1-106 Hz at various temperatures (25-300 °C). At high temperature, σAC conductivity obeys to the power law established by Jonscher. Besides, the variation of σDC with the inverse of the temperature follows Arrhenius law. This evolution suggests that the conduction process is thermally activated and the activation energy of this process is equal to 0.97 eV. Finally, the wettability tests reveal that zinc molybdates loses its hydrophobic character during aging under UV radiation to become completely hydrophilic. All these physical investigations demonstrated that such ternary oxide contains oxygen deficiency which may be of interest for photocatalytic purposes and pave the way for various sensitivity applications like gas and bio-sensors.

  15. Oxidative desulfurization of tire pyrolysis oil

    OpenAIRE

    Ahmad Shahzad; Ahmad Muhammad Imran; Naeem Khawar; Humayun Muhammad; Sebt-E-Zaeem; Faheem Farrukh

    2016-01-01

    This paper presents a low cost method for the purification of oils obtained from the pyrolysis of used tires. Oxidative desulfurization is a promising route for purification of tire pyrolysis oils as hydro-desulfurization may not be affordable for small scale industries. Different additives and acids have been employed for the enhancement of properties of pyrolytic oils. The experimental conditions were kept identical throughout, i.e. atmospheric pressure a...

  16. Pyrolysis of D-Glucose to Acrolein

    Science.gov (United States)

    Shen, Chong; Zhang, Igor Ying; Fu, Gang; Xu, Xin

    2011-06-01

    Despite of its great importance, the detailed molecular mechanism for carbohydrate pyrolysis remains poorly understood. We perform a density functional study with a newly developed XYG3 functional on the processes for D-glucose pyrolysis to acrolein. The most feasible reaction pathway starts from an isomerization from D-glucose to D-fructose, which then undergoes a cyclic Grob fragmentation, followed by a concerted electrocyclic dehydration to yield acrolein. This mechanism can account for the known experimental results.

  17. Y2O3-MgO Nano-Composite Synthesized by Plasma Spraying and Thermal Decomposition of Solution Precursors

    Science.gov (United States)

    Muoto, Chigozie Kenechukwu

    This research aims to identify the key feedstock characteristics and processing conditions to produce Y2O3-MgO composite coatings with high density and hardness using solution precursor plasma spray (SPPS) and suspension plasma spray (SPS) processes, and also, to explore the phenomena involved in the production of homogenized nano-composite powders of this material system by thermal decomposition of solution precursor mixtures. The material system would find potential application in the fabrication of components for optical applications such as transparent windows. It was shown that a lack of major endothermic events during precursor decomposition and the resultant formation of highly dense particles upon pyrolysis are critical precursor characteristics for the deposition of dense and hard Y2O3-MgO coatings by SPPS. Using these principles, a new Y2O3-MgO precursor solution was developed, which yielded a coating with Vickers hardness of 560 Hv. This was a considerable improvement over the hardness of the coatings obtained using conventional solution precursors, which was as low as 110 Hv. In the thermal decomposition synthesis process, binary solution precursor mixtures of: yttrium nitrate (Y[n]) or yttrium acetate (Y[a]), with magnesium nitrate (Mg[n]) or magnesium acetate (Mg[a]) were used in order to study the effects of precursor chemistry on the structural characteristics of the resultant Y2O3-MgO powders. The phase domains were coarse and distributed rather inhomogeneously in the materials obtained from the Y[n]Mg[n] and Y[a]Mg[a] mixtures; finer and more homogeneously-distributed phase domains were obtained for ceramics produced from the Y[a]Mg[n] and Y[n]Mg[a] mixtures. It was established that these phenomena were related to the thermal characteristics for the decomposition of the precursors and their effect on phase separation during oxide crystallization. Addition of ammonium acetate to the Y[n[Mg[n] mixture changed the endothermic process to exothermic

  18. Bio-methane via fast pyrolysis of biomass

    International Nuclear Information System (INIS)

    Görling, Martin; Larsson, Mårten; Alvfors, Per

    2013-01-01

    Highlights: ► Pyrolysis gases can efficiently be upgraded to bio-methane. ► The integration can increase energy efficiency and provide a renewable vehicle fuel. ► The biomass to bio-methane conversion efficiency is 83% (HHV). ► The efficiency is higher compared to bio-methane produced via gasification. ► Competitive alternative to other alternatives of bio-oil upgrading. - Abstract: Bio-methane, a renewable vehicle fuel, is today produced by anaerobic digestion and a 2nd generation production route via gasification is under development. This paper proposes a poly-generation plant that produces bio-methane, bio-char and heat via fast pyrolysis of biomass. The energy and material flows for the fuel synthesis are calculated by process simulation in Aspen Plus®. The production of bio-methane and bio-char amounts to 15.5 MW and 3.7 MW, when the total inputs are 23 MW raw biomass and 1.39 MW electricity respectively (HHV basis). The results indicate an overall efficiency of 84% including high-temperature heat and the biomass to bio-methane yield amounts to 83% after allocation of the biomass input to the final products (HHV basis). The overall energy efficiency is higher for the suggested plant than for the gasification production route and is therefore a competitive route for bio-methane production

  19. Catalytic and atmospheric effects on microwave pyrolysis of corn stover.

    Science.gov (United States)

    Huang, Yu-Fong; Kuan, Wen-Hui; Chang, Chi-Cheng; Tzou, Yu-Min

    2013-03-01

    Corn stover, which is one of the most abundant agricultural residues around the world, could be converted into valuable biofuels and bio based products by means of microwave pyrolysis. After the reaction at the microwave power level of 500W for the processing time of 30min, the reaction performance under N2 atmosphere was generally better than under CO2 atmosphere. This may be due to the better heat absorbability of CO2 molecules to reduce the heat for stover pyrolysis. Most of the metal-oxide catalysts effectively increased the maximum temperature and mass reduction ratio but lowered the calorific values of solid residues. The gas most produced was CO under N2 atmosphere but CO2 under CO2 atmosphere. Catalyst addition lowered the formation of PAHs and thus made liquid products less toxic. More liquid products and less gas products were generated when using the catalysts possibly due to the existence of the Fischer-Tropsch synthesis. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Numerical modelling of fuel sprays

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, C.

    1999-06-01

    The way the fuel is introduced into the combustion chamber is one of the most important parameters for the power output and the generation of emissions in the combustion of liquid fuels. The interaction between the turbulent gas flow field and the liquid fuel droplets, the vaporisation of them and the mixing of the gaseous fuel with the ambient air that are vital parameters in the combustion process. The use of numerical calculations is an important tool to better understand these complex interacting phenomena. This thesis reports on the numerical modelling of fuel sprays in non-reacting cases using an own developed spray module. The spray module uses the stochastic parcel method to represent the spray. The module was made in such manner that it could by coupled with different gas flow solver. Results obtained from four different gas flow solvers are presented in the thesis, including the use of two different kinds of turbulence models. In the first part the spray module is coupled with a k-{eta} based 2-D cylindrical gas flow solver. A thorough sensitivity analysis was performed on the spray and gas flow solver parameters, such as grid size dependence and sensitivity to initial values of k-{eta}. The results of the spray module were also compared to results from other spray codes, e.g. the well known KIVA code. In the second part of this thesis the spray was injected into a turbulent and fully developed crossflow studied. The spray module was attached to a LES (Large Eddy Simulation) based flow solvers enabling the study of the complex structures and time dependent phenomena involved in spray in crossflows. It was found that the spray performs an oscillatory motion and that the Strouhal number in the wake was about 0.1. Different spray breakup models were evaluated by comparing with experimental results 66 refs, 56 figs

  1. Sea Spray Aerosols

    DEFF Research Database (Denmark)

    Butcher, Andrew Charles

    emissions produced directly from bubble bursting as the result of air entrainment from breaking waves and particles generated from secondary emissions of volatile organic compounds. In the first paper, we study the chemical properties of particles produced from several sea water proxies with the use...... of a cloud condensation nuclei ounter. Proxy solutions with high inorganic salt concentrations and some organics produce sea spray aerosol particles with little change in cloud condensation activity relative to pure salts. Comparison is made between a frit based method for bubble production and a plunging...... a relationship between plunging jet particle ux, oceanic particle ux, and energy dissipation rate in both systems. Previous sea spray aerosol studies dissipate an order of magnitude more energy for the same particle ux production as the open ocean. A scaling factor related to the energy expended in air...

  2. Flame spraying of polymers

    International Nuclear Information System (INIS)

    Varacalle, D.J. Jr.; Zeek, D.P.; Couch, K.W.; Benson, D.M.; Kirk, S.M.

    1997-01-01

    Statistical design-of-experiment studies of the thermal spraying of polymer powders are presented. Studies of the subsonic combustion (i.e., Flame) process were conducted in order to determine the quality and economics of polyester and urethane coatings. Thermally sprayed polymer coatings are of interest to several industries for anticorrosion applications, including the chemical, automotive, and aircraft industries. In this study, the coating design has been optimized for a site-specific application using Taguchi-type fractional-factorial experiments. Optimized coating designs are presented for the two powder systems. A substantial range of thermal processing conditions and their effect on the resultant polymer coatings is presented. The coatings were characterized by optical metallography, hardness testing, tensile testing, and compositional analysis. Characterization of the coatings yielded the thickness, bond strength, Knoop microhardness, roughness, deposition efficiency, and porosity. Confirmation testing was accomplished to verify the coating designs

  3. Plasma sprayed thermoregulating coatings

    International Nuclear Information System (INIS)

    Kudinov, V.V.; Puzanov, A.A.; Zambrzhitskij, A.P.; Soboleva, V.V.

    1979-01-01

    Shown is the possibility of plasma spraying application for thermoregulating coating formation. Given are test results of service properties of BeO, Al 2 O 2 plasma coatings on the substrates of the MA2-1 magnesium alloy. Described is a device for studying durability of coating optical parameters under ultraviolet irradiation in deep vacuum. Dynamics of absorption coefficient, growth caused by an increase in absorption centers amount under such irradiation is investigated

  4. Emulsions from Aerosol Sprays

    Science.gov (United States)

    Hengelmolen; Vincent; Hassall

    1997-12-01

    An electrostatic emulsification apparatus has been designed for the purpose of studying diffusion from oil droplets which have a mean size in the range of approximately 1.5-3.5 &mgr;m, with standard deviations of 40-50%. The emulsification technique involves the collection of a spray of electrically charged oil droplets onto a rotating water film which is sustained from a reservoir. In this way, emulsions with volume fractions of approximately 10(-3) are produced within several minutes at oil flow rates of around 10(-2) ml min-1. Phase-Doppler anemometry (PDA) was used to assess droplet size distributions for the sprays and emulsions. Results show that the mean emulsion droplet size was smaller than the mean spray droplet size by several orders of magnitude. At flow rates around 10(-2) ml min-1, the spray droplet size distribution was little affected by the applied potential between about -4.20 and -4.65 kV (mean droplet size between approximately 7.6 and 7.8 &mgr;m, with standard deviations of approximately 20%), whereas the mean droplet size of the corresponding emulsion decreased more rapidly with applied potential. Above an applied potential of approximately -4.30 kV, which corresponded to an emulsion droplet size below approximately 2 &mgr;m, the measured volume fraction of the emulsion decreased with respect to the volume fraction as calculated on the basis of total amount of injected oil. Copyright 1997 Academic Press. Copyright 1997Academic Press

  5. Radiolysis of spray solutions

    International Nuclear Information System (INIS)

    Habersbergerova, A.; Janovsky, I.

    1985-01-01

    The factors were studied affecting thiosulfate radiolysis in the so-called spray solution for nuclear power plant containments. The reaction mechanism of primary radiolytic reactions leading to thiosulfate decomposition was studied using pulse radiolysis. Also measured was hydrazine loss in the irradiation of the bubbling solution intended for the capture of volatile chemical forms of radioiodine. Pulse radiolysis was used to study the kinetics of hydrazine reaction with elemental iodine. (author)

  6. Incineration and pyrolysis vs. steam gasification of electronic waste.

    Science.gov (United States)

    Gurgul, Agnieszka; Szczepaniak, Włodzimierz; Zabłocka-Malicka, Monika

    2018-05-15

    Constructional complexity of items and their integration are the most distinctive features of electronic wastes. These wastes consist of mineral and polymeric materials and have high content of valuable metals that could be recovered. Elimination of polymeric components (especially epoxy resins) while leaving non-volatile mineral and metallic phases is the purpose of thermal treatment of electronic wastes. In the case of gasification, gaseous product of the process may be, after cleaning, used for energy recovery or chemical synthesis. If not melted, metals from solid products of thermal treatment of electronic waste could be recovered by hydrometallurgical processing. Three basic, high temperature ways of electronic waste processing, i.e. smelting/incineration, pyrolysis and steam gasification were shortly discussed in the paper, giving a special attention to gasification under steam, illustrated by laboratory experiments. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Biofuels from pyrolysis in perspective: trade-offs between energy yields and soil-carbon additions.

    Science.gov (United States)

    Woolf, Dominic; Lehmann, Johannes; Fisher, Elizabeth M; Angenent, Largus T

    2014-06-03

    Coproduction of biofuels with biochar (the carbon-rich solid formed during biomass pyrolysis) can provide carbon-negative bioenergy if the biochar is sequestered in soil, where it can improve fertility and thus simultaneously address issues of food security, soil degradation, energy production, and climate change. However, increasing biochar production entails a reduction in bioenergy obtainable per unit biomass feedstock. Quantification of this trade-off for specific biochar-biofuel pathways has been hampered by lack of an accurate-yet-simple model for predicting yields, product compositions, and energy balances from biomass slow pyrolysis. An empirical model of biomass slow pyrolysis was developed and applied to several pathways for biochar coproduction with gaseous and liquid biofuels. Here, we show that biochar production reduces liquid biofuel yield by at least 21 GJ Mg(-1) C (biofuel energy sacrificed per unit mass of biochar C), with methanol synthesis giving this lowest energy penalty. For gaseous-biofuel production, the minimum energy penalty for biochar production is 33 GJ Mg(-1) C. These substitution rates correspond to a wide range of Pareto-optimal system configurations, implying considerable latitude to choose pyrolysis conditions to optimize for desired biochar properties or to modulate energy versus biochar yields in response to fluctuating price differentials for the two commodities.

  8. Catalytic pyrolysis using UZM-39 aluminosilicate zeolite

    Science.gov (United States)

    Nicholas, Christpher P; Boldingh, Edwin P

    2013-12-17

    A new family of coherently grown composites of TUN and IMF zeotypes has been synthesized and show to be effective catalysts for catalytic pyrolysis of biomass. These zeolites are represented by the empirical formula. Na.sub.nM.sub.m.sup.n+R.sub.rQ.sub.qAl.sub1-xE.sub.xSi.sub.yO.s- ub.z where M represents zinc or a metal or metals from Group 1, Group 2, Group 3 or the lanthanide series of the periodic table, R is an A,.OMEGA.-dihalosubstituted paraffin such as 1,4-dibromobutane, Q is a neutral amine containing 5 or fewer carbon atoms such as 1-methylpyrrolidine and E is a framework element such as gallium. The process involves contacting a carbonaceous biomass feedstock with UZM-39 at pyrolysis conditions to produce pyrolysis gases comprising hydrocarbons. The catalyst catalyzes a deoxygenation reaction converting oxygenated hyrdocarbons into hydrocarbons removing the oxygen as carbon oxides and water. A portion of the pyrolysis gases is condensed to produce low oxygen biomass-derived pyrolysis oil.

  9. Photocatalytic Desulfurization of Waste Tire Pyrolysis Oil

    Directory of Open Access Journals (Sweden)

    Napida Hinchiranan

    2011-11-01

    Full Text Available Waste tire pyrolysis oil has high potential to replace conventional fossil liquid fuels due to its high calorific heating value. However, the large amounts of sulfurous compounds in this oil hinders its application. Thus, the aim of this research was to investigate the possibility to apply the photo-assisted oxidation catalyzed by titanium dioxide (TiO2, Degussa P-25 to partially remove sulfurous compounds in the waste tire pyrolysis oil under milder reaction conditions without hydrogen consumption. A waste tire pyrolysis oil with 0.84% (w/w of sulfurous content containing suspended TiO2 was irradiated by using a high-pressure mercury lamp for 7 h. The oxidized sulfur compounds were then migrated into the solvent-extraction phase. A maximum % sulfur removal of 43.6% was achieved when 7 g/L of TiO2 was loaded into a 1/4 (v/v mixture of pyrolysis waste tire oil/acetonitrile at 50 °C in the presence of air. Chromatographic analysis confirmed that the photo-oxidized sulfurous compounds presented in the waste tire pyrolysis oil had higher polarity, which were readily dissolved and separated in distilled water. The properties of the photoxidized product were also reported and compared to those of crude oil.

  10. Pyrolysis of waste tyres: a review.

    Science.gov (United States)

    Williams, Paul T

    2013-08-01

    Approximately 1.5 billion tyres are produced each year which will eventually enter the waste stream representing a major potential waste and environmental problem. However, there is growing interest in pyrolysis as a technology to treat tyres to produce valuable oil, char and gas products. The most common reactors used are fixed-bed (batch), screw kiln, rotary kiln, vacuum and fluidised-bed. The key influence on the product yield, and gas and oil composition, is the type of reactor used which in turn determines the temperature and heating rate. Tyre pyrolysis oil is chemically very complex containing aliphatic, aromatic, hetero-atom and polar fractions. The fuel characteristics of the tyre oil shows that it is similar to a gas oil or light fuel oil and has been successfully combusted in test furnaces and engines. The main gases produced from the pyrolysis of waste tyres are H(2), C(1)-C(4) hydrocarbons, CO(2), CO and H(2)S. Upgrading tyre pyrolysis products to high value products has concentrated on char upgrading to higher quality carbon black and to activated carbon. The use of catalysts to upgrade the oil to a aromatic-rich chemical feedstock or the production of hydrogen from waste tyres has also been reported. Examples of commercial and semi-commercial scale tyre pyrolysis systems show that small scale batch reactors and continuous rotary kiln reactors have been developed to commercial scale. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Preparation and characterization of sprayed FTO thin films

    Science.gov (United States)

    Abd-Lefdil, M.; Diaz, R.; Bihri, H.; Aouaj, M. Ait; Rueda, F.

    2007-06-01

    Fluorine doped tin oxide (FTO) thin films have been prepared by spray pyrolysis technique with no further annealing. Films with 2.5% of fluorine grown at 400 °C present a single phase and exhibit a tetragonal structure with lattice parameters a = 4.687 Å and c = 3.160 Å. Scanning electron micrographs showed homogeneous surfaces with average grain size around 190 nm. The films are transparent in the visible zone and exhibit a high reflectance in the near infrared region. The best electrical resistivity was 6.3 × 10-4 Ω cm for FTO with 2.5% of fluorine. The ratio of transmittance in the visible to the sheet resistance are in the 0.57 × 10-2 1.96 × 10-2 {Ω }-1 range.

  12. Study on spraying water soluble resin to reduce pollution for Fukushima daiichi NPP accident

    International Nuclear Information System (INIS)

    Zhang Qiong; Guo Ruiping; Zhang Chunming; Han Fujuan; Hua Jie; Zhang Jiankui

    2012-01-01

    After Fukushima nuclear accident, Tokyo electric power company used the method of spraying water soluble resin synthesis at the scene of the accident, to restrain and control the spread of the radioactive dust, by forming consolidation layer in pollution area surface. This paper briefly introduced the accident, motivation of spraying water soluble resin, spraying range and implementation process. According to the relevant report on Fukushima nuclear accident, the effect of spraying water soluble resin for reducing pollution was analyzed. The mechanism of reducing pollution for water soluble resin and the application prospect were discussed. Spraying water soluble resin for fixing radioactive dust has reasonable reducing pollution effect. It is worth to use as reference and study in China. (authors)

  13. Pyrolysis characteristics and pyrolysis products separation for recycling organic materials from waste liquid crystal display panels

    International Nuclear Information System (INIS)

    Wang, Ruixue; Xu, Zhenming

    2016-01-01

    Highlights: • Pyrolysis characteristics are conducted for a better understanding of LCDs pyrolysis. • Optimum design is developed which is significant to guide the further industrial process. • Acetic acid and TPP are recycled and separated. - Abstract: Waste liquid crystal display (LCD) panels mainly contain inorganic materials (glass substrate with indium-tin oxide film), and organic materials (polarizing film and liquid crystal). The organic materials should be removed beforehand since the organic matters would hinder the indium recycling process. In the present study, pyrolysis process is used to remove the organic materials and recycle acetic as well as and triphenyl phosphate (TPP) from waste LCD panels in an environmental friendly way. Several highlights of this study are summarized as follows: (i) Pyrolysis characteristics and pyrolysis kinetics analysis are conducted which is significant to get a better understanding of the pyrolysis process. (ii) Optimum design is developed by applying Box–Behnken Design (BBD) under response surface methodology (RSM) for engineering application which is significant to guide the further industrial recycling process. The oil yield could reach 70.53 wt% and the residue rate could reach 14.05 wt% when the pyrolysis temperature is 570 °C, nitrogen flow rate is 6 L min"−"1 and the particle size is 0.5 mm. (iii) Furthermore, acetic acid and TPP are recycled, and then separated by rotary evaporation, which could reduce the consumption of fossil energy for producing acetic acid, and be reused in electronics manufacturing industry.

  14. Pyrolysis characteristics and pyrolysis products separation for recycling organic materials from waste liquid crystal display panels

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ruixue; Xu, Zhenming, E-mail: zmxu@sjtu.edu.cn

    2016-01-25

    Highlights: • Pyrolysis characteristics are conducted for a better understanding of LCDs pyrolysis. • Optimum design is developed which is significant to guide the further industrial process. • Acetic acid and TPP are recycled and separated. - Abstract: Waste liquid crystal display (LCD) panels mainly contain inorganic materials (glass substrate with indium-tin oxide film), and organic materials (polarizing film and liquid crystal). The organic materials should be removed beforehand since the organic matters would hinder the indium recycling process. In the present study, pyrolysis process is used to remove the organic materials and recycle acetic as well as and triphenyl phosphate (TPP) from waste LCD panels in an environmental friendly way. Several highlights of this study are summarized as follows: (i) Pyrolysis characteristics and pyrolysis kinetics analysis are conducted which is significant to get a better understanding of the pyrolysis process. (ii) Optimum design is developed by applying Box–Behnken Design (BBD) under response surface methodology (RSM) for engineering application which is significant to guide the further industrial recycling process. The oil yield could reach 70.53 wt% and the residue rate could reach 14.05 wt% when the pyrolysis temperature is 570 °C, nitrogen flow rate is 6 L min{sup −1} and the particle size is 0.5 mm. (iii) Furthermore, acetic acid and TPP are recycled, and then separated by rotary evaporation, which could reduce the consumption of fossil energy for producing acetic acid, and be reused in electronics manufacturing industry.

  15. Spray-formed tooling

    Science.gov (United States)

    McHugh, K. M.; Key, J. F.

    The United States Council for Automotive Research (USCAR) has formed a partnership with the Idaho National Engineering Laboratory (INEL) to develop a process for the rapid production of low-cost tooling based on spray forming technology developed at the INEL. Phase 1 of the program will involve bench-scale system development, materials characterization, and process optimization. In Phase 2, prototype systems will be designed, constructed, evaluated, and optimized. Process control and other issues that influence commercialization will be addressed during this phase of the project. Technology transfer to USCAR, or a tooling vendor selected by USCAR, will be accomplished during Phase 3. The approach INEL is using to produce tooling, such as plastic injection molds and stamping dies, combines rapid solidification processing and net-shape materials processing into a single step. A bulk liquid metal is pressure-fed into a de Laval spray nozzle transporting a high velocity, high temperature inert gas. The gas jet disintegrates the metal into fine droplets and deposits them onto a tool pattern made from materials such as plastic, wax, clay, ceramics, and metals. The approach is compatible with solid freeform fabrication techniques such as stereolithography, selective laser sintering, and laminated object manufacturing. Heat is extracted rapidly, in-flight, by convection as the spray jet entrains cool inert gas to produce undercooled and semi-solid droplets. At the pattern, the droplets weld together while replicating the shape and surface features of the pattern. Tool formation is rapid; deposition rates in excess of 1 ton/h have been demonstrated for bench-scale nozzles.

  16. The influence of annealing in nitrogen atmosphere on the electrical, optical and structural properties of spray- deposited ZnO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Ikhmayies, S.J. [Applied Science Private Univ., Amman (Jordan). Dept. of Physics; Abu El-Haija, N.M.; Ahmad-Bitar, R.N. [Jordan Univ., Amman (Jordan). Dept. of Physics

    2009-07-01

    Thin-film zinc oxide (ZnO) has many applications in solar cell technology and is considered to be a candidate for the substitution of indium tin oxide and tin oxide. ZnO thin films can be prepared by thermal evaporation, rf-sputtering, atomic layer deposition, chemical vapor deposition, sol-gel, laser ablation and spray pyrolysis technique. Spray pyrolysis has received much attention because of its simplicity and low cost. In this study, large area and highly uniform polycrystalline ZnO thin films were produced by spray pyrolysis using a home-made spraying system on glass substrates at 450 degrees C. The electrical, optical and structural properties of the ZnO films were enhanced by annealing the thin films in nitrogen atmosphere. X-ray diffraction revealed that the films are polycrystalline with a hexagonal wurtzite structure. The preferential orientation did not change with annealing, but XRD patterns revealed that some very weak lines had grown. There was no noticeable increase in the grain size. The transmittance of the films increased as a result of annealing. It was concluded that post-deposition annealing is essential to improve the quality of the ZnO thin films. The electrical properties improved due to a decrease in resistivity. 13 refs., 5 figs.

  17. Microplasma sprayed hydroxyapatite coatings

    CERN Document Server

    Dey, Arjun

    2015-01-01

    ""This unique book on development of microplasma sprayed HAp coating has been organized in a very compact yet comprehensive manner. This book also highlights the horizons of future research that invites the attention of global community, particularly those in bio-medical materials and bio-medical engineering field. This book will surely act as a very useful reference material for both graduate/post-graduate students and researchers in the field of biomedical, orthopedic and manufacturing engineering and research. I truly believ that this is the first ever effort which covers almost all the

  18. The catalytic cracking mechanism of lignite pyrolysis char on tar

    International Nuclear Information System (INIS)

    Lei, Z.; Huibin, H.; Xiangling, S.; Zhenhua, M.; Lei, Z.

    2017-01-01

    The influence of different pyrolysis conditions for tar catalytic cracking will be analyzed according to the lignite pyrolysis char as catalyst on pyrolytic tar in this paper. The pyrolysis char what is the by-product of the cracking of coal has an abundant of pore structure and it has good catalytic activity. On this basis, making the modified catalyst when the pyrolysis char is activation and loads Fe by impregnation method. The cracking mechanism of lignite pyrolytic tar is explored by applying gas chromatograph to analyze splitting products of tar. The experimental results showed that: (1) The effect of tar cracking as the pyrolysis temperature, the heating rate, the volatilization of pyrolysis char and particle size increasing is better and better. The effect of the catalytic and cracking of lignite pyrolysis char in tar is best when the heating rate, the pyrolysis temperature, the volatiles of pyrolysis char, particle size is in specific conditions.(2) The activation of pyrolysis char can improve the catalytic effect of pyrolysis char on the tar cracking. But it reduces the effect of the tar cracking when the pyrolysis char is activation loading Fe. (author)

  19. Co pyrolysis of biomass and PP

    International Nuclear Information System (INIS)

    Heo, Hyeon Su; Kim, Jung Hwan; Cho, Hye Jung; Ko, Jeong Huy; Park, Hye Jin; Bae, Yoon Ju; Park, Young Kwon

    2010-01-01

    Full text: While bio-oil has received considerable attention both as a source of energy and as an organic feedstock, its stability as fuel is very low due to high oxygen content. Therefore, there are many efforts to upgrade it. Among them, co pyrolysis with polyolefin can be a method to obtain stable bio-oil. Because polyolefins contain higher hydrogen and carbon content than biomass and no oxygen, plastic/ biomass co pyrolysis may upgrade the bio-oil properties by increasing the carbon and hydrogen contents while reducing oxygen content. In this study, wood biomass was mixed with PP and then co pyrolysis was carried out in a batch reactor. The produced oil and gas was analyzed using GC and GC-MS. Also elemental analysis was performed to know the hydrogen, carbon and oxygen content of bio-oil. The effect of various reaction conditions on bio-oil properties were presented in detail. (author)

  20. NMR spectroscopy of coal pyrolysis products

    Energy Technology Data Exchange (ETDEWEB)

    Polonov, V.M.; Kalabin, G.A.; Kushnarev, D.F.; Shevchenko, G.G.

    1985-12-01

    The authors consider the scope for using H 1 and C 13 NMR spectroscopy to describe the products from coal pyrolysis and hydrogenization. The accuracy of the structural information provided by the best NMR methods is also considered. The stuctural parameters derived from H 1 and C 13 NMR spectra are presented. Results demonstrate the high accuracy and sensitivity of the structural information provided by H 1 AND C 13 NMR spectra for coal products. There are substantial structural differences between the soluble products from medium-temperature coking of Cheremkhov coal and high-speed pyrolysis of Kan-Acha coal, and also differences in behavior during hydrogenation. These differences are related to the structure of the organic matter in the initial coal and to differences in the pyrolysis mechanisms.

  1. Pyrolysis and volatilization of cocaine

    International Nuclear Information System (INIS)

    Martin, B.R.; Lue, L.P.; Boni, J.P.

    1989-01-01

    The increasing popularity of inhaling cocaine vapor prompted the present study, to determine cocaine's fate during this process. The free base of [3H]cocaine (1 microCi/50 mg) was added to a glass pipe, which was then heated in a furnace to simulate freebasing. Negative pressure was used to draw the vapor through a series of glass wool, ethanol, acidic, and basic traps. Air flow rate and temperature were found to have profound effects on the volatilization and pyrolysis of cocaine. At a temperature of 260 degrees C and a flow rate of 400 mL/min, 37% of the radioactivity remained in the pipe, 39% was found in the glass wool trap, and less than 1% in the remainder of the volatilization apparatus after a 10-min volatilization. Reducing the air flow rate to 100 mL/min reduced the amount of radioactivity collected in the glass wool trap to less than 10% of the starting material and increased the amount that remained in the pipe to 58%. GC/MS analysis of the contents of the glass wool trap after volatilization at 260 degrees C and a flow rate of 400 mL/min revealed that 60% of the cocaine remained intact, while approximately 6 and 2% of the starting material was recovered as benzoic acid and methylecgonidine, respectively. As the temperature was increased to 650 degrees C, benzoic acid and methylecgonidine accounted for 83 and 89% of the starting material, respectively, whereas only 2% of the cocaine remained intact. Quantitation of cocaine in the vapor during the course of volatilization revealed high concentrations during the first two min and low concentrations for the remaining time

  2. Reaction rate of propene pyrolysis.

    Science.gov (United States)

    Han, Peipei; Su, Kehe; Liu, Yan; Wang, Yanli; Wang, Xin; Zeng, Qingfeng; Cheng, Laifei; Zhang, Litong

    2011-10-01

    The reaction rate of propene pyrolysis was investigated based on the elementary reactions proposed in Qu et al., J Comput Chem 2009, 31, 1421. The overall reaction rate was developed with the steady-state approximation and the rate constants of the elementary reactions were determined with the variational transition state theory. For the elementary reaction having transition state, the vibrational frequencies of the selected points along the minimum energy path were calculated with density functional theory at B3PW91/6-311G(d,p) level and the energies were improved with the accurate model chemistry method G3(MP2). For the elementary reaction without transition state, the frequencies were calculated with CASSCF/6-311G(d,p) and the energies were refined with the multireference configuration interaction method MRCISD/6-311G(d,p). The rate constants were evaluated within 200-2000 K and the fitted three-parameter expressions were obtained. The results are consistent with those in the literatures in most cases. For the overall rate, it was found that the logarithm of the rate and the reciprocal temperature have excellent linear relationship above 400 K, predicting that the rate follows a typical first-order law at high temperatures of 800-2000 K, which is also consistent with the experiments. The apparent activation energy in 800-2000 K is 317.3 kJ/mol from the potential energy surface of zero Kelvin. This value is comparable with the energy barriers, 365.4 and 403.7 kJ/mol, of the rate control steps. However, the apparent activation energy, 215.7 kJ/mol, developed with the Gibbs free energy surface at 1200 K is consistent with the most recent experimental result 201.9 ± 0.6 kJ/mol. Copyright © 2011 Wiley Periodicals, Inc.

  3. Spray rolling aluminum alloy strip

    Energy Technology Data Exchange (ETDEWEB)

    McHugh, Kevin M.; Delplanque, J.-P.; Johnson, S.B.; Lavernia, E.J.; Zhou, Y.; Lin, Y

    2004-10-10

    Spray rolling combines spray forming with twin-roll casting to process metal flat products. It consists of atomizing molten metal with a high velocity inert gas, cooling the resultant droplets in flight and directing the spray between mill rolls. In-flight convection heat transfer from atomized droplets teams with conductive cooling at the rolls to rapidly remove the alloy's latent heat. Hot deformation of the semi-solid material in the rolls results in fully consolidated, rapidly solidified product. While similar in some ways to twin-roll casting, spray rolling has the advantage of being able to process alloys with broad freezing ranges at high production rates. This paper describes the process and summarizes microstructure and tensile properties of spray-rolled 2124 and 7050 aluminum alloy strips. A Lagrangian/Eulerian poly-dispersed spray flight and deposition model is described that provides some insight into the development of the spray rolling process. This spray model follows droplets during flight toward the rolls, through impact and spreading, and includes oxide film formation and breakup when relevant.

  4. Characterization of Sodium Spray Aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, C. T.; Koontz, R. L.; Silberberg, M. [Atomics International, North American Rockwell Corporation, Canoga Park, CA (United States)

    1968-12-15

    The consequences of pool and spray fires require evaluation in the safety analysis of liquid metal-cooled fast breeder reactors. Sodium spray fires are characterized by high temperature and pressure, produced during the rapid combustion of sodium in air. Following the initial energy release, some fraction of the reaction products are available as aerosols which follow the normal laws of agglomeration, growth, settling, and plating. An experimental study is underway at Atomics International to study the characteristics of high concentration sprays of liquid sodium in reduced oxygen atmospheres and in air. The experiments are conducted in a 31.5 ft{sup 3} (2 ft diam. by 10 ft high) vessel, certified for a pressure of 100 lb/in{sup 2} (gauge). The spray injection apparatus consists of a heated sodium supply pot and a spray nozzle through which liquid sodium is driven by nitrogen pressure. Spray rate and droplet size can be varied by the injection velocity (nozzle size, nitrogen pressure, and sodium temperature). Aerosols produced in 0, 4, and 10 vol. % oxygen environments have been studied. The concentration and particle size distribution of the material remaining in the air after the spray injection and reaction period are measured. Fallout rates are found to be proportional to the concentration of aerosol which remains airborne following the spray period. (author)

  5. Integrating sustainable biofuel and silver nanomaterial production for in situ upgrading of cellulosic biomass pyrolysis

    International Nuclear Information System (INIS)

    Xue, Junjie; Dou, Guolan; Ziade, Elbara; Goldfarb, Jillian L.

    2017-01-01

    Graphical abstract: Integrated production of biotemplated nanomaterials and upgraded biofuels (solid lines indicate current processes, dashed lines indicated proposed pathway). - Highlights: • Novel integrated process to co-produce nanomaterials and biofuels via pyrolysis. • Impregnation of biomass with silver nitrate upgrades bio-oil during pyrolysis. • Co-synthesis enhances syngas produced with more hydrogen. • Biomass template impacts bio-fuels and morphology of resulting nanomaterials. - Abstract: Replacing fossil fuels with biomass-based alternatives is a potential carbon neutral, renewable and sustainable option for meeting the world’s growing energy demand. However, pyrolytic conversions of biomass-to-biofuels suffer marginal total energy gain, and technical limitations such as bio-oils’ high viscosity and oxygen contents that result in unstable, corrosive and low-value fuels. This work demonstrates a new integrated biorefinery process for the co-production of biofuels and silver nanomaterials. By impregnating pure cellulose and corn stalk with silver nitrate, followed by pyrolysis, the gas yield (especially hydrogen) increases substantially. The condensable bio-oil components of the impregnated samples are considerably higher in furfurals (including 5-hydroxymethylfurfural). Though the overall activation energy barrier, as determined via the Distributed Activation Energy Model, does not change significantly with the silver nitrate pre-treatment, the increase in gases devolatilized, and improved 5-hydroxymethylfurfural yield, suggest a catalytic effect, potentially increasing decarboxylation reactions. After using this metal impregnation to improve pyrolysis fuel yield, following pyrolysis, the silver-char composite materials are calcined to remove the biomass template to yield silver nanomaterials. While others have demonstrated the ability to biotemplate such nanosilver on cellulosic biomass, they consider only impregnation and oxidation of the

  6. Substrate system for spray forming

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Men G. (Export, PA); Chernicoff, William P. (Harrisburg, PA)

    2002-01-01

    A substrate system for receiving a deposit of sprayed metal droplets including a movable outer substrate on which the sprayed metal droplets are deposited. The substrate system also includes an inner substrate disposed adjacent the outer substrate where the sprayed metal droplets are deposited on the outer substrate. The inner substrate includes zones of differing thermal conductivity to resist substrate layer porosity and to resist formation of large grains and coarse constituent particles in a bulk layer of the metal droplets which have accumulated on the outer substrate. A spray forming apparatus and associated method of spray forming a molten metal to form a metal product using the substrate system of the invention is also provided.

  7. Pyrolysis of Pine Wood, Experiments and Theory

    DEFF Research Database (Denmark)

    Fjellerup, Jan Søren; Ahrenfeldt, Jesper; Henriksen, Ulrik Birk

    In this study, pinewood has been pyrolyzed using a fixed heating rate with a variable end-temperature. The pyrolysis process has been simulated using a mechanism with three parallel reactions for the formation of char, gas and tar. First order irreversible kinetics is assumed. This kind of model...... may predict the variation of product yield with operating conditions such as temperature and heating rate. The system of coupled differential equations describing the pyrolysis process is solved using the software DYMOLA. Various literature values for kinetic parameters have been compared...

  8. PYROLYSIS OF ZINC CONTAMINATED BIOMASS FROM PHYTOREMEDIATION

    OpenAIRE

    Özkan, Aysun; Günkaya, Zerrin; Banar, Müfide; Kulaç, Alev; Yalçın, Gülser; Taşpınar, Kadriye; Altay, Abdullah

    2015-01-01

    The objective of this study was to stabilize of zinc (Zn) from soil to pyrolysis solid product. For this aim, phytoremediation and pyrolysis were sequentially applied. In the first stage of the study, phytoremediation was first applied to zinc contaminated soil via  sunflower (Helianthus annuus), corn (Zea mays) and rape (Brassica napus), After harvesting, the plants were pyrolyzed at 500°C with the heating rate of 35 °C/min in a fixed bed stainless steel (380 S) 240 cm3 reactor. The phytorem...

  9. Spray deposition and spray drift in orchard spraying by multiple row sprayers

    NARCIS (Netherlands)

    Wenneker, M.; Zande, van de J.C.; Michielsen, J.G.P.; Stallinga, H.; Velde, van P.

    2016-01-01

    The evaluation of the latest data on spray drift in orchard spraying in the Netherlands, and measurements of surface water quality parameters show that the current legislation and measures are insufficient to protect the surface water. To meet the national and European objectives regarding surface

  10. Pyrolysis model for an alpha waste incinerator prototype

    International Nuclear Information System (INIS)

    Orloff, D.I.

    1978-01-01

    The development of a theoretical model of the pyrolysis stage of an SRL prototype alpha waste incinerator is discussed. Pyrolysis rates for single component porous beds of Teflon (Registered trademark of Du Pont) and natural rubber have been measured on a bench-scale furnace. Experimental pyrolysis rates compare favorably to the predictions of a quasi-steady regression model. In addition, the pyrolysis rate is shown to be a weak function of the thermal diffusivity of the porous polymer bed. As a consequence, pyrolysis is controlled by thermal degradation kinetics rather than by diffusion or conduction

  11. The lignin pyrolysis composition and pyrolysis products of palm kernel shell, wheat straw, and pine sawdust

    International Nuclear Information System (INIS)

    Chang, Guozhang; Huang, Yanqin; Xie, Jianjun; Yang, Huikai; Liu, Huacai; Yin, Xiuli; Wu, Chuangzhi

    2016-01-01

    Highlights: • The primarily pyrolysis composition of PKS lignin was p-hydroxyphenyl unit. • Higher phenol yield and lower gas energy yield were obtained from PKS pyrolysis. • PKS produced more bio-oil and biochar than WS and PS from pyrolysis at 650–850 °C. • PKS-char had poorer gasification reactivity due to higher ordering carbon degree. - Abstract: The lignin monomer composition of palm kernel shell (PKS) was characterized using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), and the characteristics and distributions of products obtained from PKS pyrolysis were investigated using Py-GC/MS, GC, and a specially designed pyrolysis apparatus. The gasification reactivity of PKS biochar was also characterized using thermogravimetry (TG) and Raman spectroscopy. All the results were compared with those obtained from wheat straw (WS) and pine sawdust (PS). The results showed that PKS lignin is primarily composed of p-hydroxyphenyl structural units, while WS and PS lignins are mainly made up of guaiacyl units. Both the mass and energy yields of non-condensable gases from PKS pyrolysis were lower than those obtained from WS and PS pyrolysis at 650–850 °C, owing to the lower volatile content (75.21%) and lack of methoxy groups in PKS. Compared with WS and PS, higher bio-oil productivity was observed during PKS pyrolysis. Phenols were the main component of PKS bio-oil from pyrolysis at 500 °C, and the phenol content of PKS bio-oil (13.49%) was higher than in WS bio-oil (1.62%) and PS bio-oil (0.55%). A higher yield of biochar (on an ash-free basis) was also obtained from PKS pyrolysis. Because of its greater relative degree of ordered carbon, PKS biochar exhibited lower in situ reactivity during CO_2 or H_2O gasification than WS and PS biochars. A longer residence time and addition of steam were found to be beneficial during PKS biochar gasification.

  12. Photoelectrocatrocatalytic hydrolysis of starch by using sprayed ZnO thin films

    Science.gov (United States)

    Sapkal, R. T.; Shinde, S. S.; Rajpure, K. Y.; Bhosale, C. H.

    2013-05-01

    Thin films of zinc oxide have been deposited onto glass/FTO substrates at optimized 400 °C by using a chemical spray pyrolysis technique. Deposited films are character photocatalytic activity by using XRD, an SEM, a UV-vis spectrophotometer, and a PEC single-cell reactor. Films are polycrystalline and have a hexagonal (wurtzite) crystal structure with c-axis (002) orientation growth perpendicular to the substrate surface. The observed direct band gap is about 3.22 eV for typical films prepared at 400 °C. The photocatalytic activity of starch with a ZnO photocatalyst has been studied by using a novel photoelectrocatalytic process.

  13. The Correlation of Pore Size and Bioactivity of Spray-Pyrolyzed Mesoporous Bioactive Glasses

    Directory of Open Access Journals (Sweden)

    Yu-Jen Chou

    2017-05-01

    Full Text Available SiO2–CaO–P2O5-based mesoporous bioactive glasses (MBGs were synthesized by spray pyrolysis in this study. Three commonly used non-ionic tri-block copolymers (L121, P123, and F127 with various lengths of hydrophilic chains were applied as structural templates to achieve different pore sizes. A mesoporous structure was observed in each as-prepared specimen, and the results showed that the L121-treated MBG had the largest pore size. The results of bioactivity tests indicated that the growth of hydroxyapatite is related to the pore size of the materials.

  14. Pyrolysis and catalytic pyrolysis as a recycling method of waste CDs originating from polycarbonate and HIPS

    Energy Technology Data Exchange (ETDEWEB)

    Antonakou, E.V. [Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Kalogiannis, K.G.; Stephanidis, S.D. [Chemical Process Engineering Research Institute, 57001 Thermi, Thessaloniki (Greece); Triantafyllidis, K.S. [Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Chemical Process Engineering Research Institute, 57001 Thermi, Thessaloniki (Greece); Lappas, A.A. [Chemical Process Engineering Research Institute, 57001 Thermi, Thessaloniki (Greece); Achilias, D.S., E-mail: axilias@chem.auth.gr [Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

    2014-12-15

    Highlights: • Thermal and catalytic pyrolysis is a powerful method for recycling of WEEEs. • Liquid products obtained from the pyrolysis of PC or HIPS found in waste CDs are very different. • Mainly phenols are obtained from pyrolysis PC based wastes while aromatics from HIPS. • Use of MgO catalyst increases the amount of phenols from CD recycling compared to ZSM-5. • Use of MgO or ZSM-5 catalysts reduces the amount of styrene recovered from HIPS. - Abstract: Pyrolysis appears to be a promising recycling process since it could convert the disposed polymers to hydrocarbon based fuels or various useful chemicals. In the current study, two model polymers found in WEEEs, namely polycarbonate (PC) and high impact polystyrene (HIPS) and their counterparts found in waste commercial Compact Discs (CDs) were pyrolysed in a bench scale reactor. Both, thermal pyrolysis and pyrolysis in the presence of two catalytic materials (basic MgO and acidic ZSM-5 zeolite) was performed for all four types of polymers. Results have shown significant recovery of the monomers and valuable chemicals (phenols in the case of PC and aromatic hydrocarbons in the case of HIPS), while catalysts seem to decrease the selectivity towards the monomers and enhance the selectivity towards other desirable compounds.

  15. Pyrolysis of Rubber in a Screw Reactor

    Science.gov (United States)

    Lozhechnik, A. V.; Savchin, V. V.

    2016-11-01

    On the basis of an analysis of thermal methods described in the literature and from the results of experimental investigations of steam conversion, the authors have developed and created a facility for thermal processing of rubber waste. Rubber crumb was used as the raw material; the temperature in the reactor was 500°C; nitrogen, steam, and a mixture of light hydrocarbons (noncondensable part of pyrolysis products) represented the working medium. The pyrolysis yielded 36-38% of a solid fraction, 54-56% of a liquid hydrocarbon fraction, and 6-9% of noncondensable gases. Changes in the composition of the gas mixture have been determined at different stages of processing. Gas chromatography of pyrolysis gases has shown that the basic gases produced by pyrolysis are H2 and hydrocarbons C2H4, C3H6, C3H8, C4H8, C2H6, C3H6O2, and C4H10, and a small amount of H2S, CO, and CO2. Noncondensable gases will be used as a fuel to heat the reactor and to implement the process.

  16. Catalytic pyrolysis using UZM-44 aluminosilicate zeolite

    Science.gov (United States)

    Nicholas, Christopher P; Boldingh, Edwin P

    2013-12-17

    A new family of aluminosilicate zeolites designated UZM-44 has been synthesized. These zeolites are represented by the empirical formula Na.sub.nM.sub.m.sup.k+T.sub.tAl.sub.1-xE.sub.xSi.sub.yO.sub.z where "n" is the mole ratio of Na to (Al+E), M represents a metal or metals from zinc, Group 1, Group 2, Group 3 and or the lanthanide series of the periodic table, "m" is the mole ratio of M to (Al+E), "k" is the average charge of the metal or metals M, T is the organic structure directing agent or agents, and E is a framework element such as gallium. The process involves contacting a carbonaceous biomass feedstock with UZM-44 at pyrolysis conditions to produce pyrolysis gases comprising hydrocarbons. The catalyst catalyzes a deoxygenation reaction converting oxygenated hydrocarbons into hydrocarbons and removing the oxygen as carbon oxides and water. A portion of the pyrolysis gases is condensed to produce low oxygen biomass-derived pyrolysis oil.

  17. Characterization of Hydrotreated Fast Pyrolysis Liquids

    NARCIS (Netherlands)

    Oasmaa, A.; Kuoppala, E.; Ardiyanti, A.; Venderbosch, R. H.; Heeres, H. J.

    This paper focuses on analytical methods to determine the composition of hydrotreated fast pyrolysis liquids. With this information, it is possible to gain insights in the chemical transformations taking place during catalytic hydrotreatment (hydrogenation and/or hydrodeoxygenation, H DO) of

  18. In Situ Flash Pyrolysis of Straw

    DEFF Research Database (Denmark)

    Bech, Niels

    In-Situ Flash Pyrolysis of Straw Ph.D. dissertation by Niels Bech Submitted: April 2007. Supervisors: Professor Kim Dam-Johansen, Associate Professor Peter Arendt Jensen Erfaringerne med forbrænding af halm opnået gennem et årti har vist, at en proces der kan koncentrere energien på marken, fjerne...

  19. Flash pyrolysis kinetics of pine wood

    NARCIS (Netherlands)

    Wagenaar, B.M.; Prins, W.; van Swaaij, Willibrordus Petrus Maria

    1993-01-01

    The kinetics of sawdust pyrolysis in the temperature range from 300 to 600 °C has been measured. A thermogravimetric analyser was applied for the temperature range from 300 to 450 °C while for measurements in the temperature range from 450 to 600 °C, an entrained flow reactor has been used. The

  20. Thermal pyrolysis characteristics of macroalgae Cladophora glomerata.

    Science.gov (United States)

    Gao, Wenhua; Chen, Kefu; Zeng, Jinsong; Xu, Jun; Wang, Bin

    2017-11-01

    The Cladophora glomerata (C. glomerata) is a kind of widely distributed macroalgae in the freshwater ecosystems. It primarily consists of carbohydrates that can be converted into biofuel by pyrolysis. In this study, thermogravimetric analysis (TGA) was used to investigate the thermal behavior and kinetics of C. glomerata during the pyrolysis process. The results showed that heating rates slightly affect the decomposition properties of C. glomerata; with the heating rates increasing, the maximum peak of weight loss rate shifted to higher temperatures. The activation energies of C. glomerata pyrolysis reaction were 244.25 and 238.07kJ/mol, respectively, as calculated by Friedman and Kissinger-Akahira-Sunose (KAS) methods. The pre-exponential factor and reaction order were determined by Coats-Redfern model, and applied to simulate the pyrolysis process of C. glomerata. The model calculated data and experimental data were consistent. This study could provide theoretical supports for designing C. glomerata conversion processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Catalytic and noncatalytic gasification of pyrolysis oil

    NARCIS (Netherlands)

    van Rossum, G.; Kersten, Sascha R.A.; van Swaaij, Willibrordus Petrus Maria

    2007-01-01

    Gasification of pyrolysis oil was studied in a fluidized bed over a wide temperature range (523−914 °C) with and without the use of nickel-based catalysts. Noncatalytically, a typical fuel gas was produced. Both a special designed fluid bed catalyst and a crushed commercial fixed bed catalyst showed

  2. Indoor spray measurement of spray drift potential using a spray drift test bench : effect of drift-reducing nozzle types, spray boom height, nozzle spacing and forward speed

    NARCIS (Netherlands)

    Moreno Ruiz, J.R.

    2014-01-01

    In a series of indoor experiments spray drift potential was assessed when spraying over a spray drift testbench with two different driving speeds, 2m/s and 4m/s, two different spray boom heights, 30 cm and 50 cm, and two different nozzle spacing, 25 cm and 50 cm, for six different nozzle types. The

  3. Investigations on microstructural and optical properties of CdS films fabricated by a low-cost, simplified spray technique using perfume atomizer for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Ravichandran, K.; Philominathan, P. [PG and Research Department of Physics, AVVM, Sri Pushpam College, Poondi, Thanjavur District, Tamil Nadu (India)

    2008-11-15

    Good quality CdS films were fabricated by employing a simplified spray pyrolysis technique using perfume atomizer. CdS films have been deposited from aqueous solutions of sulphur and cadmium, keeping the molar concentrations of S:Cd = 0.01:0.01, 0.02:0.02, 0.04:0.04 and 0.06:0.06 in the starting solutions. The structural studies reveal that the S:Cd concentration has a strong influence on the microstructural characteristics of the sprayed CdS films. It was found that there is a transition in the preferred orientation from (0 0 2) plane to (1 0 1) plane when S:Cd molar concentration increases. The SEM images depict that the films are uniform and homogeneous. All the films have high optical transmittance (>80%) in the visible range. The optical band gap values are found to be in the range of 2.46-2.52 eV. CdS films fabricated by this simple and economic spray technique without using any carrier gas are found to be good in structural and optical properties which are desirable for photovoltaic applications. Hence, this simplified version of spray technique can be considered as an economic alternative to conventional spray pyrolysis (using carrier gas), for the mass production of low-cost, large area CdS coatings for solar cell applications. (author)

  4. Modifications Of A Commercial Spray Gun

    Science.gov (United States)

    Allen, Peter B.

    1993-01-01

    Commercial spray gun modified to increase spray rate and make sprayed coats more nearly uniform. Consists of gun head and pneumatic actuator. Actuator opens valves for two chemical components, called "A" and "B," that react to produce foam. Components flow through orifices, into mixing chamber in head. Mixture then flows through control orifice to spray tip. New spray tip tapered to reduce area available for accumulation of foam and makes tip easier to clean.

  5. Characterization of viscous biofuel sprays using digital imaging in the near field region

    International Nuclear Information System (INIS)

    Sallevelt, J.L.H.P.; Pozarlik, A.K.; Brem, G.

    2015-01-01

    Highlights: • Biodiesel, vegetable oil and glycerin sprays have been studied using PDIA. • The study is focused on the effect of fuel viscosity on the spray characteristics. • Viscosity has a strong effect on the breakup length in pressure-swirl atomization. • The results are compared to combustion experiments with a micro gas turbine. • The penetration depth of ligaments can be a critical factor in burning viscous fuel. - Abstract: The atomization of biodiesel, vegetable oil and glycerin has been studied in an atmospheric spray rig by using digital imaging (PDIA). Images of the spray were captured in the near field, just 18 mm downstream of the atomizer, and processed to automatically determine the size of both ligaments and droplets. The effect of the spray structure in this region is of major interest for the combustion of biofuels in gas turbines. The sprays were produced by a pressure-swirl atomizer that originates from the multifuel micro gas turbine (MMGT) setup. Various injection conditions have been tested to investigate the influence of viscosity on the spray characteristics and to assess the overall performance of the atomizer. The spray measurements have been compared to combustion experiments with biodiesel and vegetable oil in the micro gas turbine at similar injection conditions. The results show that the primary breakup process rapidly deteriorates when the viscosity is increased. A higher viscosity increases the breakup length, which becomes visible at the measurement location in the form of ligaments. This effect leads to an unacceptable spray quality once the viscosity slightly exceeds the typical range for conventional gas turbine fuels. The SMD in the investigated spray region was not significantly affected by viscosity, but mainly influenced by injection pressure. The data furthermore indicate an increase in SMD with surface tension. It was found that the penetration depth of ligaments can have major impact on the combustion process

  6. Absorption/desorption in sprays

    International Nuclear Information System (INIS)

    Naimpally, A.

    1987-01-01

    This survey paper shall seek to present the present state of knowledge concerning absorption and desorption in spray chambers. The first part of the paper presents the theories and formulas for the atomization and break-up of sprays in nozzles. Formulas for the average (sauter-mean) diameters are then presented. For the case of absorption processes, the formulas for the dimensionless mass transfer coefficients is in drops. The total; mass transfer is the total of the transfer in individual drops. For the case of desorption of sparingly soluble gases from liquids in a spray chamber, the mass transfer occurs in the spray just at the point of break-up of the jet. Formulas for the desorption of gases are presented

  7. Magnesium Repair by Cold Spray

    National Research Council Canada - National Science Library

    Champagne, V. K; Leyman, P.F; Helfritch, D. J

    2008-01-01

    .... Army Research Laboratory has developed a cold spray process to reclaim magnesium components that shows significant improvement over existing methods and is in the process of qualification for use on rotorcraft...

  8. Reprint of: Pyrolysis technologies for municipal solid waste: A review

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Dezhen, E-mail: chendezhen@tongji.edu.cn [Thermal & Environmental Engineering Institute, Tongji University, Shanghai 200092 (China); Yin, Lijie; Wang, Huan [Thermal & Environmental Engineering Institute, Tongji University, Shanghai 200092 (China); He, Pinjing [State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China)

    2015-03-15

    Highlights: • MSW pyrolysis reactors, products and environmental impacts are reviewed. • MSW pyrolysis still has to deal with flue gas emissions and products’ contamination. • Definition of standardized products is suggested to formalize MSW pyrolysis technology. • Syngas is recommended to be the target product for single MSW pyrolysis technology. - Abstract: Pyrolysis has been examined as an attractive alternative to incineration for municipal solid waste (MSW) disposal that allows energy and resource recovery; however, it has seldom been applied independently with the output of pyrolysis products as end products. This review addresses the state-of-the-art of MSW pyrolysis in regards to its technologies and reactors, products and environmental impacts. In this review, first, the influence of important operating parameters such as final temperature, heating rate (HR) and residence time in the reaction zone on the pyrolysis behaviours and products is reviewed; then the pyrolysis technologies and reactors adopted in literatures and scale-up plants are evaluated. Third, the yields and main properties of the pyrolytic products from individual MSW components, refuse-derived fuel (RDF) made from MSW, and MSW are summarised. In the fourth section, in addition to emissions from pyrolysis processes, such as HCl, SO{sub 2} and NH{sub 3}, contaminants in the products, including PCDD/F and heavy metals, are also reviewed, and available measures for improving the environmental impacts of pyrolysis are surveyed. It can be concluded that the single pyrolysis process is an effective waste-to-energy convertor but is not a guaranteed clean solution for MSW disposal. Based on this information, the prospects of applying pyrolysis technologies to dealing with MSW are evaluated and suggested.

  9. Pyrolysis technologies for municipal solid waste: A review

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Dezhen, E-mail: chendezhen@tongji.edu.cn [Thermal and Environmental Engineering Institute, Tongji University, Shanghai 200092 (China); Yin, Lijie; Wang, Huan [Thermal and Environmental Engineering Institute, Tongji University, Shanghai 200092 (China); He, Pinjing [State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China)

    2014-12-15

    Highlights: • MSW pyrolysis reactors, products and environmental impacts are reviewed. • MSW pyrolysis still has to deal with flue gas emissions and products’ contamination. • Definition of standardized products is suggested to formalize MSW pyrolysis technology. • Syngas is recommended to be the target product for single MSW pyrolysis technology. - Abstract: Pyrolysis has been examined as an attractive alternative to incineration for municipal solid waste (MSW) disposal that allows energy and resource recovery; however, it has seldom been applied independently with the output of pyrolysis products as end products. This review addresses the state-of-the-art of MSW pyrolysis in regards to its technologies and reactors, products and environmental impacts. In this review, first, the influence of important operating parameters such as final temperature, heating rate (HR) and residence time in the reaction zone on the pyrolysis behaviours and products is reviewed; then the pyrolysis technologies and reactors adopted in literatures and scale-up plants are evaluated. Third, the yields and main properties of the pyrolytic products from individual MSW components, refuse-derived fuel (RDF) made from MSW, and MSW are summarised. In the fourth section, in addition to emissions from pyrolysis processes, such as HCl, SO{sub 2} and NH{sub 3}, contaminants in the products, including PCDD/F and heavy metals, are also reviewed, and available measures for improving the environmental impacts of pyrolysis are surveyed. It can be concluded that the single pyrolysis process is an effective waste-to-energy convertor but is not a guaranteed clean solution for MSW disposal. Based on this information, the prospects of applying pyrolysis technologies to dealing with MSW are evaluated and suggested.

  10. Biomass-to-hydrogen via fast pyrolysis and catalytic steam reforming

    Energy Technology Data Exchange (ETDEWEB)

    Chornet, E.; Wang, D.; Czernik, S. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1996-10-01

    Pyrolysis of lignocellulosic biomass and reforming the pyroligneous oils is being studied as a strategy for producing hydrogen. Novel technologies for the rapid pyrolysis of biomass have been developed in the past decade. They provide compact and efficient systems to transform biomass into vapors that are condensed to oils, with yields as high as 75-80 wt.% of the anhydrous biomass. This {open_quotes}bio-oil{close_quotes} is a mixture of aldehydes, alcohols, acids, oligomers from the constitutive carbohydrates and lignin, and some water derived from the dehydration reactions. Hydrogen can be produced by reforming the bio-oil or its fractions with steam. A process of this nature has the potential to be cost competitive with conventional means of producing hydrogen. The reforming facility can be designed to handle alternate feedstocks, such as natural gas and naphtha, if necessary. Thermodynamic modeling of the major constituents of the bio-oil has shown that reforming is possible within a wide range of temperatures and steam-to-carbon ratios. Existing catalytic data on the reforming of oxygenates have been studied to guide catalyst selection. Tests performed on a microreactor interfaced with a molecular beam mass spectrometer showed that, by proper selection of the process variables: temperature, steam-to-carbon ratio, gas hourly space velocity, and contact time, almost total conversion of carbon in the feed to CO and CO{sub 2} could be obtained. These tests also provided possible reaction mechanisms where thermal cracking competes with catalytic processes. Bench-scale, fixed bed reactor tests demonstrated high hydrogen yields from model compounds and carbohydrate-derived pyrolysis oil fractions. Reforming bio-oil or its fractions required proper dispersion of the liquid to avoid vapor-phase carbonization of the feed in the inlet to the reactor. A special spraying nozzle injector was designed and successfully tested with an aqueous fraction of bio-oil.

  11. Effects of ionic liquid to water ratio as a composite medium for the synthesis of LiFePO4 for battery

    Science.gov (United States)

    Tith, Rany; Dutta, Jaydeep; Jung, Kichang; Martinez-Morales, Alfredo A.

    2017-05-01

    LiFePO4 is a highly researched cathode material that serves as an alternative material for traditional commercial lithiumion batteries such as LiCoO2. Currently, there are a number of different methods to synthesize LiFePO4 including: hydrothermal, solid state, spray pyrolysis, and coprecipitation. Our proposed method has the potential to provide an ecologically friendly and economically competitive way to synthesize LiFePO4 by utilizing ionic liquid and water, as a composite synthesis medium. The addition of water to ionic liquid can be beneficial as it can act as a mineralizer to bring insoluble precursors to form LiFePO4 seed crystals. Furthermore, this method provides the possibility of recycling the ionic liquid for repeated synthesis processes. In this work, we study the effects of ionic liquid to water ratio on the crystallinity and morphology of the synthesized material. Our group was able to conclude a reaction medium utilizing a ratio of equal parts of 1-ethyl-3-methyl imidazolium trifluoromethane sulfonate (EMIM Otf) and water, or a slightly favored ionic liquid ratio, increases the efficacy of the synthesis route. Crystallinity and purity was determined by X-ray diffraction (XRD), scanning electron microscopy (SEM) was used to determine morphology and crystal sizes, and energy dispersion spectroscopy (EDX) was used for elemental analysis.

  12. Photoelectrochemical Characterization of Sprayed alpha-Fe2O3 Thin Films : Influence of Si Doping and SnO2 Interfacial Layer

    NARCIS (Netherlands)

    Liang, Y.; Enache, C.S.; Van De Krol, R.

    2008-01-01

    a-Fe2O3 thin film photoanodes for solar water splitting were prepared by spray pyrolysis of Fe(AcAc)3. The donor density in the Fe2O3 films could be tuned between 10171020cm-3 by doping with silicon. By depositing a 5 nm SnO2 interfacial layer between the Fe2O3 films and the transparent conducting

  13. Photochemistry Aspects of the Laser Pyrolysis Addressing the Preparation of Oxide Semiconductor Photocatalysts

    Directory of Open Access Journals (Sweden)

    R. Alexandrescu

    2008-01-01

    Full Text Available The laser pyrolysis is a powerful and a versatile tool for the gas-phase synthesis of nanoparticles. In this paper, some fundamental and applicative characteristics of this technique are outlined and recent results obtained in the preparation of gamma iron oxide (γ-Fe2O3 and titania (TiO2 semiconductor nanostructures are illustrated. Nanosized iron oxide particles (4 to 9 nm diameter values have been directly synthesized by the laser-induced pyrolysis of a mixture containing iron pentacarbonyl/air (as oxidizer/ethylene (as sensitizer. Temperature-dependent Mossbauer spectroscopy shows that mainly maghemite is present in the sample obtained at higher laser power. The use of selected Fe2O3 samples for the preparation of water-dispersed magnetic nanofluids is also discussed. TiO2 nanoparticles comprising a mixture of anatase and rutile phases were synthesized via the laser pyrolysis of TiCl4- (vapors based gas-phase mixtures. High precursor concentration of the oxidizer was found to favor the prevalent anatase phase (about 90% in the titania nanopowders.

  14. Exergy analysis of synthetic biofuel production via fast pyrolysis and hydroupgrading

    International Nuclear Information System (INIS)

    Peters, Jens F.; Petrakopoulou, Fontina; Dufour, Javier

    2015-01-01

    This paper presents the first assessment of the exergetic performance of a biorefinery process based on catalytic hydroupgrading of bio-oil from fast pyrolysis. Lignocellulosic biomass is converted into bio-oil through fast pyrolysis, which is then upgraded to synthetic fuels in a catalytic hydrotreating process. The biorefinery process is simulated numerically using commercial software and analyzed using exergetic analysis. Exergy balances are defined for each component of the plant and the exergetic efficiencies and exergy destruction rates are calculated at the component, section and plant level, identifying thermodynamic inefficiencies and revealing the potential for further improvement of the process. The overall biofuel process results in an exergetic efficiency of 60.1%, while the exergetic efficiency of the upgrading process in the biorefinery alone is 77.7%. Within the biorefinery, the steam reforming reactor is the main source of inefficiencies, followed by the two hydrotreating reactors. In spite of the high operating pressures in the hydrotreating section, the compressors have little impact on the total exergy destruction. Compared to competing lignocellulosic biofuel processes, like gasification with Fischer–Tropsch synthesis or lignocellulosic ethanol processes, the examined system achieves a significantly higher exergetic efficiency. - Highlights: • Exergetic analysis of a biorefinery for bio-oil hydroupgrading. • Detailed simulation model using 83 model compounds. • Exergy destruction quantified in each component of the plant. • Exergetic efficiency and potential for improvement determined on component level. • Highest exergy destruction in the pyrolysis plant and the steam reformer

  15. Syngas obtained by microwave pyrolysis of household wastes as feedstock for polyhydroxyalkanoate production in Rhodospirillum rubrum.

    Science.gov (United States)

    Revelles, Olga; Beneroso, Daniel; Menéndez, J Angel; Arenillas, Ana; García, J Luis; Prieto, M Auxiliadora

    2017-11-01

    The massive production of urban and agricultural wastes has promoted a clear need for alternative processes of disposal and waste management. The potential use of municipal solid wastes (MSW) as feedstock for the production of polyhydroxyalkanoates (PHA) by a process known as syngas fermentation is considered herein as an attractive bio-economic strategy to reduce these wastes. In this work, we have evaluated the potential of Rhodospirillum rubrum as microbial cell factory for the synthesis of PHA from syngas produced by microwave pyrolysis of the MSW organic fraction from a European city (Seville). Growth rate, uptake rate, biomass yield and PHA production from syngas in R. rubrum have been analysed. The results revealed the strong robustness of this syngas fermentation where the purity of the syngas is not a critical constraint for PHA production. Microwave-induced pyrolysis is a tangible alternative to standard pyrolysis, because it can reduce cost in terms of energy and time as well as increase syngas production, providing a satisfactory PHA yield. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  16. Spray Lakes reclamation project

    International Nuclear Information System (INIS)

    Zacaruk, M.R.

    1996-01-01

    When the level of the Spray Lakes (Alberta) reservoir was lowered by four metres, 208 ha of shoreline was exposed offering little to no wildlife benefit and only limited recreation potential. A reclamation plan for 128 ha of shoreline was therefore developed. A wild life-palatable, self-sustaining vegetation cover was established. Approximately 90 ha was scarified, and/or had tree stumps removed prior to seeding, while approximately 40 ha was seeded and fertilized only. The remaining 80 ha of shoreline was not revegetated due to limited access; these areas will be allowed to re-establish naturally from the forested edge. The species were selected based on their adaptation to alkaline soils, drought tolerance, persistence in a stand and rooting characteristics, as well as palatability to wildlife. Alfalfa, white clover and fall rye were seeded. In general, all areas of the reclamation plan are successfully revegetated. Areas which were recontoured are stable and non-eroding. Success was most significant in areas which had been scarified, then seeded and trackpacked. Areas that were seeded and fertilized only were less well established at the end of the first year, but showed improvement in the second and third years. The area will be monitored to ensure the reclaimed vegetation is self-sustaining

  17. ZnO THIN FILMS PREPARED BY SPRAY-PYROLYSIS TECHNIQUE FROM ORGANO-METALLIC PRECURSOR

    Directory of Open Access Journals (Sweden)

    Martin Mikulics

    2012-07-01

    Full Text Available Presented experiments utilize methanolic solution of zinc acetyl-acetonate as a precursor and sapphire (001 as a substrate for deposition of thin films of ZnO. The X-ray diffraction analysis revealed polycrystalline character of prepared films with preferential growth orientation along c-axis. The roughness of prepared films was assessed by AFM microscopy and represented by roughness root mean square (RMS value in range of 1.8 - 433 nm. The surface morphology was mapped by scanning electron microscopy showing periodical structure with several local defects. The optical transmittance spectrum of ZnO films was measured in wavelength range of 200-1000 nm. Prepared films are transparent in visible range with sharp ultra-violet cut-off at approximately 370 nm. Raman spectroscopy confirmed wurtzite structure and the presence of compressive stress within its structure as well as the occurrence of oxygen vacancies. The four-point Van der Pauw method was used to study the transport prosperities. The resistivity of presented ZnO films was found 8 × 10–2 Ω cm with carrier density of 1.3 × 1018 cm–3 and electron mobility of 40 cm2 V–1 s–1.

  18. Heavy lithium-doped ZnO thin films prepared by spray pyrolysis ...

    Indian Academy of Sciences (India)

    Administrator

    1. Introduction. Zinc oxide (ZnO) is a semiconductor with a wide and .... tal structure with preferred orientation along (0 0 2). ... This shift to higher angles could be attributed to residual ... segregated at the grain boundaries and they suppress the.

  19. Flame temperature trends in reacting vanadium and tungsten ethoxide fluid sprays during CO2-laser pyrolysis

    CSIR Research Space (South Africa)

    Mwakikunga, BW

    2011-09-01

    Full Text Available We observe the “invisible-to-the- naked-eye” flames of tungsten and vanadium ethoxide aerosols when ignited at moderate laser excitation (0 < Plaser< 70 W) by employing an IR thermo-graphic camera. No emission is seen in the visible range whether...

  20. Indium oxide thin-film transistors processed at low temperature via ultrasonic spray pyrolysis

    KAUST Repository

    Faber, Hendrik; Lin, Yenhung; Thomas, Stuart R.; Zhao, Kui; Pliatsikas, Nikos; McLachlan, Martyn A.; Amassian, Aram; Patsalas, Panos A.; Anthopoulos, Thomas D.

    2015-01-01

    that as-grown layers are extremely thin (∼7 nm) and composed of laterally large (30-60 nm) highly crystalline In2O3 domains. These unique characteristics of the In2O3 films are believed to be responsible for the high electron mobilities obtained from

  1. Spray pyrolysis of ZnO-TFTs utilizing a perfume atomizer

    Science.gov (United States)

    Ortel, Marlis; Trostyanskaya, Yulia Sergeeva; Wagner, Veit

    2013-08-01

    Successful deposition of ZnO layers from non-toxic solvent by utilizing a perfume atomizer is demonstrated. The adsorption edge of the zinc oxide films was found to be 3.22 eV which is in good agreement with literature. In addition it is found that the homogeneity of the films increases in side geometry with increasing distance to the perfume atomizer due to the droplet size distribution along the x-axis of the aerosol. The films were used to fabricate ZnO-TFTs. A dominating influence of the grain sizes can be excluded by correlating atomic force microscopy (AFM) images to the electrical properties of the transistors deposited in different geometries but a strong influence of the transistor performance on the growth rate was found. The increase in performance with decreasing growth rate was attributed to a longer reaction time decreasing the impurity level in the films. The linear mobility, the on-set voltage and the on-off current ratio are found to be 5 cm2 V-1 s-1, 0 V and 106 for small growth rates, respectively. Hence the transistors show high mobility and an excellent switching behavior.

  2. Use of co-spray pyrolysis for synthesizing nitrogen-doped TiO2 films

    Indian Academy of Sciences (India)

    the photoelectrochemical solar cell (Guo et al 2011; Zhang et al 2011; Umar et al ... as photocatalytic mechanism, bandgap narrowing, N 1s XPS assignment were ..... This work was supported by the Vietnam National Founda- tion for Science ...

  3. Pyrolysis Recovery of Waste Shipping Oil Using Microwave Heating

    Directory of Open Access Journals (Sweden)

    Wan Adibah Wan Mahari

    2016-09-01

    Full Text Available This study investigated the use of microwave pyrolysis as a recovery method for waste shipping oil. The influence of different process temperatures on the yield and composition of the pyrolysis products was investigated. The use of microwave heating provided a fast heating rate (40 °C/min to heat the waste oil at 600 °C. The waste oil was pyrolyzed and decomposed to form products dominated by pyrolysis oil (up to 66 wt. % and smaller amounts of pyrolysis gases (24 wt. % and char residue (10 wt. %. The pyrolysis oil contained light C9–C30 hydrocarbons and was detected to have a calorific value of 47–48 MJ/kg which is close to those traditional liquid fuels derived from fossil fuel. The results show that microwave pyrolysis of waste shipping oil generated an oil product that could be used as a potential fuel.

  4. TG-FTIR analysis of biomass pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Bassilakis, R.; Carangelo, R.M.; Wojtowicz, M.A. [Advanced Fuel Research Inc., Hartford, CT (United States)

    2001-10-09

    A great need exists for comprehensive biomass-pyrolysis models that could predict yields and evolution patterns of selected volatile products as a function of feedstock characteristics and process conditions. A thermogravimetric analyzer coupled with Fourier transform infrared analysis of evolving products (TG-FTIR) can provide useful input to such models in the form of kinetic information obtained under low heating rate conditions. In this work, robust TG-FTIR quantification routes were developed for infrared analysis of volatile products relevant to biomass pyrolysis. The analysis was applied to wheat straw, three types of tobacco (Burley, Oriental, and Bright) and three biomass model compounds (xylan, chlorogenic acid, and D-glucose). Product yields were compared with literature data, and species potentially quantifiable by FT-IR are reviewed. Product-evolution patterns are reported for all seven biomass samples. 41 refs., 7 figs., 2 tabs.

  5. Methods and apparatuses for deoxygenating pyrolysis oil

    Science.gov (United States)

    Baird, Lance Awender; Brandvold, Timothy A.; Frey, Stanley Joseph

    2017-09-12

    Methods and apparatuses are provided for deoxygenating pyrolysis oil. A method includes contacting a pyrolysis oil with a deoxygenation catalyst in a first reactor at deoxygenation conditions to produce a first reactor effluent. The first reactor effluent has a first oxygen concentration and a first hydrogen concentration, based on hydrocarbons in the first reactor effluent, and the first reactor effluent includes an aromatic compound. The first reactor effluent is contacted with a dehydrogenation catalyst in a second reactor at conditions that deoxygenate the first reactor effluent while preserving the aromatic compound to produce a second reactor effluent. The second reactor effluent has a second oxygen concentration lower than the first oxygen concentration and a second hydrogen concentration that is equal to or lower than the first hydrogen concentration, where the second oxygen concentration and the second hydrogen concentration are based on the hydrocarbons in the second reactor effluent.

  6. Decarbonisation of fossil energy via methane pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Kreysa, G.; Agar, D.W.; Schultz, I. [Technische Univ. Dortmund (Germany)

    2010-12-30

    Despite the rising consumption of energy over the last few decades, the proven reserves of fossil fuels have steadily increased. Additionally, there are potentially tremendous reserves of methane hydrates available, which remain to be exploited. The use of fossil energy sources is thus increasingly being dictated less by supply than by the environmental concerns raised by climate change. In the context of the decarbonisation of the global energy system that this has stimulated, new means must be explored for using methane as energy source. Noncatalytic thermal pyrolysis of methane is proposed here as a promising concept for utilising methane with low to zero carbon dioxide emissions. Following cracking, only the energy content of the hydrogen is used, while the carbon can be stored safely and retrievably in disused coal mines. The thermodynamics and different process engineering concepts for the technical realisation of such a carbon moratorium technology are discussed. The possible contribution of methane pyrolysis to carbon negative geoengineering is also addressed. (orig.)

  7. Catalytic flash pyrolysis of oil-impregnated-wood and jatropha cake using sodium based catalysts

    KAUST Repository

    Imran, Ali; Bramer, Eddy A.; Seshan, Kulathuiyer; Brem, Gerrit

    2015-01-01

    Catalytic pyrolysis of wood with impregnated vegetable oil was investigated and compared with catalytic pyrolysis of jatropha cake making use of sodium based catalysts to produce a high quality bio-oil. The catalytic pyrolysis was carried out in two

  8. Slurry spray distribution within a simulated laboratory scale spray dryer

    International Nuclear Information System (INIS)

    Bertone, P.C.

    1979-01-01

    It was found that the distribution of liquid striking the sides of a simulated room temperature spray dryer was not significantly altered by the choice of nozles, nor by a variation in nozzle operating conditions. Instead, it was found to be a function of the spray dryer's configuration. A cocurrent flow of air down the drying cylinder, not possible with PNL's closed top, favorably altered the spray distribution by both decreasing the amount of liquid striking the interior of the cylinder from 72 to 26% of the feed supplied, and by shifting the zone of maximum impact from 1.0 to 1.7 feet from the nozzle. These findings led to the redesign of the laboratory scale spray dryer to be tested at the Savannah River Plant. The diameter of the drying chamber was increased from 5 to 8 inches, and a cocurrent flow of air was established with a closed recycle. Finally, this investigation suggested a drying scheme which offers all the advantages of spray drying without many of its limitations

  9. Plasma Sprayed Hydroxyapatite Coatings: Influence of Spraying Power on Microstructure

    International Nuclear Information System (INIS)

    Mohd, S. M.; Abd, M. Z.; Abd, A. N.

    2010-01-01

    The plasma sprayed hydroxyapatite (HA) coatings are used on metallic implants to enhance the bonding between the implant and bone in human body. The coating process was implemented at different spraying power for each spraying condition. The coatings formed from a rapid solidification of molten and partly molten particles that impact on the surface of substrate at high velocity and high temperature. The study was concentrated on different spraying power that is between 23 to 31 kW. The effect of different power on the coatings microstructure was investigated using scanning electron microscope (SEM) and phase composition was evaluated using X-ray diffraction (XRD) analysis. The coatings surface morphology showed distribution of molten, partially melted particles and some micro-cracks. The produced coatings were found to be porous as observed from the cross-sectional morphology. The coatings XRD results indicated the presence of crystalline phase of HA and each of the patterns was similar to the initial powder. Regardless of different spraying power, all the coatings were having similar XRD patterns.

  10. Pyrolysis Processing of Waste Peanuts Crisps

    Directory of Open Access Journals (Sweden)

    Grycová Barbora

    2015-12-01

    Full Text Available Wastes are the most frequent "by-product" of human society. The Czech Republic still has a considerable room for energy reduction and material intensiveness of production in connection with the application of scientific and technical expertise in the context of innovation cycles. Pyrolysis waste treatment is a promising alternative to the production of renewable hydrogen as a clean fuel. It can also reduce the environmental burden and the amount of waste in the environment at the same time.

  11. Reaction mechanisms in cellulose pyrolysis: a literature review

    Energy Technology Data Exchange (ETDEWEB)

    Molton, P.M.; Demmitt, T.F.

    1977-08-01

    A bibliographic review of 195 references is presented outlining the history of the research into the mechanisms of cellulose pyrolysis. Topics discussed are: initial product identification, mechanism of initial formation of levoglucosan, from cellulose and from related compounds, decomposition of cellulose to other compounds, formation of aromatics, pyrolysis of levoglucosan, crosslinking of cellulose, pyrolytic reactions of cellulose derivatives, and the effects of inorganic salts on the pyrolysis mechanism. (JSR)

  12. Experimental investigation of pyrolysis process of corn straw

    OpenAIRE

    Lei Wang; Shengqiang Shen; Shuhua Yang; Xinguang Shi

    2010-01-01

    The present paper was performed to analyze the pyrolysis process of corn straw. Based on the thermogravimetric analysis, the component of pyrolysis gas of corn straw was tested using the gas chromatograph analyzer. Experimental results showed that, as the reaction temperature increases, the component of H 2 and CH 4 increases, whereas the component of CO and CO 2 decreases. Finally, the mechanism of pyrolysis process of corn straw was revealed from the point of view of the molecular structure...

  13. Rapid quantification of biomarkers during kerogen microscale pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Stott, A.W.; Abbott, G.D. [Fossil Fuels and Environmental Geochemistry NRG, The University, Newcastle-upon-Tyne (United Kingdom)

    1995-02-01

    A rapid, reproducible method incorporating closed system microscale pyrolysis and thermal desorption-gas chromatography/mass spectrometry has been developed and applied to the quantification of sterane biomarkers released during pyrolysis of the Messel oil shale kerogen under confined conditions. This method allows a substantial experimental concentration-time data set to be collected at accurately controlled temperatures, due to the low thermal inertia of the microscale borosilicate glass reaction vessels, which facilitates kinetic studies of biomarker reactions during kerogen microscale pyrolysis

  14. Flash pyrolysis fuel oil: BIO-POK

    Energy Technology Data Exchange (ETDEWEB)

    Gust, S [Neste Oy, Porvoo (Finland)

    1996-12-31

    Flash pyrolysis oil from Ensyn Tech., Canada and Union Fenosa, Spain was combusted with simple pressure atomisation equipment commonly used with light fuel oils in intermediate size (0.1-1 MW) boilers. With a number of modifications to the combustion system, carbon monoxide (CO) and nitrous oxide (NO{sub x}) could be reduced to acceptable levels: CO < 30 ppm and NO{sub x} < 140 ppm. Particulate emissions which were initially very high (Bacharach 4-5) were reduced (Bach. 2-3) by system changes but are still higher than from light fuel oil (Bach. <1). The modifications to the combustion system were: acid resistant progressive cavity pump, higher oil preheat temperature and higher oil pressure than for light fuel oils, refractory section between burner and boiler warmed up to at least 800 deg C. In addition, it was necessary to store pyrolysis oil samples under inert conditions to prevent oxidation and to rinse nozzles with alcohol after shutdown to prevent coking. The complexity and cost of these system modifications are considered to be too great for current grades of flash pyrolysis oil to be sold as a light fuel oil replacement. Improvements to fuel quality will be necessary. The main improvements are lowering of viscosity and improving of stability

  15. Oxidative desulfurization of tire pyrolysis oil

    Directory of Open Access Journals (Sweden)

    Ahmad Shahzad

    2016-01-01

    Full Text Available This paper presents a low cost method for the purification of oils obtained from the pyrolysis of used tires. Oxidative desulfurization is a promising route for purification of tire pyrolysis oils as hydro-desulfurization may not be affordable for small scale industries. Different additives and acids have been employed for the enhancement of properties of pyrolytic oils. The experimental conditions were kept identical throughout, i.e. atmospheric pressure and 50°C temperature for comparison of performance of various additives. The use of hydrogen peroxide-acetic acid mixture (10 wt.% was found more economical and effective in desulfurization and improvement of fuel properties of sample oils. The contribution of sulfuric acid in desulfurization and decreasing viscosity was also satisfactory but due to high price of concentrated sulfuric acid its use may not be economical. Calcium oxide and Fuller’s earth was not found to be effective in desulfurization. Results indicate that oxidative desulfurization could render tire pyrolysis oils suitable for blending as heating fuel.

  16. Flash pyrolysis fuel oil: BIO-POK

    Energy Technology Data Exchange (ETDEWEB)

    Gust, S. [Neste Oy, Porvoo (Finland)

    1995-12-31

    Flash pyrolysis oil from Ensyn Tech., Canada and Union Fenosa, Spain was combusted with simple pressure atomisation equipment commonly used with light fuel oils in intermediate size (0.1-1 MW) boilers. With a number of modifications to the combustion system, carbon monoxide (CO) and nitrous oxide (NO{sub x}) could be reduced to acceptable levels: CO < 30 ppm and NO{sub x} < 140 ppm. Particulate emissions which were initially very high (Bacharach 4-5) were reduced (Bach. 2-3) by system changes but are still higher than from light fuel oil (Bach. <1). The modifications to the combustion system were: acid resistant progressive cavity pump, higher oil preheat temperature and higher oil pressure than for light fuel oils, refractory section between burner and boiler warmed up to at least 800 deg C. In addition, it was necessary to store pyrolysis oil samples under inert conditions to prevent oxidation and to rinse nozzles with alcohol after shutdown to prevent coking. The complexity and cost of these system modifications are considered to be too great for current grades of flash pyrolysis oil to be sold as a light fuel oil replacement. Improvements to fuel quality will be necessary. The main improvements are lowering of viscosity and improving of stability

  17. Thermogravimetric analysis and fast pyrolysis of Milkweed.

    Science.gov (United States)

    Kim, Seung-Soo; Agblevor, Foster A

    2014-10-01

    Pyrolysis of Milkweed was carried out in a thermogravimetric analyzer and a bubbling fluidized bed reactor. Total liquid yield of Milkweed pyrolysis was between 40.74% and 44.19 wt% between 425 °C and 550 °C. The gas yield increased from 27.90 wt% to 33.33 wt% with increasing reaction temperature. The higher heating values (HHV) of the Milkweed bio-oil were relatively high (30.33-32.87 MJ/kg) and varied with reaction temperature, feeding rate and fluidization velocity. The selectivity for CO2 was highest within non-condensable gases, and the molar ratio of CO2/CO was about 3 at the different reaction conditions. The (13)C NMR analysis, of the bio-oil showed that the relative concentration carboxylic group and its derivatives was higher at 425 °C than 475 °C, which resulted in slightly higher oxygen content in bio-oil. The pH of aqueous phase obtained at 475 °C was 7.37 which is the highest reported for any lignocellulosic biomass pyrolysis oils. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Catalytic Pyrolysis of Waste Plastic Mixture

    Science.gov (United States)

    Sembiring, Ferdianta; Wahyu Purnomo, Chandra; Purwono, Suryo

    2018-03-01

    Inorganic waste especially plastics still become a major problem in many places. Low biodegradability of this materials causes the effort in recycling become very difficult. Most of the municipal solid waste (MSW) recycling facilities in developing country only use composting method to recover the organic fraction of the waste, while the inorganic fraction is still untreated. By pyrolysis, plastic waste can be treated to produce liquid fuels, flammable gas and chars. Reduction in volume and utilization of the liquid and gas as fuel are the major benefits of the process. By heat integration actually this process can become a self-sufficient system in terms of energy demand. However, the drawback of this process is usually due to the diverse type of plastic in the MSW creating low grade of liquid fuel and harmful gases. In this study, the mixture of plastics i.e. polypropylene (PP) and polyethylene terephthalate (PET) is treated using pyrolysis with catalyst in several operating temperature. PET is problematic to be treated using pyrolysis due to wax-like byproduct in liquid which may cause pipe clogging. The catalyst is the mixture of natural zeolite and bentonite which is able to handle PP and PET mixture feed to produce high grade liquid fuels in terms of calorific value and other fuel properties.

  19. Olive bagasse (Olea europa L.) pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Sensoz, S.; Demiral, I. [Osmangazi Univ., Eskisehir (Turkey). Dept. of Chemical Engineering; Gercel, H.F. [Anadolu Univ., Eskisehir (Turkey). Dept. of Chemical Engineering

    2006-02-15

    Olive bagasse (Olea europea L.) was pyrolysed in a fixed-bed reactor. The effects of pyrolysis temperature, heating rate, particle size and sweep gas flow rates on the yields of the products were investigated. Pyrolysis runs were performed using pyrolysis temperatures between 350 and 550 {sup o}C with heating rates of 10 and 50 {sup o}C min{sup -} {sup 1}. The particle size and sweep gas flow rate varied in the ranges 0.224-1.8 mm and 50-200 cm{sup 3} min {sup -1}, respectively. The bio-oil obtained at 500 {sup o}C was analysed and at this temperature the liquid product yield was the maximum. The various characteristics of bio-oil obtained under these conditions were identified on the basis of standard test methods. The empirical formula of the bio-oil with heating value of 31.8 MJ kg{sup -1} was established as CH{sub 1.65}O{sub 0.25}N{sub 0.03}. The chemical characterization showed that the bio-oil obtained from olive bagasse may be potentially valuable as a fuel and chemical feedstock. (author)

  20. Coal pyrolysis. VII. Economic viability of pyrolysis. Pirolisis del carbon. VII. Viabilidad economica de la pirolisis

    Energy Technology Data Exchange (ETDEWEB)

    Molinar, R.; Adanez, J.; Miranda, J.L.; Ibarra, J.V. (Instituto de Carboquimica, Zaragoza (Spain))

    1989-04-01

    Analyses the most important economic parameters of the main pyrolysis processes. Considers the markets available for semi-coke and tars. Concludes that no single technology or process has clear advantages over the others because all depends on the type of coal being used and the purpose for which the end product is to be used. Refers to studies carried out in Canada and the USA on the same subject and reports their findings. Concludes optimistically that coal pyrolysis shows promise of being economically viable in the future because although initially, costs reflect the high financial outlay necessary to begin operations, after a certain period, these costs fall and the end product can be sold at a lower price. A further point in favour of pyrolysis is that coal prices are likely to rise more slowly than oil prices. 5 refs., 8 tabs.