Effect of temperature and time on solvothermal synthesis of ...

Indian Academy of Sciences (India)

Effect of temperature and time study on solvothermal synthesis of BaTiO3 revealed that a moderate reaction temperature i.e. 185◦C and longer reaction time favour tetragonal phase stabiliza- tion. Dissolution–precipitation appears to be the transformation mechanism for the crystallization of BaTiO3 from particulate TiO2 ...

Key insights on the structural characterization of textured Er{sub 2}O{sub 3}-ZrO{sub 2} nano-oxides prepared by a surfactant-free solvothermal route

Energy Technology Data Exchange (ETDEWEB)

Julian-Lopez, Beatriz, E-mail: julian@qio.uji.es [Departamento de Quimica Inorganica y Organica, Universitat Jaume I, Avda. Vicente Sos Baynat s/n, 12071 Castellon (Spain); Luz, Veronica de la; Gonell, Francisco; Cordoncillo, Eloisa [Departamento de Quimica Inorganica y Organica, Universitat Jaume I, Avda. Vicente Sos Baynat s/n, 12071 Castellon (Spain); Lopez-Haro, Miguel; Calvino, Jose J. [Departamento de Ciencia de los Materiales e Ingenieria Metalurgica y Quimica Inorganica, Facultad de Ciencias, Universidad de Cadiz, Campus Rio San Pedro, Puerto Real, 11510 Cadiz (Spain); Escribano, Purificacion [Departamento de Quimica Inorganica y Organica, Universitat Jaume I, Avda. Vicente Sos Baynat s/n, 12071 Castellon (Spain)

2012-04-05

Highlights: Black-Right-Pointing-Pointer Structural resolution of fluorite vs. pyrochlore in small nanocrystals. Black-Right-Pointing-Pointer Simple template-free solvothermal synthesis of Er{sub 2}O{sub 3}-ZrO{sub 2} nanooxides. Black-Right-Pointing-Pointer Good control over size, morphology and surface properties (280 m{sup 2} g{sup -1}). - Abstract: Zirconia-mixed oxides can exhibit cubic fluorite and pyrochlore structure. Their discrimination is not easy in nanooxides with a crystal size close to that of a few unit cells. In this work, high resolution transmission electron microscopy (HRTEM) has been employed to provide key insights on the structural characterization of a nanometric and porous mixed Er{sub 2}O{sub 3}-ZrO{sub 2} oxide. The material was prepared by a simple template-free solvothermal route that provided nanocrystalline powders at low temperature (170 Degree-Sign C) with spherical morphology, and high surface area ({approx}280 m{sup 2} g{sup -1}). The porosity was mainly originated from the assembling of organic complexing agents used in the synthesis to limit the crystal growth and to control hydrolysis and condensation reaction rates. The samples were characterized by thermal analysis, X-ray diffraction, scanning electron microscopy and N{sub 2} adsorption measurements. A detailed study by HRTEM was conducted on microtomed samples. It was observed that the material was made of nanocrystals packed into spherical agglomerates. HRTEM simulations indicated that it is not possible to identify the pyrochlore phase in nanoparticles with diameter below 2 nm. In our samples, the analysis of the HRTEM lattice images by means of fast Fourier transform (FFT) techniques revealed well defined spots that can be assigned to different planes of a cubic fluorite-type phase, even in the raw material. Raman spectroscopy was also a powerful technique to elucidate the crystalline phase of the materials with the smallest nanoparticles. HREM and Raman results evidenced

Synthesis and optical properties of CuS nanoplate-based architectures by a solvothermal method

International Nuclear Information System (INIS)

Li Fei; Kong Tao; Bi Wentuan; Li Dachang; Li Zhen; Huang Xintang

2009-01-01

The controlled synthesis of copper sulfide (CuS) nanoplate-based architectures in different solvents has been realized at low cost by simply reaction of Cu(NO 3 ) 2 .3H 2 O and S under solvothermal conditions without the use of any template. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis spectrometer and fluorescence measurement were used to characterize the products. The products were all in hexagonal phase with high crystallinity and the morphology was significantly influenced by the solvents. The CuS products synthesized in dimethylformamide (DMF) were nanoplates and the samples prepared in ethanol were flower-like morphology composed of large numbers of nanoplates, but those synthesized in ethylene glycol (EG) were CuS architectures with high symmetry made up of several nanoplates arranged in a certain mode. The optical properties were investigated and the growth mechanisms of these CuS crystals were also proposed.

ROOM TEMPERATURE BULK AND TEMPLATE-FREE SYNTHESIS OF LEUCOEMARLDINE POLYANILINE NANOFIBERS

Science.gov (United States)

An extremely simple single-step method is described for the bulk synthesis of nanofibers of the electronic polymer polyaniline in fully reduced state (leucoemarldine form) without using any reducing agents, surfactants, and/or large amounts of insoluble templates. Chemical oxida...

One-pot solvothermal synthesis of three-dimensional (3D) BiOI/BiOCl composites with enhanced visible-light photocatalytic activities for the degradation of bisphenol-A

International Nuclear Information System (INIS)

Xiao, Xin; Hao, Rong; Liang, Min; Zuo, Xiaoxi; Nan, Junmin; Li, Laisheng; Zhang, Weide

2012-01-01

Highlights: ► Synthesis of 3D BiOI/BiOCl microspheres by a one-pot template-free solvothermal method. ► Photocatalyst is BiOI/BiOCl composites. ► BiOI/BiOCl composites have enhanced visible-light photocatalytic ability to bisphenol-A. ► A simple and direct photodegradation pathway of bisphenol-A is proposed. - Abstract: Three-dimensional (3D) BiOI/BiOCl composite microspheres with enhanced visible-light photodegradation activity of bisphenol-A (BPA) are synthesized by a simple, one-pot, template-free, solvothermal method using BiI 3 and BiCl 3 as precursors. These 3D hierarchical microspheres with heterojunction structures are composed of 2D nanosheets and have composition-dependent absorption properties in the ultraviolet and visible light regions. The photocatalytic oxidation of BPA over BiOI/BiOCl composites followed pseudo first-order kinetics according to the Langmuir–Hinshelwood model. The highest photodegradation efficiency of BPA, i.e., nearly 100%, was observed with the BiOI/BiOCl composite (containing 90% BiOI) using a catalyst dosage of 1 g L −1 in the BPA solution (C 0 = 20 mg L −1 , pH = 7.0) under visible light irradiation for 60 min. Under these conditions, the reaction rate constant was more than 4 and 20 times greater than that of pure BiOI and the commercially available Degussa P25, respectively. The superior photocatalytic activity of this composite catalyst is attributed to the suitable band gap energies and the low recombination rate of the photogenerated electron–hole pairs due to the presence of BiOI/BiOCl heterostructures. Only one intermediate at m/z 151 was observed in the photodegradation process of BPA by liquid chromatography combined with mass spectrometry (LC–MS) analysis, and a simple and hole-predominated photodegradation pathway of BPA was subsequently proposed. Furthermore, this photocatalyst exhibited a high mineralization ratio, high stability and easy separation for recycling use, suggesting that it is a

Rate in template-directed polymer synthesis.

Science.gov (United States)

Saito, Takuya

2014-06-01

We discuss the temporal efficiency of template-directed polymer synthesis, such as DNA replication and transcription, under a given template string. To weigh the synthesis speed and accuracy on the same scale, we propose a template-directed synthesis (TDS) rate, which contains an expression analogous to that for the Shannon entropy. Increasing the synthesis speed accelerates the TDS rate, but the TDS rate is lowered if the produced sequences are diversified. We apply the TDS rate to some production system models and investigate how the balance between the speed and the accuracy is affected by changes in the system conditions.

Shape-controlled solvothermal synthesis of bismuth subcarbonate nanomaterials

International Nuclear Information System (INIS)

Cheng Gang; Yang Hanmin; Rong Kaifeng; Lu Zhong; Yu Xianglin; Chen Rong

2010-01-01

Much effort has been devoted to the synthesis of novel nanostructured materials because of their unique properties and potential applications. Bismuth subcarbonate ((BiO) 2 CO 3 ) is one of commonly used antibacterial agents against Helicobacter pylori (H. pylori). Different (BiO) 2 CO 3 nanostructures such as cube-like nanoparticles, nanobars and nanoplates, were fabricated from bismuth nitrate via a simple solvothermal method. The nanostructures were characterized by powder X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). It was found that the solvents and precursors have an influence on the morphologies of (BiO) 2 CO 3 nanostructures. The possible formation mechanism of different (BiO) 2 CO 3 nanostructures fabricated under different conditions was also discussed. - Graphical abstract: Different bismuth subcarbonate ((BiO) 2 CO 3 ) nanostructures were successfully synthesized by a simple solvothermal method. It was found that the solvents and precursors have an influence on the morphologies of (BiO) 2 CO 3 nanostructures.

Synthesis of alumina powders by precipitation method and solvothermal treatment

International Nuclear Information System (INIS)

Politchuk, J.O.; Lima, N.B.; Lazar, D.R.R.; Ussui, V.; Yoshito, W.K.

2012-01-01

The improvement of alumina powders synthesis processes has been focused on the preparation of ceramic powders with well defined crystalline structure and with high specific surface area and nanometric particle size without formation of hard agglomerates. For this purpose the precipitation step should be studied and and also the temperature of alumina crystallization should be reduced. The aim of this study was to obtain alumina powders by hydroxide precipitation with ammonia in the presence of cationic surfactant, followed by solvothermal treatment and calcination. The powders were characterized by TG/DTA, X-ray diffraction, surface area measurements by gas adsorption (BET) and scanning electron microscopy. The results showed that powders produced by solvothermal treatment without surfactant have higher crystallinity. However the presence of CTAB enhances 240% the specific surface area compared with powders produced without this reagent (author)

Preparation of Hierarchical BiOBr Microspheres for Visible Light-Induced Photocatalytic Detoxification and Disinfection

Directory of Open Access Journals (Sweden)

Ayla Ahmad

2016-01-01

Full Text Available Photocatalytic degradation is a promising alternative to traditional wastewater treatment methods. Recently developed visible light-responsive photocatalyst, BiOBr, has attracted extensive attentions. Hereby, a detailed investigation of application of BiOBr to bacterial inactivation and organic pollutants degradation is reported. Hydrothermal catalyst was prepared using template-free method. While, for solvothermal synthesis, CTAB was used as a template. Results indicate a higher photocatalytic activity by the solvothermally prepared catalyst. Solvothermally prepared BiOBr exhibited high photocatalytic activities in both water detoxification and disinfection.

Synthesis and characterization of pharmaceutical surfactant templated mesoporous silica: Its application to controlled delivery of duloxetine

Energy Technology Data Exchange (ETDEWEB)

Mani, Ganesh; Pushparaj, Hemalatha; Peng, Mei Mei; Muthiahpillai, Palanichamy [Department of Chemical Engineering, Hanseo University, Seosan-si 356 706 (Korea, Republic of); Udhumansha, Ubaidulla [Department of Chemical Engineering, Hanseo University, Seosan-si 356 706 (Korea, Republic of); Department of Pharmaceutics, C.L. Baid Metha College of Pharmacy, Chennai (India); Jang, Hyun Tae, E-mail: htjang@hanseo.ac.kr [Department of Chemical Engineering, Hanseo University, Seosan-si 356 706 (Korea, Republic of)

2014-03-01

Graphical abstract: - Highlights: • Usefulness of dual pharmaceutical surfactants in silica synthesis was evaluated. • Effects of concentration of secondary template (Tween-40) were studied. • Effects of fixed solvothermal condition on mesostructure formation were studied. • Duloxetine drug loading capability was studied. • Sustained release of duloxetine was evaluated. - Abstract: A new group of mesoporous silica nanoparticles (MSNs) were synthesized using combination pharmaceutical surfactants, Triton X-100 and Tween-40 as template and loaded with duloxetine hydrochloride (DX), for improving the sustained release of DX and patterns with high drug loading. Agglomerated spherical silica MSNs were synthesized by sol–gel and solvothermal methods. The calcined and drug loaded MSNs were characterized using X-ray diffraction (XRD), Braunner–Emmett–Teller (BET), thermogravimetric analysis (TGA), Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), diffuse reflectance ultraviolet–visible (DRS-UV–vis) spectroscopy. MSNs with high surface area and pore volume were selected and studied for their DX loading and release. The selected MSNs can accommodate a maximum of 34% DX within it. About 90% was released at 200 h and hence, the synthesized MSNs were capable of engulfing DX and sustain its release. Further form the Ritger and Peppas, Higuchi model for mechanism drug release from all the MSN matrices follows anomalous transport or Non-Fickian diffusion with the ‘r’ and ‘n’ value 0.9 and 0.45 < n < 1, respectively. So, from this study it could be concluded that the MSNs synthesized using pharmaceutical templates were better choice of reservoir for the controlled delivery of drug which requires sustained release.

Solvothermal synthesis: a new route for preparing nitrides

CERN Document Server

Demazeau, G; Denis, A; Largeteau, A

2002-01-01

Solvothermal synthesis appears to be an interesting route for preparing nitrides such as gallium nitride and aluminium nitride, using ammonia as solvent. A nitriding additive is used to perform the reaction and, in the case of gallium nitride, is encapsulated by melt gallium. The syntheses are performed in the temperature range 400-800 deg. C and in the pressure range 100-200 MPa. The synthesized powders are characterized by x-ray diffraction and scanning electron microscopy. Finely divided gallium nitride GaN and aluminium nitride AlN, both with wurtzite-type structure, can be obtained by this route.

Water-assisted and surfactant-free synthesis of cobalt ferrite nanospheres via solvothermal method

Energy Technology Data Exchange (ETDEWEB)

Bi, Yiqing [CAS Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190 (China); University of the Chinese Academy of Sciences, Beijing 100049 (China); Ren, Yanan [CAS Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190 (China); Bi, Feng [CAS Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190 (China); University of the Chinese Academy of Sciences, Beijing 100049 (China); He, Tao, E-mail: het@nanoctr.cn [CAS Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190 (China)

2015-10-15

With ethylene glycol as the solvent, monodispersed cobalt ferrite nanospheres were prepared via a solvothermal method assisted by water. The samples were mainly characterized by X-ray diffraction, scanning electron microscope, and transmission electron microscope. The size of as-prepared products ranges from 10 nm to 200 nm. Size distribution and chemical composition were controlled by the amount of water and pH value in the reaction system. More important, suitable amount of water can avoid the use of surfactant. - Highlights: • Cobalt ferrite nanospheres were synthesized via solvothermal method assisted by water. • An introduction of suitable amount of water can avoid the use of surfactant. • The pH value of the precursor can be used to adjust the product composition.

TiO2/carbon nanotube hybrid nanostructures: Solvothermal synthesis and their visible light photocatalytic activity

International Nuclear Information System (INIS)

Tian Lihong; Ye Liqun; Deng Kejian; Zan Ling

2011-01-01

MWCNT/TiO 2 hybrid nanostructures were prepared via solvothermal synthesis and sol-gel method with benzyl alcohol as a surfactant. As-prepared hybrid materials were characterized by X-ray diffraction, transmission electron microscopy, UV-vis diffuse reflectance spectra and X-ray photoelectron spectroscopy. The results showed that MWCNTs were uniformly decorated with anatase nanocrystals in solvothermal condition, but MWCNTs were embedded in a majority of TiO 2 nanoparticles by sol-gel method. When the weight ratio of MWCNTs to TiO 2 was 20%, MWCNT/TiO 2 hybrid nanostructures prepared by solvothermal synthesis exhibited higher visible-light-driven photocatalytic activity than that prepared by sol-gel method. Post-annealing of MWCNT/TiO 2 nanostructures at 400 deg. C resulted in the formation of the carbonaceous Ti-C bonds on the interface between TiO 2 and MWCNTs, which enhanced the photoabsorbance of the hybrid materials in the visible light region and improved the visible-light degradation efficiency of methylene blue. - Graphical abstract: MWCNT/TiO 2 nanostructures have been prepared by solvothermal method, which exhibited higher visible-light-driven photocatalytic activity than that prepared by sol-gel method. The carbonaceous Ti-C bonds on the interface between TiO 2 and MWCNTs enhanced the photoabsorbance of the hybrid materials in the visible light region. Highlights: → Anatase TiO 2 nanoparticles were anchored on CNTs surface uniformly via solvothermal method → The morphology facilitated the electron transfer between CNTs and TiO 2 → Ti-C bonds extended the absorption of MWCNT/TiO 2 to the whole visible light region. → The hybrid nanostructures showed enhanced visible-light induced photocatalytic activity.

A Facile Solvothermal Method for Synthesis of CuInS2 Nanostructures

Directory of Open Access Journals (Sweden)

M. Mousavi-Kamazani

2012-09-01

Full Text Available CuInS2 nanostructures were  synthesized  via  a  simple  surfactant-free solvothermal  route.  In  this  synthesis,  thiosemicarbazide  and thioglycolic acid were used as sulfur sources. The effects of different parameters such as type of precursor and time on the morphology and particle  size  of  the  samples  have  been  investigated.  The nanostructures  were  characterized  by  means  of  X-ray  diffraction (XRD,  scanning  electron microscopy  (SEM,  energy-dispersive X- ray  analysis  (EDX,  Fourier  transform  infrared  (FT-IR  and photoluminescence  (PL  spectroscopy.  The  fill  factor  (FF,  open circuit voltage  (Voc, and  short circuit current  (Isc were obtained by I–V characterization.

One-pot solvothermal synthesis of three-dimensional (3D) BiOI/BiOCl composites with enhanced visible-light photocatalytic activities for the degradation of bisphenol-A

Energy Technology Data Exchange (ETDEWEB)

Xiao, Xin [School of Chemistry and Environment, South China Normal University, Key Lab of Theoretical Chemistry of Environment, Guangzhou 510006 (China); Nano Science Research Center, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640 (China); Hao, Rong; Liang, Min; Zuo, Xiaoxi [School of Chemistry and Environment, South China Normal University, Key Lab of Theoretical Chemistry of Environment, Guangzhou 510006 (China); Nan, Junmin, E-mail: jmnan@scnu.edu.cn [School of Chemistry and Environment, South China Normal University, Key Lab of Theoretical Chemistry of Environment, Guangzhou 510006 (China); Li, Laisheng [School of Chemistry and Environment, South China Normal University, Key Lab of Theoretical Chemistry of Environment, Guangzhou 510006 (China); Zhang, Weide [Nano Science Research Center, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640 (China)

2012-09-30

Highlights: Black-Right-Pointing-Pointer Synthesis of 3D BiOI/BiOCl microspheres by a one-pot template-free solvothermal method. Black-Right-Pointing-Pointer Photocatalyst is BiOI/BiOCl composites. Black-Right-Pointing-Pointer BiOI/BiOCl composites have enhanced visible-light photocatalytic ability to bisphenol-A. Black-Right-Pointing-Pointer A simple and direct photodegradation pathway of bisphenol-A is proposed. - Abstract: Three-dimensional (3D) BiOI/BiOCl composite microspheres with enhanced visible-light photodegradation activity of bisphenol-A (BPA) are synthesized by a simple, one-pot, template-free, solvothermal method using BiI{sub 3} and BiCl{sub 3} as precursors. These 3D hierarchical microspheres with heterojunction structures are composed of 2D nanosheets and have composition-dependent absorption properties in the ultraviolet and visible light regions. The photocatalytic oxidation of BPA over BiOI/BiOCl composites followed pseudo first-order kinetics according to the Langmuir-Hinshelwood model. The highest photodegradation efficiency of BPA, i.e., nearly 100%, was observed with the BiOI/BiOCl composite (containing 90% BiOI) using a catalyst dosage of 1 g L{sup -1} in the BPA solution (C{sub 0} = 20 mg L{sup -1}, pH = 7.0) under visible light irradiation for 60 min. Under these conditions, the reaction rate constant was more than 4 and 20 times greater than that of pure BiOI and the commercially available Degussa P25, respectively. The superior photocatalytic activity of this composite catalyst is attributed to the suitable band gap energies and the low recombination rate of the photogenerated electron-hole pairs due to the presence of BiOI/BiOCl heterostructures. Only one intermediate at m/z 151 was observed in the photodegradation process of BPA by liquid chromatography combined with mass spectrometry (LC-MS) analysis, and a simple and hole-predominated photodegradation pathway of BPA was subsequently proposed. Furthermore, this photocatalyst

The growth of high density network of MOF nano-crystals across macroporous metal substrates - Solvothermal synthesis versus rapid thermal deposition

Science.gov (United States)

Maina, James W.; Gonzalo, Cristina Pozo; Merenda, Andrea; Kong, Lingxue; Schütz, Jürg A.; Dumée, Ludovic F.

2018-01-01

Fabrication of metal organic framework (MOF) films and membranes across macro-porous metal substrates is extremely challenging, due to the large pore sizes across the substrates, poor wettability, and the lack of sufficient reactive functional groups on the surface, which prevent high density nucleation of MOF crystals. Herein, macroporous stainless steel substrates (pore size 44 × 40 μm) are functionalized with amine functional groups, and the growth of ZIF-8 crystals investigated through both solvothermal synthesis and rapid thermal deposition (RTD), to assess the role of synthesis routes in the resultant membranes microstructure, and subsequently their performance. Although a high density of well interconnected MOF crystals was observed across the modified substrates following both techniques, RTD was found to be a much more efficient route, yielding high quality membranes under 1 h, as opposed to the 24 h required for solvothermal synthesis. The RTD membranes also exhibited high gas permeance, with He permeance of up to 2.954 ± 0.119 × 10-6 mol m-2 s-1 Pa-1, and Knudsen selectivities for He/N2, Ar/N2 and CO2/N2, suggesting the membranes were almost defect free. This work opens up route for efficient fabrication of MOF films and membranes across macro-porous metal supports, with potential application in electrically mediated separation applications.

A Facile Solvothermal Synthesis of Octahedral Fe3O4 Nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Ooi, Frances; DuChene, Joseph S.; Qiu, Jianqing; Graham, Jeremy O.; Engelhard, Mark H.; Cao, Guixin; Gai, Zheng; Wei, Wei

2015-06-01

Magnetic nanoparticles are of great technological interest because they promise numerous potential opportunities in biomedicine and data storage. Although intriguing, these applications require exquisite control over nanostructure morphology in order to appropriately harness their magnetic properties. Most synthesis strategies reported to date are unable to routinely produce anisotropic Fe3O4 nanostructures with appropriate sizes to enable integration into biological systems. Here, we report a simple solvothermal synthesis for obtaining octahedral Fe3O4 nanoparticles with suitable sizes for cellular internalization. Furthermore, these ferromagnetic Fe3O4 octahedrons exhibit substantial saturation magnetization with minimal remanence, suggesting their potential applicability for a host of biomedical applications.

Template-free sonochemical synthesis of flower-like ZnO nanostructures

International Nuclear Information System (INIS)

Yu, Huawa; Fan, Huiqing; Wang, Xin; Wang, Jing; Cheng, Pengfei; Zhang, Xiaojun

2014-01-01

Flower-like ZnO nanostructures have been successfully synthesized via a facile and template-free sonochemical method, using zinc acetate and potassium hydroxide as reactants only. The as-synthesized flower-like ZnO nanostructures were composed of nanorods with the width of ∼300–400 nm and the length of ∼2–3 μm. The structures, morphologies and optical properties of the as-prepared products were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscopy, UV-Vis spectrophotometry and Raman-scattering spectroscopy. A plausible formation mechanism of flower-like ZnO nanostructures was studied by SEM which monitors an intermediate morphology transformation of the product at the different ultrasonic time (t=80,90,95,105, and 120 min). - Highlights: • A facile and template-free sonochemical method to fabricate flower-like ZnO nanostructures was proposed. • The flower-like ZnO nanostructures follow the ingrowth of ZnO from the matrix of Zn(OH) 2 crystals. • The flower-like ZnO nanostructures are also expected to explore their application in the field of nano-electronic devices

Facile and template-free method toward chemical synthesis of polyaniline film/nanotube structures

Energy Technology Data Exchange (ETDEWEB)

Liu, Pei [Department of Electrical and Computer Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh Pennsylvania 15261; Zhu, Yisi [Materials Science Division, Argonne National Lab, Lemont Illinois 60439; Torres, Jorge [Department of Electrical and Computer Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh Pennsylvania 15261; Lee, Seung Hee [Department of BIN Fusion Technology, Chonbuk National University, Jeonju 561-786 Korea; Yun, Minhee [Department of Electrical and Computer Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh Pennsylvania 15261

2017-09-05

A facile and template-free method is reported to synthesize a new thin film structure: polyaniline (PANI) film/nanotubes (F/N) structure. The PANI F/N is a 100-nm thick PANI film embedded with PANI nanotubes. This well-controlled method requires no surfactant or organic acid as well as relatively low concentration of reagents. Synthesis condition studies reveal that aniline oligomers with certain structures are responsible for guiding the growth of the nanotubes. Electrical characterization also indicates that the PANI F/N possesses similar field-effect transistor characteristics to bare PANI film. With its 20% increased surface-area-to-volume (S/V) ratio contributed by surface embedded nanotubes and the excellent p-type semiconducting characteristic, PANI F/N shows clear superiority compared with bare PANI film. Such advantages guarantee the PANI F/N a promising future toward the development of ultra-high sensitivity and low-cost biosensors.

Solvothermal synthesis and analysis of Bi1-xSbx nanoparticles

International Nuclear Information System (INIS)

Sumithra, S.; Misra, D.K.; Wei, C.; Gabrisch, H.; Poudeu, P.F.P.; Stokes, K.L.

2011-01-01

Bismuth-antimony alloy nanoparticles have been synthesized by a facile solvothermal method using N,N-dimethylformamide and ethylene glycol as solvent/reducing agent; BiCl 3 , SbCl 3 and Bi(NO 3 ) 3 as precursors; and citric acid as a surface modifier/stabilizing agent. The particle size and size distribution of Bi nanoparticles were analyzed as a function of the synthesis conditions: molar ratio of precursor to surfactant, precursor concentration and reducing agent. Synthesis of Sb and Bi 0.88 Sb 0.12 under similar conditions was also investigated. The phase purity of nanoparticles was confirmed from X-ray diffraction and thermogravimetry and the nanoparticle morphology was investigated by transmission electron microscopy. A case study of Bi nanoparticles with detailed analysis of the particle morphology and size distribution of the nanoparticles is reported.

Template-free sonochemical synthesis of flower-like ZnO nanostructures

Energy Technology Data Exchange (ETDEWEB)

Yu, Huawa [State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi' an 710072 (China); School of Science, Xi' an Polytechnic University, Xi' an 710048 (China); Fan, Huiqing, E-mail: hqfan3@163.com [State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi' an 710072 (China); Wang, Xin [Shaanxi Province Thin Film Technology and Optical Test Open Key Laboratory, School of Photoelectrical Engineering, Xi' an Technological University, Xi' an 710032 (China); Wang, Jing [State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi' an 710072 (China); Cheng, Pengfei; Zhang, Xiaojun [School of Science, Xi' an Polytechnic University, Xi' an 710048 (China)

2014-10-03

Flower-like ZnO nanostructures have been successfully synthesized via a facile and template-free sonochemical method, using zinc acetate and potassium hydroxide as reactants only. The as-synthesized flower-like ZnO nanostructures were composed of nanorods with the width of ∼300–400 nm and the length of ∼2–3 μm. The structures, morphologies and optical properties of the as-prepared products were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscopy, UV-Vis spectrophotometry and Raman-scattering spectroscopy. A plausible formation mechanism of flower-like ZnO nanostructures was studied by SEM which monitors an intermediate morphology transformation of the product at the different ultrasonic time (t=80,90,95,105, and 120 min). - Highlights: • A facile and template-free sonochemical method to fabricate flower-like ZnO nanostructures was proposed. • The flower-like ZnO nanostructures follow the ingrowth of ZnO from the matrix of Zn(OH){sub 2} crystals. • The flower-like ZnO nanostructures are also expected to explore their application in the field of nano-electronic devices.

Template-free synthesis and luminescent properties of hollow Ln:YOF (Ln = Eu or Er + Yb) microspheres

Energy Technology Data Exchange (ETDEWEB)

Martinez-Castro, E. [Instituto de Ciencia de Materiales de Sevilla (CSIC-US), Americo Vespucio 49, Isla de La Cartuja, 41092 Sevilla (Spain); García-Sevillano, J.; Cussó, F. [Dpto. Física de Materiales, C-04, Universidad Autónoma de Madrid, Avda. Francisco Tomás y Valiente, 7, 28049 Madrid (Spain); Ocaña, M., E-mail: mjurado@icmse.csic.es [Instituto de Ciencia de Materiales de Sevilla (CSIC-US), Americo Vespucio 49, Isla de La Cartuja, 41092 Sevilla (Spain)

2015-01-15

Highlights: • Hollow lanthanide doped YOF spheres have been synthesised through a template-free procedure. • Strong red emissions are observed for Eu-doped spheres under UV illumination. • Concentration quenching of luminescence takes place in the spheres at very high Eu doping levels. • Bright red emission is observed for Er, Yb codoped spheres, making this matrix advantageous for biomedical imaging. - Abstract: A method for the synthesis of hollow lanthanide doped yttrium oxyfluoride (YOF) spheres in the micrometer size range with cubic structure based on the pyrolysis at 600 °C of liquid aerosols generated from aqueous solutions containing the corresponding rare earth chlorides and trifluoroacetic acid has been developed. This procedure, which has been used for the first time for the synthesis of YFO based materials, is simpler and advantageous when compared with other methods usually employed for the production of hollow spheres since it does not require the use of sacrificial templates. In addition, it is continuous, which is desirable because of practical reasons. The procedure is also suitable for doping the YOF spheres with europium cations resulting in down converting red phosphors when activated with UV light, or for co-doping with both Er{sup 3+} and Yb{sup 3+} giving rise to up-converting phosphors, which emit intense red light under near infrared (NIR) irradiation. Because of their optical properties and hollow architecture, the developed materials may find applications in optoelectronic devices and biotechnology.

TiO2 synthesized by microwave assisted solvothermal method: Experimental and theoretical evaluation

International Nuclear Information System (INIS)

Moura, K.F.; Maul, J.; Albuquerque, A.R.; Casali, G.P.; Longo, E.; Keyson, D.; Souza, A.G.; Sambrano, J.R.; Santos, I.M.G.

2014-01-01

In this study, a microwave assisted solvothermal method was used to synthesize TiO 2 with anatase structure. The synthesis was done using Ti (IV) isopropoxide and ethanol without templates or alkalinizing agents. Changes in structural features were observed with increasing time of synthesis and evaluated using periodic quantum chemical calculations. The anatase phase was obtained after only 1 min of reaction besides a small amount of brookite phase. Experimental Raman spectra are in accordance with the theoretical one. Micrometric spheres constituted by nanometric particles were obtained for synthesis from 1 to 30 min, while spheres and sticks were observed after 60 min. - Graphical abstract: FE-SEM images of anatase obtained with different periods of synthesis associated with the order–disorder degree. Display Omitted - Highlights: • Anatase microspheres were obtained by the microwave assisted hydrothermal method. • Only ethanol and titanium isopropoxide were used as precursors during the synthesis. • Raman spectra and XRD patterns were compared with quantum chemical calculations. • Time of synthesis increased the short-range disorder in one direction and decreased in another

Annealing-free synthesis of C-N co-doped TiO{sub 2} hierarchical spheres by using amine agents via microwave-assisted solvothermal method and their photocatalytic activities

Energy Technology Data Exchange (ETDEWEB)

Wu, Yu-Chun, E-mail: yuchunwu@mail.ncku.edu.tw; Ju, Lung-Shen

2014-08-01

Highlights: • The synthesis method for C-N co-doped TiO{sub 2} hierarchical spheres is proposed. • Microwave-assisted solvothermal method is applied. • C and N are doped into TiO{sub 2} via a direct chelating reaction of amine compounds. • The photodegradation rate is eightfold higher than the commercial P25 powders. - Abstract: The annealing-free synthesis of C-N co-doped TiO{sub 2} hierarchical spheres is proposed in this study. C and N were doped into the TiO{sub 2} structure via a direct chelating process to the Ti-precursor by using different amine agents, including hexadecylamine (HDA), diethylamine (DEA), trimethylamine (TMA), and diethylenetriamine (DETA). C-N co-doped TiO{sub 2} spheres (300 nm to 500 nm) composed of nanoparticles approximately 11 nm to 13 nm in size were obtained via an efficient microwave-assisted solvothermal reaction at 190 °C for 60 min. The effects of C and N doping by using different amine compounds on the bandgap energy and photocatalytic performance of TiO{sub 2} were investigated. Among the amine compounds, DETA provided the highest chelating efficiency because it provides two primary amine groups, which resulted in the highest C and N doping concentrations and the largest degree of bandgap narrowing (2.77 eV); nevertheless, the high chelating ratio of C and N restrained the crystallization of TiO{sub 2} and considerably decreased its photocatalytic activity. The use of TMA produced optimal C and N doping concentrations, which effectively reduced the bandgap of TiO{sub 2} to 2.85 eV without affecting its crystallization. Its photodecomposition activity to rhodamine B was eightfold of that of commercial Degussa P25 powders under visible light irradiation.

Facile Synthesis of Long, Straight and Uniform Copper Nanowires via a Solvothermal Method

Institute of Scientific and Technical Information of China (English)

Chunfu Lin; Hong Lin; Ning Wang; Xing Zhang; Jun Yang; Jianbo Li; Xiaozhan Yang

2006-01-01

Copper nanowires were facilely prepared via a solvothermal method. In this method, cetyltrimethylammonium bromide (CTAB) was used as a soft template, copper nitrate was an inorganic precursor, and absolute ethanol served as a reducing agent as well as a solvent. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the as-prepared copper nanowires. The as-prepared copper nanowires are fairly uniform and long. The majority of them are longer than 100 μm and some even longer than 200 μm. Furthermore, most nanowires are quite straight. In addition,The mechanism of the growth process of copper nanowires was discussed.

Solvothermal synthesis of Li–Al layered double hydroxides and their electrochemical performance

International Nuclear Information System (INIS)

Wei, Jinbo; Gao, Zan; Song, Yanchao; Yang, Wanlu; Wang, Jun; Li, Zhanshuang; Mann, Tom; Zhang, Milin; Liu, Lianhe

2013-01-01

In this paper, for the first time, Li/Al layered double hydroxides (LDHs) were synthesized by a facile and environment-friendly solvothermal approach. X-ray diffraction patterns show that the as-prepared products belong to the hexagonal phase. Well-defined LDHs particles with spiral-shape (1–2 μm), hexagonal (2–3 μm) and petal-like structures (10–15 μm) have been successfully fabricated by adjusting the content of water/ethanol in the synthesis process. A possible growth mechanism was proposed for the formation of these structures. Their electrochemical performances were investigated by cyclic voltammetry, galvanostatic charge/discharge test and electrochemical impedance spectroscopy. The hexagonal Li/Al LDHs calcined at 450 °C exhibit the specific capacitance of 848 F g −1 at a current density of 1.25 A g −1 . The high specific capacitance and remarkable rate capacity of Li/Al LDHs are promising for applications in capacitors and low-cost aqueous lithium ion batteries. - Graphical abstract: Hexagonal Li/Al layered double hydroxides (LDHs) with high specific surface area and remarkable rate capacity via a facile and environmentally friendly solvothermal approach. Highlights: ► Li/Al LDHs with different morphologies were fabricated by a solvothermal method. ► Hexagonal Li/Al LDHs display better electrochemical performance. ► A possible growth mechanism to explain the different morphology is proposed

Facile solvothermal synthesis of abnormal growth of one-dimensional ZnO nanostructures by ring-opening reaction of polyvinylpyrrolidone

Energy Technology Data Exchange (ETDEWEB)

Xu, G., E-mail: gxu@alum.imr.ac.cn; Wang, X.L.; Liu, G.Z.

2015-02-28

Graphical abstract: - Highlights: • Facile solvothermal synthesis of ZnO nanostructures in super high alkaline alcoholic condition. • The exact role and chemical transformations of PVP in solvothermal synthesis of ZnO nanostructures was revealed. • Mechanism of abnormal growth of ZnO nanopyramids was proposed based on ring-opening reaction of PVP. - Abstract: Abnormal growth of one-dimensional (1-D) ZnO nanostructures (NSs) have been accomplished with the assistance of polyvinylpyrrolidone (PVP) under a super high alkaline alcoholic solvothermal condition. The products were characterized by transmission electron microscopy (TEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and proton nuclear magnetic resonance ({sup 1}H NMR) spectroscopy. The effect of synthetic conditions, such as reaction temperature and the addition of PVP, on the morphologies of ZnO products were investigated. The results show that PVP molecules had the significant role in the transformation of morphologies of ZnO NSs ranging from nanorods, nanoparticles to pyramids, as well as flower-like assembly features. The possible growth mechanism of ZnO pyramids was proposed based on ring-opening reaction of PVP.

Facile one-step template-free synthesis of uniform hollow microstructures of cryptomelane-type manganese oxide K-OMS-2.

Science.gov (United States)

Galindo, Hugo M; Carvajal, Yadira; Njagi, Eric; Ristau, Roger A; Suib, Steven L

2010-08-17

Hollow microstructures of cryptomelane-type manganese oxide were produced in a template-free one-step process based on the fine-tuning of the oxidation rate of manganese species during the synthesis. The tuning of the reaction rate brought about by a mixture of the oxidants oxone and potassium nitrate becomes apparent from the gradual physical changes taking place in the reaction medium at early times of the synthesis. The successful synthesis of the hollow uniform structures could be performed in the ranges 120-160 degrees C and 8.2-10.7 for temperature and mass ratio oxone/potassium nitrate, respectively. Independent of the conditions of the synthesis, all of the complex microstructures showed the same pattern for the array of very long nanofibers in which some of these elongated around the surface confining the cavity and the other fibers grew normal to the surface created by the previous arrangement. A mechanism based on the heterogeneous nucleation of the cryptomelane phase on the surface of an amorphous precursor and the growth of the nanoscale fibers by processes such as dissolution-crystallization and lateral attachment of primary nanocrystalline fibers is proposed to explain the formation of the hollow structures.

Hard template synthesis of metal nanowires

Science.gov (United States)

Kawamura, Go; Muto, Hiroyuki; Matsuda, Atsunori

2014-11-01

Metal nanowires (NWs) have attracted much attention because of their high electron conductivity, optical transmittance and tunable magnetic properties. Metal NWs have been synthesized using soft templates such as surface stabilizing molecules and polymers, and hard templates such as anodic aluminum oxide, mesoporous oxide, carbon nanotubes. NWs prepared from hard templates are composites of metals and the oxide/carbon matrix. Thus, selecting appropriate elements can simplify the production of composite devices. The resulting NWs are immobilized and spatially arranged, as dictated by the ordered porous structure of the template. This avoids the NWs from aggregating, which is common for NWs prepared with soft templates in solution. Herein, the hard template synthesis of metal NWs is reviewed, and the resulting structures, properties and potential applications are discussed.

High-Quality ZnCdS Nanosheets Prepared Using Solvothermal Synthesis

International Nuclear Information System (INIS)

Mahdi, M.A.; Hassan, J.J.; Ng, S.S.; Hassan, Z.

2013-01-01

For the first time, Zn X Cd 1-X S nanosheets with different Zn and Cd ion concentrations were prepared using solvothermal synthesis at 200 degree C for 4 and 24 h. The crystalline structure of the nanosheets was wurtzite. The optical band gaps of the nanosheets increased with increasing Zn ratio; this increase is consistent with the band gaps estimated using Vegard’s formula. The photoluminescence spectra for the 24 h nanosheets had higher emission intensities than those for the 4 h nanosheets. The emission band corresponding to intrinsic near-band-edge emission and a broad peak associated with extrinsic deep-level emission were observed in the photoluminescence spectra.

Hard template synthesis of metal nanowires

Directory of Open Access Journals (Sweden)

Go eKawamura

2014-11-01

Full Text Available Metal nanowires (NWs have attracted much attention because of their high electron conductivity, optical transmittance and tunable magnetic properties. Metal NWs have been synthesized using soft templates such as surface stabilizing molecules and polymers, and hard templates such as anodic aluminum oxide, mesoporous oxide, carbon nanotubes. NWs prepared from hard templates are composites of metals and the oxide/carbon matrix. Thus, selecting appropriate elements can simplify the production of composite devices. The resulting NWs are immobilized and spatially arranged, as dictated by the ordered porous structure of the template. This avoids the NWs from aggregating, which is common for NWs prepared with soft templates in solution. Herein, the hard template synthesis of metal NWs is reviewed, and the resulting structures, properties and potential applications are discussed.

Silver nanoplates with ground or metastable structures obtained from template-free two-phase aqueous/organic synthesis

Energy Technology Data Exchange (ETDEWEB)

Zhelev, Doncho V., E-mail: dontcho.jelev@nih.gov; Zheleva, Tsvetanka S. [Army Research Laboratory, 2800 Adelphi, Maryland 20783 (United States)

2014-01-28

Silver has unique electrical, catalytic, and plasmonic characteristics and has been widely sought for fabrication of nanostructures. The properties of silver nanostructures are intimately coupled to the structure of silver crystals. Two crystal structures are known for silver: the stable (ground) state cubic face centered 3C-Ag structure and the metastable hexagonal 4H-Ag structure. Recently, Chackraborty et al. [J. Phys.: Condens. Matter 23, 325401 (2011)] discovered a low density, highly reactive metastable hexagonal 2H-Ag structure accessible during electrodeposition of silver nanowires in porous anodic alumina templates. This 2H-Ag structure has enhanced electrical and catalytic characteristics. In the present work we report template-free synthesis of silver nanoplates with the metastable 2H-Ag crystal structure, which appears together with the ground 3C-Ag and the metastable 4H-Ag structures in a two-phase solution synthesis with citric acid as the capping agent. The capacity of citric acid to stabilize both the stable and the metastable structures is explained by its preferential binding to the close packed facets of Ag crystals, which are the (111) planes for 3C-Ag and the (0001) planes for 4H-Ag and 2H-Ag. Nanoplate morphology and structure are characterized using scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. The synthesized nanoplates have thickness from 15 to 17 nm and edge length from 1 to 10 μm. Transmission electron microscopy selected area electron diffraction is used to uniquely identify and distinguish between nanoplates with 2H-Ag or 4H-Ag or 3C-Ag structures.

A novel ethanol templating synthesis of ordered lamellar superstructured crystalline zirconia

International Nuclear Information System (INIS)

Liu Chao; Wang Bin; Ji Xiujie; Zhao Shanshan; Wu Jie; Jia Jianlong; Ma Dongxia

2012-01-01

Soft template technique has attracted great interest, because it is a facile, inexpensive and efficient synthesis strategy for ordered superstructural systems. Here, a novel ethanol template was used to synthesize the ordered lamellar superstructured crystalline zirconia (Lα-ZrO 2 ) without post-treatments and surfactants. ZrOCl 2 and NaOH were served as Zr source and precipitant, respectively. XRD analysis showed that Lα-ZrO 2 is crystalline. XPS spectra indicated the physical adsorption of ethanol molecules in Lα-ZrO 2 . TEM further observed and proved the 1.36-nm period of superstructure detected and calculated by SAXRD (1.35 nm), which is composed of 0.68-nm thick ZrO 2 and pore alternatively. In contrast, the template-free ZrO 2 (TF-ZrO 2 ) presents no superstructure and is poorly crystallized. As a soft template, ethanol presents the roles of (i) inducing the growth of zirconia layers, (ii) directing the self-assembly of ordered lamellar superstructure, and (iii) decreasing the crystallization temperature. The possible mechanism of ethanol serving as a soft template was proposed and discussed in thermodynamics.

Solvothermal synthesis of 3D photonic crystals based on ZnS/opal system

Energy Technology Data Exchange (ETDEWEB)

Chang Xin [Nanomaterials Research Institute, College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Cao Jieming [Nanomaterials Research Institute, College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China)]. E-mail: jmcao@nuaa.edu.cn; Ji Hongmei [Nanomaterials Research Institute, College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Fang Baoqing [Nanomaterials Research Institute, College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Feng Jie [Nanomaterials Research Institute, College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Pan Lijia [Nanomaterials Research Institute, College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Zhang Fang [Nanomaterials Research Institute, College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Wang, Haiyan [Nanomaterials Research Institute, College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China)

2005-01-15

We made photonic crystals composed of artificial opals infiltrated with ZnS semiconductor nanocrystals by using self-assembly and solvothermal methods. SEM images show that the silica spheres exhibit a well-ordered arrangement and the ZnS nanocrystals infiltrate within the opal templates by heterogeneous nucleation and growth processing, and the as-synthesized ZnS nanocrystals reveal a cubic phase from X-ray diffraction pattern. Furthermore, the optical properties of the infiltrated opals with different ZnS filling ratio are also studied by transmission spectroscopy, respectively. It is proposed that the position of the stop band can be easily designed by controlling the infiltration ratio of ZnS. These results demonstrate an easy-to-handle and efficient route to obtain high performance photonic crystal structures.

Solvothermal synthesis of 3D photonic crystals based on ZnS/opal system

International Nuclear Information System (INIS)

Chang Xin; Cao Jieming; Ji Hongmei; Fang Baoqing; Feng Jie; Pan Lijia; Zhang Fang; Wang, Haiyan

2005-01-01

We made photonic crystals composed of artificial opals infiltrated with ZnS semiconductor nanocrystals by using self-assembly and solvothermal methods. SEM images show that the silica spheres exhibit a well-ordered arrangement and the ZnS nanocrystals infiltrate within the opal templates by heterogeneous nucleation and growth processing, and the as-synthesized ZnS nanocrystals reveal a cubic phase from X-ray diffraction pattern. Furthermore, the optical properties of the infiltrated opals with different ZnS filling ratio are also studied by transmission spectroscopy, respectively. It is proposed that the position of the stop band can be easily designed by controlling the infiltration ratio of ZnS. These results demonstrate an easy-to-handle and efficient route to obtain high performance photonic crystal structures

One-pot solvothermal synthesis of ordered intermetallic Pt2In3 as stable and efficient electrocatalyst towards direct alcohol fuel cell application

Science.gov (United States)

Jana, Rajkumar; Peter, Sebastian C.

2016-10-01

Ordered intermetallic Pt2In3 nanoparticles have been synthesized by superhydride reduction of K2PtCl4 and InCl3.xH2O precursors using facile, one-pot solvothermal method. We report surfactant free solvothermal synthesis of a novel ordered Pt2In3 intermetallic nanoparticles for the first time. The structure and morphology of the catalyst has been confirmed by powder X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, energy-dispersive spectrometry and X-ray photoelectron spectroscopy. The electrocatalytic properties of the catalysts have been investigated by cyclic voltammetry and chronoamperometry. The as prepared Pt2In3 catalyst exhibit far superior electrocatalytic activity and stability towards alcohol oxidation over commercial Pt/C. The specific activity of as synthesized catalyst was found to be 3.2 and 2.3 times higher than commercial Pt/C for methanol and ethanol oxidation, respectively. This improved activity and durability of the Pt2In3 nanoparticles can make the catalyst an ideal catalyst candidate for direct alcohol fuel cell.

Solid-Phase Synthesis of Molecularly Imprinted Polymer Nanoparticles with a Reusable Template - "Plastic Antibodies".

Science.gov (United States)

Poma, Alessandro; Guerreiro, Antonio; Whitcombe, Michael J; Piletska, Elena V; Turner, Anthony P F; Piletsky, Sergey A

2013-06-13

Molecularly Imprinted Polymers (MIPs) are generic alternatives to antibodies in sensors, diagnostics and separations. To displace biomolecules without radical changes in infrastructure in device manufacture, MIPs should share their characteristics (solubility, size, specificity and affinity, localized binding domain) whilst maintaining the advantages of MIPs (low-cost, short development time and high stability) hence the interest in MIP nanoparticles. Herein we report a reusable solid-phase template approach (fully compatible with automation) for the synthesis of MIP nanoparticles and their precise manufacture using a prototype automated UV photochemical reactor. Batches of nanoparticles (30-400 nm) with narrow size distributions imprinted with: melamine (d = 60 nm, K d = 6.3 × 10 -8 m), vancomycin (d = 250 nm, K d = 3.4 × 10 -9 m), a peptide (d = 350 nm, K d = 4.8 × 10 -8 m) and proteins have been produced. Our instrument uses a column packed with glass beads, bearing the template. Process parameters are under computer control, requiring minimal manual intervention. For the first time we demonstrate the reliable re-use of molecular templates in the synthesis of MIPs (≥ 30 batches of nanoMIPs without loss of performance). NanoMIPs are produced template-free and the solid-phase acts both as template and affinity separation medium.

Arraying proteins by cell-free synthesis.

Science.gov (United States)

He, Mingyue; Wang, Ming-Wei

2007-10-01

Recent advances in life science have led to great motivation for the development of protein arrays to study functions of genome-encoded proteins. While traditional cell-based methods have been commonly used for generating protein arrays, they are usually a time-consuming process with a number of technical challenges. Cell-free protein synthesis offers an attractive system for making protein arrays, not only does it rapidly converts the genetic information into functional proteins without the need for DNA cloning, but also presents a flexible environment amenable to production of folded proteins or proteins with defined modifications. Recent advancements have made it possible to rapidly generate protein arrays from PCR DNA templates through parallel on-chip protein synthesis. This article reviews current cell-free protein array technologies and their proteomic applications.

A novel ethanol templating synthesis of ordered lamellar superstructured crystalline zirconia

Energy Technology Data Exchange (ETDEWEB)

Liu Chao, E-mail: liuchao_tj@yahoo.com; Wang Bin [Key Laboratory for New Type of Functional Materials in Hebei Province, Hebei University of Technology (China); Ji Xiujie, E-mail: jxjchem@yahoo.com [State Key Laboratory of Hollow Fiber Membrane Materials and Processes, Tianjin Polytechnic University (China); Zhao Shanshan; Wu Jie; Jia Jianlong; Ma Dongxia [Key Laboratory for New Type of Functional Materials in Hebei Province, Hebei University of Technology (China)

2012-03-15

Soft template technique has attracted great interest, because it is a facile, inexpensive and efficient synthesis strategy for ordered superstructural systems. Here, a novel ethanol template was used to synthesize the ordered lamellar superstructured crystalline zirconia (L{alpha}-ZrO{sub 2}) without post-treatments and surfactants. ZrOCl{sub 2} and NaOH were served as Zr source and precipitant, respectively. XRD analysis showed that L{alpha}-ZrO{sub 2} is crystalline. XPS spectra indicated the physical adsorption of ethanol molecules in L{alpha}-ZrO{sub 2}. TEM further observed and proved the 1.36-nm period of superstructure detected and calculated by SAXRD (1.35 nm), which is composed of 0.68-nm thick ZrO{sub 2} and pore alternatively. In contrast, the template-free ZrO{sub 2} (TF-ZrO{sub 2}) presents no superstructure and is poorly crystallized. As a soft template, ethanol presents the roles of (i) inducing the growth of zirconia layers, (ii) directing the self-assembly of ordered lamellar superstructure, and (iii) decreasing the crystallization temperature. The possible mechanism of ethanol serving as a soft template was proposed and discussed in thermodynamics.

Cell-free unnatural amino acid incorporation with alternative energy systems and linear expression templates.

Science.gov (United States)

Shrestha, Prashanta; Smith, Mark Thomas; Bundy, Bradley Charles

2014-01-25

Site-specific incorporation of unnatural amino acids (uAAs) during protein synthesis expands the proteomic code through the addition of unique residue chemistry. This field provides a unique tool to improve pharmacokinetics, cancer treatments, vaccine development, proteomics and protein engineering. The limited ability to predict the characteristics of proteins with uAA-incorporation creates a need for a low-cost system with the potential for rapid screening. Escherichia coli-based cell-free protein synthesis is a compelling platform for uAA incorporation due to the open and accessible nature of the reaction environment. However, typical cell-free systems can be expensive due to the high cost of energizing reagents. By employing alternative energy sources, we reduce the cost of uAA-incorporation in CFPS by 55%. While alternative energy systems reduce cost, the time investment to develop gene libraries can remain cumbersome. Cell-free systems allow the direct use of PCR products known as linear expression templates, thus alleviating tedious plasmid library preparations steps. We report the specific costs of CFPS with uAA incorporation, demonstrate that LETs are suitable expression templates with uAA-incorporation, and consider the substantial reduction in labor intensity using LET-based expression for CFPS uAA incorporation. Copyright © 2013 Elsevier B.V. All rights reserved.

Template-Independent Enzymatic Oligonucleotide Synthesis (TiEOS): Its History, Prospects, and Challenges.

Science.gov (United States)

Jensen, Michael A; Davis, Ronald W

2018-03-27

There is a growing demand for sustainable methods in research and development, where instead of hazardous chemicals, an aqueous medium is chosen to perform biological reactions. In this Perspective, we examine the history and current methodology of using enzymes to generate artificial single-stranded DNA. By using traditional solid-phase phosphoramidite chemistry as a metric, we also explore criteria for the method of template-independent enzymatic oligonucleotide synthesis (TiEOS). As its key component, we delve into the biology of one of the most enigmatic enzymes, terminal deoxynucleotidyl transferase (TdT). As TdT is found to exponentially increase antigen receptor diversity in the vertebrate immune system by adding nucleotides in a template-free manner, researchers have exploited this function as an alternative to the phosphoramidite synthesis method. Though TdT is currently the preferred enzyme for TiEOS, its random nucleotide incorporation presents a barrier in synthesis automation. Taking a closer look at the TiEOS cycle, particularly the coupling step, we find it is comprised of additions > n+1 and deletions. By tapping into the physical and biochemical properties of TdT, we strive to further elucidate its mercurial behavior and offer ways to better optimize TiEOS for production-grade oligonucleotide synthesis.

Recycling of surfactant template in mesoporous MCM-41 synthesis

Science.gov (United States)

Lai, J. Y.; Twaiq, F.; Ngu, L. H.

2017-06-01

The recycling of surfactant template is investigated through the reuse of the surfactant template in the mesoporous MCM-41 synthesis process. In the synthesis of MCM-41, tetraethylorthosilicate (TEOS) solution in water was utilized as the silica source while hexadecyltrimethylammonium bromide (CTAB) solution in ethyl alcohol was used as a surfactant template. The synthesized gel is formed thoroughly by mixing the two solutions under acid conditions with a pH value of 0.5 for 1 hour and kept for crystallization for 48 hours. The as-synthesized MCM-41 powder is recovered by filtration while the filtrate (mother liquor) was then reused for the second synthesis cycle. The synthesis procedure was repeated till no further solid product was formed. The synthesized gel was not produced in the unifying solution in the fifth cycle of MCM-41 synthesis. The quality of the calcined MCM-41 powder produced in each synthesis cycle was evaluated by calculating the amount of MCM-41 produced and the surface area of the powder product. The result showed that 1.28, 0.37, 1.64, 1.90 and 0.037 g were obtained in the 1st, 2nd, 3rd, 4th and 5th synthesis cycle, respectively. The surface area of the powder produced was found to be 1170, 916, 728, and 508 m2/g for 1st, 2nd, 3rd and 4th respectively. The concentration of the surfactant template has reached value lower than the critical micelle concentration (CMC) and remained constant after the 4th cycle. There was no further formation of gel due to low availability in the interaction between silicate anions and surfactant cations when the amount of TEOS was fixed for every synthesis cycle.

Solvothermal synthesis of high molecular weight dithienogermole ...

Indian Academy of Sciences (India)

polymers were synthesized by the solvothermal method. Optical ... compounds, especially to synthesize conjugated pol- ... analyses were performed under nitrogen flow using a .... Coffin R C, Peet J, Rogers J and Bazan G C 2009 Nat. Chem.

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

Solvothermal indium fluoride chemistry: Syntheses and crystal structures of K5In3F14, β-(NH4)3InF6 and [NH4]3[C6H21N4]2[In4F21

International Nuclear Information System (INIS)

Jayasundera, Anil C.A.; Goff, Richard J.; Li Yang; Finch, Adrian A.; Lightfoot, Philip

2010-01-01

The solvothermal syntheses and crystal structures of three indium fluorides are presented. K 5 In 3 F 14 (1) and β-(NH 4 ) 3 InF 6 (2) are variants on known inorganic structure types chiolite and cryolite, respectively, with the latter exhibiting a complex and apparently novel structural distortion. [NH 4 ] 3 [C 6 H 21 N 4 ] 2 [In 4 F 21 ] (3) represents a new hybrid composition displaying a unique trimeric metal fluoride building unit. - Graphical abstract: Solvothermal synthesis has been used to prepare three indium fluorides, including a novel hybrid material containing a unique [In 3 F 15 ] trimer templated by tren.

Solid-Phase Synthesis of Molecularly Imprinted Polymer Nanoparticles with a Reusable Template – “Plastic Antibodies”

Science.gov (United States)

Poma, Alessandro; Guerreiro, Antonio; Whitcombe, Michael J.; Piletska, Elena V.; Turner, Anthony P.F.; Piletsky, Sergey A.

2016-01-01

Molecularly Imprinted Polymers (MIPs) are generic alternatives to antibodies in sensors, diagnostics and separations. To displace biomolecules without radical changes in infrastructure in device manufacture, MIPs should share their characteristics (solubility, size, specificity and affinity, localized binding domain) whilst maintaining the advantages of MIPs (low-cost, short development time and high stability) hence the interest in MIP nanoparticles. Herein we report a reusable solid-phase template approach (fully compatible with automation) for the synthesis of MIP nanoparticles and their precise manufacture using a prototype automated UV photochemical reactor. Batches of nanoparticles (30-400 nm) with narrow size distributions imprinted with: melamine (d = 60 nm, Kd = 6.3 × 10−8 m), vancomycin (d = 250 nm, Kd = 3.4 × 10−9 m), a peptide (d = 350 nm, Kd = 4.8 × 10−8 m) and proteins have been produced. Our instrument uses a column packed with glass beads, bearing the template. Process parameters are under computer control, requiring minimal manual intervention. For the first time we demonstrate the reliable re-use of molecular templates in the synthesis of MIPs (≥ 30 batches of nanoMIPs without loss of performance). NanoMIPs are produced template-free and the solid-phase acts both as template and affinity separation medium. PMID:26869870

One-pot solvothermal synthesis of ordered intermetallic Pt{sub 2}In{sub 3} as stable and efficient electrocatalyst towards direct alcohol fuel cell application

Energy Technology Data Exchange (ETDEWEB)

Jana, Rajkumar; Peter, Sebastian C., E-mail: sebastiancp@jncasr.ac.in

2016-10-15

Ordered intermetallic Pt{sub 2}In{sub 3} nanoparticles have been synthesized by superhydride reduction of K{sub 2}PtCl{sub 4} and InCl{sub 3}.xH{sub 2}O precursors using facile, one-pot solvothermal method. We report surfactant free solvothermal synthesis of a novel ordered Pt{sub 2}In{sub 3} intermetallic nanoparticles for the first time. The structure and morphology of the catalyst has been confirmed by powder X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, energy-dispersive spectrometry and X-ray photoelectron spectroscopy. The electrocatalytic properties of the catalysts have been investigated by cyclic voltammetry and chronoamperometry. The as prepared Pt{sub 2}In{sub 3} catalyst exhibit far superior electrocatalytic activity and stability towards alcohol oxidation over commercial Pt/C. The specific activity of as synthesized catalyst was found to be ~3.2 and ~2.3 times higher than commercial Pt/C for methanol and ethanol oxidation, respectively. This improved activity and durability of the Pt{sub 2}In{sub 3} nanoparticles can make the catalyst an ideal catalyst candidate for direct alcohol fuel cell. - Graphical abstract: The ordered structure of Pt{sub 2}In{sub 3} nanoparticles synthesized by solvothermal method has confirmed through XRD and TEM. Cyclic voltametry and chronoamperometry showed improved catalytic activity and stability compared to commercial Pt/C. - Highlights: • Ordered Pt{sub 2}In{sub 3} nanoparticles were synthesized by solvothermal method. • Electrooxidation of alcohols on Pt{sub 2}In{sub 3} catalyst was investigated in acidic medium. • Pt{sub 2}In{sub 3} catalyst has superior catalytic activity compared to commercial Pt/C. • Pt{sub 2}In{sub 3} catalyst exhibited much higher stability than commercial Pt/C.

Template-free hydrothermal synthesis and high photocatalytic activity of ZnWO4 nanorods

International Nuclear Information System (INIS)

Gao, Bin; Fan, Huiqing; Zhang, Xiaojun; Song, Lixun

2012-01-01

Highlights: ► ZnWO 4 nanorods with uniform diameter are successfully prepared through a template-free hydrothermal method. ► The crystallinity of the products is influenced by the pH value of initial precursor suspension. ► Photocatalytic activity of the ZnWO 4 nanorods for degradation of methylene blue is evaluated. ► The ZnWO 4 nanorods exhibit good stability of photocatalytic activity. - Abstract: ZnWO 4 nanorods are successfully synthesized by a template-free hydrothermal method, and are characterized in detail by X-ray diffractometer (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED). The results show that the ZnWO 4 nanorods with wolframite structure are well-crystallized single crystallites. The crystallinity of the products is influenced by the pH value of initial precursor suspension. The width and length of the synthesized samples increase with hydrothermal reaction temperature. The photocatalytic efficiency of the ZnWO 4 nanorods for degradation of methylene blue (MB) in aqueous solution under UV light irradiation declines greatly with increasing crystallinity. The ZnWO 4 nanorods prepared at pH of 4 have the best activity in photo-degradation of MB. After six recycles, photocatalytic activity loss of the catalyst is not obvious.

Surfactant-assisted mild solvothermal synthesis of nanostructured LiFePO4/C cathodes evidencing ultrafast rate capability

International Nuclear Information System (INIS)

Di Lupo, F.; Meligrana, G.; Gerbaldi, C.; Bodoardo, S.; Penazzi, N.

2015-01-01

Highlights: • Nanostructured LiFePO 4 /C by surfactant assisted solvothermal synthesis. • Novel and simple preparation method, with no critical parameters. • Noticeable stability, good capacity values and capacity retention after prolonged cycling. • Improved rate capability at a very high C-rate (100C). • High performance for the next generation of advanced high power Li-ion batteries. - Abstract: A surfactant-assisted solvothermal synthesis is hereby applied to produce carbon-coated LiFePO 4 /C nanostructured Li-ion battery cathodes. The use of different mixed alcohol/water solutions for the dissolution of a cationic surfactant is absolutely peculiar in this field and herewith exploited to tailor-make the properties of the active material particles (e.g., morphology and electrochemical behaviour). Thorough investigation is carried out by means of X-ray powder diffraction, scanning and transmission electron microscopy, cyclic voltammetry and constant current charge-discharge cycling. The best performing sample, obtained in a 20:80 w/w ethanol:water solution, demonstrates good specific capacity values, high Coulombic efficiency and rate capability, with stable behaviour upon long-term cycling even at ultrafast 100C discharge regime. This is definitely remarkable for a nanosized powder specifically conceived for high power applications obtained by means of low cost raw materials, simple and reliable procedures

Template-free synthesis of sub-micrometric cobalt fibers with controlled shape and structure. Characterization and magnetic properties

Energy Technology Data Exchange (ETDEWEB)

Lakhdar, Allagui [Laboratoire de Physique des Matériaux Lamellaires et Nano-Matériaux Hybrides, Faculté des Sciences de Bizerte, Université de Carthage, 7021 Bizerte (Tunisia); Borges, Joao P. [i3N/CENIMAT, Department of Materials Science, Faculty of Science and Technology, Universidade NOVA de Lisboa, Campus de Caparica, 2829-516 Caparica (Portugal); Ben Haj Amara, Abdesslam [Laboratoire de Physique des Matériaux Lamellaires et Nano-Matériaux Hybrides, Faculté des Sciences de Bizerte, Université de Carthage, 7021 Bizerte (Tunisia); Dakhlaoui-Omrani, Amel, E-mail: dakhlaoui_amel@yahoo.fr [Department of Chemistry, Faculty of Sciences and Arts-Khulais, University of Jeddah, Khulais, P. O. Box 355, Postal Code 21921 (Saudi Arabia); Laboratoire de Physico-Chimie des Matériaux Minéraux et leurs Applications, Centre National des Recherches en Sciences des Matériaux, Technopôle de Bordj Cedria, BP 73, 8027 Soliman (Tunisia)

2017-03-01

Sub-micrometric Co fibers were prepared via a modified polyol process at 90 °C under an external magnetic field of about 550 Oe, using ethelyne glycol as solvent and hydrazine as reducing agent. The structure, the size and the morphology of the as-elaborated products were highly controlled through properly monitoring the synthesis parameters (amount of NaOH added, the amount of the reducing agent, precursor’ concentration and precursors mixing protocol). The XRD characterization confirmed the formation of pure cobalt powders with either hexagonal compact (hcp) or face-centered-cubic (fcc) structure depending on the concentration of the metal precursor and sodium hydroxide. The scanning electron microscopy observations of the powders shows sub-micrometric fibers with about 0.4–0.6 µm in diameter and a length that could reach 15 µm. Fibers prepared at high reducing ratio were constituted of flower-like spheres that coalesce in the direction of the applied magnetic field. For their high contact surface, these fibers offer new opportunities for catalysis applications. The hysteresis loop measurements show an enhancement of the Hc of the as-obtained fibers compared to their bulk counterparts and permit to confirm the relationship between the structure and the magnetic properties of the materials. - Highlights: • Template free synthesis of cobalt sub-micrometric fibers. • High control of the structure the structure, the size and the morphology of the products through properly monitoring the synthesis parameters. • cobalt sub-micrometric fibers with enhanced magnetic properties compared to bulk cobalt.

Synthesis and characterizations of Pt nanorods on electrospun polyamide-6 nanofibers templates

International Nuclear Information System (INIS)

Nirmala, R.; Navamathavan, R.; Won, Jeong Jin; Jeon, Kyung Soo; Yousef, Ayman; Kim, Hak Yong

2012-01-01

Highlights: ► Electrospun polyamide-6 nanofibers were used as the templates for synthesis Pt nanorods. ► Polyamide-6 nanofibers surfaces were plasma treated to coat Pt. ► High quality Pt nanorods were obtained by calcinations process. ► Pt nanorods with a diameter of few hundred nanometers were obtained. ► Polyamide-6 nanofibers template based Pt nanorods synthesis are a feasible method. - Abstract: We report on the synthesis of platinum (Pt) nanorods by using ultrafine polyamide-6 nanofibers templates produced via electrospinning technique. These ultrafine polyamide-6 nanofibers can be utilized as the templates for growing Pt nanorods after modifying them optimally by plasma passivations. The morphological, structural, optical and electrical properties of the template assisted Pt nanorods were studied by field-emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), photoluminescence (PL) and current–voltage (I–V) characteristics. The ability to fabricate the ultrafine size controlled Pt nanorods on polyamide-6 templates with optimized growth parameters in real time can be utilized for the variety of technological applications. Therefore, it is possible to obtain high quality with size control Pt nanorods. Once obtaining the high quality metal nanorods on polymer templates, the same can be adapted for the electronic device fabrication.

Pseudo template synthesis of poly (1-naphthylamine): effect of environment on nanostructured morphology

International Nuclear Information System (INIS)

Riaz, Ufana; Ahmad, Sharif; Ashraf, S. M.

2008-01-01

A template free approach was adopted to explore the effect of polymerization environment on the synthesis of nanostructured poly (1-naphthylamine) (PNA) using cupric chloride as oxidant and methyl alcohol as medium. The polymerization environment was varied by carrying out the synthesis in the presence of nitrogen and oxygen. The morphology of the synthesized nanostructured PNA was investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis and FT-IR spectroscopies. PNA nanorods of sizes varying between 50-100 nm were obtained in presence of nitrogen while in presence of oxygen, it formed aggregated globular particles of sizes varying between 80-100 nm. The results provide valuable information on controlling the synthesis of one-dimensional nanostructured conducting polymers that exhibit superior processibility as compared to the conventional conducting polymers.

Simple extraction-solvothermal synthesis of single-crystalline silver microplates

Energy Technology Data Exchange (ETDEWEB)

You, Ting; Sun, Sixiu; Song, Xinyu; Xu, Shuling [Department of Chemistry and Chemical Engineering, Shandong University (China)

2009-08-15

Single-crystalline silver microplates, with average edge length of about 1.5{mu}m and thickness of 100 nm, have been synthesized by a simple extraction-solvothermal method. Samples were characterized in detail by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and High-resolution transmission electron microscopy (HRTEM) technologies. Extractant primary amine N1923 can also act as reducing agent. It has been found that microstructure of the silver can be controlled by the n-octanol during the solvothermal treatment. Based on a series of experimental analysis, the possible formation mechanism of these microplates was discussed briefly. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Conducting polymer nanostructures: template synthesis and applications in energy storage.

Science.gov (United States)

Pan, Lijia; Qiu, Hao; Dou, Chunmeng; Li, Yun; Pu, Lin; Xu, Jianbin; Shi, Yi

2010-07-02

Conducting polymer nanostructures have received increasing attention in both fundamental research and various application fields in recent decades. Compared with bulk conducting polymers, conducting polymer nanostructures are expected to display improved performance in energy storage because of the unique properties arising from their nanoscaled size: high electrical conductivity, large surface area, short path lengths for the transport of ions, and high electrochemical activity. Template methods are emerging for a sort of facile, efficient, and highly controllable synthesis of conducting polymer nanostructures. This paper reviews template synthesis routes for conducting polymer nanostructures, including soft and hard template methods, as well as its mechanisms. The application of conducting polymer mesostructures in energy storage devices, such as supercapacitors and rechargeable batteries, are discussed.

Conducting Polymer Nanostructures: Template Synthesis and Applications in Energy Storage

Directory of Open Access Journals (Sweden)

Lijia Pan

2010-07-01

Full Text Available Conducting polymer nanostructures have received increasing attention in both fundamental research and various application fields in recent decades. Compared with bulk conducting polymers, conducting polymer nanostructures are expected to display improved performance in energy storage because of the unique properties arising from their nanoscaled size: high electrical conductivity, large surface area, short path lengths for the transport of ions, and high electrochemical activity. Template methods are emerging for a sort of facile, efficient, and highly controllable synthesis of conducting polymer nanostructures. This paper reviews template synthesis routes for conducting polymer nanostructures, including soft and hard template methods, as well as its mechanisms. The application of conducting polymer mesostructures in energy storage devices, such as supercapacitors and rechargeable batteries, are discussed.

Synthesis of hierarchical porous materials with ZSM-5 structures via template-free sol–gel method

Directory of Open Access Journals (Sweden)

Wei Han et al

2007-01-01

Full Text Available Interests are focused on preparation of hierarchical porous materials with zeolite structures by using soft or rigid templates in order to solve diffusion and mass transfer limitations resulting from the small pore sizes of zeolites. Here we develop a convenient template-free sol–gel method to synthesize hierarchical porous materials with ZSM-5 structures. This method involves hydrothermal recrystallization of the xerogel converted from uniform ZSM-5 sol by a vacuum drying process. By utilizing this method we can manipulate the size of zeolite nanocrystals as building units of porous structures based on controlling temperature of recrystallization, consequently obtain hierarchical porous materials with different intercrystalline pore sizes and ZSM-5 structures.

Scaled-up solvothermal synthesis of nanosized metastable indium oxyhydroxide (InOOH) and corundum-type rhombohedral indium oxide (rh-In{sub 2}O{sub 3})

Energy Technology Data Exchange (ETDEWEB)

Schlicker, Lukas; Bekheet, Maged F.; Gurlo, Aleksander [Technische Univ. Berlin (Germany). Fachgebiet Keramische Werkstoffe

2017-03-01

Phase pure metastable indium oxyhydroxide (InOOH) with crystallite size in the range ca. 2-7 nm is synthesized by a nonaqueous solvothermal synthesis route in ethanol. The influence of synthesis parameters such as temperature, basicity (pH), synthesis time, and water content is carefully addressed. T-pH maps summarize the impact of synthesis temperature and pH and reveal that phase pure InOOH is obtained in water-free solutions at mild temperatures (150-180 C) in highly basic conditions (pH>12). Subsequent calcination of InOOH at 375-700 C in ambient air atmosphere results in metastable nanoscaled rhombohedral indium oxide (rh-In{sub 2}O{sub 3}). The synthesis protocol for phase pure nanocrystalline InOOH material was successfully upscaled allowing for obtaining ca. 3 g of phase-pure InOOH with a yield of ca. 78%. The upscaled InOOH and rh-In{sub 2}O{sub 3} batches are now available for a detailed in-situ characterization of the mechanism of decomposition of InOOH to rh-In{sub 2}O{sub 3} to c-In{sub 2}O{sub 3} as well as for the characterization of the functional properties of InOOH and rh-In{sub 2}O{sub 3} materials.

Solvothermal synthesis and characterization of CZTS nanocrystals

Science.gov (United States)

Dumasiya, Ajay; Shah, N. M.

2017-05-01

Cu2ZnSnS4 (CZTS) is a promising thin film absorber material for low cost solar cell applications. CZTS nanoparticle ink synthesized using solvothermal route is an attractive option to deposit absorber layer using screen printing or spin coating method in CZTS thin film solar cell. In this study we have synthesized CZTS nanocrystals using solvothermal method from aqueous solution of Copper nitrate [Cu(NO3)2], Zinc nitrate [Zn(NO3)2], tin chloride [SnCl4] and thiourea with varying concentration of Cu(NO3)2 (viz 0.82 mmol,1.4 mmol, 1.7 mmol) keeping concentrations of rest of solutions constant. As synthesized CZTS nanocrystals are characterized using Energy Dispersive Analysis of X-rays (EDAX) to verify stoichiometry of elements. Analysis of EDAX data suggests that CZTS nanocrystals having Copper nitrate [Cu (NO3)2] concentration of 1.4 m mole is near stoichiometric. X-ray diffraction analysis study of CZTS nanocrystals having Copper nitrate [Cu (NO3)2] concentration of 1.4 m mole reveals the preferred orientation of the grains in (112), (220) and (312) direction confirming Kesterite structure of CZTS.

Effects of hydrazine on the solvothermal synthesis of Cu2ZnSnSe4 and Cu2CdSnSe4 nanocrystals for particle-based deposition of films

International Nuclear Information System (INIS)

Chiang, Ming-Hung; Fu, Yaw-Shyan; Shih, Cheng-Hung; Kuo, Chun-Cheng; Guo, Tzung-Fang; Lin, Wen-Tai

2013-01-01

The effects of hydrazine on the synthesis of Cu 2 ZnSnSe 4 (CZTSe) and Cu 2 CdSnSe 4 (CCTSe) nanocrystals in an autoclave as a function of temperature and time were explored. On heating at 190 °C for 24-72 h, pure CZTSe and CCTSe nanocrystals could readily grow in the hydrazine-added solution, while in the hydrazine-free solution the intermediate phases such as ZnSe, Cu 2 Se, and Cu 2 SnSe 3 , and Cu 2 SnSe 3 and CdSe associated with the CZTSe and CCTSe nanocrystals grew, respectively. This result reveals that hydrazine can speed up the synthesis of pure CZTSe and CCTSe nanocrystals via a solvothermal process. The mechanisms for the hydrazine-enhanced growth of CZTSe and CCTSe nanocrystals were discussed. The pure CZTSe and CCTSe nanocrystals were subsequently fabricated to the smooth films by spin coating without further annealing in selenium atmosphere. This processing may be beneficial to the fabrication of the absorber layer for solar cells and thermoelectric devices. - Highlights: • Hydrazine enhances the growth of pure Cu 2 ZnSnSe 4 and Cu 2 CdSnSe 4 nanocrystals. • The nanocrystals can be fabricated to films by spin coating without annealing. • This solvothermal processing is promising for the fabrication of thin film devices

Hydrothermal synthesis and characterisation of amine-templated ...

African Journals Online (AJOL)

Hydrothermal synthesis and characterisation of amine-templated metal phosphate framework. ... The complexes were thermally stable up to 3000C, after which the organic components starts decomposing. The solubility test in a wide spectrum of solvents (at room temperature) showed that the complexes were insoluble in ...

C(3i)-symmetric octanuclear cadmium cages: double-anion-templated synthesis, formation mechanism, and properties.

Science.gov (United States)

Sun, Jie; Sun, Di; Yuan, Shuai; Tian, Dongxu; Zhang, Liangliang; Wang, Xingpo; Sun, Daofeng

2012-12-14

A series of C(3i)-symmetric bicapped trigonal antiprismatic Cd(8) cages [2X@Cd(8)L(6)(H(2)O)(6)]⋅n Y⋅solvents (X = Cl(-), Y = NO(3)(-), n = 2: MOCC-4; X = Br(-), Y = NO(3)(-), n = 2: MOCC-5; X = NO(3)(-), Y = NO(3)(-), n = 2: MOCC-6; X = NO(3)(-), Y = BF(4)(-), n = 2: MOCC-7; X = NO(3)(-), Y = ClO(4)(-), n = 2: MOCC-8; X = CO(3)(2-), n = 0: MOCC-9), doubly anion templated by different anions, were solvothermally synthesized by means of a flexible ligand. Interestingly, the CO(3)(2-) template for MOCC-9 was generated in situ by two-step decomposition of DMF solvent. For other MOCCs, spherical or trigonal monovalent anions could also play the role of template in their formation. The template abilities of these anions in the formation of the cages were experimentally studied and are discussed for the first time. Anion exchange of MOCC-8 was carried out and showed anion-size selectivity. All of the cage-like compounds emit strong luminescence at room temperature. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lyotropic liquid crystal based on zinc oxide nanoparticles obtained by microwave solvothermal synthesis

Energy Technology Data Exchange (ETDEWEB)

Omelchenko, M.M., E-mail: momelchenko@chem.uw.edu.pl [Department of Chemistry, Warsaw University, Al. Zwirki i Wigury 101, 02-089, Warsaw (Poland); Wojnarowicz, J. [Institute of High Pressure Physics, Polish Academy of Sciences, Sokolowska 29/37, Warsaw, 01-142 (Poland); Salamonczyk, M. [Department of Chemistry, Warsaw University, Al. Zwirki i Wigury 101, 02-089, Warsaw (Poland); Lojkowski, W. [Institute of High Pressure Physics, Polish Academy of Sciences, Sokolowska 29/37, Warsaw, 01-142 (Poland)

2017-05-01

Abstract: The ZnO nanoparticles, obtained by microwave solvothermal synthesis, were used for the liquid crystal phase preparation. The structure of the material was investigated by X-ray diffraction (XRD), helium pycnometry, specific surface area (SSA), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM). The stability of aqueous suspensions was monitored by Multiple Light Scattering (MLS) technique and the average agglomerate size in suspensions was obtained by dynamic light scattering (DLS) technique. The lyotropic columnar hexagonal phase was formed by doping ZnO nanoparticles into the cetylpiridinium chloride/water/hexanol system. The structure of this phase was confirmed by x-ray diffraction. The luminescent properties of the LC phase were compared with properties of ZnO nanoparticles isolated in solution and analogues lyotropic system without nanoparticles.

Organic or organometallic template mediated clay synthesis

Science.gov (United States)

Gregar, Kathleen C.; Winans, Randall E.; Botto, Robert E.

1994-01-01

A method for incorporating diverse Varieties of intercalants or templates directly during hydrothermal synthesis of clays such as hectorite or montmorillonite-type layer-silicate clays. For a hectorite layer-silicate clay, refluxing a gel of silica sol, magnesium hydroxide sol and lithium fluoride for two days in the presence of an organic or organometallic intercalant or template results in crystalline products containing either (a) organic dye molecules such as ethyl violet and methyl green, (b) dye molecules such as alcian blue that are based on a Cu(II)-phthalocyannine complex, or (c) transition metal complexes such as Ru(II)phenanthroline and Co(III)sepulchrate or (d) water-soluble porphyrins and metalloporphyrins. Montmorillonite-type clays are made by the method taught by U.S. Pat. No. 3,887,454 issued to Hickson, Jun. 13, 1975; however, a variety of intercalants or templates may be introduced. The intercalants or templates should have (i) water-solubility, (ii) positive charge, and (iii) thermal stability under moderately basic (pH 9-10) aqueous reflux conditions or hydrothermal pressurized conditions for the montmorillonite-type clays.

Synthesis of the Complex Fluoride LiBaF3 through a Solvothermal Process

Institute of Scientific and Technical Information of China (English)

无

2002-01-01

The complex fluoride LiBaF3 is solvothermally synthesized at 180℃ and characterized by means of X-ray powder diffraction, scanning electron microscopy, thermogravimetric analysis and infrared spectroscopy. In the solvothermal process, the solvents, mole ratios of initial mixtures and reaction temperature play important roles in the growth of the single crystal.

Template Synthesis of Nanostructured Polymeric Membranes by Inkjet Printing.

Science.gov (United States)

Gao, Peng; Hunter, Aaron; Benavides, Sherwood; Summe, Mark J; Gao, Feng; Phillip, William A

2016-02-10

The fabrication of functional nanomaterials with complex structures has been serving great scientific and practical interests, but current fabrication and patterning methods are generally costly and laborious. Here, we introduce a versatile, reliable, and rapid method for fabricating nanostructured polymeric materials. The novel method is based on a combination of inkjet printing and template synthesis, and its utility and advantages in the fabrication of polymeric nanomaterials is demonstrated through three examples: the generation of polymeric nanotubes, nanowires, and thin films. Layer-by-layer-assembled nanotubes can be synthesized in a polycarbonate track-etched (PCTE) membrane by printing poly(allylamine hydrochloride) and poly(styrenesulfonate) sequentially. This sequential deposition of polyelectrolyte ink enables control over the surface charge within the nanotubes. By a simple change of the printing conditions, polymeric nanotubes or nanowires were prepared by printing poly(vinyl alcohol) in a PCTE template. In this case, the high-throughput nature of the method enables functional nanomaterials to be generated in under 3 min. Furthermore, we demonstrate that inkjet printing paired with template synthesis can be used to generate patterns comprised of chemically distinct nanomaterials. Thin polymeric films of layer-by-layer-assembled poly(allylamine hydrochloride) and poly(styrenesulfonate) are printed on a PCTE membrane. Track-etched membranes covered with the deposited thin films reject ions and can potentially be utilized as nanofiltration membranes. When the fabrication of these different classes of nanostructured materials is demonstrated, the advantages of pairing template synthesis with inkjet printing, which include fast and reliable deposition, judicious use of the deposited materials, and the ability to design chemically patterned surfaces, are highlighted.

Synthesis of CdS nanoparticles based on DNA network templates

International Nuclear Information System (INIS)

Yao Yong; Song Yonghai; Wang Li

2008-01-01

CdS nanoparticles have been successfully synthesized by using DNA networks as templates. The synthesis was carried out by first dropping a mixture of cadmium acetate and DNA on a mica surface for the formation of the DNA network template and then transferring the sample into a heated thiourea solution. The Cd 2+ reacted with thiourea at high temperature and formed CdS nanoparticles on the DNA network template. UV-vis spectroscopy, photoluminescence, x-ray diffraction and atomic force microscopy (AFM) were used to characterize the CdS nanoparticles in detail. AFM results showed that the resulted CdS nanoparticles were directly aligned on the DNA network templates and that the synthesis and assembly of CdS nanoparticles was realized in one step. CdS nanoparticles fabricated with this method were smaller than those directly synthesized in a thiourea solution and were uniformly aligned on the DNA networks. By adjusting the density of the DNA networks and the concentration of Cd 2+ , the size and density of the CdS nanoparticles could be effectively controlled and CdS nanoparticles could grow along the DNA chains into nanowires. The possible growth mechanism has also been discussed in detail

Synthesis of belt-like BiOBr hierarchical nanostructure with high photocatalytic performance

Energy Technology Data Exchange (ETDEWEB)

Li, Haiping [National Engineering Technology Research Center for Colloidal Materials, Shandong University, Jinan 250100 (China); Liu, Jingyi; Hu, Tingxia [Environment Research Institute, Shandong University, Jinan 250100 (China); Du, Na; Song, Shue [Key Laboratory of Colloid and Interface Chemistry (Ministry of Education), Shandong University, Jinan 250100 (China); Hou, Wanguo, E-mail: wghou@sdu.edu.cn [Key Laboratory of Colloid and Interface Chemistry (Ministry of Education), Shandong University, Jinan 250100 (China)

2016-05-15

Highlights: • BiOBr hierarchical nanobelts (NBs) were solvothermally prepared. • NBs show higher specific surface area and photoabsorption than BiOBr nanosheets. • NBs exhibit higher photoactivity than the nanosheets. - Abstract: One-dimensional (1D) bismuth oxyhalide (BiOX) hierarchical nanostructures are always difficult to prepare. Herein, we report, for the first time, a simple synthesis of BiOBr nanobelts (NBs) via a facile solvothermal route, using bismuth subsalicylate as the template and bismuth source. The BiOBr nanobelts are composed of irregular single crystal nanoparticles with highly exposed (0 1 0) facets. Compared with the BiOBr nanosheets (NSs) with dominant exposed (0 0 1) facets, they exhibit higher photocatalytic activity toward degradation of Rhodamine B and Methylene Blue under visible light irradiation. The higher photocatalytic performance of BiOBr NBs arises from their larger specific surface area and higher photoabsorption capability. This study provides a simple route for synthesis of belt-like Bi-based hierarchical nanostructures.

Solution-based synthesis and design of late transition metal chalcogenide materials for oxygen reduction reaction (ORR).

Science.gov (United States)

Gao, Min-Rui; Jiang, Jun; Yu, Shu-Hong

2012-01-09

Late transition metal chalcogenide (LTMC) nanomaterials have been introduced as a promising Pt-free oxygen reduction reaction (ORR) electrocatalysts because of their low cost, good ORR activity, high methanol tolerance, and facile synthesis. Herein, an overview on the design and synthesis of LTMC nanomaterials by solution-based strategies is presented along with their ORR performances. Current solution-based synthetic approaches towards LTMC nanomaterials include a hydrothermal/solvothermal approach, single-source precursor approach, hot-injection approach, template-directed soft synthesis, and Kirkendall-effect-induced soft synthesis. Although the ORR activity and stability of LTMC nanomaterials are still far from what is needed for practical fuel-cell applications, much enhanced electrocatalytic performance can be expected. Recent advances have emphasized that decorating the surface of the LTMC nanostructures with other functional nanoparticles can lead to much better ORR catalytic activity. It is believed that new synthesis approaches to LTMCs, modification techniques of LTMCs, and LTMCs with desirable morphology, size, composition, and structures are expected to be developed in the future to satisfy the requirements of commercial fuel cells. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Kinetically-controlled template-free synthesis of hollow silica micro-/nanostructures with unusual morphologies

International Nuclear Information System (INIS)

Zhang, An-Qi; Li, Hui-Jun; Qian, Dong-Jin; Chen, Meng

2014-01-01

We report a kinetically-controlled template-free room-temperature production of hollow silica materials with various novel morphologies, including tubes, crutches, ribbons, bundles and bells. The obtained products, which grew in a well-controlled manner, were monodispersed in shape and size. The role of ammonia, sodium citrate, polyvinylpyrrolidone, chloroauric acid and NaCl in shape control is discussed in detail. The oriented growth of these micro-/nanostructures directed by reverse micelles followed a solution–solution–solid (SSS) mechanism, similar to the classic vapor–liquid–solid mechanism. The evolution processes of silica rods, tubes, crutches, bundles and bells were recorded using transmission electron microscopy to prove the SSS mechanism. (paper)

Modified solvothermal synthesis and characterization of CdS/ZnS core/shell nanorods

International Nuclear Information System (INIS)

Baby Suganthi, A.R.; Sagayaraj, P.

2013-01-01

Core/shell CdS/ZnS nanorods were synthesized using a two-step solvothermal approach. The first step is the formation of CdS nanoparticles initiated using nucleation followed by growth through coalescence-exchange and particle coagulation. The second step leads to the formation of ZnS and further coalescence-exchange leading to deposition and growth of a ZnS shell around CdS nanoparticles. The structural, morphological and chemical studies were performed using X-ray diffraction, Energy Dispersive X-ray spectroscopy (EDX) Scanning electron Microscopy (SEM), UV–vis absorption spectra and Transmission Electron Microscopy (TEM), provide direct evidence for shell growth. The present synthesis provides a rational approach to the design of novel core/shell nanomaterials with appealing applications in optoelectronic devices. - Graphical abstract: From the resulting TEM images, the formation of core/shell could be observed. The apparent microscopy contrast between the CdS core and the ZnS shell offers evidence for the formation of CdS/ZnS core/shell nanostructures. It is clearly evident that the surfaces of the nanorods became rough after coating and also the diameter of the nanorod is seen increased up to 40–50 nm. Highlights: ► CdS/ZnS core/shell nanorods were synthesized using two-step solvothermal approach. ► The nanoparticles were characterized by XRD, EDX, SEM, UV–vis and TEM. ► SEM images revealed the surface roughness after ZnS shell growth. ► TEM microscopy offers evidence for the formation of core/shell nanostructures

Review on the progress in synthesis and application of magnetic carbon nanocomposites

Science.gov (United States)

Zhu, Maiyong; Diao, Guowang

2011-07-01

This review focuses on the synthesis and application of nanostructured composites containing magnetic nanostructures and carbon-based materials. Great progress in fabrication of magnetic carbon nanocomposites has been made by developing methods including filling process, template-based synthesis, chemical vapor deposition, hydrothermal/solvothermal method, pyrolysis procedure, sol-gel process, detonation induced reaction, self-assembly method, etc. The applications of magnetic carbon nanocomposites expanded to a wide range of fields such as environmental treatment, microwave absorption, magnetic recording media, electrochemical sensor, catalysis, separation/recognization of biomolecules and drug delivery are discussed. Finally, some future trends and perspectives in this research area are outlined.

Surfactant-free solvothermal synthesis of Hydroxyapatite nested bundles for the effective photodegradation of cationic dyes

Science.gov (United States)

Reeta Mary, I.; Sonia, S.; Navadeepthy, D.; Mangalaraj, D.; Viswanathan, C.; Ponpandian, N.

2018-05-01

In this study, hydroxyapatite nested bundles (HNBs) were successfully constructed from nanosticks as nanoscale building blocks via a facile, solvothermal process without using any surfactant. The fabricated HNBs were structurally analyzed using X-ray diffraction and Fourier transform infrared spectroscopy, which confirmed the purity of the HNBs. The surface characteristics were determined by field emission scanning electron microscopy and Brunauer-Emmett-Teller analysis, and the optical characteristics by ultraviolet (UV)-visible spectroscopy. The synthesized HNBs were tested to determine their activity during the degradation of methylene blue, methylene violet, and rhodamine B via photocatalysis under UV irradiation. The degradation efficiency of HNBs and the rate of degradation can be explained based on the properties of the HNBs and cationic dyes.

One-step synthesis of hierarchically porous hybrid TiO2 hollow spheres with high photocatalytic activity

Science.gov (United States)

Liu, Ruiping; Ren, Feng; Yang, Jinlin; Su, Weiming; Sun, Zhiming; Zhang, Lei; Wang, Chang-an

2016-03-01

Hierarchically porous hybrid TiO2 hollow spheres were solvothermally synthesized successfully by using tetrabutyl titanate as titanium precursor and hydrated metal sulfates as soft templates. The as-prepared TiO2 spheres with hierarchically pore structures and high specific surface area and pore volume consisted of highly crystallized anatase TiO2 nanocrystals hybridized with a small amount of metal oxide from the hydrated sulfate. The proposed hydrated-sulfate assisted solvothermal (HAS) synthesis strategy was demonstrated to be widely applicable to various systems. Evaluation of the hybrid TiO2 hollow spheres for the photo-decomposition of methyl orange (MO) under visible-light irradiation revealed that they exhibited excellent photocatalytic activity and durability.

Nanostructured electrocatalyst for fuel cells : silica templated synthesis of Pt/C composites.

Energy Technology Data Exchange (ETDEWEB)

Stechel, Ellen Beth; Switzer, Elise E.; Fujimoto, Cy H.; Atanassov, Plamen Borissov; Cornelius, Christopher James; Hibbs, Michael R.

2007-09-01

Platinum-based electrocatalysts are currently required for state-of-the-art fuel cells and represent a significant portion of the overall fuel cell cost. If fuel cell technology is to become competitive with other energy conversion technologies, improve the utilization of precious metal catalysts is essential. A primary focus of this work is on creating enhanced nanostructured materials which improve precious-metal utilization. The goal is to engineer superior electrocatalytic materials through the synthesis, development and investigation of novel templated open frame structures synthesized in an aerosol-based approach. Bulk templating methods for both Pt/C and Pt-Ru composites are evaluated in this study and are found to be limited due to the fact that the nanostructure is not maintained throughout the entire sample. Therefore, an accurate examination of structural effects was previously impossible. An aerosol-based templating method of synthesizing nanostructured Pt-Ru electrocatalysts has been developed wherein the effects of structure can be related to electrocatalytic performance. The aerosol-based templating method developed in this work is extremely versatile as it can be conveniently modified to synthesize alternative materials for other systems. The synthesis method was able to be extended to nanostructured Pt-Sn for ethanol oxidation in alkaline media. Nanostructured Pt-Sn electrocatalysts were evaluated in a unique approach tailored to electrocatalytic studies in alkaline media. At low temperatures, nanostructured Pt-Sn electrocatalysts were found to have significantly higher ethanol oxidation activity than a comparable nanostructured Pt catalyst. At higher temperatures, the oxygen-containing species contribution likely provided by Sn is insignificant due to a more oxidized Pt surface. The importance of the surface coverage of oxygen-containing species in the reaction mechanism is established in these studies. The investigations in this work present

Room temperature chemical synthesis of highly oriented PbSe nanotubes based on negative free energy of formation

Energy Technology Data Exchange (ETDEWEB)

Sankapal, B.R., E-mail: brsankapal@rediffmail.com [Thin Film and Nano Science Laboratory, Department of Physics, School of Physical Sciences, North Maharashtra University, Jalgaon 425 001 (MS) (India); Ladhe, R.D.; Salunkhe, D.B.; Baviskar, P.K. [Thin Film and Nano Science Laboratory, Department of Physics, School of Physical Sciences, North Maharashtra University, Jalgaon 425 001 (MS) (India); Gupta, V.; Chand, S. [Organic and Hybrid Solar Cell, Physics of Energy Harvesting Division, Dr. K.S. Krishnan Marg, National Physical Laboratory, New Delhi 110012 (India)

2011-10-13

Highlights: > Simple, inexpensive and room temperature chemical synthesis route. > Highly oriented PbSe nanotubes from Cd(OH){sub 2} nanowires through lead hydroxination. > The process was template free without the use of any capping agent. > Reaction kinetics was accomplished due to more negative free energy of formation. > The ion exchange mechanism due to difference in the solubility products. - Abstract: The sacrificial template free chemical synthesis of PbSe nanotubes at room temperature has been performed by lead hydroxination from cadmium hydroxide nanowires. This process was based on the ion exchange reaction to replace Cd{sup 2+} with Pb{sup 2+} ions from hydroxyl group followed by replacement of hydroxyl group with selenium ions. The reaction kinetics was accomplished due to more negative free energy of formation and thus the difference in the solubility products. The formed nanotubes were inclusive of Pb and Se with proper inter-chemical bonds with preferred orientations having diameter in tens of nanometer. These nanotubes can have future applications in electronic, optoelectronics and photovoltaic's as well.

Room temperature chemical synthesis of highly oriented PbSe nanotubes based on negative free energy of formation

International Nuclear Information System (INIS)

Sankapal, B.R.; Ladhe, R.D.; Salunkhe, D.B.; Baviskar, P.K.; Gupta, V.; Chand, S.

2011-01-01

Highlights: → Simple, inexpensive and room temperature chemical synthesis route. → Highly oriented PbSe nanotubes from Cd(OH) 2 nanowires through lead hydroxination. → The process was template free without the use of any capping agent. → Reaction kinetics was accomplished due to more negative free energy of formation. → The ion exchange mechanism due to difference in the solubility products. - Abstract: The sacrificial template free chemical synthesis of PbSe nanotubes at room temperature has been performed by lead hydroxination from cadmium hydroxide nanowires. This process was based on the ion exchange reaction to replace Cd 2+ with Pb 2+ ions from hydroxyl group followed by replacement of hydroxyl group with selenium ions. The reaction kinetics was accomplished due to more negative free energy of formation and thus the difference in the solubility products. The formed nanotubes were inclusive of Pb and Se with proper inter-chemical bonds with preferred orientations having diameter in tens of nanometer. These nanotubes can have future applications in electronic, optoelectronics and photovoltaic's as well.

Microwave solvothermal synthesis and characterization of manganese-doped ZnO nanoparticles

Directory of Open Access Journals (Sweden)

Jacek Wojnarowicz

2016-05-01

Full Text Available Mn-doped zinc oxide nanoparticles were prepared by using the microwave solvothermal synthesis (MSS technique. The nanoparticles were produced from a solution of zinc acetate dihydrate and manganese(II acetate tetrahydrate using ethylene glycol as solvent. The content of Mn2+ in Zn1−xMnxO ranged from 1 to 25 mol %. The following properties of the nanostructures were investigated: skeleton density, specific surface area (SSA, phase purity (XRD, lattice parameters, dopant content, average particle size, crystallite size distribution, morphology. The average particle size of Zn1−xMnxO was determined using Scherrer’s formula, the Nanopowder XRD Processor Demo web application and by converting the specific surface area results. X-ray diffraction of synthesized samples shows a single-phase wurtzite crystal structure of ZnO without any indication of additional phases. Spherical Zn1−xMnxO particles were obtained with monocrystalline structure and average particle sizes from 17 to 30 nm depending on the content of dopant. SEM images showed an impact of the dopant concentration on the morphology of the nanoparticles.

Solution-phase synthesis of nanomaterials at low temperature

Science.gov (United States)

Zhu, Yongchun; Qian, Yitai

2009-01-01

This paper reviews the solution-phase synthesis of nanoparticles via some routes at low temperatures, such as room temperature route, wave-assisted synthesis (γ-irradiation route and sonochemical route), directly heating at low temperatures, and hydrothermal/solvothermal methods. A number of strategies were developed to control the shape, the size, as well as the dispersion of nanostructures. Using diethylamine or n-butylamine as solvent, semiconductor nanorods were yielded. By the hydrothermal treatment of amorphous colloids, Bi2S3 nanorods and Se nanowires were obtained. CdS nanowires were prepared in the presence of polyacrylamide. ZnS nanowires were obtained using liquid crystal. The polymer poly (vinyl acetate) tubule acted as both nanoreactor and template for the CdSe nanowire growth. Assisted by the surfactant of sodium dodecyl benzenesulfonate (SDBS), nickel nanobelts were synthesized. In addition, Ag nanowires, Te nanotubes and ZnO nanorod arrays could be prepared without adding any additives or templates.

Solvothermal preparation of micro/nanostructured TiO_2 with enhanced lithium storage capability

International Nuclear Information System (INIS)

Li, Jie; Wang, Chao; Zheng, Ping; Zhang, Lei; Chen, Gongxuan; Tang, Chengchun; Wu, Tian

2017-01-01

Facile and controllable preparation of TiO_2 is of prime importance to elaborately tailor and then fully exploit its intriguing functionalities in energy storage, catalysis and environmental remediation. Herein, a solvothermal method combined with post annealing is conducted, in which the hydrolysis of tetrabutyl titanate is controlled by the in-situ generated water during solvothermal treatment. By controlling synthetic conditions (i.e. reactant ratio, solvothermal temperature and reaction time), we manage to tailor the morphologies of TiO_2. Specially, three typical structures (nanoparticle, nanoneedle and nanorod) are studied to reveal the growth mechanism and the effects of the synthesis conditions. Nanoneedle-structured TiO_2 shows higher specific capacity and enhanced cycle stability as anode material for lithium ion batteries. - Highlights: • Controllable preparation of nano-TiO_2 is achieved by a solvothermal method. • TiO_2 morphology is tailored by tuning reactant ratio, temperature and duration. • Needle structured TiO_2 shows enhanced lithium storage capability.

Template-less surfactant-free hydrothermal synthesis NiO nanoflowers and their photoelectrochemical hydrogen production

KAUST Repository

Qurashi, Ahsanulhaq

2015-12-01

A facile direct surfactant-free template-less hydrothermal method is employed for the growth of high surface-area NiO nanoflowers made up of complex and assembled nanosheets network.Field emission scanning electron microscopy revealed that each nanosheet is about 50-60nm thick. Detailed structural analysis reveals single-crystalline nature of NiO nanoflowers with cubic crystal structure. The optical absorption bands in the wavelength range of 350-800nm illustrated in terms of ligand field theory. The photoelectrochemical (PEC), water splitting performance on the NiO nanoflowers were also investigated. © 2015 Hydrogen Energy Publications, LLC.

Template-less surfactant-free hydrothermal synthesis NiO nanoflowers and their photoelectrochemical hydrogen production

KAUST Repository

Qurashi, Ahsanulhaq; Zhang, Zhongai; Asif, M.; Yamazaki, Toshinari

2015-01-01

A facile direct surfactant-free template-less hydrothermal method is employed for the growth of high surface-area NiO nanoflowers made up of complex and assembled nanosheets network.Field emission scanning electron microscopy revealed that each nanosheet is about 50-60nm thick. Detailed structural analysis reveals single-crystalline nature of NiO nanoflowers with cubic crystal structure. The optical absorption bands in the wavelength range of 350-800nm illustrated in terms of ligand field theory. The photoelectrochemical (PEC), water splitting performance on the NiO nanoflowers were also investigated. © 2015 Hydrogen Energy Publications, LLC.

Synthesis of mesoporous zeolite catalysts by in situ formation of carbon template over nickel nanoparticles

DEFF Research Database (Denmark)

Abildstrøm, Jacob Oskar; Kegnæs, Marina; Hytoft, Glen

2016-01-01

A novel synthesis procedure for the preparation of the hierarchical zeolite materials with MFI structure based on the carbon templating method with in situ generated carbon template is presented in this study. Through chemical vapour deposition of coke on nickel nanoparticles supported on silica...... oxide, a carbon-silica composite is obtained and exploited as a combined carbon template/silica source for zeolite synthesis. This approach has several advantages in comparison with conventional carbon templating methods, where relatively complicated preparative strategies involving multistep...... impregnation procedures and rather expensive chemicals are used. Removal of the carbon template by combustion results in zeolite single crystals with intracrystalline pore volumes between 0.28 and 0.48 cm3/g. The prepared zeolites are characterized by XRD, SEM, TEM and physisorption analysis. The isomerization...

Template-free synthesis of three-dimensional nanoporous N-doped graphene for high performance fuel cell oxygen reduction reaction in alkaline media

International Nuclear Information System (INIS)

Tang, Sheng; Zhou, Xuejun; Xu, Nengneng; Bai, Zhengyu; Qiao, Jinli; Zhang, Jiujun

2016-01-01

Highlights: • 3-D porous N-doped graphene was prepared using one-step silica template-free method. • High specific surface area of 920 m 2 g −1 was achieved for 3-D porous N-doped graphene. • Much higher ORR activity was observed for N-doped graphene than S-doped one in 0.1 M KOH. • The as-prepared catalyst gave a peak power density of 275 mW cm −2 as zinc–air battery cathode. - Abstract: Three-dimensional nanoporous nitrogen-doped graphene (3D-PNG) has been synthesized through a facial one-step synthesis method without additional silica template. The as-prepared 3D-PNGwas used as an electrocatalyst for the oxygen reduction reaction (ORR), which shows excellent electrochemistry performance, demonstrated by half-cell electrochemical evaluation in 0.1 M KOH including prominent ORR activity, four electron-selectivity and remarkable methanol poisoning stability compared to commercial 20%Pt/C catalyst. The physical and surface properties of 3D-PNG catalyst were characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and BET surface area analysis. The experiments show that 3D-PNG catalyst possesses super-large specific surface area reaching 920 m 2 g −1 , which is superior to our most recently reported 3D-PNG synthesized by silica template (670 m 2 g −1 ) and other doped graphene catalysts in literature. When used for constructing a zinc–air battery cathode, such an 3D-PNG catalyst can give a discharge peak power density of 275 mW cm −2 . All the results announce a unique procedure to product high-efficiency graphene-based non-noble metal catalyst materials for electrochemical energy devices including both fuel cells and metal–air batteries.

Electrochemical synthesis of magnetic nanostructures using anodic aluminum oxide templates

Science.gov (United States)

Gong, Jie

In this dissertation, template electrodeposition was employed to fabricate high quality magnetic nanostructures suited for the reliable investigation of novel spintronics phenomena such as CIMS, BMR, and CPP-GMR. Several critical aspects/steps relating to the synthesis process were investigated in this work. In order to obtain high quality magnetic nanostructures, free-standing and Si-supported anodic aluminum oxide templates with closely controlled pore diameters, lengths, as well as constriction sizes, were synthesized by anodization, followed by appropriate post-processing. The pore opening size on the barrier layer can be controlled down to 5 nm by ion beam etching. After optimization of the compositional, structural, and magnetic properties of homogeneous FeCoNiCu layers electrodeposited under different conditions, the pulsed deposition process of FeCoNI/Cu multilayers on n-Si was studied. The influence of Cu deposition potential and Fe2+ concentration on microstructure, chemical and electrochemical properties, magnetic properties, and hence magnetotransport properties were assessed. The dissolution of the FM layer during potential transition was minimized in order to control interface sharpness. Combined with the systematic sublayer thickness and FM layer composition optimization, unprecedented GMR sensitivity of 0.11%/Oe at 5-15 Oe was obtained. Growth of multilayer nanowires was performed, and contact to a single wire was attempted using an electrochemical technique. We succeeded in addressing a small number of nanowires and measured a CPP-GMR of 17%. Template electrodeposition thus provides a promising way to repeatably fabricate prototypes for spin dependent transport studies.

Molecular structure design and soft template synthesis of aza-, oxaaza- and thiaazamacrocyclic metal chelates in the gelatin matrix

OpenAIRE

Oleg V. Mikhailov

2017-01-01

The data about of soft template synthesis proceeding in gelatin matrices in [3d-element M(II) ion – (N,S)- or (N,O,S)-ambidentate ligson – mono- or dicarbonyl ligson] systems, have been considered and discussed. The chemical nature of the final products of template synthesis formed under these specific conditions, has been compared with the chemical nature of the final products formed by template synthesis in solutions. It has been noted that in many cases, the nature and chemical composition...

Molecular structure design and soft template synthesis of aza-, oxaaza- and thiaazamacrocyclic metal chelates in the gelatin matrix

Directory of Open Access Journals (Sweden)

Oleg V. Mikhailov

2017-01-01

Full Text Available The data about of soft template synthesis proceeding in gelatin matrices in [3d-element M(II ion – (N,S- or (N,O,S-ambidentate ligson – mono- or dicarbonyl ligson] systems, have been considered and discussed. The chemical nature of the final products of template synthesis formed under these specific conditions, has been compared with the chemical nature of the final products formed by template synthesis in solutions. It has been noted that in many cases, the nature and chemical composition of these products differ substantially. Specific features of the DFT calculated molecular structures of the macrocyclic compounds that can be formed due to the template synthesis in the systems indicated above, have been discussed, too. The review covers the period 1990–2015.

Solvothermal synthesis of nanorods of ZnO, N-doped ZnO and CdO

International Nuclear Information System (INIS)

Varghese, Neenu; Panchakarla, L.S.; Hanapi, M.; Govindaraj, A.; Rao, C.N.R.

2007-01-01

ZnO nanorods with diameters in the 80-800 nm range are readily synthesized by the reaction of zinc acetate, ethanol and ethylenediamine under solvothermal conditions. The best products are obtained at 330 deg. C with a slow heating rate. Addition of the surfactant Triton -X 100 gave nanorods of uniform (300 nm) diameter. By adding a small amount of liquid NH 3 to the reaction mixture, N-doped ZnO nanorods, with distinct spectroscopic features are obtained. CdO nanorods of 80 nm diameter have been prepared under solvothermal conditions using a mixture of cadmium cupferronate, ethylenediamine and ethanol at 330 deg. C. Similarly, Zn 1-x Cd x O nanorods of a 70 nm diameter are obtained under solvothermal conditions starting with a mixture of zinc acetate, cadmium cupferronate, ethanol and ethylenediamine

Controllable 5-sulfosalicylic acid assisted solvothermal synthesis of monodispersed superparamagnetic Fe{sub 3}O{sub 4} nanoclusters with tunable size

Energy Technology Data Exchange (ETDEWEB)

Wang, Wentao [State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024 (China); Tang, Bingtao, E-mail: tangbt@dlut.edu.cn [State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024 (China); Wu, Suli; Gao, Zhanming; Ju, Benzhi [State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024 (China); Teng, Xiaoxu [School of Chemistry and Chemical Engineering, Yangtze Normal University, Chongqing 408100 (China); Zhang, Shufen [State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024 (China)

2017-02-01

Monodispersed Fe{sub 3}O{sub 4} nanoclusters were synthesized in a one-pot solvothermal route with 5-sulfosalicylic acid (SSA) as the functional ligand in a mixed-solvent system of diethylene glycol/ethylene glycol (DEG/EG). Nucleation and aggregation growth model was responsible for the formation of secondary structure of the clusters. In the process, the size of the clusters can be effectively controlled by varying the amounts of SSA and the volume ratio of DEG/EG. The nanoclusters exhibited superparamagnetic properties with high saturation magnetization value of about 68.7 emu g{sup −1} at room temperature. The water-soluble small-molecule SSA grafted on the surface of Fe{sub 3}O{sub 4} nanocrystals rendered the superparamagnetic clusters dispersible in water, which is crucial for potential applications in biomedical fields. - Graphical abstract: 5-sulfosalicylic acid assisted solvothermal synthesis of monodispersed superparamagnetic Fe{sub 3}O{sub 4} nanoclusters with tunable size by a mixed-solvent system of DEG/EG. - Highlights: • Monodispersed Fe{sub 3}O{sub 4} nanoclusters were synthesized in a one-pot 5-sulfosalicylic acid assisted solvothermal route. • The size of the clusters are tunable by varying the amounts of 5-sulfosalicylic acid and the volume ratio of DEG/EG. • The nanoclusters exhibited superparamagnetic properties with high saturation magnetization value. • The 5-sulfosalicylic acid grafted Fe{sub 3}O{sub 4} nanoclusters can be dispersed in water.

Effects of hydrazine on the solvothermal synthesis of Cu{sub 2}ZnSnSe{sub 4} and Cu{sub 2}CdSnSe{sub 4} nanocrystals for particle-based deposition of films

Energy Technology Data Exchange (ETDEWEB)

Chiang, Ming-Hung [Department of Materials Science and Engineering, National Cheng Kung University, Tainan, Taiwan 701 (China); Fu, Yaw-Shyan, E-mail: ysfu@mail.nutn.edu.tw [Department of Greenergy, National University of Tainan, Tainan, Taiwan 700 (China); Shih, Cheng-Hung; Kuo, Chun-Cheng [Department of Materials Science and Engineering, National Cheng Kung University, Tainan, Taiwan 701 (China); Guo, Tzung-Fang [Department of Photonics, Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan, Taiwan 701 (China); Lin, Wen-Tai, E-mail: wtlin@mail.ncku.edu.tw [Department of Materials Science and Engineering, National Cheng Kung University, Tainan, Taiwan 701 (China)

2013-10-01

The effects of hydrazine on the synthesis of Cu{sub 2}ZnSnSe{sub 4} (CZTSe) and Cu{sub 2}CdSnSe{sub 4} (CCTSe) nanocrystals in an autoclave as a function of temperature and time were explored. On heating at 190 °C for 24-72 h, pure CZTSe and CCTSe nanocrystals could readily grow in the hydrazine-added solution, while in the hydrazine-free solution the intermediate phases such as ZnSe, Cu{sub 2}Se, and Cu{sub 2}SnSe{sub 3}, and Cu{sub 2}SnSe{sub 3} and CdSe associated with the CZTSe and CCTSe nanocrystals grew, respectively. This result reveals that hydrazine can speed up the synthesis of pure CZTSe and CCTSe nanocrystals via a solvothermal process. The mechanisms for the hydrazine-enhanced growth of CZTSe and CCTSe nanocrystals were discussed. The pure CZTSe and CCTSe nanocrystals were subsequently fabricated to the smooth films by spin coating without further annealing in selenium atmosphere. This processing may be beneficial to the fabrication of the absorber layer for solar cells and thermoelectric devices. - Highlights: • Hydrazine enhances the growth of pure Cu{sub 2}ZnSnSe{sub 4} and Cu{sub 2}CdSnSe{sub 4} nanocrystals. • The nanocrystals can be fabricated to films by spin coating without annealing. • This solvothermal processing is promising for the fabrication of thin film devices.

New organically templated photoluminescence iodocuprates(I)

International Nuclear Information System (INIS)

Hou Qin; Zhao Jinjing; Zhao Tianqi; Jin Juan; Yu Jiehui; Xu Jiqing

2011-01-01

Two types of organic cyclic aliphatic diamine molecules piperazine (pip) and 1,3-bis(4-piperidyl)propane (bpp) were used, respectively, to react with an inorganic mixture of CuI and KI in the acidic CH 3 OH solutions under the solvothermal conditions, generating finally three new organically templated iodocuprates as 2-D layered [(Hpip)Cu 3 I 4 ] 1, 1-D chained [tmpip][Cu 2 I 4 ] 2 (tmpip=N,N,N',N'-tetramethylpiperazinium) and dinuclear [H 2 bpp] 2 [Cu 2 I 5 ] I.2H 2 O 3. Note that the templating agent tmpip 2+ in compound 2 originated from the in situ N-alkylation reaction between the pip molecule and the methanol solvent. The photoluminescence analysis indicates that the title compounds emit the different lights: yellow for 1, blue for 2 and yellow-green for 3, respectively. - Graphical abstract: The solvothermal self-assemblies of CuI, KI and pip/bpp in acidic CH 3 OH solutions created three iodocuprates 2-D layered [(Hpip)Cu 3 I 4 ] 1, 1-D chained [tmpip][Cu 2 I 4 ] 2 and dinuclear [H 2 bpp] 2 [Cu 2 I 5 ] I.2H 2 O 3. Highlights: → A new layered iodocuprate(I) with 20-membered rings was hydrothermally prepared. → A simple approach to prepare the new organic templating agent was reported. → Photoluminescence analysis indicates the emission for iodocuprate(I) is associated with the Cu...Cu interactions.

DEXTROSE-TEMPLATED MICROWAVE-ASSISTED COMBUSTION SYNTHESIS OF SPONGY METAL OXIDES

Science.gov (United States)

Microwave-assisted combustion synthesis of porous nanocrystalline titania and carbon coated titania is reported using dextrose as template and the product was compared with the one obtained using conventional heating furnace. Out of three compositions viz., 1:1, 1:3, and 1:5 (met...

Colloidal templating : a route towards controlled synthesis of functional polymeric nanoparticles

NARCIS (Netherlands)

Ali, S.I.

2010-01-01

Template-directed synthesis of polymeric nanoparticles offers better control over particle morphology, shape, structure, composition and properties compare to the conventional emulsion polymerization routes. For the production of anisotropic polymer-clay composite latex particles and polymeric

Solvothermal preparation of micro/nanostructured TiO{sub 2} with enhanced lithium storage capability

Energy Technology Data Exchange (ETDEWEB)

Li, Jie [School of Physics and Mechanical & Electronical Engineering, Hubei University of Education, Wuhan, 430205 (China); Wang, Chao [Department of Architecture and Material Engineering, Hubei University of Education, Wuhan, 430205 (China); Zheng, Ping; Zhang, Lei; Chen, Gongxuan [College of Chemistry and Life Science, Hubei University of Education, Wuhan, 430205 (China); Tang, Chengchun [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130 (China); Wu, Tian, E-mail: twu@whu.edu.cn [School of Physics and Mechanical & Electronical Engineering, Hubei University of Education, Wuhan, 430205 (China); College of Chemistry and Life Science, Hubei University of Education, Wuhan, 430205 (China); Department of Architecture and Material Engineering, Hubei University of Education, Wuhan, 430205 (China)

2017-04-01

Facile and controllable preparation of TiO{sub 2} is of prime importance to elaborately tailor and then fully exploit its intriguing functionalities in energy storage, catalysis and environmental remediation. Herein, a solvothermal method combined with post annealing is conducted, in which the hydrolysis of tetrabutyl titanate is controlled by the in-situ generated water during solvothermal treatment. By controlling synthetic conditions (i.e. reactant ratio, solvothermal temperature and reaction time), we manage to tailor the morphologies of TiO{sub 2}. Specially, three typical structures (nanoparticle, nanoneedle and nanorod) are studied to reveal the growth mechanism and the effects of the synthesis conditions. Nanoneedle-structured TiO{sub 2} shows higher specific capacity and enhanced cycle stability as anode material for lithium ion batteries. - Highlights: • Controllable preparation of nano-TiO{sub 2} is achieved by a solvothermal method. • TiO{sub 2} morphology is tailored by tuning reactant ratio, temperature and duration. • Needle structured TiO{sub 2} shows enhanced lithium storage capability.

Facile solvothermal synthesis of highly active and robust Pd1.87Cu0.11Sn electrocatalyst towards direct ethanol fuel cell applications

Science.gov (United States)

Jana, Rajkumar; Dhiman, Shikha; Peter, Sebastian C.

2016-08-01

Ordered intermetallic Pd1.87Cu0.11Sn ternary electrocatalyst has been synthesized by sodium borohydride reduction of precursor salts Pd(acac)2, CuCl2.2H2O and SnCl2 using one-pot solvothermal synthesis method at 220 °C with a reaction time of 24 h. To the best of our knowledge, here for the first time we report surfactant free synthesis of a novel ordered intermetallic ternary Pd1.87Cu0.11Sn nanoparticles. The ordered structure of the catalyst has been confirmed by powder x-ray diffraction, transmission electron microscopy (TEM). Composition and morphology of the nanoparticles have been confirmed through field emission scanning electron microscopy, energy-dispersive spectrometry and TEM. The electrocatalytic activity and stability of the ternary electrocatalyst towards ethanol oxidation in alkaline medium was investigated by cyclic voltammetry and chronoamperometry techniques. The catalyst is proved to be highly efficient and stable upto 500th cycle and even better than commercially available Pd/C (20 wt%) electrocatalysts. The specific and mass activity of the as synthesized ternary catalyst are found to be ∼4.76 and ∼2.9 times better than that of commercial Pd/C. The enhanced activity and stability of the ordered ternary Pd1.87Cu0.11Sn catalyst can make it as a promising candidate for the alkaline direct ethanol fuel cell application.

Synthesis of a hierarchically structured zeolite-templated carbon starting from fly ash-derived zeolite X

CSIR Research Space (South Africa)

Musyoka, Nicholas M

2014-05-01

Full Text Available A hierarchically structured zeolite derived from coal fly ash was used as a hard templating agent for the synthesis of a templated carbonaceous material. The samples were characterized using XRD, SEM, TEM, TGA, EDS and BET. The resulting carbon had...

Synthesis and photocatalytic properties of graphitic carbon nitride nanofibers using porous anodic alumina templates

Science.gov (United States)

Suchitra, S. M.; Udayashankar, N. K.

2017-12-01

In the present study, we describe an effective method for the synthesis of Graphitic carbon nitride (GCN) nanostructures using porous anodic alumina (AAO) membrane as template by simple thermal condensation of cyanamide. Synthesized nanostructure was fully analysed by various techniques to detect its crystalline nature, morphology, luminescent properties followed by the evaluation of its photocatalytic activity in the degradation of Methylene blue dye. Structural analysis of synthesized GCNNF was systematically carried out using x-ray powder diffraction (XRD) and scanning electron microscope (SEM), and. The results confirmed the growth of GCN inside the nanochannels of anodic alumina templates. Luminescent properties of GCNNF were studied using photoluminescence (PL) spectroscopy. PL analysis showed the presence of a strong emission peak in the wavelength range of 350-600 nm in blue region. GCNNF displays higher photocatalytic performance in the photodegradation of methylene blue compare to the bulk GCN. Highlights 1. In the present paper, we report the synthesis of graphitic carbon nitride nanofibers (GCNNF) using porous anodic aluminium oxide membranes as templates through thermal condensation of cyanamide at 500 °C. 2. The synthesis of Graphitic carbon nitride nanofibers using porous andic alumina template is the efficient approach for increasing crystallinity and surface area. 3. The high surface area of graphitic carbon nitride nanofibers has a good impact on novel optical and photocatalytic properties of the bulkGCN. 4. AAO templating of GCN is one of the versatile method to produce tailorable GCN nanostructures with higher surface area and less number of structural defects. 5. Towards photocatalytic degradation of dyes, the tuning of physical properties is very essential thing hence we are succeeded in achieving better catalytic performance of GCN nanostructures by making use of AAO templates.

Low temperature synthesis & characterization of lead-free BCZT ceramics using molten salt method

Science.gov (United States)

Jai Shree, K.; Chandrakala, E.; Das, Dibakar

2018-04-01

Piezoelectric properties are greatly influenced by the synthesis route, microstructure, stoichiometry of the chemical composition, purity of the starting materials. In this study, molten salt method was used to prepare lead-free BCZT ceramics. Molten salt method is one of the simplestmethods to prepare chemically-purified, single phase powders in high yield often at lower temperatures and shorten reaction time. Calcination of the molten salt synthesized powders resulted in asingle-phase perovskite structure at 1000 °C which is ˜ 350 °C less than the conventional solid-sate reaction method. With increasing calcination temperature the average template size was increased (˜ 0.5-2 µm). Formation of well dispersive templates improves the sinterability at lower temperatures. Lead-free BCZT ceramics sintered at 1500 °C for 2 h resulted in homogenous and highly dense microstructure with ˜92% of the theoretical density and a grain size of ˜ 35 µm. This highly dense microstructure could enhance the piezoelectric properties of the system.

Solvothermal synthesis of monodisperse LiFePO4 micro hollow spheres as high performance cathode material for lithium ion batteries.

Science.gov (United States)

Yang, Shiliu; Hu, Mingjun; Xi, Liujiang; Ma, Ruguang; Dong, Yucheng; Chung, C Y

2013-09-25

A microspherical, hollow LiFePO4 (LFP) cathode material with polycrystal structure was simply synthesized by a solvothermal method using spherical Li3PO4 as the self-sacrificed template and FeCl2·4H2O as the Fe(2+) source. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that the LFP micro hollow spheres have a quite uniform size of ~1 μm consisting of aggregated nanoparticles. The influences of solvent and Fe(2+) source on the phase and morphology of the final product were chiefly investigated, and a direct ion exchange reaction between spherical Li3PO4 templates and Fe(2+) ions was firstly proposed on the basis of the X-ray powder diffraction (XRD) transformation of the products. The LFP nanoparticles in the micro hollow spheres could finely coat a uniform carbon layer ~3.5 nm by a glucose solution impregnating-drying-sintering process. The electrochemical measurements show that the carbon coated LFP materials could exhibit high charge-discharge capacities of 158, 144, 125, 101, and even 72 mAh g(-1) at 0.1, 1, 5, 20, and 50 C, respectively. It could also maintain 80% of the initial discharge capacity after cycling for 2000 times at 20 C.

Removal of brominated flame retardant from electrical and electronic waste plastic by solvothermal technique

International Nuclear Information System (INIS)

Zhang, Cong-Cong; Zhang, Fu-Shen

2012-01-01

Highlights: ► A process for brominated flame retardants (BFRs) removal in plastic was established. ► The plastic became bromine-free with the structure maintained after this treatment. ► BFRs transferred into alcohol solvent were easily debrominated by metallic copper. - Abstract: Brominated flame retardants (BFRs) in electrical and electronic (E and E) waste plastic are toxic, bioaccumulative and recalcitrant. In the present study, tetrabromobisphenol A (TBBPA) contained in this type of plastic was tentatively subjected to solvothermal treatment so as to obtain bromine-free plastic. Methanol, ethanol and isopropanol were examined as solvents for solvothermal treatment and it was found that methanol was the optimal solvent for TBBPA removal. The optimum temperature, time and liquid to solid ratio for solvothermal treatment to remove TBBPA were 90 °C, 2 h and 15:1, respectively. After the treatment with various alcohol solvents, it was found that TBBPA was finally transferred into the solvents and bromine in the extract was debrominated catalyzed by metallic copper. Bisphenol A and cuprous bromide were the main products after debromination. The morphology and FTIR properties of the plastic were generally unchanged after the solvothermal treatment indicating that the structure of the plastic maintained after the process. This work provides a clean and applicable process for BFRs-containing plastic disposal.

Hierarchical assembly of inorganic nanostructure building blocks to octahedral superstructures-a true template-free self-assembly

International Nuclear Information System (INIS)

Kuchibhatla, Satyanarayana V N T; Karakoti, Ajay S; Seal, Sudipta

2007-01-01

A room temperature, template-free, wet chemical synthesis of ceria nanoparticles and their long term ageing characteristics are reported. High resolution transmission electron microscopy and UV-visible spectroscopy techniques are used to observe the variation in size, structure and oxidation state, respectively as a function of time. The morphology variation and the hierarchical assembly (octahedral superstructure) of nanostructures are imputed to the inherent structural aspects of cerium oxide. It is hypothesized that the 3-5 nm individual building blocks will undergo an intra-agglomerate re-orientation to attain the low energy configuration. This communication also emphasizes the need for long term ageing studies of nanomaterials in various solvents for multiple functionalities

Ambient template synthesis of multiferroic MnWO4 nanowires and nanowire arrays

International Nuclear Information System (INIS)

Zhou Hongjun; Yiu Yuen; Aronson, M.C.; Wong, Stanislaus S.

2008-01-01

The current report describes the systematic synthesis of polycrystalline, multiferroic MnWO 4 nanowires and nanowire arrays with controllable chemical composition and morphology, using a modified template-directed methodology under ambient room-temperature conditions. We were able to synthesize nanowires measuring 55±10, 100±20, and 260±40 nm in diameter, respectively, with lengths ranging in the microns. Extensive characterization of as-prepared samples has been performed using X-ray diffraction, scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM, and energy-dispersive X-ray spectroscopy. Magnetic behavior in these systems was also probed. - Graphical abstract: Systematic synthesis of crystalline, multiferroic MnWO4 nanowires and nanowire arrays with controllable chemical composition and morphology, using a modified template-directed methodology under ambient room-temperature conditions

Template Dimerization Promotes an Acceptor Invasion-Induced Transfer Mechanism during Human Immunodeficiency Virus Type 1 Minus-Strand Synthesis

Science.gov (United States)

Balakrishnan, Mini; Roques, Bernard P.; Fay, Philip J.; Bambara, Robert A.

2003-01-01

The biochemical mechanism of template switching by human immunodeficiency virus type 1 (HIV-1) reverse transcriptase and the role of template dimerization were examined. Homologous donor-acceptor template pairs derived from the HIV-1 untranslated leader region and containing the wild-type and mutant dimerization initiation sequences (DIS) were used to examine the efficiency and distribution of transfers. Inhibiting donor-acceptor interaction was sufficient to reduce transfers in DIS-containing template pairs, indicating that template dimerization, and not the mere presence of the DIS, promotes efficient transfers. Additionally, we show evidence that the overall transfer process spans an extended region of the template and proceeds through a two-step mechanism. Transfer is initiated through an RNase H-facilitated acceptor invasion step, while synthesis continues on the donor template. The invasion then propagates towards the primer terminus by branch migration. Transfer is completed with the translocation of the primer terminus at a site distant from the invasion point. In our system, most invasions initiated before synthesis reached the DIS. However, transfer of the primer terminus predominantly occurred after synthesis through the DIS. The two steps were separated by 60 to 80 nucleotides. Sequence markers revealed the position of primer terminus switch, whereas DNA oligomers designed to block acceptor-cDNA interactions defined sites of invasion. Within the region of homology, certain positions on the template were inherently more favorable for invasion than others. In templates with DIS, the proximity of the acceptor facilitates invasion, thereby enhancing transfer efficiency. Nucleocapsid protein enhanced the overall efficiency of transfers but did not alter the mechanism. PMID:12663778

Polyol-mediated synthesis of copper indium sulphide by solvothermal process

International Nuclear Information System (INIS)

Gorai, S.; Chaudhuri, S.

2005-01-01

A simple polyol-mediated solvothermal method has been proposed to synthesize copper indium sulphide. XRD studies reveal that the products are well crystallized. SEM indicates rod-like (with different aspect ratio) and star-shaped flake-like morphology of the products. The products are also characterized by optical studies and compositional analysis (XRF). XRF results show the formation of stoichiometric and non-stoichiometric copper indium sulphides depending on the reaction conditions

Solvothermal synthesis of LiFePO4 nanoplates with (010) plane and the uniform carbon coated on their surface by esterification reaction

International Nuclear Information System (INIS)

Ma, Zhipeng; Shao, Guangjie; Wang, Xu; Song, Jianjun; Wang, Guiling; Liu, Tingting

2014-01-01

A facile solvothermal synthesis and esterification reaction combined with a high temperature calcination technique has been developed to prepare the uniform carbon coating LiFePO 4 nanoplates. The carbon coating LiFePO 4 nanoplates are investigated by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM), transmission electron microscope (TEM), galvanostatic intermittent titration technique (GITT) and galvanostatic charge–discharge test. A reasonable growth mechanism of LiFePO 4 nanoplates is proposed on the basis of time dependent experimental results. The results show that each nanoplate is a LiFePO 4 single crystal with the large (010) plane. According to Raman spectroscopy analysis, carbon is uniformly coated on the surface of LiFePO 4 nanoplates. Electrochemical test results also indicate that the carbon coating LiFePO 4 nanoplates exhibit a high reversible specific capacity of 144.8 mAh g −1 at 0.5 C and 116.9 mAh g −1 under lower discharging rate at −20 °C. - Highlights: • LiFePO 4 nanoplates prepared by facile solvothermal synthesis expose large (010) plane. • The polyester network formed by the esterification reaction could entirely wrap LiFePO 4 . • The polyester wrapped on the surface of LiFePO 4 transformed into the uniform carbon layer after calcination. • LiFePO 4 /C nanoplates have good high-rate and low-temperature performance

A new route of synthesizing perovskite nanotubes by templating approach

Science.gov (United States)

Habiballah, Anisah Shafiqah; Osman, Nafisah; Jani, Abdul Mutalib Md

2017-09-01

A perovskite oxide for example Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) has attracted growing attention due to its high catalytic activity and mixed ionic/electronic conductivity. Recent research of BSCF is more comprehensively based on a remarkable trajectory of innovation, in particular with regards to the synthesis of perovskite structures in one-dimensional (1-D) nanometric scales as they promote not only to increase an active electrode area for the oxygen reduction reaction, but also allow the tailoring of electrode's architecture. Nevertheless, achieving the desired 1-D structure by a conventional method such as hydrothermal, solvothermal, or sonochemical are far from satisfactory. Herein, the aim of this work is to synthesize the BSCF perovskite nanotubes via soft templating approach, particularly using anodic aluminium oxide (AAO) as a template, focusing on the morphology, composition and structural properties were demonstrated. After the AAO template was anodized at 80 V, the fabricated template was clamped between apair of spectroscopic cells containing BSCF sol and deionized water (with a hole of both sides) for 24 hours. After that, the sample was removed from the cells followed by heat treatment process. The FESEM images showed that BSCF nanotubes were successfully achieved, with the diameter of the nanotubes' approximately 80 nm. The EDX result also confirmed the nominal stoichiometry of Ba0.5Sr0.5Co0.8Fe0.2O3-δ. Meanwhile, the XRD pattern confirmed a single crystalline phase of BSCF nanotubes was successfully obtained and congruent to a cubic perovskite structure of BSCF. Possible formation mechanism,as well as the schematic illustration of BSCF nanotubes inside the template was also discussed in this paper.

Template assisted synthesis and optical properties of gold nanoparticles.

Science.gov (United States)

Fodor, Petru; Lasalvia, Vincenzo

2009-03-01

A hybrid nanofabrication method (interference lithography + self assembly) was explored for the fabrication of arrays of gold nanoparticles. To ensure the uniformity of the nanoparticles, a template assisted synthesis was used in which the gold is electrodeposited in the pores of anodized aluminum membranes. The spacing between the pores and their ordering is controlled in the first fabrication step of the template in which laser lithography and metal deposition are used to produce aluminum films with controlled strain profiles. The diameter of the pores produced after anodizing the aluminum film in acidic solution determines the diameter of the gold particles, while their aspect ratio is controlled through the deposition time. Optical absorbance spectroscopy is used to evaluate the ability to tune the nanoparticles plasmon resonance spectra through control over their size and aspect ratio.

Ultrathin SnO2 nanorods: template- and surfactant-free solution phase synthesis, growth mechanism, optical, gas-sensing, and surface adsorption properties.

Science.gov (United States)

Xi, Guangcheng; Ye, Jinhua

2010-03-01

A novel template- and surfactant-free low temperature solution-phase method has been successfully developed for the controlled synthesis of ultrathin SnO(2) single-crystalline nanorods for the first time. The ultrathin SnO(2) single-crystalline nanorods are 2.0 +/- 0.5 nm in diameter, which is smaller than its exciton Bohr radius. The ultrathin SnO(2) nanorods show a high specific area (191.5 m(2) g(-1)). Such a thin SnO(2) single-crystalline nanorod is new in the family of SnO(2) nanostrucures and presents a strong quantum confinement effect. Its formation depends on the reaction temperature as well as on the concentration of the urea solution. A nonclassical crystallization process, Ostwald ripening process followed by an oriented attachment mechanism, is proposed based on the detailed observations from a time-dependent crystal evolution process. Importantly, such structured SnO(2) has shown a strong structure-induced enhancement of gas-sensing properties and has exhibited greatly enhanced gas-sensing property for the detection of ethanol than that of other structured SnO(2), such as the powders of nanobelts and microrods. Moreover, these ultrathin SnO(2) nanorods exhibit excellent ability to remove organic pollutant in wastewater by enormous surface adsorption. These properties are mainly attributed to its higher surface-to-volume ratio and ultrathin diameter. This work provides a novel low temperature, green, and inexpensive pathway to the synthesis of ultrathin nanorods, offering a new material form for sensors, solar cells, catalysts, water treatments, and other applications.

Template synthesis of test tube nanoparticles using non-destructive replication.

Science.gov (United States)

Wagner, Jonathan; Yao, Jingyuan; Rodgers, David; Hinds, Bruce

2013-03-01

Nano test tubes are a promising delivery vehicle for a range of therapeutics, including small molecule drugs and biologics. However, current template synthesis methods of producing nano test tubes are prohibitively expensive and time consuming. Here, non-destructive template replication was used to increase nano test tube yield from porous alumina by more than a hundredfold. We demonstrate how to produce nano test tubes of several sizes and compositions, including hybrid tubes with different inner and outer surfaces for targeted surface chemistry. Nano test tubes were readily suspended and stored in aqueous solutions without the need for chemical treatment. These nano test tubes should find application as delivery vehicles for therapeutics, particularly for processive 'bionanoreactors' loaded with enzymes.

Solvothermal Synthesis of Copper Indium Diselenide in Toluene

International Nuclear Information System (INIS)

Chang, Ju Yeon; Han, Jae Eok; Jung, Duk Young

2011-01-01

Polycrystalline CuInSe 2 (CIS) was synthesized through solvothermal reactions in toluene with selected alkyl amines as complexing agents. The alkyl amines were used as reducing agent of selenium and catalytic ligands, enhancing the formation of CIS compounds in the colloidal solution. Toluene does not contribute the syntheses directly but minimizes the amounts of amines required for single phase CIS. We systematically studied the reactivity of amine compounds for the solovothermal syntheses, determined critical concentration of amine and the shortest reaction time. Crystallinity, morphology, chemical composition, and band gap of the prepared CuInSe 2 were respectively measured by X-ray diffraction, scanning electron microscopy, inductively coupled plasma atomic emission spectroscopy and UV-vis spectroscopy

Removal of brominated flame retardant from electrical and electronic waste plastic by solvothermal technique

Energy Technology Data Exchange (ETDEWEB)

Zhang, Cong-Cong [Research Center For Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Zhang, Fu-Shen, E-mail: fszhang@rcees.ac.cn [Research Center For Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China)

2012-06-30

Highlights: Black-Right-Pointing-Pointer A process for brominated flame retardants (BFRs) removal in plastic was established. Black-Right-Pointing-Pointer The plastic became bromine-free with the structure maintained after this treatment. Black-Right-Pointing-Pointer BFRs transferred into alcohol solvent were easily debrominated by metallic copper. - Abstract: Brominated flame retardants (BFRs) in electrical and electronic (E and E) waste plastic are toxic, bioaccumulative and recalcitrant. In the present study, tetrabromobisphenol A (TBBPA) contained in this type of plastic was tentatively subjected to solvothermal treatment so as to obtain bromine-free plastic. Methanol, ethanol and isopropanol were examined as solvents for solvothermal treatment and it was found that methanol was the optimal solvent for TBBPA removal. The optimum temperature, time and liquid to solid ratio for solvothermal treatment to remove TBBPA were 90 Degree-Sign C, 2 h and 15:1, respectively. After the treatment with various alcohol solvents, it was found that TBBPA was finally transferred into the solvents and bromine in the extract was debrominated catalyzed by metallic copper. Bisphenol A and cuprous bromide were the main products after debromination. The morphology and FTIR properties of the plastic were generally unchanged after the solvothermal treatment indicating that the structure of the plastic maintained after the process. This work provides a clean and applicable process for BFRs-containing plastic disposal.

Cloning nanocrystal morphology with soft templates

Science.gov (United States)

Thapa, Dev Kumar; Pandey, Anshu

2016-08-01

In most template directed preparative methods, while the template decides the nanostructure morphology, the structure of the template itself is a non-general outcome of its peculiar chemistry. Here we demonstrate a template mediated synthesis that overcomes this deficiency. This synthesis involves overgrowth of silica template onto a sacrificial nanocrystal. Such templates are used to copy the morphologies of gold nanorods. After template overgrowth, gold is removed and silver is regrown in the template cavity to produce a single crystal silver nanorod. This technique allows for duplicating existing nanocrystals, while also providing a quantifiable breakdown of the structure - shape interdependence.

New immobilisation protocol for the template used in solid-phase synthesis of MIP nanoparticles

Science.gov (United States)

Chen, Lu; Muhammad, Turghun; Yakup, Burabiye; Piletsky, Sergey A.

2017-06-01

As a novel imprinting method, solid-phase synthesis has proven to be a promising approach to prepare polymer nanoparticles with specific recognition sites for a template molecule. In this method, imprinted polymer nanoparticles were synthesized using template immobilized on a solid support. Herein, preparation of immobilized templates on quartz chips through homogeneous route was reported as an efficient alternative strategy to heterogeneous one. The template molecule indole-3-butyric acid (IBA) was reacted with 3-aminopropyltriethoxysilane (APTES) to produce silylated template (IBA-APTES), and it was characterized by IR, 1H NMR and GC-MS. Then, the silylated template molecule was grafted onto the activated surfaces of quartz chip to prepare immobilized template (SiO2@IBA-APTES). The immobilization was confirmed by contact angle, XPS, UV and fluorescence measurement. Immobilization protocol has shown good reproducibility and stability of the immobilized template. MIP nanoparticles were prepared with high selectivity toward the molecule immobilized onto the solid surface. This provides a new approach for the development of molecularly imprinted nanoparticles.

Long-chain amine-templated synthesis of gallium sulfide and gallium selenide nanotubes

Science.gov (United States)

Seral-Ascaso, A.; Metel, S.; Pokle, A.; Backes, C.; Zhang, C. J.; Nerl, H. C.; Rode, K.; Berner, N. C.; Downing, C.; McEvoy, N.; Muñoz, E.; Harvey, A.; Gholamvand, Z.; Duesberg, G. S.; Coleman, J. N.; Nicolosi, V.

2016-06-01

We describe the soft chemistry synthesis of amine-templated gallium chalcogenide nanotubes through the reaction of gallium(iii) acetylacetonate and the chalcogen (sulfur, selenium) using a mixture of long-chain amines (hexadecylamine and dodecylamine) as a solvent. Beyond their role as solvent, the amines also act as a template, directing the growth of discrete units with a one-dimensional multilayer tubular nanostructure. These new materials, which broaden the family of amine-stabilized gallium chalcogenides, can be tentatively classified as direct large band gap semiconductors. Their preliminary performance as active material for electrodes in lithium ion batteries has also been tested, demonstrating great potential in energy storage field even without optimization.We describe the soft chemistry synthesis of amine-templated gallium chalcogenide nanotubes through the reaction of gallium(iii) acetylacetonate and the chalcogen (sulfur, selenium) using a mixture of long-chain amines (hexadecylamine and dodecylamine) as a solvent. Beyond their role as solvent, the amines also act as a template, directing the growth of discrete units with a one-dimensional multilayer tubular nanostructure. These new materials, which broaden the family of amine-stabilized gallium chalcogenides, can be tentatively classified as direct large band gap semiconductors. Their preliminary performance as active material for electrodes in lithium ion batteries has also been tested, demonstrating great potential in energy storage field even without optimization. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01663d

Application of a novel design paradigm to generate general nonpeptide combinatorial templates mimicking beta-turns: synthesis of ligands for melanocortin receptors.

Science.gov (United States)

Webb, Thomas R; Jiang, Luyong; Sviridov, Sergey; Venegas, Ruben E; Vlaskina, Anna V; McGrath, Douglas; Tucker, John; Wang, Jian; Deschenes, Alain; Li, Rongshi

2007-01-01

We report the further application of a novel approach to template and ligand design by the synthesis of agonists of the melanocortin receptor. This design method uses the conserved structural data from the three-dimensional conformations of beta-turn peptides to design rigid nonpeptide templates that mimic the orientation of the main chain C-alpha atoms in a peptide beta-turn. We report details on a new synthesis of derivatives of template 1 that are useful for the synthesis of exploratory libraries. The utility of this technique is further exemplified by several iterative rounds of high-throughput synthesis and screening, which result in new partially optimized nonpeptide agonists for several melanocortin receptors.

Solvothermal synthesis of gallium-indium-zinc-oxide nanoparticles for electrolyte-gated transistors.

Science.gov (United States)

Santos, Lídia; Nunes, Daniela; Calmeiro, Tomás; Branquinho, Rita; Salgueiro, Daniela; Barquinha, Pedro; Pereira, Luís; Martins, Rodrigo; Fortunato, Elvira

2015-01-14

Solution-processed field-effect transistors are strategic building blocks when considering low-cost sustainable flexible electronics. Nevertheless, some challenges (e.g., processing temperature, reliability, reproducibility in large areas, and cost effectiveness) are requirements that must be surpassed in order to achieve high-performance transistors. The present work reports electrolyte-gated transistors using as channel layer gallium-indium-zinc-oxide nanoparticles produced by solvothermal synthesis combined with a solid-state electrolyte based on aqueous dispersions of vinyl acetate stabilized with cellulose derivatives, acrylic acid ester in styrene and lithium perchlorate. The devices fabricated using this approach display a ION/IOFF up to 1 × 10(6), threshold voltage (VTh) of 0.3-1.9 V, and mobility up to 1 cm(2)/(V s), as a function of gallium-indium-zinc-oxide ink formulation and two different annealing temperatures. These results validates the usage of electrolyte-gated transistors as a viable and promising alternative for nanoparticle based semiconductor devices as the electrolyte improves the interface and promotes a more efficient step coverage of the channel layer, reducing the operating voltage when compared with conventional dielectrics gating. Moreover, it is shown that by controlling the applied gate potential, the operation mechanism of the electrolyte-gated transistors can be modified from electric double layer to electrochemical doping.

Fabrication of mesoporous polymer monolith: a template-free approach.

Science.gov (United States)

Okada, Keisuke; Nandi, Mahasweta; Maruyama, Jun; Oka, Tatsuya; Tsujimoto, Takashi; Kondoh, Katsuyoshi; Uyama, Hiroshi

2011-07-14

Mesoporous polyacrylonitrile (PAN) monolith has been fabricated by a template-free approach using the unique affinity of PAN towards a water/dimethyl sulfoxide (DMSO) mixture. A newly developed Thermally Induced Phase Separation Technique (TIPS) has been used to obtain the polymer monoliths and their microstructures have been controlled by optimizing the concentration and cooling temperature.

Template synthesis of test tube nanoparticles using non-destructive replication

International Nuclear Information System (INIS)

Wagner, Jonathan; Rodgers, David; Yao Jingyuan; Hinds, Bruce

2013-01-01

Nano test tubes are a promising delivery vehicle for a range of therapeutics, including small molecule drugs and biologics. However, current template synthesis methods of producing nano test tubes are prohibitively expensive and time consuming. Here, non-destructive template replication was used to increase nano test tube yield from porous alumina by more than a hundredfold. We demonstrate how to produce nano test tubes of several sizes and compositions, including hybrid tubes with different inner and outer surfaces for targeted surface chemistry. Nano test tubes were readily suspended and stored in aqueous solutions without the need for chemical treatment. These nano test tubes should find application as delivery vehicles for therapeutics, particularly for processive ‘bionanoreactors’ loaded with enzymes. (paper)

Solvothermal synthesis of copper sulfide semiconductor micro/nanostructures

International Nuclear Information System (INIS)

Liu, Jun; Xue, Dongfeng

2010-01-01

Covellite copper sulfide (CuS) micro/nanometer crystals in the shape of hierarchical doughnut-shaped, superstructured spheric-shaped and flowerlike architectures congregated from those nanoplates with the thickness of 20-100 nm have been prepared by a solvothermal method. The as-obtained CuS products were characterized by means of scanning electron microscopy (SEM), X-ray diffractometry (XRD) and energy-dispersive X-ray spectroscopy (EDS). A systematic investigation has been carried out to understand the factors influencing the evolution of CuS particle morphology which found to be predominant by solvent, surfactant, sulfur resource and copper salt. The possible formation mechanism for the nanostructure formation was also discussed. These CuS products show potential applications in solar cell, photothermal conversion and chemical sensor.

Solvothermal synthesis of graphene-Sb2S3 composite and the degradation activity under visible light

International Nuclear Information System (INIS)

Tao, Wenguang; Chang, Jiuli; Wu, Dapeng; Gao, Zhiyong; Duan, Xiaoli; Xu, Fang; Jiang, Kai

2013-01-01

Graphical abstract: Display Omitted Highlights: ► Graphene-Sb 2 S 3 composites were synthesized through a facile solvothermal method. ► Hydroxyl radicals are the main species responsible for the photodegradation activity. ► Graphene-Sb 2 S 3 demonstrated dramatically improved visible light degradation activity. -- Abstract: Novel graphene-Sb 2 S 3 (G-Sb 2 S 3 ) composites were synthesized via a facile solvothermal method with graphene oxide (GO), SbCl 3 and thiourea as the reactants. GO played an important role in controlling the size and the distribution of the formed Sb 2 S 3 nanoparticles on the graphene sheets with different density. Due to the negative surface charge, smaller Sb 2 S 3 particles size and efficient electrons transfer from Sb 2 S 3 to graphene, the composites demonstrated improved photodegradation activity on rhodamine B (RhB). Among these composites, the product G-Sb 2 S 3 0.1, which was synthesized with the GO concentration of 0.1 mg/mL, exhibited the highest photodegradation activity owing to the considerable density of Sb 2 S 3 nanoparticles onto graphene sheet free of aggregation. Hydroxyl radicals (·OH) derived from conduction band (CB) electrons of Sb 2 S 3 is suggested to be responsible for the photodegradation of RhB. The high visible light degradation activity and the satisfactory cycling stability made the as-prepared G-Sb 2 S 3 0.1 an applicable photocatalyst.

Template-based preparation of free-standing semiconducting polymeric nanorod arrays on conductive substrates.

Science.gov (United States)

Haberkorn, Niko; Weber, Stefan A L; Berger, Rüdiger; Theato, Patrick

2010-06-01

We describe the synthesis and characterization of a cross-linkable siloxane-derivatized tetraphenylbenzidine (DTMS-TPD), which was used for the fabrication of semiconducting highly ordered nanorod arrays on conductive indium tin oxide or Pt-coated substrates. The stepwise process allow fabricating of macroscopic areas of well-ordered free-standing nanorod arrays, which feature a high resistance against organic solvents, semiconducting properties and a good adhesion to the substrate. Thin films of the TPD derivate with good hole-conducting properties could be prepared by cross-linking and covalently attaching to hydroxylated substrates utilizing an initiator-free thermal curing at 160 degrees C. The nanorod arrays composed of cross-linked DTMS-TPD were fabricated by an anodic aluminum oxide (AAO) template approach. Furthermore, the nanorod arrays were investigated by a recently introduced method allowing to probe local conductivity on fragile structures. It revealed that more than 98% of the nanorods exhibit electrical conductance and consequently feature a good electrical contact to the substrate. The prepared nanorod arrays have the potential to find application in the fabrication of multilayered device architectures for building well-ordered bulk-heterojunction solar cells.

Low-temperature solvothermal approach to the synthesis of La4Ni3O8 by topotactic oxygen deintercalation.

Science.gov (United States)

Blakely, Colin K; Bruno, Shaun R; Poltavets, Viktor V

2011-07-18

A chimie douce solvothermal reduction method is proposed for topotactic oxygen deintercalation of complex metal oxides. Four different reduction techniques were employed to qualitatively identify the relative reduction activity of each including reduction with H(2) and NaH, solution-based reduction using metal hydrides at ambient pressure, and reduction under solvothermal conditions. The reduction of the Ruddlesden-Popper nickelate La(4)Ni(3)O(10) was used as a test case to prove the validity of the method. The completely reduced phase La(4)Ni(3)O(8) was produced via the solvothermal technique at 150 °C--a lower temperature than by other more conventional solid state oxygen deintercalation methods.

Biomimetic synthesis of calcium carbonate bilayers interfaced by a diblock copolymer template

NARCIS (Netherlands)

Goos, J.A.C.M.; Vo, C.D.; Dey, A.; Hoogen, van den C.J.; Lousberg, N.J.H.G.M.; Hendrix, M.M.R.M.; Tirelli, N.; With, de G.; Sommerdijk, N.A.J.M.

2012-01-01

The synthesis of a new class of hybrid materials with two differently oriented layers of calcite at adjacent sides of an organic template is demonstrated. A Langmuir monolayer of the amphiphilic block copolymer poly(butyl acrylate)-b-poly(hydroxypropyl acrylate) directs the formation of a first

Growth of ZnO nanoparticles from nanowhisker precursor with a simple solvothermal route

International Nuclear Information System (INIS)

Wang Chunlei; Wang Enbo; Shen Enhong; Gao Lei; Kang Zhenhui; Tian Chungui; Zhang Chao; Lan Yang

2006-01-01

Methods of preparing nanoparticles have long been a topic experiencing extensive investigation. Among those methods developed, using template or polymer and surfactant as capping reagents were often effective. However, obtaining nanoparticles in high amounts and high purity still remains an unresolved challenge. Here, a simple two-step solvothermal method without using any surfactant or coating reactant to prepare ZnO nanoparticles with high purity in large scale was developed. X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) were used to characterize the as-prepared ZnO nanoparticles, and the formation process of the nanoparticles was discussed finally

One-pot solvothermal synthesis of highly water-dispersible size-tunable functionalized magnetite nanocrystal clusters for lipase immobilization.

Science.gov (United States)

Zhu, Hao; Hou, Chen; Li, Yijing; Zhao, Guanghui; Liu, Xiao; Hou, Ke; Li, Yanfeng

2013-07-01

A facile one-pot synthesis of highly water-dispersible size-tunable magnetite (Fe3O4) nanocrystal clusters (MNCs) end-functionalized with amino or carboxyl groups by a modified solvothermal reduction reaction has been developed. Dopamine and 3,4-dihydroxyhydroxycinnamic acid were used for the first time as both a surfactant and interparticle linker in a polylol process for economical and environment-friendly purposes. Morphology, chemical composition, and magnetic properties of the prepared particles were investigated by several methods, including FESEM, TEM, XRD, XPS, Raman, FTIR, TGA, zeta potential, and VSM. The sizes of the particles could be easily tuned over a wide range from 175 to 500 nm by varying the surfactant concentration. Moreover, ethylene glycol/diethylene glycol (EG/DEG) solvent mixtures with different ratios could be used as reductants to obtain the particles with smaller sizes. The XRD data demonstrated that the surfactants restrained the crystal growth of the grains. The nanoparticles showed superior magnetic properties and high colloidal stability in water. The cytotoxicity results indicated the feasibility of using the synthesized nanocrystals in biology-related fields. To estimate the applicability of the obtained MNCs in biotechnology, Candida rugosa lipase was selected for the enzyme immobilization process. The immobilized lipase exhibited excellent thermal stability and reusability in comparison with the free enzyme. This novel strategy would simplify the reaction protocol and improve the efficiency of materials functionalization, thus offering new potential applications in biotechnology and organocatalysis. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Termination of DNA synthesis in vitro at apurinic sites but not at ethyl adducts of the template

Energy Technology Data Exchange (ETDEWEB)

Lockhart, M.L.; Deutsch, J.F.; Yamaura, I.; Cavalieri, L.F.; Rosenberg, B.H.

1982-01-01

The effects of DNA lesions produced by the carcinogenic alkylating agents ethylnitrosourea and diethylsulfate on the extent of DNA synthesis have been studied in a system utilizing circular single-stranded phi X174 DNA as template and a 392-base restriction fragment as primer with E. coli polymerase I (Klenow fragment). Apurinic sites produced by loss of unstable ethylated bases from the template terminate DNA synthesis at the first such site encountered, but ethyl adducts at most, if not all, locations permit readthrough. 22 references, 3 figures, 1 table.

Biomimetic synthesis and biocompatibility evaluation of carbonated apatites template-mediated by heparin

Energy Technology Data Exchange (ETDEWEB)

Deng, Yi [Department of Oral and Maxillofacial Surgery, Laboratory of Interdisciplinary Studies, School and Hospital of Stomatology, Peking University, Beijing 100081 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Sun, Yuhua [Department of Oral and Maxillofacial Surgery, Laboratory of Interdisciplinary Studies, School and Hospital of Stomatology, Peking University, Beijing 100081 (China); Chen, Xiaofang [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zhu, Peizhi, E-mail: pzzhu@umich.edu [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Wei, Shicheng, E-mail: sc-wei@pku.edu.cn [Department of Oral and Maxillofacial Surgery, Laboratory of Interdisciplinary Studies, School and Hospital of Stomatology, Peking University, Beijing 100081 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China)

2013-07-01

Biomimetic synthesis of carbonated apatites with good biocompatibility is a promising strategy for the broadening application of apatites for bone tissue engineering. Most researchers were interested in collagen or gelatin-based templates for synthesis of apatite minerals. Inspired by recent findings about the important role of polysaccharides in bone biomineralization, here we reported that heparin, a mucopolysaccharide, was used to synthesize carbonated apatites in vitro. The results indicated that the Ca/P ratio, carbon content, crystallinity and morphology of the apatites varied depending on the heparin concentration and the initial pH value. The morphology of apatite changed from flake-shaped to needle-shaped, and the degree of crystallinity decreased with the increasing of heparin concentration. Biocompatibility of the apatites was tested by proliferation and alkaline phosphatase activity of MC3T3-E1 cells. The results suggested that carbonated apatites synthesized in the presence of heparin were more favorable to the proliferation and differentiation of MC3T3-E1 cells compared with traditional method. In summary, the heparin concentration and the initial pH value play a key role in the chemical constitution and morphology, as well as biological properties of apatites. These biocompatible nano-apatite crystals hold great potential to be applied as bioactive materials for bone tissue engineering. - Highlights: • Heparin was used as a template to synthesize needle-shaped nano-apatite. • Changing the pH value and concentration led to different properties of apatite. • Apatite prepared by heparin was more favorable to the osteogenic differentiation. • Possible synthesis mechanism of apatite templated by heparin was described.

Mesoporous anatase TiO2/reduced graphene oxide nanocomposites: A simple template-free synthesis and their high photocatalytic performance

International Nuclear Information System (INIS)

Zhou, Qi; Zhong, Yong-Hui; Chen, Xing; Huang, Xing-Jiu; Wu, Yu-Cheng

2014-01-01

Graphical abstract: - Highlights: • Mesoporous TiO 2 nanoparticles with anatase phase were assembled on reduced graphene oxide via a template-free one-step hydrothermal method. • The TiO 2 /rGO nanocomposites have better adsorption capacity and photocatalytic degradation efficiency for dyes removal. • Improved dye adsorption and photogenerated charge separation are responsible for enhanced activity. - Abstract: Mesoporous anatase phase TiO 2 was assembled on reduced graphene oxide (rGO) using a template-free one-step hydrothermal process. The nanocomposites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and Brunauer–Emmett–Teller (BET) surface area. Morphology of TiO 2 was related to the content of graphene oxide. TiO 2 /rGO nanocomposites exhibited excellent photocatalytic activity for the photo-degradation of methyl orange. The degradation rate was 4.5 times greater than that of pure TiO 2 nanoparticles. This difference was attributed to the thin two-dimensional graphene sheet. The graphene sheet had a large surface area, high adsorption capacity, and acted as a good electron acceptor for the transfer of photo-generated electrons from the conduction band of TiO 2 . The enhanced surface adsorption characteristics and excellent charge transport separation were independent properties of the photocatalytic degradation process

Synthesis of three-dimensionally ordered macro-/mesoporous Pt with high electrocatalytic activity by a dual-templating approach

Science.gov (United States)

Zhang, Chengwei; Yang, Hui; Sun, Tingting; Shan, Nannan; Chen, Jianfeng; Xu, Lianbin; Yan, Yushan

2014-01-01

Three dimensionally ordered macro-/mesoporous (3DOM/m) Pt catalysts are fabricated by chemical reduction employing a dual-templating synthesis approach combining both colloidal crystal (opal) templating (hard-templating) and lyotropic liquid crystal templating (soft-templating) techniques. The macropore walls of the prepared 3DOM/m Pt exhibit a uniform mesoporous structure composed of polycrystalline Pt nanoparticles. Both the size of the mesopores and Pt nanocrystallites are in the range of 3-5 nm. The 3DOM/m Pt catalyst shows a larger electrochemically active surface area (ECSA), and higher catalytic activity as well as better poisoning tolerance for methanol oxidation reaction (MOR) than the commercial Pt black catalyst.

The initial step of silicate versus aluminosilicate formation in zeolite synthesis: a reaction mechanism in water with a tetrapropylammonium template

KAUST Repository

Trinh, Thuat T.

2012-01-01

The initial step for silicate and aluminosilicate condensation is studied in water in the presence of a realistic tetrapropylammonium template under basic conditions. The model corresponds to the synthesis conditions of ZSM5. The free energy profile for the dimer formation ((OH) 3Si-O-Si-(OH) 2O - or [(OH) 3Al-O-Si-(OH) 3] -) is calculated with ab initio molecular dynamics and thermodynamic integration. The Si-O-Si dimer formation occurs in a two-step manner with an overall free energy barrier of 75 kJ mol -1. The first step is associated with the Si-O bond formation and results in an intermediate with a five-coordinated Si, and the second one concerns the removal of the water molecule. The template is displaced away from the Si centres upon dimer formation, and a shell of water molecules is inserted between the silicate and the template. The main effect of the template is to slow down the backward hydrolysis reaction with respect to the condensation one. The Al-O-Si dimer formation first requires the formation of a metastable precursor state by proton transfer from Si(OH) 4 to Al(OH) 4 - mediated by a solvent molecule. It then proceeds through a single step with an overall barrier of 70 kJ mol -1. The model with water molecules explicitly included is then compared to a simple calculation using an implicit continuum model for the solvent. The results underline the importance of an explicit and dynamical treatment of the water solvent, which plays a key role in assisting the reaction. © the Owner Societies 2012.

Template-Assisted Synthesis and Characterization of Passivated Nickel Nanoparticles

Directory of Open Access Journals (Sweden)

Al-Omari IA

2010-01-01

Full Text Available Abstract Potential applications of nickel nanoparticles demand the synthesis of self-protected nickel nanoparticles by different synthesis techniques. A novel and simple technique for the synthesis of self-protected nickel nanoparticles is realized by the inter-matrix synthesis of nickel nanoparticles by cation exchange reduction in two types of resins. Two different polymer templates namely strongly acidic cation exchange resins and weakly acidic cation exchange resins provided with cation exchange sites which can anchor metal cations by the ion exchange process are used. The nickel ions which are held at the cation exchange sites by ion fixation can be subsequently reduced to metal nanoparticles by using sodium borohydride as the reducing agent. The composites are cycled repeating the loading reduction cycle involved in the synthesis procedure. X-Ray Diffraction, Scanning Electron Microscopy, Transmission Electron microscopy, Energy Dispersive Spectrum, and Inductively Coupled Plasma Analysis are effectively utilized to investigate the different structural characteristics of the nanocomposites. The hysteresis loop parameters namely saturation magnetization and coercivity are measured using Vibrating Sample Magnetometer. The thermomagnetization study is also conducted to evaluate the Curie temperature values of the composites. The effect of cycling on the structural and magnetic characteristics of the two composites are dealt in detail. A comparison between the different characteristics of the two nanocomposites is also provided.

Ordered molecular arrays as templates: A new approach to synthesis of mesoporous materials

Science.gov (United States)

Behrens, P.; Stucky, G.

There has been a growing interest in the extension of the microporous molecular sieve synthesis and applications to mesoscopic dimensions. Typical areas for the application of mesoscopic zeolite-type structures are in separation (e.g., protein separation and selective adsorption of large organic molecules from waste waters) and catalysis (e.g., processing of tar sand and of the high distillates of crude oils to valuable low-boiling products). Another is in the supramolecular assembly of molecular array and polymers for electronic and optical applications. In a new concept in the synthesis of porous material the templating agent is no longer a single, solvated, organic molecule or metal ion, but rather a self-assembled molecular array. This template leads to mesoporous materials with adjustable pore sizes between 16 and greater than 100 Angstrom, covering well the mesophorous range of greatest interest. The periodic arrangement of pores is very regular, and the pore size distribution measured by absorption is nearly as sharp as that of conventional zeolites.

Novel Evaporation Process for Deposition of Kesterite Thin Films Synthesized by Solvothermal Method

Directory of Open Access Journals (Sweden)

J. A. Estrada-Ayub

2017-01-01

Full Text Available Kesterite, a quaternary compound of Cu2ZnSnS4, is a promising option as a material absorber to reduce the cost of photovoltaic solar cells. The solvothermal method is a way to synthesize nanoparticles of this material. In this work, once synthesized, particles were deposited on a substrate through evaporation, and their morphological, structural, and optical properties were studied. Results show that changes of precursor ratios during solvothermal synthesis result in a modification of particle morphology but not on its size. The deposition of already synthesized kesterite through evaporation preserves kesterite structure and permits the formation of a homogenous film on a substrate. Optical reflectance and transmittance measurements allowed estimating the band-gap energy between 1.41 and 1.46 eV for representative samples, which is near the optimum for the absorber material.

Conformational sampling in template-free protein loop structure modeling: an overview.

Science.gov (United States)

Li, Yaohang

2013-01-01

Accurately modeling protein loops is an important step to predict three-dimensional structures as well as to understand functions of many proteins. Because of their high flexibility, modeling the three-dimensional structures of loops is difficult and is usually treated as a "mini protein folding problem" under geometric constraints. In the past decade, there has been remarkable progress in template-free loop structure modeling due to advances of computational methods as well as stably increasing number of known structures available in PDB. This mini review provides an overview on the recent computational approaches for loop structure modeling. In particular, we focus on the approaches of sampling loop conformation space, which is a critical step to obtain high resolution models in template-free methods. We review the potential energy functions for loop modeling, loop buildup mechanisms to satisfy geometric constraints, and loop conformation sampling algorithms. The recent loop modeling results are also summarized.

CONFORMATIONAL SAMPLING IN TEMPLATE-FREE PROTEIN LOOP STRUCTURE MODELING: AN OVERVIEW

Directory of Open Access Journals (Sweden)

Yaohang Li

2013-02-01

Full Text Available Accurately modeling protein loops is an important step to predict three-dimensional structures as well as to understand functions of many proteins. Because of their high flexibility, modeling the three-dimensional structures of loops is difficult and is usually treated as a “mini protein folding problem” under geometric constraints. In the past decade, there has been remarkable progress in template-free loop structure modeling due to advances of computational methods as well as stably increasing number of known structures available in PDB. This mini review provides an overview on the recent computational approaches for loop structure modeling. In particular, we focus on the approaches of sampling loop conformation space, which is a critical step to obtain high resolution models in template-free methods. We review the potential energy functions for loop modeling, loop buildup mechanisms to satisfy geometric constraints, and loop conformation sampling algorithms. The recent loop modeling results are also summarized.

Coordinated leading and lagging strand DNA synthesis by using the herpes simplex virus 1 replication complex and minicircle DNA templates.

Science.gov (United States)

Stengel, Gudrun; Kuchta, Robert D

2011-01-01

The origin-specific replication of the herpes simplex virus 1 genome requires seven proteins: the helicase-primase (UL5-UL8-UL52), the DNA polymerase (UL30-UL42), the single-strand DNA binding protein (ICP8), and the origin-binding protein (UL9). We reconstituted these proteins, excluding UL9, on synthetic minicircular DNA templates and monitored leading and lagging strand DNA synthesis using the strand-specific incorporation of dTMP and dAMP. Critical features of the assays that led to efficient leading and lagging stand synthesis included high helicase-primase concentrations and a lagging strand template whose sequence resembled that of the viral DNA. Depending on the nature of the minicircle template, the replication complex synthesized leading and lagging strand products at molar ratios varying between 1:1 and 3:1. Lagging strand products (∼0.2 to 0.6 kb) were significantly shorter than leading strand products (∼2 to 10 kb), and conditions that stimulated primer synthesis led to shorter lagging strand products. ICP8 was not essential; however, its presence stimulated DNA synthesis and increased the length of both leading and lagging strand products. Curiously, human DNA polymerase α (p70-p180 or p49-p58-p70-p180), which improves the utilization of RNA primers synthesized by herpesvirus primase on linear DNA templates, had no effect on the replication of the minicircles. The lack of stimulation by polymerase α suggests the existence of a macromolecular assembly that enhances the utilization of RNA primers and may functionally couple leading and lagging strand synthesis. Evidence for functional coupling is further provided by our observations that (i) leading and lagging strand synthesis produce equal amounts of DNA, (ii) leading strand synthesis proceeds faster under conditions that disable primer synthesis on the lagging strand, and (iii) conditions that accelerate helicase-catalyzed DNA unwinding stimulate decoupled leading strand synthesis but not

Self-templated synthesis of single-crystal and single-domain ferroelectric nanoplates

KAUST Repository

Chao, Chunying; Ren, Zhaohui; Zhu, Yihan; Xiao, Zhen; Liu, Zhenya; Xú , Gang; Mai, Jiangquan; Li, Xiang; Shen, Ge; Han, Gaorong

2012-01-01

Free-standing single-crystal PbTiO 3 nanoplates (see picture) were synthesized by a facile hydrothermal method. A "self-templated" crystal growth is presumed to lead to the formation of the PbTiO 3 nanoplates, which have ferroelectric single

Hierarchical structures of ZnO spherical particles synthesized solvothermally

Science.gov (United States)

Saito, Noriko; Haneda, Hajime

2011-12-01

We review the solvothermal synthesis, using a mixture of ethylene glycol (EG) and water as the solvent, of zinc oxide (ZnO) particles having spherical and flower-like shapes and hierarchical nanostructures. The preparation conditions of the ZnO particles and the microscopic characterization of the morphology are summarized. We found the following three effects of the ratio of EG to water on the formation of hierarchical structures: (i) EG restricts the growth of ZnO microcrystals, (ii) EG promotes the self-assembly of small crystallites into spheroidal particles and (iii) the high water content of EG results in hollow spheres.

Nanowires and nanostructures fabrication using template methods

DEFF Research Database (Denmark)

Mátéfi-Tempfli, Stefan; Mátéfi-Tempfli, M.; Vlad, A.

2009-01-01

One of the great challenges of today is to find reliable techniques for the fabrication of nanomaterials and nanostructures. Methods based on template synthesis and on self organization are the most promising due to their easiness and low cost. This paper focuses on the electrochemical synthesis ...... of nanowires and nanostructures using nanoporous host materials such as supported anodic aluminum considering it as a key template for nanowires based devices. New ways are opened for applications by combining such template synthesis methods with nanolithographic techniques....

Solvothermal synthesis and electrochemical performance of Li2MnSiO4/C cathode materials for lithium ion batteries

International Nuclear Information System (INIS)

Wang, Yan-Chao; Zhao, Shi-Xi; Zhai, Peng-Yuan; Li, Fang; Nan, Ce-Wen

2014-01-01

Highlights: • Li 2 MnSiO 4 /C nanocomposite has been synthesized by the solvothermal method. • The particles of Li 2 MnSiO 4 /C are much smaller and more uniform. • The presence of Ni improves discharge capacity of Li 2 MnSiO 4 /C cathode material. • The initial discharge capacity of Ni-modified Li 2 MnSiO 4 /C is 274.5 mAh g −1 at 25 °C. - Abstract: Orthorhombic structure Li 2 MnSiO 4 /C with Pmn2 1 space group is synthesized by the solvothermal method. Carbon coating and Ni 2+ doping are used to improve the electronic conductivity and the cycling performance of Li 2 MnSiO 4 cathode material, respectively. The particles of Li 2 MnSiO 4 /C are much smaller and more uniform than those of Li 2 MnSiO 4 due to the carbon coating. It is shown that Ni 2+ has been reduced into metal Ni during the synthesis process. The synthesized Ni-modified Li 2 MnSiO 4 /C (denoted as (LMS@Ni)/C) cathode material exhibits better electrochemical performance in comparison with Li 2 MnSiO 4 /C, attributing to higher lithium ion diffusion coefficient as well as electronic conductivity. The initial discharge capacity of (LMS@Ni)/C is 274.5 mA h g −1 and the reversible capacity after 20 cycles is 119.8 mA h g −1 at 25 °C

Nanocrystal conversion chemistry: A unified and materials-general strategy for the template-based synthesis of nanocrystalline solids

International Nuclear Information System (INIS)

Vasquez, Yolanda; Henkes, Amanda E.; Chris Bauer, J.; Schaak, Raymond E.

2008-01-01

The concept of nanocrystal conversion chemistry, which involves the use of pre-formed nanoparticles as templates for chemical transformation into derivative solids, has emerged as a powerful approach for designing the synthesis of complex nanocrystalline solids. The general strategy exploits established synthetic capabilities in simple nanocrystal systems and uses these nanocrystals as templates that help to define the composition, crystal structure, and morphology of product nanocrystals. This article highlights key examples of 'conversion chemistry' approaches to the synthesis of nanocrystalline solids using a variety of techniques, including galvanic replacement, diffusion, oxidation, and ion exchange. The discussion is organized according to classes of solids, highlighting the diverse target systems that are accessible using similar chemical concepts: metals, oxides, chalcogenides, phosphides, alloys, intermetallic compounds, sulfides, and nitrides. - Graphical abstract: Nanocrystal conversion chemistry uses pre-formed nanoparticles as templates for chemical transformation into derivative solids, helping to define the composition, crystal structure, and morphology of product nanocrystals that have more complex features than their precursor templates. This article highlights the application of this concept to diverse classes of solids, including metals, oxides, chalcogenides, phosphides, alloys, intermetallics, sulfides, and nitrides

Template-directed synthesis of MS (M=Cd, Zn) hollow microsphere via hydrothermal method

Science.gov (United States)

Wang, Shi-Ming; Wang, Qiong-Sheng; Wan, Qing-Li

2008-05-01

CdS, ZnS hollow microspheres were prepared with chitosan as the synthesis template at 140 and 150 °C, respectively, by hydrothermal method. The resultant products were characterized by X-ray diffraction (XRD) measurements in order to determine the crystalline phase of the products. The structural and morphological features of the nanoparticles were investigated by transmission electron microscopy (TEM) and ultraviolet-visible diffuse reflection spectroscopy (DRS). The experimental results indicated that all the nanoparticles aggregated into hollow microspheres and chitosan as a template played an important role in the formation of hollow microspheres. In addition, an intermediate complex structure-controlling possible reaction mechanism was proposed in this paper.

Solvothermal synthesis of hierarchical TiO{sub 2} nanostructures with tunable morphology and enhanced photocatalytic activity

Energy Technology Data Exchange (ETDEWEB)

Fan, Zhenghua [School of Physics and Materials Science, Anhui University, Hefei 230601 (China); Meng, Fanming, E-mail: mrmeng@ahu.edu.cn [School of Physics and Materials Science, Anhui University, Hefei 230601 (China); Key laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024 (China); Zhang, Miao [School of Physics and Materials Science, Anhui University, Hefei 230601 (China); Wu, Zhenyu [College of Chemistry & Chemical Engineering, Anhui University, Hefei 230601 (China); Sun, Zhaoqi; Li, Aixia [School of Physics and Materials Science, Anhui University, Hefei 230601 (China)

2016-01-01

Graphical abstract: - Highlights: • Hierarchical anatase TiO{sub 2} nanostructures with enhanced photocatalytic activity are synthesized by solvothermal method. • A mechanism for enhanced photocatalytic activity of chrysanthemum-like hierarchical TiO{sub 2} nanostructures is proposed. • A possible formation mechanism is suggested to explain the transformation from rose-like to chrysanthemum-like, and to sea-urchin-like. - Abstract: This paper presents controllable growth and photocatalytic activity of TiO{sub 2} hierarchical nanostructures by solvothermal method at different temperatures. It is revealed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) that the morphology of TiO{sub 2} can be effectively controlled as rose-like, chrysanthemum-like and sea-urchin-like only changing solvothermal temperature. BET surface area analysis confirms the presence of a mesoporous network in all the nanostructures, and shows high surface area at relatively high temperature. The photocatalytic activities of the photocatalysts are evaluated by the photodegradation of RhB under UV light irradiation. The TiO{sub 2} samples exhibit high activity on the photodegradation of RhB, which is higher than that of the commercial P25. The enhancement in photocatalytic performance can be attributed to the synergetic effect of the surface area, crystallinity, band gap and crystalline size.

Synthesis of hydroxyapatite nanoparticles by a novel ultrasonic assisted with mixed hollow sphere template method

Science.gov (United States)

Gopi, D.; Indira, J.; Kavitha, L.; Sekar, M.; Mudali, U. Kamachi

Hydroxyapatite (HAP) is the main inorganic component of bone material and is widely used in various biomedical applications due to its excellent bioactivity and biocompatibility. In this paper, we have reported the synthesis of hydroxyapatite nanoparticles by a novel ultrasonic assisted mixed template directed method. In this method glycine-acrylic acid (GLY-AA) hollow spheres were used as an organic template which could be prepared by mixing of glycine with acrylic acid. The as-synthesized HAP nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and tunnelling electron microscope (TEM) to investigate the nature of bonding, crystallinity, size and shape. The thermal stability of as-synthesized nanoparticles was also investigated by the thermo gravimetric analysis (TGA). The effect of ultrasonic irradiation time on the crystallinity and size of the HAP nanoparticles in presence of glycine-acrylic acid hollow spheres template were investigated. From the inspection of the above results it is confirmed that the crystallinity and size of the HAP nanoparticles decrease with increasing ultrasonic irradiation time. Hence the proposed synthesis strategy provides a facile pathway to obtain nano sized HAP with high quality, suitable size and morphology.

Influence of platinum group metal-free catalyst synthesis on microbial fuel cell performance

Science.gov (United States)

Santoro, Carlo; Rojas-Carbonell, Santiago; Awais, Roxanne; Gokhale, Rohan; Kodali, Mounika; Serov, Alexey; Artyushkova, Kateryna; Atanassov, Plamen

2018-01-01

Platinum group metal-free (PGM-free) ORR catalysts from the Fe-N-C family were synthesized using sacrificial support method (SSM) technique. Six experimental steps were used during the synthesis: 1) mixing the precursor, the metal salt, and the silica template; 2) first pyrolysis in hydrogen rich atmosphere; 3) ball milling; 4) etching the silica template using harsh acids environment; 5) the second pyrolysis in ammonia rich atmosphere; 6) final ball milling. Three independent batches were fabricated following the same procedure. The effect of each synthetic parameters on the surface chemistry and the electrocatalytic performance in neutral media was studied. Rotating ring disk electrode (RRDE) experiment showed an increase in half wave potential and limiting current after the pyrolysis steps. The additional improvement was observed after etching and performing the second pyrolysis. A similar trend was seen in microbial fuel cells (MFCs), in which the power output increased from 167 ± 2 μW cm-2 to 214 ± 5 μW cm-2. X-ray Photoelectron Spectroscopy (XPS) was used to evaluate surface chemistry of catalysts obtained after each synthetic step. The changes in chemical composition were directly correlated with the improvements in performance. We report outstanding reproducibility in both composition and performance among the three different batches.

Solvothermal crystallization of nanocrystals of metal oxides

International Nuclear Information System (INIS)

Furukawa, S; Amino, H; Iwamoto, S; Inoue, M

2008-01-01

Solvothermal crystallization of the hydroxide gels obtained by hydrolysis of alkoxides (Zr, Ta, Nb, ln, Sn, Ti and Al) was examined. Nanocrystals having high surface areas (S BET > 170 m 2 g -1 ) were obtained except for the product derived from indium isopropoxide. The effect of water in organic solvent upon the crystallinity of the product was investigated. The increase in the activity of water by using high concentration of alkoxide or intentional addition of water to the solvothermal medium led to crystal growth of the products. In contrast, decrease in activity of water by adding ethylene glycol before solvothermal treatment caused a decrease in crystallinity of the product

Solvothermal crystallization of nanocrystals of metal oxides

Science.gov (United States)

Furukawa, S.; Amino, H.; Iwamoto, S.; Inoue, M.

2008-07-01

Solvothermal crystallization of the hydroxide gels obtained by hydrolysis of alkoxides (Zr, Ta, Nb, ln, Sn, Ti and Al) was examined. Nanocrystals having high surface areas (SBET > 170 m2 g-1) were obtained except for the product derived from indium isopropoxide. The effect of water in organic solvent upon the crystallinity of the product was investigated. The increase in the activity of water by using high concentration of alkoxide or intentional addition of water to the solvothermal medium led to crystal growth of the products. In contrast, decrease in activity of water by adding ethylene glycol before solvothermal treatment caused a decrease in crystallinity of the product.

A facile soft template synthesis and characterization of PbHAsO4 nanocrystals

International Nuclear Information System (INIS)

Xiu Zhiliang; Lue Mengkai; Zhou Guangjun; Gu Feng; Zhang Haiping; Xu Dong; Yuan Duorong

2004-01-01

Monoclinic lead hydrogen arsenate (LHA) nanocrystals with different crystallization morphologies and crystallite sizes were prepared successfully by a soft template synthesis method in the presence of sodium dodecylbenzenesulfonate (SDBS) or polyvinylpyrrolidone (PVP). The products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The possible mechanism of SDBS and PVP in the experiment was briefly illustrated

Solvothermal synthesis and electrochemical performance of hollow LiFePO{sub 4} nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Zheng, Zhenmiao [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Pang, Wei Kong [Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW 2522 (Australia); Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Tang, Xincun, E-mail: tangxincun@163.com [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Jia, Dianzeng; Huang, Yudai [Institute of Applied Chemistry, Xinjiang University, Urumqi 840046 (China); Guo, Zaiping [Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW 2522 (Australia)

2015-08-15

Highlights: • Hollow LiFePO{sub 4} nanoparticles were successfully synthesized via solvothermal method. • The shorter b lattice parameter allows the shorter diffusion path of lithium ion. • Hollow LiFePO{sub 4} nanoparticles show better rate capability than solid LiFePO{sub 4}. - Abstract: Hollow LiFePO{sub 4} nanoparticles were synthesized via a solvothermal technique, using ammonium tartrate as additive and carbon source, and ethylene glycol/water as solvent. The as-prepared samples were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, Raman spectroscopy, scanning and transmission electron microscopies, and Brunauer–Emmett–Teller specific surface area measurements. The electrochemical properties of the LiFePO{sub 4} cathode were examined in coin-type cell configuration and the cathode exhibited excellent rate capability (i.e., discharge capacity of 120.9 mA h g{sup −1} at 10 C) and cycling performance (i.e., >98% of capacity retention rate after 50 cycles). It is believed that the enhanced performance is correlated to the hollow structure, small crystallite and particle sizes, and relatively shorter lattice parameter b.

BULK AND TEMPLATE-FREE SYNTHESIS OF SILVER NANOWIRES USING CAFFEINE AT ROOM TEMPERATURE

Science.gov (United States)

A simple eco-friendly one-pot method is described to synthesize bulk quantities of nanowires of silver (Ag) using caffeine without the need of reducing agent, surfactants, and/or large amounts of insoluble templates. Chemical reduction of silver salts with caffeine dramatically c...

Designed synthesis of tunable amorphous carbon nanotubes (a ...

Indian Academy of Sciences (India)

Administrator

The as-prepared a-CNTs were a kind of hydrogenated a-CNTs containing both ... aluminium oxide (AAO) template, solvothermal method, etc., have been developed to ... above products were treated by dilute HCl solution to remove VOx in the ...

Hard template synthesis of metal nanowires

OpenAIRE

Kawamura, Go; Muto, Hiroyuki; Matsuda, Atsunori

2014-01-01

Metal nanowires (NWs) have attracted much attention because of their high electron conductivity, optical transmittance, and tunable magnetic properties. Metal NWs have been synthesized using soft templates such as surface stabilizing molecules and polymers, and hard templates such as anodic aluminum oxide, mesoporous oxide, carbon nanotubes. NWs prepared from hard templates are composites of metals and the oxide/carbon matrix. Thus, selecting appropriate elements can simplify the production o...

Template-free electrochemical nanofabrication of polyaniline nanobrush and hybrid polyaniline with carbon nanohorns for supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Wei Di; Andrew, Piers; Ryhaenen, Tapani [Nokia Research Centre Cambridge, Broers Building, 21 J J Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Wang, Haolan; Hiralal, Pritesh; Amaratunga, Gehan A J [Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 J J Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Hayashi, Yasuhiko, E-mail: di.wei@nokia.com, E-mail: gaja1@cam.ac.uk [Department of Materials Science, Nagoya Institute of Technology, Nagoya 466-8555 (Japan)

2010-10-29

Polyaniline (PANI) nanobrushes were synthesized by template-free electrochemical galvanostatic methods. When the same method was applied to the carbon nanohorn (CNH) solution containing aniline monomers, a hybrid nanostructure containing PANI and CNHs was enabled after electropolymerization. This is the first report on the template-free method to make PANI nanobrushes and homogeneous hybrid soft matter (PANI) with carbon nanoparticles. Raman spectroscopy was used to analyze the interaction between CNH and PANI. Electrochemical nanofabrication offers simplicity and good control when used to make electronic devices. Both of these materials were applied in supercapacitors and an improvement capacitive current by using the hybrid material was observed.

Template-free electrochemical nanofabrication of polyaniline nanobrush and hybrid polyaniline with carbon nanohorns for supercapacitors

Science.gov (United States)

Wei, Di; Wang, Haolan; Hiralal, Pritesh; Andrew, Piers; Ryhänen, Tapani; Hayashi, Yasuhiko; Amaratunga, Gehan A. J.

2010-10-01

Polyaniline (PANI) nanobrushes were synthesized by template-free electrochemical galvanostatic methods. When the same method was applied to the carbon nanohorn (CNH) solution containing aniline monomers, a hybrid nanostructure containing PANI and CNHs was enabled after electropolymerization. This is the first report on the template-free method to make PANI nanobrushes and homogeneous hybrid soft matter (PANI) with carbon nanoparticles. Raman spectroscopy was used to analyze the interaction between CNH and PANI. Electrochemical nanofabrication offers simplicity and good control when used to make electronic devices. Both of these materials were applied in supercapacitors and an improvement capacitive current by using the hybrid material was observed.

PEG-nanotube liquid crystals as templates for construction of surfactant-free gold nanorods.

Science.gov (United States)

Kameta, Naohiro; Shiroishi, Hidenobu

2018-04-23

Lyotropic liquid crystals, in which nanotubes coated with polyethylene glycol were aligned side-by-side in aqueous dispersions, acted as templates for the construction of surfactant-free gold nanorods with controllable diameters, functionalizable surfaces, and tunable optical properties.

Particle size-controllable microwave-assisted solvothermal synthesis of the high-voltage cathode material LiCoPO4 using water/ethylene glycol solvent blends

Science.gov (United States)

Ludwig, Jennifer; Haering, Dominik; Doeff, Marca M.; Nilges, Tom

2017-03-01

Particle size-tuned platelets of the high-voltage cathode material LiCoPO4 for Li-ion batteries have been synthesized by a simple one-step microwave-assisted solvothermal process using an array of water/ethylene glycol (EG) solvent mixtures. Particle size control was achieved by altering the concentration of the EG co-solvent in the mixture between 0 and 100 vol%, with amounts of 0-80 vol% EG producing single phase, olivine-type LiCoPO4. The particle sizes of the olivine materials were significantly reduced from about 1.2 μm × 1.2 μm × 500 nm (0 vol% EG) to 200 nm × 100 nm × 50 nm (80 vol% EG) with increasing EG content, while specific surface areas increased from 2 to 13 m2 g-1. The particle size reduction could mainly be attributed to the modified viscosities of the solvent blends. Owing to the soft template effect of EG, the crystals exhibited the smallest dimensions along the [010] direction of the Li diffusion pathways in the olivine crystal structure, resulting in enhanced lithium diffusion properties. The relationship between the synthesis, crystal properties and electrochemical performance was further elucidated, indicating that the electrochemical performances of the as-prepared materials mainly depend on the solvent composition and the respective particle size range. LiCoPO4 products obtained from reaction media with low and high EG contents exhibited good electrochemical performances (initial discharge capacities of 87-124 mAh g-1 at 0.1 C), whereas materials made from medium EG concentrations (40-60 vol% EG) showed the highest capacities and gravimetric energy densities (up to 137 mAh g-1 and 658 Wh kg-1 at 0.1 C), excellent rate capabilities, and cycle life.

Facile synthesis of porous TiO_2 photocatalysts using waste sludge as the template

International Nuclear Information System (INIS)

Wang, Xiaopeng; Huang, Shouqiang; Zhu, Nanwen; Lou, Ziyang; Yuan, Haiping

2015-01-01

Graphical abstract: Waste sludge is introduced to synthesize the waste sludge templated TiO_2 photocatalyst with porous structure, which possesses better photocatalytic activity compared to pure TiO_2. - Highlights: • Waste sludge is introduced to synthesize the TiO_2 photocatalyst. • Waste sludge templated TiO_2 sample possesses porous structure. • Waste sludge templated TiO_2 sample exhibits high photocatalytic activity. - Abstract: A resource utilization method of waste sludge is present by the synthesis of waste sludge templated TiO_2 photocatalysts. The organic materials in waste sludge are used as the pore-forming agents, and the transition metals included in the remaining waste sludge through calcination (WSC) can serve as the dopants for the WSC-TiO_2 (WSCT) photocatalyst. The visible and UV–visible light driven photocatalytic activities of WSCT are much better compared to those of pure TiO_2 and WSC, and it is originated from the higher light absorption property and the efficient electron–hole pair separation provided by waste sludge.

organic template free synthesis of zsm11 from kaolinite clay

African Journals Online (AJOL)

user

diffusion assistance and tortuosity, as depicted in Figure. 1. Hongyuan and others [6] .... characterized by nearly equal peak height of Al and Si, another means to ..... method for nanocrystalline zeolite synthesis. Chemical communication.

Synthesis of hydroxyapatite nanoparticles by a novel ultrasonic assisted with mixed hollow sphere template method.

Science.gov (United States)

Gopi, D; Indira, J; Kavitha, L; Sekar, M; Mudali, U Kamachi

2012-07-01

Hydroxyapatite (HAP) is the main inorganic component of bone material and is widely used in various biomedical applications due to its excellent bioactivity and biocompatibility. In this paper, we have reported the synthesis of hydroxyapatite nanoparticles by a novel ultrasonic assisted mixed template directed method. In this method glycine-acrylic acid (GLY-AA) hollow spheres were used as an organic template which could be prepared by mixing of glycine with acrylic acid. The as-synthesized HAP nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and tunnelling electron microscope (TEM) to investigate the nature of bonding, crystallinity, size and shape. The thermal stability of as-synthesized nanoparticles was also investigated by the thermo gravimetric analysis (TGA). The effect of ultrasonic irradiation time on the crystallinity and size of the HAP nanoparticles in presence of glycine-acrylic acid hollow spheres template were investigated. From the inspection of the above results it is confirmed that the crystallinity and size of the HAP nanoparticles decrease with increasing ultrasonic irradiation time. Hence the proposed synthesis strategy provides a facile pathway to obtain nano sized HAP with high quality, suitable size and morphology. Copyright © 2012 Elsevier B.V. All rights reserved.

Synthesis of ZnFe2O4/SiO2 composites derived from a diatomite template.

Science.gov (United States)

Liu, Zhaoting; Fan, Tongxiang; Zhou, Han; Zhang, Di; Gong, Xiaolu; Guo, Qixin; Ogawa, Hiroshi

2007-03-01

A novel porous ZnFe2O4/SiO2 composite product has been generated with a template-directed assembly method from porous diatomite under different synthesis conditions, such as precursor concentrations (metallic nitrates), calcination temperature and diatomite type. The phase composition and morphology of all the materials were examined by x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The results indicated that an inherited hierarchical porous structure from the diatomite template can be obtained, and the synthesis conditions were found to have clear effects on the formation of the ZnFe2O4/SiO2 composite. The ideal composite of ZnFe2O4/SiO2 can be obtained through optimization of diatomite template type, precursor solution and calcination temperature. Furthermore, the adsorption abilities of two types of diatomites were analyzed in detail using FTIR spectra and nitrogen adsorption measurements etc, which proved that A-diatomite (Shengzhou-diatomite) is better than B-diatomite (Changbai-diatomite) on the aspect of adsorbing Zn and Fe ions, and of forming the ZnFe2O4.

A rational repeating template method for synthesis of 2D hexagonally ordered mesoporous precious metals.

Science.gov (United States)

Takai, Azusa; Doi, Yoji; Yamauchi, Yusuke; Kuroda, Kazuyuki

2011-03-01

A repeating template method is presented for the synthesis of mesoporous metals with 2D hexagonal mesostructures. First, a silica replica (i.e., silica nanorods arranged periodically) is prepared by using 2D hexagonally ordered mesoporous carbon as the template. After that, the obtained silica replica is used as the second template for the preparation of mesoporous ruthenium. After the ruthenium species are introduced into the silica replica, the ruthenium species are then reduced by a vapor-infiltration method by using the reducing agent dimethylamine borane. After the ruthenium deposition, the silica is chemically removed. Analysis by transmission and scanning electron microscopies, a nitrogen-adsorption-desorption isotherm, and small-angle X-ray scattering revealed that the mesoporous ruthenium had a 2D hexagonal mesostructure, although the mesostructural ordering is decreased compared to that of the original mesoporous carbon template. This method is widely applicable to other metal systems. By changing the metal species introduced into the silica replica, several mesoporous metals (palladium and platinum) can be synthesized. Ordered mesoporous ruthenium and palladium, which are not easily attainable by the soft-templating methods, can be prepared. This study has overcome the composition variation limitations of the soft-templating method. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

MnO/N–C anode materials for lithium-ion batteries prepared by cotton-templated combustion synthesis

Directory of Open Access Journals (Sweden)

Cheng-Gong Han

2017-10-01

Full Text Available We herein report a facile one-pot synthesis of MnO/N-doped carbon (N–C composites via a sustainable cotton-template glycine–nitrate combustion synthesis to yield superior anode materials for Li ion batteries. MnO nanoparticles with several nanometers were well-embedded in a porous N-doped carbon matrix. It displays the unique characteristics, including the shortened Li+-ion transport path, increased contact areas with the electrolyte solution, inhibited volume changes and agglomeration of nanoparticles, as well as good conductivity and structural stability during the cycling process, thereby benefiting the superior cycling performance and rate capability. This favorable electrochemical performance of obtained MnO/N–C composites via a one-pot biomass-templated glycine/nitrate combustion synthesis renders the suitability as anode materials for Li-ion batteries. Keywords: Biomass, Cotton, Manganese oxide, Lithium ion battery, Porous carbon

Direct access to highly crystalline mesoporous nano TiO2 using sterically bulky organic acid templates

Science.gov (United States)

Bakre, Pratibha V.; Tilve, S. G.

2018-05-01

Sterically bulky monocarboxylic acid templates pivalic acid and phenoxyacetic acid are reported for the first time as organic templates in the sol-gel synthesis of TiO2. Mesoporous nanoparticulates of pure anatase phase and of well defined size were synthesized. The characterization of the materials prepared was done by various methods such as XRD, SEM, TEM, FTIR, UV-DRS, BET, etc. The prepared TiO2 samples were evaluated for the day light photodegradation of methylene blue by comparing with Degussa P25 and templates free synthesized TiO2 and were found to be more efficient.

Ultra-flexible lithium ion batteries fabricated by electrodeposition and solvothermal synthesis

International Nuclear Information System (INIS)

Wang, Jian; Zhang, Lei; Zhou, Qingwen; Wu, Wenlu; Zhu, Chao; Liu, Ziqiang; Chang, Shaozhong; Pu, Jun; Zhang, Huigang

2017-01-01

Cathodes have been one of the major challenges of flexible batteries. The traditional slurry-based technologies lead to loose interparticle connection, which is vulnerable upon bending. The direct fabrication of cathode materials requires high temperatures, which may destroy flexible substrates. Here we developed an electrodepostion and solvothermal route to conformally coat cathode material on a flexible scaffold. The monolithic electrode enables an ultra-flexible lithium ion battery because of the close attachment of active materials to flexible scaffolds and the interlock effect between the hard shell and soft core. This ultra-flexible battery retains 58.8% of initial capacity even after bending 4000 cycles.

Silver nanoparticles: Large scale solvothermal synthesis and optical properties

Energy Technology Data Exchange (ETDEWEB)

Wani, Irshad A.; Khatoon, Sarvari [Nanochemistry Laboratory, Department of Chemistry, Jamia Millia Islamia, New Delhi 110025 (India); Ganguly, Aparna [Nanochemistry Laboratory, Department of Chemistry, Jamia Millia Islamia, New Delhi 110025 (India); Department of Chemistry, Indian Institute of Technology, Hauz Khas, New Delhi 110016 (India); Ahmed, Jahangeer; Ganguli, Ashok K. [Department of Chemistry, Indian Institute of Technology, Hauz Khas, New Delhi 110016 (India); Ahmad, Tokeer, E-mail: tokeer.ch@jmi.ac.in [Nanochemistry Laboratory, Department of Chemistry, Jamia Millia Islamia, New Delhi 110025 (India)

2010-08-15

Silver nanoparticles have been successfully synthesized by a simple and modified solvothermal method at large scale using ethanol as the refluxing solvent and NaBH{sub 4} as reducing agent. The nanopowder was investigated by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), UV-visible and BET surface area studies. XRD studies reveal the monophasic nature of these highly crystalline silver nanoparticles. Transmission electron microscopic studies show the monodisperse and highly uniform nanoparticles of silver of the particle size of 5 nm, however, the size is found to be 7 nm using dynamic light scattering which is in good agreement with the TEM and X-ray line broadening studies. The surface area was found to be 34.5 m{sup 2}/g. UV-visible studies show the absorption band at {approx}425 nm due to surface plasmon resonance. The percentage yield of silver nanoparticles was found to be as high as 98.5%.

Utilization of solvothermally grown InP/ZnS quantum dots as wavelength converters for fabrication of white light-emitting diodes.

Science.gov (United States)

Jang, Eun-Pyo; Yang, Heesun

2013-09-01

This work reports on a simple solvothermal synthesis of InP/ZnS core/shell quantum dots (QDs) using a much safer and cheaper phosphorus precursor of tris(dimethylamino)phosphine than the most popularly chosen tris(trimethylsilyl)phosphine. The band gap of InP QDs is facilely controlled by varying the solvothermal core growth time (4 vs. 6 h) with a fixed temperature of 150 degrees C, and the successive solvothermal ZnS shelling at 220 degrees C for 6 h results in green- and yellow-emtting InP/ZnS QD with emission quantum yield of 41-42%. The broad size distribution of as-synthesized InP/ZnS QDs, which appears to be inherent in the current solvothermal approach, is improved by a size-selective sorting procedure, and the emission properties of the resulting size-sorted QD fractions are investigated. To produce white emission for general lighting source, a blue light-emitting diode (LED) is combined with non-size-soroted green or yellow QDs as wavelength converters. Furthermore, the QD-LED that includes a blend of green and yellow QDs is fabricated to generate a white lighting source with an enhanced color rendering performance, and its electroluminescent properties are characterized in detail.

One-pot synthesis of magnetic hybrid materials based on ovoid-like carboxymethyl-cellulose/cetyltrimethylammonium-bromide templates

Energy Technology Data Exchange (ETDEWEB)

Torres-Martínez, Nubia E. [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, 66450 Nuevo León (Mexico); Garza-Navarro, M.A., E-mail: marco.garzanr@uanl.edu.mx [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, 66450 Nuevo León (Mexico); Universidad Autónoma de Nuevo León, Centro de Innovación, Investigación y Desarrollo en Ingeniería y Tecnología, Apodaca, 66600 Nuevo León (Mexico); Lucio-Porto, Raúl [Université de Nantes, CNRS, Institut des Matériaux Jean Rouxel (IMN), 2 rue de la Houssinière, BP32229, 44322 Nantes Cedex 3 (France); and others

2013-09-16

A novel one-pot synthetic procedure to obtain magnetic hybrid nanostructured materials (HNM), based on magnetic spinel-metal-oxide (SMO) nanoparticles stabilized in ovoid-like carboxymethyl-cellulose (CMC)/cetyltrimethylammonium-bromide (CTAB) templates, is reported. The HNM were synthesized from the controlled hydrolysis of inorganic salts of Fe (II) and Fe (III) into aqueous dissolutions of CMC and CTAB. The synthesized HNM were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy and static magnetic measurements. The experimental evidence suggests that, due to the competition between CTAB molecules and SMO nanoparticles to occupy CMC intermolecular sites nearby to its carboxylate functional groups, the size of both, SMO nanoparticles and ovoid-like CMC/CTAB templates can be tuned, varying the CTAB:SMO weight ratio. Moreover, it was found that the magnetic response of the HNM depends on the confinement degree of the SMO nanoparticles into the CMC/CTAB template. Hence, their magnetic characteristics can be adjusted controlling the size of the template, the quantity and distribution of the SMO nanoparticles within the template and their size. - Graphical abstract: Display Omitted - Highlights: • The synthesis of magnetic hybrid materials is reported. • The hybrid materials were synthesized following a novel one-pot procedure. • The magnetic nanoparticles were stabilized in ovoid-like templates. • The size of the templates was tuned adjusting nanoparticles weight content. • The magnetic properties of hybrid materials depend on the size of the template.

Tin phosphide-based anodes for sodium-ion batteries: synthesis via solvothermal transformation of Sn metal and phase-dependent Na storage performance

Science.gov (United States)

Shin, Hyun-Seop; Jung, Kyu-Nam; Jo, Yong Nam; Park, Min-Sik; Kim, Hansung; Lee, Jong-Won

2016-01-01

There is a great deal of current interest in the development of rechargeable sodium (Na)-ion batteries (SIBs) for low-cost, large-scale stationary energy storage systems. For the commercial success of this technology, significant progress should be made in developing robust anode (negative electrode) materials with high capacity and long cycle life. Sn-P compounds are considered promising anode materials that have considerable potential to meet the required performance of SIBs, and they have been typically prepared by high-energy mechanical milling. Here, we report Sn-P-based anodes synthesised through solvothermal transformation of Sn metal and their electrochemical Na storage properties. The temperature and time period used for solvothermal treatment play a crucial role in determining the phase, microstructure, and composition of the Sn-P compound and thus its electrochemical performance. The Sn-P compound prepared under an optimised solvothermal condition shows excellent electrochemical performance as an SIB anode, as evidenced by a high reversible capacity of ~560 mAh g−1 at a current density of 100 mA g−1 and cycling stability for 100 cycles. The solvothermal route provides an effective approach to synthesising Sn-P anodes with controlled phases and compositions, thus tailoring their Na storage behaviour. PMID:27189834

Template-free synthesis of renewable macroporous carbon via yeast cells for high-performance supercapacitor electrode materials.

Science.gov (United States)

Sun, Hongmei; He, Wenhui; Zong, Chenghua; Lu, Lehui

2013-03-01

The urgent need for sustainable development has forced material scientists to explore novel materials for next-generation energy storage devices through a green and facile strategy. In this context, yeast, which is a large group of single cell fungi widely distributed in nature environments, will be an ideal candidate for developing effective electrode materials with fascinating structures for high-performance supercapacitors. With this in mind, herein, we present the first example of creating three-dimensional (3D) interpenetrating macroporous carbon materials via a template-free method, using the green, renewable, and widespread yeast cells as the precursors. Remarkably, when the as-prepared materials are used as the electrode materials for supercapacitors, they exhibit outstanding performance with high specific capacitance of 330 F g(-1) at a current density of 1 A g(-1), and good stability, even after 1000 charge/discharge cycles. The approach developed in this work provides a new view of making full use of sustainable resources endowed by nature, opening the avenue to designing and producing robust materials with great promising applications in high-performance energy-storage devices.

Influence of porewidening duration on the template assisted growth of graphitic carbon nitride nanostructures

Science.gov (United States)

Suchitra, S. M.; Udayashankar, N. K.

2018-01-01

Porous anodic aluminium oxide (AAO) membranes with a highly ordered pore arrangement are typically used as ideal templates for the synthesis of numerous nanostructured materials. Highly ordered templates gained significant attraction due to the fact that they are readily fabricated through self-organised simple anodization process. In this paper, the effect of different pore-widening treatments on the quality of the pores of the AAO templates prepared with different electrolytes were inspected. Results confirmed that, without altering the interpore distance different pore dimensions and diameters of the AAO templates can be easily achieved by chemical pore widening process at room temperature. Also, graphitic carbon nitride nanorods of different dimension have been fabricated from AAO template after porewidening process. These nanostructures are widely used in case of metal free visible light driven photo catalysis, photo degradation of organic pollutants, photo electric conversion and water splitting applications.

Facile and low temperature route to synthesis of CuS nanostructure in mesoporous material by solvothermal method.

Science.gov (United States)

Sohrabnezhad, Sh; Zanjanchi, M A; Hosseingholizadeh, S; Rahnama, R

2014-04-05

The synthesis of CuS nanomaterial in MCM-41 matrix has been realized by chemical synthesis between MCM-41, copper sulfate pentahydrate and thiourea via a solvothermal method in ethylene glycol and water, separately. X-ray diffraction analysis (XRD), diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and fourier transform infrared (FT-IR) were used to characterize the products. At synthesized CuS/MCM-41 sample in ethylene glycol, X-ray diffraction and diffuse reflectance spectroscopy showed pure covellite phase of copper sulfide with high crystality. But prepared CuS/MCM-41 sample in water shows the covellite, chalcocite and the djurleite phase of copper sulfide nanostructures. The formation of CuS nanostructures was confirmed by FT-IR. Photocatalytic activity of CuS/MCM-41 nanocomposites was studied for degradation of Methylene Blue (MB) under visible light. The CuS/MCM-41 nanocomposite is more effective nanocatalyst than synthesized CuS/MCM-41 sample in water for degradation of methylene blue. Several parameters were examined, catalyst amount (0.1-1gL(-1)), pH (1-13) and initial concentration of MB (0.96-10ppm). The extent of degradation was estimated from the residual concentration by spectrophotometrically. The support size was obtained in the range 60-145nm by TEM. In the same way, the average size of copper sulfide in CuSMCM-41E and CuS/MCM-41W nanostructures were obtained about 10nm and 16nm, respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

Preparation and thermoelectric properties of sulfur doped Ag2Te nanoparticles via solvothermal methods.

Science.gov (United States)

Zhou, Wenwen; Zhao, Weiyun; Lu, Ziyang; Zhu, Jixin; Fan, Shufen; Ma, Jan; Hng, Huey Hoon; Yan, Qingyu

2012-07-07

In this work, n-type Ag(2)Te nanoparticles are prepared by a solvothermal approach with uniform and controllable sizes, e.g. 5-15 nm. The usage of dodecanethiol during the synthesis effectively introduces sulfur doping into the sample, which optimizes the charge carrier concentration of the nanoparticles to >1 × 10(20) cm(-3). This allows us to achieve the desired electrical resistivities of nanoparticles with effective sulphur doping show a maximum ZT value of ~0.62 at 550 K.

The role anions on the synthesis of AlOOH nanoparticles using simple solvothermal method

Directory of Open Access Journals (Sweden)

Mozaffar Abdollahifar

2018-03-01

Full Text Available Effect of aluminium salts on the synthesis of AlOOH nanostructures has been successfully investigated in detail using solvothermal method, when ethanol and NaOH are solvent and pH adjusting agent, respectively. Fourier transform infrared spectroscopy (FTIR, X-ray powder diffraction (XRD, and field emission scanning electron microscopy (FESEM, were used to characterize the synthesized samples. The specific surface area, pore size distribution and pore structure of the different AlOOH structures were also discussed by the N2 adsorption/desorption test. According to our experimental results, the structure characterization revealed that for synthesized AlOOH nanostructures no obvious XRD peaks arising from other phases of alumina are found indicating pure AlOOH phase of products. Furthermore, the nitrogen adsorption and desorption measurements indicated that the obtained AlOOH nanoparticles from aluminium chloride at basic condition possess a high BET surface area of approximately 90 m2/g. Resumen: El efecto de las sales de aluminio sobre la síntesis de las nanoestructuras de AlOOH ha sido analizado en detalle satisfactoriamente usando el método solvotérmico, cuando el etanol y el NaOH son el disolvente y el agente de regulación del pH, respectivamente. Para clasificar las muestras sintetizadas se utilizaron la espectroscopia infrarroja por transformada de Fourier (FTIR, difracción de rayos X por polvo (XRD y microscopia electrónica de barrido de emisión de campo (FESEM. El área superficial específica, la distribución del tamaño del poro y la estructura de poros de las diferentes estructuras de AlOOH también se debatieron mediante la prueba de adsorción/desorción de N2. De acuerdo con nuestros resultados experimentales, la clasificación de la estructura reveló que en las nanoestructuras de AlOOH sintetizadas no se observan picos XRD evidentes derivados de otras fases de la alúmina que indican la fase pura de AlOOH de los productos

One-step solvothermal synthesis, a worm-shaped morphology and luminescence properties of green-emitting Y2O2S:Tb3+ nanophosphors

Science.gov (United States)

Liu, Fan; Lian, Jingbao; Wu, Nianchu; He, Jiao; Zhang, Xue; Liu, Feng

2018-02-01

The worm-shaped Y2O2S:Tb3+ nanophosphors have been successfully prepared via one-step solvothermal synthesis, using ethanediamine as the main solvent and sublimed sulfur powder as the source of sulfur without adding additional structure-directing reagents. XRD, FT-IR, FESEM, PL and CIE chromaticity diagram were used to characterize the obtained products. XRD results demonstrate that all diffraction peaks of the sample can be well indexed to pure hexagonal phase of Y2O2S with optimal condition, i.e. the molar ration of S/Y3+m = 10, solvothermal temperature T = 220 °C and synthetic time t = 24 h. When t varies from 2 h to 24 h, the morphology of Y2O2S transforms from cauliflower-like structure to worm-shaped nanoparticles with the length of ∼80 nm. The formation mechanism depending on t has also been proposed. Upon 250 nm ultraviolet (UV) light excitation, the worm-shaped Y2O2S:Tb3+ nanophosphors exhibit green emissions, corresponding to the 5D4 → 7FJ (J = 6, 5, 4, 3) transitions of Tb3+ions. The quenching concentration is 7% and its corresponding lifetime is 1216 μs. The CIE chromaticity coordinates show the tuneable emission shifting from yellow green to yellowish green with increasing concentration of Tb3+ions from 1% to 7%. Those results suggest that the worm-shaped Y2O2S:Tb3+ nanophosphors may have potential applications in X-ray intensifying screens, fluorescence and biomedical fields.

Replisome-mediated Translesion Synthesis and Leading Strand Template Lesion Skipping Are Competing Bypass Mechanisms*

Science.gov (United States)

Gabbai, Carolina B.; Yeeles, Joseph T. P.; Marians, Kenneth J.

2014-01-01

A number of different enzymatic pathways have evolved to ensure that DNA replication can proceed past template base damage. These pathways include lesion skipping by the replisome, replication fork regression followed by either correction of the damage and origin-independent replication restart or homologous recombination-mediated restart of replication downstream of the lesion, and bypass of the damage by a translesion synthesis DNA polymerase. We report here that of two translesion synthesis polymerases tested, only DNA polymerase IV, not DNA polymerase II, could engage productively with the Escherichia coli replisome to bypass leading strand template damage, despite the fact that both enzymes are shown to be interacting with the replicase. Inactivation of the 3′ → 5′ proofreading exonuclease of DNA polymerase II did not enable bypass. Bypass by DNA polymerase IV required its ability to interact with the β clamp and act as a translesion polymerase but did not require its “little finger” domain, a secondary region of interaction with the β clamp. Bypass by DNA polymerase IV came at the expense of the inherent leading strand lesion skipping activity of the replisome, indicating that they are competing reactions. PMID:25301949

Scalable and template-free synthesis of nanostructured Na{sub 1.08}V{sub 6}O{sub 15} as high-performance cathode material for lithium-ion batteries

Energy Technology Data Exchange (ETDEWEB)

Zheng, Shili, E-mail: slzheng@ipe.ac.cn [National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing (China); Wang, Xinran; Yan, Hong [National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing (China); University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing (China); Du, Hao; Zhang, Yi [National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing (China)

2016-09-15

Highlights: • Nanostructured Na{sub 1.08}V{sub 6}O{sub 15} was synthesized through additive-free sol-gel process. • Prepared Na{sub 1.08}V{sub 6}O{sub 15} demonstrated high capacity and sufficient cycling stability. • The reaction temperature was optimized to allow scalable Na{sub 1.08}V{sub 6}O{sub 15} fabrication. - Abstract: Developing high-capacity cathode material with feasibility and scalability is still challenging for lithium-ion batteries (LIBs). In this study, a high-capacity ternary sodium vanadate compound, nanostructured NaV{sub 6}O{sub 15}, was template-free synthesized through sol-gel process with high producing efficiency. The as-prepared sample was systematically post-treated at different temperature and the post-annealing temperature was found to determine the cycling stability and capacity of NaV{sub 6}O{sub 15}. The well-crystallized one exhibited good electrochemical performance with a high specific capacity of 302 mAh g{sup −1} when cycled at current density of 0.03 mA g{sup −1}. Its relatively long-term cycling stability was characterized by the cell performance under the current density of 1 A g{sup −1}, delivering a reversible capacity of 118 mAh g{sup −1} after 300 cycles with 79% capacity retention and nearly 100% coulombic efficiency: all demonstrating its significant promise of proposed strategy for large-scale synthesis of NaV{sub 6}O{sub 15} as cathode with high-capacity and high energy density for LIBs.

Conformational Sampling in Template-Free Protein Loop Structure Modeling: An Overview

OpenAIRE

Li, Yaohang

2013-01-01

Accurately modeling protein loops is an important step to predict three-dimensional structures as well as to understand functions of many proteins. Because of their high flexibility, modeling the three-dimensional structures of loops is difficult and is usually treated as a “mini protein folding problem” under geometric constraints. In the past decade, there has been remarkable progress in template-free loop structure modeling due to advances of computational methods as well as stably increas...

Novelty of Dynamic Process in the Synthesis of Biocompatible Silica Nanotubes by Biomimetic Glycyldodecylamide as a Soft Template.

Science.gov (United States)

Choi, Hyejung; Kim, Joong-Jo; Mo, Yong-Hwan; Reddy, Benjaram M; Park, Sang-Eon

2017-10-10

A dynamic process in the synthesis of silica nanotubes (SNTs) by utilizing glycyldodecylamide (GDA) as a soft template was thoroughly investigated. The morphological evolution from GDA to SNTs was deeply explored to elucidate the formation mechanism for optimizing the synthesis procedure. Various analytical tools, namely, XRD, FTIR, SEM, TEM, Z-potential, and N 2 adsorption/desorption isotherms, were employed during the synthesis procedure. The interactive structure of GDA was also investigated using TEM-EDX as a function of aging time. These studies revealed the stepwise morphology of nanograin, nanofiber, curved plate, and nanotube in the ethanol/water solution when aged at room temperature. The supramolecular GDA molded the vesicle type nanostructure which was surrounded by silica and facilitated the formation of uniform SNTs. The stimulus for GDA to be curved into a vesicle was the intermolecular hydrogen bonding between adjacent amide groups of the template molecules. This was illustrated by FTIR spectra of GDA-silica intermediate by detecting the transition of amide I peak from 1678 to 1635 cm -1 . The effect of hydrogen bonding became stronger when the sample was aged.

Phase controlled solvothermal synthesis of Cu_2ZnSnS_4, Cu_2ZnSn(S,Se)_4 and Cu_2ZnSnSe_4 Nanocrystals: The effect of Se and S sources on phase purity

International Nuclear Information System (INIS)

Pal, Mou; Mathews, N.R.; Paraguay-Delgado, F.; Mathew, X.

2015-01-01

In this study, we have reported the synthesis of Cu_2ZnSnSe_4 (CZTSe), Cu_2ZnSnS_4 (CZTS) and Cu_2ZnSn(S,Se)_4 (CZTSSe) nanocrystals with tunable band gap and composition obtained by solvothermal method. The crystalline structure, composition, morphology and optical properties of the nanoparticles were characterized by X-ray diffraction (XRD), Raman scattering, energy dispersive X-ray spectroscopy, transmission electron microscopy and diffuse reflectance (DR) spectroscopy. While the XRD patterns of CZTS and CZTSe nanoparticles prepared with elemental S/Se powder revealed the presence of phase pure nanoparticles, the CZTSSe nanoparticles obtained using a mixture of S and Se, were found to contain many secondary phases under the same synthesis protocol. Formation of impurity phases in CZTSSe sample, can be avoided by using a mixture of 1-dodecanethiol (DT; CH_3(CH_2)_1_1SH)/oleylamine (OLA) instead of S powder and following the same experimental procedure. The incorporation of S in CZTSe nanocrystals prepared in presence of DDT/OLA mixture was confirmed through structural and optical characterizations. The optical properties of the quaternary chalcogenide nanocrystals were found to vary with the chemical composition of the material. - Highlights: • Solvothermal synthesis of CZTS, CZTSSe and CZTSe nanocrystals and discussion on possible formation mechanism. • Use of dodecanethiol/oleylamine mixture to synthesize phase-pure CZTSSe nanocrystals. • Formation of impurity phases can be controlled with proper S and Se sources.

Innovative synthesis of meso-structured YSZ using V2O5 complex fluids as a template

International Nuclear Information System (INIS)

Guiot, Camille; Grandjean, Stephane; Batail, Patrick

2008-01-01

Full text of publication follows: Within the framework of generation IV nuclear reactors, the prospect of a closed fuel cycle generate a need for new advanced materials integrating the actinides jointly. Researches are conducted on fuel material precursors synthesized by soft chemistry processes, which allow a fine control of the homogeneity and ordering at a nano-scale[1]. In a view to meso-structure an inorganic matrix, recent studies[2,3] have highlighted the potential of mineral liquid crystals as templates in new soft chemistry synthesis routes. The studies presently exposed relate to an original synthesis of an inorganic-inorganic hybrid material consisting in a main zirconia matrix tem plated by ribbon-like vanadium pentoxide. After eliminating the V 2 O 5 template, the obtained solid is to be a meso-porous material with ordered pores, and becomes a prime choice material, for example to immobilize actinides. The zirconia matrix has been chosen for its ability to host actinides, which are surrogated by neodymium. It is also a preliminary material for the study of the synthesis of uranium oxide based materials, thus preventing from the drawbacks of working with radioactive materials. The vanadium pentoxide is used as a template since it structure itself as ribbon-like mineral liquid crystals that can be aligned in weak magnetic field; consequently, the final material may be structured at a nano-scale over a macroscopic range. Since the shape of vanadium oxide in solution is very sensitive to the ionic strength of the medium and the pH, the real challenge is to establish a synthesis protocol which is compatible with the presence of vanadium pentoxide, remaining in its ribbon-like liquid crystal form. References: [1] Masson, M.; Grandjean, S.; Lacquement, J.; Bourg, S.; Delauzun, J. M.; Lacombe, J.; Nuclear Engineering and Design, 236 (5-6),516 (2006). [2] Camerel, F.; Gabriel, J.-C.P.; Batail, P.; Adv. Funct. Mater., 13 (5), 377 (2003). [3] Gabriel, J

Facile Solvothermal Synthesis of BiOCl/ZnO Heterostructures with Enhanced Photocatalytic Activity

Directory of Open Access Journals (Sweden)

Yong-Fang Li

2014-01-01

Full Text Available Well-defined nanosheet-assembled (BiOClx(ZnO1−x nanoflowers were synthesized by a solvothermal method. It was found that ZnO nanoparticles were anchored on the flower-like BiOCl nanostructures, as demonstrated by varying the initial compositions of the Bi precursor and the volume ratios of mixed solvents (ethylene glycol to water. The as-prepared (BiOCl0.6(ZnO0.4 nanocomposites showed enhanced photocatalytic activity toward rhodamine B degradation under ultraviolet (UV irradiation. And the photocatalytic mechanism was discussed in detail.

From dihydrated iron(III) phosphate to monohydrated ammonium-iron(II) phosphate: Solvothermal reaction mediated by acetone-urea mixtures

Energy Technology Data Exchange (ETDEWEB)

Alfonso, Belen F., E-mail: mbafernandez@uniovi.es [Departamento de Fisica, Universidad de Oviedo, Calvo Sotelo, s/n 33007 Oviedo (Spain); Trobajo, Camino [Departamento de Quimica Organica e Inorganica, Universidad de Oviedo-CINN, Julian Claveria 8, 33006 Oviedo (Spain); Pique, Carmen [Departamento de Fisica, Universidad de Oviedo, Calvo Sotelo, s/n 33007 Oviedo (Spain); Garcia, Jose R. [Departamento de Quimica Organica e Inorganica, Universidad de Oviedo-CINN, Julian Claveria 8, 33006 Oviedo (Spain); Blanco, Jesus A. [Departamento de Fisica, Universidad de Oviedo, Calvo Sotelo, s/n 33007 Oviedo (Spain)

2012-12-15

By reaction between synthetic phosphosiderite FePO{sub 4}{center_dot}2H{sub 2}O, urea (NH{sub 2}){sub 2}CO, and acetone (CH{sub 3}){sub 2}CO, we report a novel solvothermal synthesis of polycrystalline NH{sub 4}FePO{sub 4}{center_dot}H{sub 2}O. The preparation of other two individual phases, NH{sub 4}Fe{sub 2}(OH)(PO{sub 4}){sub 2}{center_dot}2H{sub 2}O and NH{sub 4}Fe{sub 2}(PO{sub 4}){sub 2}, is also described. The obtained product is a function of the reaction time and the N/P molar ratio in the reagent mixture, and the existence of structural memory in the dissolution-precipitation processes is discussed. Below 25 K, NH{sub 4}FePO{sub 4}{center_dot}H{sub 2}O behaves magnetically in a complex way, because both ferromagnetic and antiferromagnetic signals are superimposed, suggesting the existence of a canting of iron(II) magnetic moments. - Graphical abstract: Solvothermal synthesis of polycrystalline NH{sub 4}FePO{sub 4}{center_dot}H{sub 2}O is presented. The preparation of other two individual phases, NH{sub 4}Fe{sub 2}(OH)(PO{sub 4}){sub 2}{center_dot}2H{sub 2}O and NH{sub 4}Fe{sub 2}(PO{sub 4}){sub 2} as a function of the N/P molar ratio in the reagent mixture and the reaction time, is also described. Highlights: Black-Right-Pointing-Pointer Solvothermal synthesis of NH{sub 4}FePO{sub 4}{center_dot}H{sub 2}O from an Fe(III) phosphate: reduction process. Black-Right-Pointing-Pointer Formation of two intermediate metastable phases: phase diagram. Black-Right-Pointing-Pointer Thermal decomposition in two steps: mass loss of both water and ammonia. Black-Right-Pointing-Pointer Magnetic behaviour: AF+constant spontaneous magnetization.

Solvothermal synthesis and enhanced CO2 adsorption ability of mesoporous graphene oxide-ZnO nanocomposite

International Nuclear Information System (INIS)

Li, Weidong; Jiang, Xia; Yang, Huayun; Liu, Qi

2015-01-01

Highlights: • GO–ZnO nanocomposite was prepared by solvothermal method. • Several technologies have been used to ensure and analyze the composite. • GO–ZnO has CO 2 adsorption capacity of up to 44.8 cm 3 /g at 298 K and 1 bar. • The composite has excellent adsorption/desorption recycling ability. - Abstract: Mesoporous graphene oxide–ZnO (GO–ZnO) nanocomposite has been synthesized by GO and ZnO which was prepared by solvothermal method. Power X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) have been used to characterize the structure and morphology of the porous GO–ZnO hybrid. With visible porosity of ZnO and GO–ZnO, N 2 adsorption–desorption measurements and pore size analysis have been investigated and compared. Comparing to ZnO, GO–ZnO showed larger Brunauer–Emmett–Teller (BET) surface area and enhanced ability on capturing CO 2 at different temperatures. Several cycles of adsorption–desorption experiments on CO 2 have been tested and it proved GO–ZnO to be potential adsorbent material with excellent cycling stability.

Templated electrodeposition of functional nanostructures: nanowires, nanotubes and nanocubes

NARCIS (Netherlands)

Maijenburg, A.W.

2014-01-01

This thesis is entitled “Templated electrodeposition of functional nanostructures: nanowires, nanotubes and nanocubes”. Templated electrodeposition is the synthesis technique that was used throughout this thesis, and it comprises the use of a template with specific shape and dimensions for the

Synthesis of Hybrid Conducting Nanowire Using AAO Template

Science.gov (United States)

2006-09-28

oxide and alujminum oxide in anodized aluminum oxide ( AAO ) template with various aspect ratio and...than 3 nm. 2. Experimentals Anodized aluminum oxide ( AAO ) template was prepared from 99.999% purity aluminum foil by performing the following...to prepare uniform dimension of nanomaterials is to use anodized alumina membrane as template. The work emphasized self-organized arrangement of

Preparation of micro/nanostructure TiO2 spheres by controlling pollen as hard template and soft template.

Science.gov (United States)

Yang, Xiaohui; Xu, Bin; Zhang, Xuehong; Song, Xiuqin; Chen, Rufen

2014-09-01

In this paper, micro/nanostructure TiO2 spheres were synthesized by a sunflower pollen induced and self-assembly mineralization process, in which a titania precursor and pollen reacted in one-pot at normal pressure. In this paper, the bio-template advantage, as hard and soft template is fully demonstrated. The superiority of our synthesis is that we not only can control pollen as hard template, but also can control it as soft template only by changing reactions temperature. Under 80 degrees C of water bath, TiO2 microspheres which replicated the morphology of pollen were prepared by controlling pollen as hard template. Under 100 degrees C, hierarchical TiO2 spheres with complicated morphology, different from pollen template, were synthesized by using pollen as soft template. At the same time, judicious choice of the amount of pollen affords the synthesis of hierarchical structures spheres with adjustable morphology and crystal structure. The morphology can be tuned from microspheres constructed from TiO2 nanorods to nanospheres constructed from TiO2 nanoparticles, and the crystal structure can be tuned from rutile to anatase. More over this anatase phase can be keep better even at high temperature of 1000 degrees C. The as-prepared micro/nano structure photocatalysts not only have high photocatalytic activities, but also have good separability and reuse performance.

Facile and efficient one-pot solvothermal and microwave-assisted synthesis of stable colloidal solutions of MFe2O4 spinel magnetic nanoparticles

International Nuclear Information System (INIS)

Solano, Eduardo; Perez-Mirabet, Leonardo; Martinez-Julian, Fernando; Guzmán, Roger; Arbiol, Jordi; Puig, Teresa; Obradors, Xavier; Yañez, Ramón; Pomar, Alberto; Ricart, Susagna; Ros, Josep

2012-01-01

Well-defined synthesis conditions of high quality MFe 2 O 4 (M = Mn, Fe, Co, Ni, Zn, and Cu) spinel ferrite magnetic nanoparticles, with diameters below 10 nm, have been described based on facile and efficient one-pot solvothermal or microwave-assisted heating procedures. Both methods are reproducible and scalable and allow forming concentrated stable colloidal solutions in polar solvents, but microwave-assisted heating allows reducing 15 times the required annealing time and leads to an enhanced monodispersity of the nanoparticles. Non-agglomerated nanoparticles dispersions have been achieved using a simple one-pot approach where a single compound, triethyleneglycol, behaves at the same time as solvent and capping ligand. A narrow nanoparticle size distribution and high quality crystallinity have been achieved through selected nucleation and growth conditions. High resolution transmission electron microscopy images and electron energy loss spectroscopy analysis confirm the expected structure and composition and show that similar crystal faceting has been formed in both synthetic approaches. The spinel nanoparticles behave as ferrimagnets with a high saturation magnetization and are superparamagnetic at room temperature. The influence of synthesis route on phase purity and unconventional magnetic properties is discussed in some particular cases such as CuFe 2 O 4 , CoFe 2 O 4 , and ZnFe 2 O 4 .

A reproducible and scalable procedure for preparing bacterial extracts for cell-free protein synthesis.

Science.gov (United States)

Katsura, Kazushige; Matsuda, Takayoshi; Tomabechi, Yuri; Yonemochi, Mayumi; Hanada, Kazuharu; Ohsawa, Noboru; Sakamoto, Kensaku; Takemoto, Chie; Shirouzu, Mikako

2017-11-01

Cell-free protein synthesis is a useful method for preparing proteins for functional or structural analyses. However, batch-to-batch variability with regard to protein synthesis activity remains a problem for large-scale production of cell extract in the laboratory. To address this issue, we have developed a novel procedure for large-scale preparation of bacterial cell extract with high protein synthesis activity. The developed procedure comprises cell cultivation using a fermentor, harvesting and washing of cells by tangential flow filtration, cell disruption with high-pressure homogenizer and continuous diafiltration. By optimizing and combining these methods, ∼100 ml of the cell extract was prepared from 150 g of Escherichia coli cells. The protein synthesis activities, defined as the yield of protein per unit of absorbance at 260 nm of the cell extract, were shown to be reproducible, and the average activity of several batches was twice that obtained using a previously reported method. In addition, combinatorial use of the high-pressure homogenizer and diafiltration increased the scalability, indicating that the cell concentration at disruption varies from 0.04 to 1 g/ml. Furthermore, addition of Gam protein and examinations of the N-terminal sequence rendered the extract prepared here useful for rapid screening with linear DNA templates. © The Authors 2017. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

Solvothermal tuning of photoluminescent graphene quantum dots: from preparation to photoluminescence mechanism

Science.gov (United States)

Qi, Bao-Ping; Zhang, Xiaoru; Shang, Bing-Bing; Xiang, Dongshan; Zhang, Shenghui

2018-02-01

Solvothermal synthesis was employed to tune the surface states of graphene quantum dots (GQDs). Two series of GQDs with the particle sizes from 2.6 to 4.5 nm were prepared as follows: (I) GQDs with the same size but different oxygen degrees; (II) GQDs with different core sizes but the similar surface chemistry. Both the large sizes and the high surface oxidation degrees led to the redshift photoluminescence (PL) of GQDs. Electrochemiluminescence (ECL) spectra from two series of GQDs were all in accordance with their PL spectra, respectively, which provided good evidence for the conjugated structures in GQDs responsible for PL. [Figure not available: see fulltext.

Durability of template-free Fe-N-C foams for electrochemical oxygen reduction in alkaline solution

Science.gov (United States)

Mufundirwa, Albert; Harrington, George F.; Smid, Břetislav; Cunning, Benjamin V.; Sasaki, Kazunari; Lyth, Stephen M.

2018-01-01

Due to the high cost and limited availability of platinum, the development of non-platinum-group metals (non-PGM) catalysts is of paramount importance. A promising alternative to Pt are Fe-N-C-based materials. Here we present the synthesis, characterization and electrochemistry of a template-free nitrogen-doped carbon foam, impregnated with iron. This low-cost and gram-scale method results in materials with micron-scale pore size and large surface area (1600 m2g-1). When applied as an oxygen reduction reaction (ORR) electrocatalyst in alkaline solution, the Fe-N-C foams display extremely high initial activity, slightly out-performing commercially available non-PGM catalysts (NCP-2000, Pajarito Powder). The load-cycle durability in alkaline solution is investigated, and the performance steadily degrades over 60,000 potential cycles, whilst the commercial catalyst is remarkably stable. The post-operation catalyst microstructure is elucidated by transmission electron microscopy (TEM), to provide insight into the degradation processes. The resulting images suggest that potential cycling leads to leaching of atomically dispersed Fe-N2/4 sites in all the catalysts, whereas encapsulated iron nanoparticles are protected.

Self-templated synthesis of single-crystal and single-domain ferroelectric nanoplates

KAUST Repository

Chao, Chunying

2012-08-15

Free-standing single-crystal PbTiO 3 nanoplates (see picture) were synthesized by a facile hydrothermal method. A "self-templated" crystal growth is presumed to lead to the formation of the PbTiO 3 nanoplates, which have ferroelectric single-domain structures, whose polarization areas can be manipulated by writing and reading. The nanoplates are also effective catalysts for the oxidation of carbon monoxide. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Controlled synthesis of ZnO hollow microspheres via precursor-template method and its gas sensing property

International Nuclear Information System (INIS)

Tian, Yu; Li, Jinchai; Xiong, Hui; Dai, Jiangnan

2012-01-01

Highlights: ► Zn powder as precursor template for synthesis ZnO hollow spheres. ► Different precursor templates result in different ZnO nanostructures. ► Different experimental conditions enable growth of different surface morphologies of ZnO sphere. ► ZnO hollow sphere materials have good gas sensing performance for detecting ethanol gas. - Abstract: Using Zn powder as precursor templates, ZnO hollow microspheres were successfully prepared by thermal evaporation method and characterized by X-ray diffraction analysis, scanning electron microscope and transmission electron microscope. It was found that different size and shape of precursor resulted in different ZnO nanostructures. When varying experimental conditions, such as air flow rate and working pressure, ZnO hollow spheres with different surface morphologies could be obtained. The advantages of the present synthetic technology are simple, relatively low cost, and high reproducibility. A gas sensor was fabricated from the as-prepared ZnO hollow microspheres and tested to the ethanol gas at different operating temperatures.

One-step synthesis and antibacterial property of water-soluble silver nanoparticles by CGJ bio-template

International Nuclear Information System (INIS)

Zhu Zichun; Wu Qingsheng; Chen Ping; Yang Xiaohong

2011-01-01

In this article, a new synthetic method of nanoparticles with fresh Chinese gooseberry juice (CGJ) as bio-template was developed. One-step synthesis of highly water-soluble silver nanoparticles at room temperature without using any harmful reducing agents and special capping agent was fulfilled with this method. In the process, the products were obtained by adding AgNO 3 to CGJ, which was used as reducing agent, capping agent, and the bio-template. The products of silver nanoparticles with diameter of 10–30 nm have strong water solubility and excellent antibiotic function. With the same concentration 0.047 μg mL −1 , the antibacterial effect of water-soluble silver particles by fresh CGJ was 53%, whereas only 27% for silver nanoparticles synthesized using the template method of fresh onion inner squama coat (OISC). The excellent water solubility of the products would enable them have better applications in the bio-medical field. The synthetic method would also have potential application in preparing other highly water-soluble particles, because of its simple apparatus, high yield, mild conditions, and facile operation.

Structural and optical characterization of CdS nanorods synthesized by a PVA-assisted solvothermal method

International Nuclear Information System (INIS)

Wang Hongmei; Fang Pengfei; Chen Zhe; Wang Shaojie

2008-01-01

Cadmium sulphide (CdS) 1D nanocrystals were prepared using a simple poly(vinyl-alcohol) (PVA)-assisted solvothermal method which employed ethylenediamine (en) as solvent. The obtained nanorods were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), ultraviolet-visible (UV-vis) absorption, and photoluminescence (PL) spectra. XRD results show that the nanorods are hexagonal phase. The TEM results indicate that the synthesized CdS nanorods with PVA-assisted showed larger aspect ratio and uniform faces compared with the sample prepared in the absence of PVA. The results of the photoluminescence and UV-vis spectroscopy measurements reveal that the as-prepared CdS nanorods show a quantum confinement effect. It is also found that the dosage of PVA is a vital factor in the morphology and optical properties of CdS nanorods. Moreover, when the best dosage of 3 g PVA/70 ml en was used, CdS nanorods with regular morphology and longer length were obtained. The probable mechanism for PVA-assisted solvothermal synthesis of CdS nanorods was also discussed

Indium telluride nanotubes: Solvothermal synthesis, growth mechanism, and properties

Energy Technology Data Exchange (ETDEWEB)

Zhou, Liyan [National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China); Yan, Shancheng, E-mail: yansc@njupt.edu.cn [National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China); School of Geography and Biological Information, Nanjing University of Posts and Telecommunications, Nanjing 210046 (China); Lu, Tao; Shi, Yi; Wang, Jianyu [National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China); Yang, Fan [School of Geography and Biological Information, Nanjing University of Posts and Telecommunications, Nanjing 210046 (China)

2014-03-15

A convenient solvothermal approach was applied for the first time to synthesize In{sub 2}Te{sub 3} nanotubes. The morphology of the resultant nanotubes was studied by scanning electron microscopy and transmission electron microscopy. Nanotubes with a relatively uniform diameter of around 500 nm, tube wall thickness of 50–100 nm, and average length of tens of microns were obtained. X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy were used to study the crystal structures, composition, and optical properties of the products. To understand the growth mechanism of the In{sub 2}Te{sub 3} nanotubes, we studied the influences of temperature, reaction time, and polyvinylpyrrolidone (PVP) and ethylene diamine (EDA) dosages on the final products. Based on the experimental results, a possible growth mechanism of In{sub 2}Te{sub 3} nanotubes was proposed. In this mechanism, TeO{sub 3}{sup −2} is first reduced to allow nucleation. Circumferential edges of these nucleated molecules attract further deposition, and nanotubes finally grow rapidly along the c-axis and relatively slowly along the circumferential direction. The surface area of the products was determined by BET and found to be 137.85 m{sup 2} g{sup −1}. This large surface area indicates that the nanotubes may be suitable for gas sensing and hydrogen storage applications. The nanotubes also showed broad light detection ranging from 300 nm to 1100 nm, which covers the UV–visible–NIR regions. Such excellent optical properties indicate that In{sub 2}Te{sub 3} nanotubes may enable significant advancements in new photodetection and photosensing applications. -- Graphical abstract: A convenient solvothermal approach was applied to synthesize In{sub 2}Te{sub 3} nanotubes, which has not been reported in the literature for our knowledge. Surface area of this material is 137.85 m{sup 2} g{sup −1} from the BET testing, and such a high value makes it probably suitable for gas sensing and

Template-directed synthesis of nets based upon octahemioctahedral cages that encapsulate catalytically active metalloporphyrins

KAUST Repository

Zhang, ZhenJie

2012-01-18

meso-Tetra(N-methyl-4-pyridyl)porphine tetratosylate (TMPyP) templates the synthesis of six new metal-organic materials by the reaction of benzene-1,3,5-tricarboxylate with transition metals, five of which exhibit HKUST-1 or tbo topology (M = Fe, Mn, Co, Ni, Mg). The resulting materials, porph@MOMs, selectively encapsulate the corresponding metalloporphyrins in octahemioctahedral cages and can serve as size-selective heterogeneous catalysts for oxidation of olefins. © 2011 American Chemical Society.

Template-directed synthesis of nets based upon octahemioctahedral cages that encapsulate catalytically active metalloporphyrins

KAUST Repository

Zhang, ZhenJie; Zhang, Linping; Wojtas, Łukasz; Eddaoudi, Mohamed; Zaworotko, Michael J.

2012-01-01

meso-Tetra(N-methyl-4-pyridyl)porphine tetratosylate (TMPyP) templates the synthesis of six new metal-organic materials by the reaction of benzene-1,3,5-tricarboxylate with transition metals, five of which exhibit HKUST-1 or tbo topology (M = Fe, Mn, Co, Ni, Mg). The resulting materials, porph@MOMs, selectively encapsulate the corresponding metalloporphyrins in octahemioctahedral cages and can serve as size-selective heterogeneous catalysts for oxidation of olefins. © 2011 American Chemical Society.

Synthesis of Nickel Oxide Nanoparticles Using Gelatine as a Green Template for Photocatalytic Degradation of Dye

OpenAIRE

JAY YANG LEE

2018-01-01

Nickel oxide (NiO) nanoparticles were synthesized through sol-gel method with an environmentally friendly templating agent, which is gelatin. The synthesized NiO were characterized to determine the chemical and physical properties of the nanoparticles. The optimum synthesis parameters were used in photocatalytic degradation of Reactive Black 5 and Acid Yellow 25 dye to determine the catalytic activity of the nanoparticles.

A combined salt-hard templating approach for synthesis of multi-modal porous carbons used for probing the simultaneous effects of porosity and electrode engineering on EDLC performance

KAUST Repository

Bhandari, Nidhi

2015-06-01

A new approach, based on a combination of salt and hard templating for producing multi-modal porous carbons is demonstrated. The hard template, silica nanoparticles, generate mesopores (∼22 nm), and in some cases borderline-macropores (∼64 nm), resulting in high pore volume (∼3.9 cm3/g) while the salt template, zinc chloride, generates borderline-mesopores (∼2 nm), thus imparting high surface area (∼2100 m2/g). The versatility of the proposed synthesis technique is demonstrated using: (i) dual salt templates with hard template resulting in magnetic, nanostructured-clay embedded (∼27% clay content), high surface area (∼1527 m2/g) bimodal carbons (∼2 and 70 nm pores), (ii) multiple hard templates with salt template resulting in tri-modal carbons (∼2, 12 and 28 nm pores), (iii) low temperature (450 °C) synthesis of bimodal carbons afforded by the presence of hygroscopic salt template, (iv) easy coupling with physical activation approaches. A selected set of thus synthesized carbons were used to evaluate, for the first time, the simultaneous effects of carbon porosity and pressure applied during electrode fabrication on EDLC performance. Electrode pressing was found to be more favorable for carbons containing hard-templated mesopores (∼87% capacitance retention at current density of 40 A/g) as compared to those without (∼54% capacitance retention). © 2015 Elsevier Ltd. All rights reserved.

Enhanced photocatalytic CO₂-reduction activity of electrospun mesoporous TiO₂ nanofibers by solvothermal treatment.

Science.gov (United States)

Fu, Junwei; Cao, Shaowen; Yu, Jiaguo; Low, Jingxiang; Lei, Yongpeng

2014-06-28

Photocatalytic reduction of CO2 into renewable hydrocarbon fuels using semiconductor photocatalysts is considered as a potential solution to the energy deficiency and greenhouse effect. In this work, mesoporous TiO2 nanofibers with high specific surface areas and abundant surface hydroxyl groups are prepared using an electrospinning strategy combined with a subsequent calcination process, followed by a solvothermal treatment. The solvothermally treated mesoporous TiO2 nanofibers exhibit excellent photocatalytic performance on CO2 reduction into hydrocarbon fuels. The significantly improved photocatalytic activity can be attributed to the enhanced CO2 adsorption capacity and the improved charge separation after solvothermal treatment. The highest activity is achieved for the sample with a 2-h solvothermal treatment, showing 6- and 25-fold higher CH4 production rate than those of TiO2 nanofibers without solvothermal treatment and P25, respectively. This work may also provide a prototype for studying the effect of solvothermal treatment on the structure and photocatalytic activity of semiconductor photocatalysts.

Cell-Free, De Nova Synthesis of Poliovirus

Science.gov (United States)

Molla, Akhteruzzaman; Paul, Aniko V.; Wimmer, Eckard

1991-12-01

Cell-free translation of poliovirus RNA in an extract of uninfected human (HeLa) cells yielded viral proteins through proteolysis of the polyprotein. In the extract, newly synthesized proteins catalyzed poliovirus-specific RNA synthesis, and formed infectious poliovirus de novo. Newly formed virions were neutralized by type-specific antiserum, and infection of human cells with them was prevented by poliovirus receptor-specific antibodies. Poliovirus synthesis was increased nearly 70-fold when nucleoside triphosphates were added, but it was abolished in the presence of inhibitors of translation or viral genome replication. The ability to conduct cell-free synthesis of poliovirus will aid in the study of picornavirus proliferation and in the search for the control of picornaviral disease.

In Situ Studies and Magnetic Properties of the Cmcm Polymorph of LiCoPO4 with a Hierarchical Dumbbell-Like Morphology Synthesized by Easy Single-Step Polyol Synthesis

Directory of Open Access Journals (Sweden)

Carlos Alarcón-Suesca

2016-11-01

Full Text Available LiCoPO4 (LCP exists in three different structural modifications: LCP-Pnma (olivine structure, LCP-Pn21a (KNiPO4 structure type, and LCP-Cmcm (Na2CrO4 structure type. The synthesis of the LCP-Cmcm polymorph has been reported via high pressure/temperature solid-state methods and by microwave-assisted solvothermal synthesis. Phase transitions from both LCP-Pn21a and LCP-Cmcm to LCP-Pnma upon heating indicates a metastable behavior. However, a precise study of the structural changes during the heating process and the magnetic properties of LCP-Cmcm are hitherto unknown. Herein, we present the synthesis and characterization of LCP-Cmcm via a rapid and facile soft-chemistry approach using two different kinetically controlled pathways, solvothermal and polyol syntheses, both of which only require relatively low temperatures (~200 °C. Additionally, by polyol, method a dumbbell-like morphology is obtained without the use of any additional surfactant or template. A temperature-dependent in situ powder XRD shows a transition from LCP-Cmcm at room temperature to LCP-Pnma and finally to LCP-Pn21a at 575 and 725 °C, respectively. In addition to that, the determination of the magnetic susceptibility as a function of temperature indicates a long-range antiferromagnetic order below TN = 11 K at 10 kOe and 9.1 K at 25 kOe. The magnetization curves suggests the presence of a metamagnetic transition.

Diamond network: template-free fabrication and properties.

Science.gov (United States)

Zhuang, Hao; Yang, Nianjun; Fu, Haiyuan; Zhang, Lei; Wang, Chun; Huang, Nan; Jiang, Xin

2015-03-11

A porous diamond network with three-dimensionally interconnected pores is of technical importance but difficult to be produced. In this contribution, we demonstrate a simple, controllable, and "template-free" approach to fabricate diamond networks. It combines the deposition of diamond/β-SiC nanocomposite film with a wet-chemical selective etching of the β-SiC phase. The porosity of these networks was tuned from 15 to 68%, determined by the ratio of the β-SiC phase in the composite films. The electrochemical working potential and the reactivity of redox probes on the diamond networks are similar to those of a flat nanocrystalline diamond film, while their surface areas are hundreds of times larger than that of a flat diamond film (e.g., 490-fold enhancement for a 3 μm thick diamond network). The marriage of the unprecedented physical/chemical features of diamond with inherent advantages of the porous structure makes the diamond network a potential candidate for various applications such as water treatment, energy conversion (batteries or fuel cells), and storage (capacitors), as well as electrochemical and biochemical sensing.

Synthesis of Porous Carbon Monoliths Using Hard Templates.

Science.gov (United States)

Klepel, Olaf; Danneberg, Nina; Dräger, Matti; Erlitz, Marcel; Taubert, Michael

2016-03-21

The preparation of porous carbon monoliths with a defined shape via template-assisted routes is reported. Monoliths made from porous concrete and zeolite were each used as the template. The porous concrete-derived carbon monoliths exhibited high gravimetric specific surface areas up to 2000 m²·g -1 . The pore system comprised macro-, meso-, and micropores. These pores were hierarchically arranged. The pore system was created by the complex interplay of the actions of both the template and the activating agent as well. On the other hand, zeolite-made template shapes allowed for the preparation of microporous carbon monoliths with a high volumetric specific surface area. This feature could be beneficial if carbon monoliths must be integrated into technical systems under space-limited conditions.

Morphological evolution of Bi2Se3 nanocrystalline materials synthesized by microwave assisted solvothermal method

Science.gov (United States)

Bera, Sumit; Behera, P.; Mishra, A. K.; Krishnan, M.; Patidar, M. M.; Singh, D.; Gangrade, M.; Venkatesh, R.; Deshpande, U. P.; Phase, D. M.; Ganesan, V.

2018-04-01

Structural, morphological and spectroscopic properties of Bi2Se3 nanoparticles synthesized by microwave assisted solvothermal method were investigated systematically. A controlled synthesis of different morphologies by a small variation in synthesis procedure is demonstrated. Powder X-ray diffraction (XRD) confirmed the formation of single phase. Crystallite and particle size reductions were studied with XRD and AFM (Atomic Force Microscopy). Different morphologies such as hexagonal nanoflakes with cross section of around˜6µm, nanoflower and octahedral agglomerated crystals of nearly ˜60 nm size have been observed in scanning electron microscope while varying the microwave assisted synthesis procedures. A significant blue shift observed in diffuse reflectance spectroscopy evidences the energy gap tuning as a result of morphological evolution. The difference in morphology observed in this three fast, facile and scalable synthesis is advantageous for tuning the thermoelectric figure of merit and for probing the surface states of these topological insulators. Low temperature resistivity remains similar for all three variants depicting a 2D character as evidenced by a -lnT term of localization.

Size-controlled synthesis of gold bipyramids using an aqueous mixture of CTAC and salicylate anions as the soft template.

Science.gov (United States)

Yoo, Hyojong; Jang, Min Hoon

2013-08-07

One-dimensional (1D) gold (Au) bipyramids are successfully synthesized through a facile seed-mediated method using cetyltrimethylammonium chloride (CTAC), Au seed nanoparticles, Ag(+) ions, and ascorbic acid. The length and optical properties of the synthesized Au bipyramids are controlled with precision by varying the amount of salicylate anions (Sal(-)) added during the synthesis. The micelles formed from CTA(+)-Sal(-) mixtures in aqueous solutions act as effective templates for the size-controlled synthesis of 1D nanocrystals.

Assessment of CASP7 structure predictions for template free targets.

Science.gov (United States)

Jauch, Ralf; Yeo, Hock Chuan; Kolatkar, Prasanna R; Clarke, Neil D

2007-01-01

In CASP7, protein structure prediction targets that lacked substantial similarity to a protein in the PDB at the time of assessment were considered to be free modeling targets (FM). We assessed predictions for 14 FM targets as well as four other targets that were deemed to be on the borderline between FM targets and template based modeling targets (TBM/FM). GDT_TS was used as one measure of model quality. Model quality was also assessed by visual inspection. Visual inspection was performed by three independent assessors who were blinded to GDT_TS scores and other quantitative measures of model quality. The best models by visual inspection tended to rank among the top few percent by GDT_TS, but were typically not the highest scoring models. Thus, visual inspection remains an essential component of assessment for FM targets. Overall, group TS020 (Baker) performed best, but success on individual targets was widely distributed among many groups. Among these other groups, TS024 and TS025 (Zhang and Zhang server) performed notably well without exceptionally large computing resources. This should be considered encouraging for future CASPs. There was a sense of progress in template FM relative to CASP6, but we were unable to demonstrate this progress objectively. (c) 2007 Wiley-Liss, Inc.

Solvothermal synthesis and high optical performance of three-dimensional sea-urchin-like TiO2

International Nuclear Information System (INIS)

Zhou, Yi; Wang, Yutang; Li, Mengyao; Li, Xuzhi; Yi, Qin; Deng, Pan; Wu, Hongyan

2015-01-01

Graphical abstract: I–V characteristics of different TiO 2 microspheres based DSSCs (a) 3D sphere-like, (b) 3D flower-like, (c) 3D sea-urchin-like. - Highlights: • 3D sea-urchin-like TiO 2 was synthesized by solvothermal method. • The effects of preparation parameters on the microstructure of the microspheres were investigated. • The photoelectric properties of 3D sea-urchin-like TiO 2 were studied upon DSSCs. • The PCE of the 3D sea-urchin-like TiO 2 was higher than that of other morphologies. - Abstract: Three-dimensional (3D) sea-urchin-like TiO 2 microspheres were successfully synthesised by solvothermal method. The effects of preparation parameters including reaction temperature, concentration and mass fraction of precursor, and solvent volume on the microstructure of the microspheres were investigated. Results of scanning electron microscopy showed that the preparation parameters played a critical role in the morphology of 3D sea-urchin-like TiO 2 . In addition, when the sea-urchin-like TiO 2 nanostructures were used as the dye-sensitized solar cells (DSSCs) anode, the power-conversion efficiency was higher than that of other morphologies, which was due to the special 3D hierarchical nanostructure, large specific surface area, and enhanced absorption of UV–vis of the TiO 2 nanostructures

Structure-directing effects of ionic liquids in the ionothermal synthesis of metal-organic frameworks.

Science.gov (United States)

Vaid, Thomas P; Kelley, Steven P; Rogers, Robin D

2017-07-01

Traditional synthesis of metal-organic frameworks (MOFs) involves the reaction of a metal-containing precursor with an organic linker in an organic solvent at an elevated temperature, in what is termed a 'solvothermal' reaction. More recently, many examples have been reported of MOF synthesis in ionic liquids (ILs), rather than an organic solvent, in 'ionothermal' reactions. The high concentration of both cations and anions in an ionic liquid allows for the formation of new MOF structures in which the IL cation or anion or both are incorporated into the MOF. Most commonly, the IL cation is included in the open cavities of the MOF, countering the anionic charge of the MOF framework itself and acting as a template around which the MOF structure forms. Ionic liquids can also serve other structure-directing roles, for example, when an IL containing a single enantiomer of a chiral anion leads to a homochiral MOF, even though the IL anion is not itself incorporated into the MOF. A comprehensive review of ionothermal syntheses of MOFs, and the structure-directing effects of the ILs, is given.

Synthesis of Mesoporous ?-Fe2O3 Nanoparticles by Non-ionic Soft Template and Their Applications to Heavy Oil Upgrading

OpenAIRE

Park, Chulwoo; Jung, Jinhwan; Lee, Chul Wee; Cho, Joungmo

2016-01-01

This paper reports the synthetic route of 3-D network shape ?-Fe2O3 from aqueous solutions of iron precursor using a non-ionic polymeric soft-template, Pluronic P123. During the synthesis of ?-Fe2O3, particle sizes, crystal phases and morphologies were significantly influenced by pH, concentrations of precursor and template. The unique shape of worm-like hematite was obtained only when a starting solution was prepared by a weakly basic pH condition and a very specific composition of constitue...

POROUS MEMBRANE TEMPLATED SYNTHESIS OF POLYMER PILLARED LAYER

Institute of Scientific and Technical Information of China (English)

Zhong-wei Niu; Dan Li; Zhen-zhong Yang

2003-01-01

The anodic porous alumina membranes with a definite pore diameter and aspect ratio were used as templates to synthesize polymer pillared layer structures. The pillared polymer was produced in the template membrane pores, and the layer on the template surfaces. Rigid cured epoxy resin, polystyrene and soft hydrogel were chosen to confirm the methodology. The pillars were in the form of either tubes or fibers, which were controlled by the alumina membrane pore surface wettability. The structural features were confirmed by scanning electron microscopy results.

Biological Synthesis of Silver Nanoparticles by Cell-Free Extract of Spirulina platensis

Directory of Open Access Journals (Sweden)

Gaurav Sharma

2015-01-01

Full Text Available The present study explores biological synthesis of silver nanoparticles (AgNPs using the cell-free extract of Spirulina platensis. Biosynthesised AgNPs were characterised by UV-Vis spectroscopy, SEM, TEM, and FTIR analysis and finally evaluated for antibacterial activity. Extracellular synthesis using aqueous extract of S. platensis showed the formation of well scattered, highly stable, spherical AgNPs with an average size of 30–50 nm. The size and morphology of the nanoparticles were confirmed by SEM and TEM analysis. FTIR and UV-Vis spectra showed that biomolecules, proteins and peptides, are mainly responsible for the formation and stabilisation of AgNPs. Furthermore, the synthesised nanoparticles exhibited high antibacterial activity against pathogenic Gram-negative, that is, Escherichia coli, MTCC-9721; Proteus vulgaris, MTCC-7299; Klebsiella pneumoniae, MTCC-9751, and Gram-positive, that is, Staphylococcus aureus, MTCC-9542; S. epidermidis, MTCC-2639; Bacillus cereus, MTCC-9017, bacteria. The AgNPs had shown maximum zone of inhibition (ZOI that is 31.3±1.11 in P. vulgaris. Use of such a microalgal system provides a simple, cost-effective alternative template for the biosynthesis of nanomaterials of silver in a large scale that could be of great use in biomedical applications.

LiFePO4 mesocrystals for lithium-ion batteries.

Science.gov (United States)

Popovic, Jelena; Demir-Cakan, Rezan; Tornow, Julian; Morcrette, Mathieu; Su, Dang Sheng; Schlögl, Robert; Antonietti, Markus; Titirici, Maria-Magdalena

2011-04-18

Olivine LiFePO(4) is considered one of the most promising cathode materials for Li-ion batteries. A simple one-step, template-free, low-temperature solvothermal method is developed for the synthesis of urchinlike hierarchical mesocrystals of pristine LiFePO(4) as well as carbon-coated LiFePO(4) composites. Each urchinlike mesocrystal consists of LiFePO(4) sheets self-assembled via a dipolar field in spheres during a solvothermal process under the influence of Cl(-) anions. The obtained primary sheets of LiFePO(4) are single crystalline in nature and can be coated in situ with an amorphous nitrogen-doped carbonaceous layer several nanometers in thickness. To increase the conductivity of the carbon coating, the materials are subjected to further temperature treatment (700 °C) under an inert atmosphere. The lithium storage performance of the pure LiFePO(4) is compared with that of its carbon-coated counterparts. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mixed-solvothermal synthesis of CdS micro/nanostructures and their optical properties

International Nuclear Information System (INIS)

Zhong Shengliang; Zhang Linfei; Huang Zhenzhong; Wang Shangping

2011-01-01

Several novel cadmium sulfide (CdS) micro/nanostructures, including cauliflower-like microspheres, football-like microspheres, tower-like microrods, and dendrites were controllably prepared via an oxalic acid-assisted solvothermal route using ethylene glycol (EG) and H 2 O as pure and mixed solvents with different S sources. The as-prepared products were characterized by X-ray powder diffraction (XRD), scanning electronic microscope (SEM) and UV-vis spectrophotometer (UV). It was found that CdS micro/nanostructures can be selectively obtained by varying the composition of solvent, concentration of oxalic acid, and sulfur sources. UV-vis absorption spectra reveal that their absorption properties are shape-dependent. The possible formation process of the CdS micro/nanostructures was briefly discussed. This route provides a facile way to tune the morphologies of CdS over a wide range.

Hollow Micro-/Nanostructures: Synthesis and Applications

KAUST Repository

Lou, Xiong Wen (David)

2008-11-03

Hollow micro-nanostructures are of great interest in many current and emerging areas of technology. Perhaps the best-known example of the former is the use of fly-ash hollow particles generated from coal power plants as partial replacement for Portland cement, to produce concrete with enhanced strength and durability. This review is devoted to the progress made in the last decade in synthesis and applications of hollow micro-nanostructures. We present a comprehensive overview of synthetic strategies for hollow structures. These strategies are broadly categorized into four themes, which include well-established approaches, such as conventional hard-templating and soft-templating methods, as well as newly emerging methods based on sacrificial templating and template-free synthesis. Success in each has inspired multiple variations that continue to drive the rapid evolution of the field. The Review therefore focuses on the fundamentals of each process, pointing out advantages and disadvantages where appropriate. Strategies for generating more complex hollow structures, such as rattle-type and nonspherical hollow structures, are also discussed. Applications of hollow structures in lithium batteries, catalysis and sensing, and biomedical applications are reviewed. © 2008 WILEY-VCH Verlag GmbH & Co. KGaA,.

One-pot solvothermal synthesis of highly efficient, daylight active and recyclable Ag/AgBr coupled photocatalysts with synergistic dual photoexcitation

International Nuclear Information System (INIS)

Zhang, Caihong; Ai, Lunhong; Li, Lili; Jiang, Jing

2014-01-01

Highlights: • Ag/AgBr photocatalysts were controllably synthesized by solvothermal process. • Ag/AgBr composites showed excellent daylight driven photocatalytic activity. • The remarkable activity is attributed to the synergistic dual photoexcitation. -- Abstract: Efficient light harvesting has been considered to be critical for manipulating the photocatalytic behavior of photocatalysts, because it directly determines the generation of reactive redox charge carriers involved in photoreaction process. In this study, we present a successful example on efficient conversion of solar energy by Ag/AgBr coupled photocatalysts that hold unique synergistic dual photoexcitation. A series of Ag/AgBr coupled photocatalysts were controllably synthesized by an easily manipulated mild solvothermal process. The physicochemical properties of the as-prepared Ag/AgBr coupled photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS) and UV–vis diffuse reflectance spectroscopy (DRS). The results showed the solvothermal reaction time played key role for control of crystalline structure, morphology, composition, and visible light absorption ability of the resulting photocatalysts. The as-prepared Ag/AgBr coupled photocatalysts exhibited remarkable photocatalytic performance and good reusability for decomposing organic dyes in aqueous solution under the irradiation of commercial 20 W cool daylight fluorescent lamp, owing to the synergistic dual photoexcitation cooperating between plasmonic Ag nanoparticles and narrow-band-gap AgBr

Seedless Synthesis of Monodispersed Gold Nanorods with Remarkably High Yield: Synergistic Effect of Template Modification and Growth Kinetics Regulation.

Science.gov (United States)

Liu, Kang; Bu, Yanru; Zheng, Yuanhui; Jiang, Xuchuan; Yu, Aibing; Wang, Huanting

2017-03-08

Gold nanorods (AuNRs) are versatile materials due to their broadly tunable optical properties associated with their anisotropic feature. Conventional seed-mediated synthesis is, however, not only limited by the operational complexity and over-sensitivity towards subtle changes of experimental conditions but also suffers from low yield (≈15 %). A facile seedless method is reported to overcome these challenges. Monodispersed AuNRs with high yield (≈100 %) and highly adjustable longitudinal surface plasmon resonance (LSPR) are reproducibly synthesized. The parameters that influence the AuNRs growth were thoroughly investigated in terms of growth kinetics and soft-template regulation, offering a better understanding of the template-based mechanism. The facile synthesis, broad tunability of LSRP, high reproducibility, high yield, and ease of scale-up make this method promising for the future mass production of monodispersed AuNRs for applications in catalysis, sensing, and biomedicine. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Use of protein cages as a template for confined synthesis of inorganic and organic nanoparticles.

Science.gov (United States)

Uchida, Masaki; Qazi, Shefah; Edwards, Ethan; Douglas, Trevor

2015-01-01

Protein cages are hollow spherical proteins assembled from a defined number of subunits. Because they are extremely homogeneous in size and structure, their interior cavities can serve as ideal templates to encapsulate and synthesize well-defined nanoparticles. Here, we describe the exemplary synthesis of a hard and a soft material in two representative protein cages, i.e., magnetite nanoparticles in ferritin and a poly(2-aminoethyl)methacrylate inside a viral capsid derived from the bacteriophage P22.

Synthesis of fused azole-piperidionoses: A free radical cyclization approach

Energy Technology Data Exchange (ETDEWEB)

Marco-Contelles, Jose; Alhambra Jimenez, Carolina [Instituto de Quimica Organica General (CSIC), Madrid (Spain)

1999-08-01

A new strategy has been reported for the synthesis of fused azole-piperidinoses featuring and unprecedented and very efficient 6-exo-trig free radical cyclization onto heterocyclic sugar templates. These compounds are key intermediates for the synthesis of known or analogues of azole-glycosidase inhibitors. In this communication we describe our recent and successful results on the synthesis of fused triazole-piperidinoses. Radical precursors have been prepared by standard methodologies from 1, 2:5, 6-bis-O-isopropylidene-{alpha}-D-glucofuranose (4) via triazoles linked at C3 with {beta}-orientation, readily obtained by 1, 3-dipolar cycloaddition of azide 5 with diethyl acetylenedicarboxylate or methyl propiolate, and by S{sub N}2 displacement of the tosylate at C3 with 1, 2, 4-triazole in compound 20. The key 6-exp-trig free radical cyclizations proceeded in the usual conditions [tributyltin hydride or tris(trimethylsily)silane, AIBN, toluene] yielding the azaannulated sugars 9, 11, 19 and 23 in good or excellent yields. A mechanism for these cyclizations has been proposed. [Spanish] Se ha informado una nueva estrategia para la sintesis azol-piperidinosas fusionadas mediante una ciclizacion 6-exo-trig muy eficiente y sin precedentes, sobre plantillas de azucares heterociclicos. Estos compuestos son intermediarios claves para la sintesis de inhibidores de azol-glicosidasa conocidos analogos de ellos. En esta comunicacion describimos nuestros resultados recientes y exitosos sobre la sintesis de triazol-piperidinosas. Los precursores de radicales fueron preparados por la metodologia usual a partir de 1, 2:5, 6-bis-O-isopropiliden-{alpha}-D-glucofuranosa (4) via triazoles unidos en C3, con orientacion {beta}, los cuales se obtienen facilmente por cicloadicion 1, 3-dipolar de la azida 5 con acetilendicarboxilato de dietilo o propiolato de metilo y por desplazamiento S{sub N}2 del tosilato en C3 con 1, 2, 4-triazol en el compuesto 20. Las ciclizaciones 6-exo

Bi-template assisted synthesis of mesoporous manganese oxide nanostructures: Tuning properties for efficient CO oxidation.

Science.gov (United States)

Roy, Mouni; Basak, Somjyoti; Naskar, Milan Kanti

2016-02-21

A simple soft bi-templating process was used for the synthesis of mesoporous manganese oxide nanostructures using KMnO4 as a precursor and polyethylene glycol and cetyltrimethylammonium bromide as templates in the presence of benzaldehyde as an organic additive in alkaline media, followed by calcination at 400 °C. X-ray diffraction and Raman spectroscopic analysis of the calcined products confirmed the existence of stoichiometric (MnO2 and Mn5O8) and non-stoichiometric mixed phases (MnO2 + Mn5O8) of Mn oxides obtained by tuning the concentration of the additive and the synthesis time. The surface properties of the prepared Mn oxides were determined by X-ray photoelectron spectroscopy. The mesoporosity of the samples was confirmed by N2 adsorption-desorption. Different synthetic conditions resulted in the formation of different morphologies of the Mn oxides (α-MnO2, Mn5O8, and α-MnO2 + Mn5O8), such as nanoparticles, nanorods, and nanowires. The synthesized mesoporous Mn oxide nanostructures were used for the catalytic oxidation of the harmful air pollutant carbon monoxide. The Mn5O8 nanoparticles with the highest Brunauer-Emmett-Teller surface area and the non-stoichiometric manganese oxide (α-MnO2 + Mn5O8) nanorods with a higher Mn(3+) concentration had the best catalytic efficiency.

Mixed-solvothermal synthesis of CdS micro/nanostructures and their optical properties

Energy Technology Data Exchange (ETDEWEB)

Zhong Shengliang, E-mail: zslxhx@yahoo.com.cn [College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022 (China); Zhang Linfei; Huang Zhenzhong; Wang Shangping [College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022 (China)

2011-01-15

Several novel cadmium sulfide (CdS) micro/nanostructures, including cauliflower-like microspheres, football-like microspheres, tower-like microrods, and dendrites were controllably prepared via an oxalic acid-assisted solvothermal route using ethylene glycol (EG) and H{sub 2}O as pure and mixed solvents with different S sources. The as-prepared products were characterized by X-ray powder diffraction (XRD), scanning electronic microscope (SEM) and UV-vis spectrophotometer (UV). It was found that CdS micro/nanostructures can be selectively obtained by varying the composition of solvent, concentration of oxalic acid, and sulfur sources. UV-vis absorption spectra reveal that their absorption properties are shape-dependent. The possible formation process of the CdS micro/nanostructures was briefly discussed. This route provides a facile way to tune the morphologies of CdS over a wide range.

Iron (III) oxyhydroxide in isopropyl alcohol preparation, characterization and solvothermal treatment

International Nuclear Information System (INIS)

Carvalho, E.L.C.N.; Jafelicci Junior, M.

1989-01-01

Iron (III) nitrate hydrolysis was carried out in isopropyl alcohol solution by an aqueous amonia gas stream resulting in iron (III) oxyhydroxide sol. It has been investigated in this work the solvothermal treatment of this colloidal system at 120 0 C and 24 hours. Iron (III) oxyhydroxide freshly obtained and solvothermally treated. Samples were dryed by lyophilization. Products obtained were characterized by the following techniques: spectrophotometric iron analysis by 1,10-orthophenantroline complexation method, powder X-ray diffraction, vibrational infrared spectra and differential thermal analysis. After solvothermal treatment resulting product was crystallized into hematite, while freshly iron (III) oxyhydroxide was non crystalline. Both of them are very active powder, showing high water adsorption [pt

Template-free synthesis of ZnWO{sub 4} powders via hydrothermal process in a wide pH range

Energy Technology Data Exchange (ETDEWEB)

Hojamberdiev, Mirabbos, E-mail: mirabbos_uz@yahoo.com [Shaanxi Key Laboratory of Nano-materials and Technology, Xi' an University of Architecture and Technology, Xi' an 710055 (China); Zhu, Gangqiang [School of Physics and Information Technology, Shaanxi Normal University, Xi' an 710062 (China); Xu, Yunhua [Shaanxi Key Laboratory of Nano-materials and Technology, Xi' an University of Architecture and Technology, Xi' an 710055 (China)

2010-12-15

ZnWO{sub 4} powders with different morphologies were fabricated through a template-free hydrothermal method at 180 {sup o}C for 8 h in a wide pH range. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible and luminescence spectrophotometers were applied to study the effects of pH values on crystallinity, morphology, optical and luminescence properties. The XRD results showed that the WO{sub 3} + ZnWO{sub 4}, ZnWO{sub 4}, and ZnO phases could form after hydrothermal processing at 180 {sup o}C for 8 h with the pH values of 1, 3-11, and 13, respectively. The SEM and TEM observation revealed that the morphological transformation of ZnWO{sub 4} powders occurred with an increase in pH values as follows: star anise-, peony-, and desert rose-like microstructures and soya bean- and rod-like nanostructures. The highest luminescence intensity was found to be in sample consisting of star anise-like crystallites among all the samples due to the presence of larger particles with high crystallinity resulted from the favorable pH under the current hydrothermal conditions.

Template-free synthesis of novel SnS2 array and its superior performances for lithium ion battery

Science.gov (United States)

Zhu, Anquan; Qiao, Lulu; Tan, Pengfei; Ma, Yongjin; Liu, Yi; Pan, Jun

2018-05-01

A kind of novel three-dimensional SnS2 array was fabricated by an ethylenediamine (EDA) assisting low-temperature solvothermal method. It was observed that as-obtained SnS2 array was composed of numerous SnS2 nanosheets with the thickness of about 22 nm. When used as lithium ion batteries (LIBs) anode, the SnS2 array displayed remarkable capacities on rate and cycling performances, delivering the rates with reversible capacities of 763.3, 658.6, 593.6, 554.4 and 450.3 mAh g-1 at the current densities of 0.2, 0.5, 1, 2 and 5 A g-1, respectively. Moreover, the satisfactory cycling performance was also disclosed, remaining capacity of 547.8 mAh g-1 after 100th cycle at 0.2 A g-1, better than some reported pure SnS2 nanostructures. Based on the characterization and experimental results, the reasons of such superior electrochemical performances were determined and elaborated. It means that the SnS2 array possesses promising potential on the renewable energy field.

Tailoring the porosity of hierarchical zeolites by carbon-templating

DEFF Research Database (Denmark)

Zhu, Kake; Egeblad, Kresten; Christensen, Claus H.

2008-01-01

We report the synthesis and characterization of a series of hierarchical porous zeolite single crystal materials with a range of porosities made available by carbon-templating using differently-sized carbon particles as templates for the additional non-micropore porosity. The materials were...

Solvothermal synthesis and high optical performance of three-dimensional sea-urchin-like TiO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Zhou, Yi, E-mail: zhouyihn@163.com; Wang, Yutang; Li, Mengyao; Li, Xuzhi; Yi, Qin; Deng, Pan; Wu, Hongyan

2015-06-15

Graphical abstract: I–V characteristics of different TiO{sub 2} microspheres based DSSCs (a) 3D sphere-like, (b) 3D flower-like, (c) 3D sea-urchin-like. - Highlights: • 3D sea-urchin-like TiO{sub 2} was synthesized by solvothermal method. • The effects of preparation parameters on the microstructure of the microspheres were investigated. • The photoelectric properties of 3D sea-urchin-like TiO{sub 2} were studied upon DSSCs. • The PCE of the 3D sea-urchin-like TiO{sub 2} was higher than that of other morphologies. - Abstract: Three-dimensional (3D) sea-urchin-like TiO{sub 2} microspheres were successfully synthesised by solvothermal method. The effects of preparation parameters including reaction temperature, concentration and mass fraction of precursor, and solvent volume on the microstructure of the microspheres were investigated. Results of scanning electron microscopy showed that the preparation parameters played a critical role in the morphology of 3D sea-urchin-like TiO{sub 2}. In addition, when the sea-urchin-like TiO{sub 2} nanostructures were used as the dye-sensitized solar cells (DSSCs) anode, the power-conversion efficiency was higher than that of other morphologies, which was due to the special 3D hierarchical nanostructure, large specific surface area, and enhanced absorption of UV–vis of the TiO{sub 2} nanostructures.

Fabricating hydroxyapatite nanorods using a biomacromolecule template

Energy Technology Data Exchange (ETDEWEB)

Zhu Aiping, E-mail: apzhu@yzu.edu.cn [College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002 (China); Lu Yan; Si Yunfeng [College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002 (China); Dai Sheng [School of Chemical Engineering, University of Adelaide, Adelaide, SA 5005 (Australia)

2011-02-01

Rod-like hydroxyapatite (HAp) nanoparticles with various aspect ratios are synthesized by means of low-temperature hydrothermal method in the presence of a N-[(2-hydroxy-3-trimethylammonium) propyl]chitosan chloride (HTCC) template. The synthesized HAps were examined by X-ray diffraction (XRD), Fourier transform infrared spectrophotometer (FTIR) and transmission electron microscopy (TEM) techniques. The results reveal that HAps are rod-like monocrystals, where the size and morphology can be tailored by varying synthesis conditions, such as pH, hydrothermal synthesis temperature and the ratio of PO{sub 4}{sup 3-} to the quaternary ammonium in HTCC. The mechanism of HTCC template on HAp nanorod preparation is analyzed.

Fabricating hydroxyapatite nanorods using a biomacromolecule template

International Nuclear Information System (INIS)

Zhu Aiping; Lu Yan; Si Yunfeng; Dai Sheng

2011-01-01

Rod-like hydroxyapatite (HAp) nanoparticles with various aspect ratios are synthesized by means of low-temperature hydrothermal method in the presence of a N-[(2-hydroxy-3-trimethylammonium) propyl]chitosan chloride (HTCC) template. The synthesized HAps were examined by X-ray diffraction (XRD), Fourier transform infrared spectrophotometer (FTIR) and transmission electron microscopy (TEM) techniques. The results reveal that HAps are rod-like monocrystals, where the size and morphology can be tailored by varying synthesis conditions, such as pH, hydrothermal synthesis temperature and the ratio of PO 4 3- to the quaternary ammonium in HTCC. The mechanism of HTCC template on HAp nanorod preparation is analyzed.

Frabicating hydroxyapatite nanorods using a biomacromolecule template

Science.gov (United States)

Zhu, Aiping; Lu, Yan; Si, Yunfeng; Dai, Sheng

2011-02-01

Rod-like hydroxyapatite (HAp) nanoparticles with various aspect ratios are synthesized by means of low-temperature hydrothermal method in the presence of a N-[(2-hydroxy-3-trimethylammonium) propyl]chitosan chloride (HTCC) template. The synthesized HAps were examined by X-ray diffraction (XRD), Fourier transform infrared spectrophotometer (FTIR) and transmission electron microscopy (TEM) techniques. The results reveal that HAps are rod-like monocrystals, where the size and morphology can be tailored by varying synthesis conditions, such as pH, hydrothermal synthesis temperature and the ratio of PO43- to the quaternary ammonium in HTCC. The mechanism of HTCC template on HAp nanorod preparation is analyzed.

Soft templated mesoporous carbons: Tuning the porosity for the adsorption of large organic pollutants

OpenAIRE

Libbrecht, Wannes; Verberckmoes, An; Thybaut, Joris; Van Der Voort, Pascal; De Clercq, Jeriffa

2017-01-01

Mesoporous carbons have been the subject of various studies, both fundamental and applied. Fundamental studies revealed numerous synthesis routes which can adjust material characteristics as specific surface area, pore volume, pore size or morphology and elemental composition. The indirect synthesis or hard template method was developed first. An extensive collection of template materials exist, which can be impregnated with carbon precursors to provide various hard templated mesoporous carbo...

Synthesis of Hollow Silver Spheres using Spherical Vaterite-type Calcium Carbonate as Template

Energy Technology Data Exchange (ETDEWEB)

Park, Minyoung; Go, Hani; Kim, Jae-Hyun; Rhee, Seog Woo [Kongju National University, Kongju (Korea, Republic of)

2016-03-15

In this work, we describe the synthesis of hollow silver spheres using vaterite-type CaCO{sub 3} as template. The spherical vaterite-type CaCO{sub 3} was selectively precipitated d reaction of aqueous CaCl{sub 2} and Na{sub 2}CO{sub 3} in the presence of the polyelectrolyte poly(4-styrenesulfonate). Aqueous AgNO{sub 3} solution containing NH{sub 2}-functionalized CaCO{sub 3} particles was treated with reducing agents such as ascorbic acid, NaBH{sub 4}, and acetaldehyde, and the reduced silver particles were deposited on the surface of CaCO{sub 3}particles to form uniform silvershells. The CaCO{sub 3} used as template was removed from the CaCO{sub 3}/Ag composite by treatment with acid. Finally, the hollow silver sphere was obtained. The morphologies of product were investigated using electron microscopy, the chemical composition of the composite was analyzed using energy-dispersive X-ray spectroscopy, the vibration modes of the carbonate ion were investigated by Fourier transform infrared spectroscopy, the thermal mass change was measured using the thermogravimetric analysis, and the solid phases were confirmed by powder X-ray diffraction.

Mesoporous MEL, BEA, and FAU zeolite crystals obtained by in situ formation of carbon template over metal nanoparticles

DEFF Research Database (Denmark)

Abildstrøm, Jacob Oskar; Ali, Zahra Nasrudin; Mentzel, Uffe Vie

2016-01-01

Here, we report the synthesis and characterization of hierarchical zeolite materials with MEL, BEA and FAU structures. The synthesis is based on the carbon templating method with an in situ-generated carbon template. Through the decomposition of methane and deposition of coke over nickel nanopart......Here, we report the synthesis and characterization of hierarchical zeolite materials with MEL, BEA and FAU structures. The synthesis is based on the carbon templating method with an in situ-generated carbon template. Through the decomposition of methane and deposition of coke over nickel...... nanoparticles supported on silica, a carbon–silica composite is obtained and exploited as a combined carbon template/silica source for the zeolite synthesis. The mesoporous zeolite materials were all prepared by hydrothermal crystallization in alkaline media followed by removal of the carbon template...... by combustion, which results in zeolite single crystals with intracrystalline pore volumes of up to 0.44 cm3 g−1. The prepared zeolite structures are characterized by XRD, SEM, TEM and N2 physisorption measurements....

GREEN APPROACH TO BULK AND TEMPLATE-FREE SYNTHESIS OF THERMALLY STABLE REDUCED POLYANILINE NANOFIBERS FOR CAPACITOR APPLICATIONS

Science.gov (United States)

An extremely simple green approach is described that generates bulk quantities of nanofibers of the electronic polymer polyaniline in fully reduced state (leucoemeraldine form) in one step without using any reducing agent, surfactants, and/or large amounts of insoluble templates....

Role of alkali carbonate and salt in topochemical synthesis of K1/2Na1/2NbO3 and NaNbO3 templates

Science.gov (United States)

Lee, Jae-Seok; Jeon, Jae-Ho; Choi, Si-Young

2013-11-01

Since the properties of lead-free piezoelectric materials have thus far failed to meet those of lead-based materials, either chemical doping or morphological texturing should be employed to improve the piezoelectric properties of lead-free piezoelectric ceramics. The goal of this study was to synthesize plate-like K1/2Na1/2NbO3 and NaNbO3 particles, which are the most favorable templates for morphological texturing of K1/2Na1/2NbO3 ceramics. To achieve this goal, Bi2.5Na3.5Nb5O18 precursors in a plate-like shape were first synthesized and subsequently converted into K1/2Na1/2NbO3 or NaNbO3 particles that retain the morphology of Bi2.5Na3.5Nb5O18. In this study, we found that sodium or potassium carbonate does not play a major role in converting the Bi2.5Na3.5Nb5O18 precursor to K1/2Na1/2NbO3 or NaNbO3, on the contrary to previous reports; however, the salt contributes to the conversion reaction. All synthesis processes have been performed via a molten salt method, and scanning electron microscopy, scanning probe microscopy, and inductively coupled plasma mass spectroscopy were used to characterize the synthesized K1/2Na1/2NbO3 or NaNbO3 templates.

Solid-phase synthesis of molecularly imprinted nanoparticles.

Science.gov (United States)

Canfarotta, Francesco; Poma, Alessandro; Guerreiro, Antonio; Piletsky, Sergey

2016-03-01

Molecularly imprinted polymers (MIPs) are synthetic materials, generally based on acrylic or methacrylic monomers, that are polymerized in the presence of a specific target molecule called the 'template' and capable of rebinding selectively to this target molecule. They have the potential to be low-cost and robust alternatives to biomolecules such as antibodies and receptors. When prepared by traditional synthetic methods (i.e., with free template in solution), their usefulness has been limited by high binding site heterogeneity, the presence of residual template and the fact that the production methods are complex and difficult to standardize. To overcome some of these limitations, we developed a method for the synthesis of MIP nanoparticles (nanoMIPs) using an innovative solid-phase approach, which relies on the covalent immobilization of the template molecules onto the surface of a solid support (glass beads). The obtained nanoMIPs are virtually free of template and demonstrate high affinity for the target molecule (e.g., melamine and trypsin in our published work). Because of an affinity separation step performed on the solid phase after polymerization, poor binders and unproductive polymer are removed, so the final product has more uniform binding characteristics. The overall protocol, starting from the immobilization of the template onto the solid phase and including the purification and characterization of the nanoparticles, takes up to 1 week.

Solvothermal synthesis and electrical conductivity model for the zinc oxide-insulated oil nanofluid

International Nuclear Information System (INIS)

Shen, L.P.; Wang, H.; Dong, M.; Ma, Z.C.; Wang, H.B.

2012-01-01

A new kind of nanofluid, ZnO-insulated oil nanofluid was prepared from ZnO nanoparticles synthesized by solvothermal method. Electrical property measurement shows that the electrical conductivity increases by 973 times after adding 0.75% volumetric fraction of ZnO nanoparticles into the insulated oil. A linear dependence of the electrical conductivity on the volumetric fraction has been observed, while the temperature dependence of the electrical conductivity reveals a nonlinear relationship. An electrical conductivity model is established for the nanofluid by considering both the Brownian motion and electrophoresis of the ZnO nanoparticles. -- Highlights: ► Stable ZnO-insulated oil nanofluid was successfully prepared. ► The electrical conductivity of the ZnO nanofluid is investigated. ► A new model is established to explain the electrical properties of the nanofluid.

Templated electrodeposition of functional nanostructures: nanowires, nanotubes and nanocubes

OpenAIRE

Maijenburg, A.W.

2014-01-01

This thesis is entitled “Templated electrodeposition of functional nanostructures: nanowires, nanotubes and nanocubes”. Templated electrodeposition is the synthesis technique that was used throughout this thesis, and it comprises the use of a template with specific shape and dimensions for the formation of different types of nanostructures. Throughout this thesis, three different nanostructures were made: nanowires (Chapters 2 to 6), nanotubes (Chapters 2 and 5) and nanocubes (Chapters 7 and ...

Surfactant-assisted sacrificial template-mediated synthesis

Indian Academy of Sciences (India)

... spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopyand photoluminescence studies. Influence of surfactant and solvents on morphology and luminescence of the final product in sacrificial template-assisted method has been investigated in detail.

Multi-objective superstructure-free synthesis and optimization of thermal power plants

International Nuclear Information System (INIS)

Wang, Ligang; Lampe, Matthias; Voll, Philip; Yang, Yongping; Bardow, André

2016-01-01

The merits of superstructure-free synthesis are demonstrated for bi-objective design of thermal power plants. The design of thermal power plants is complex and thus best solved by optimization. Common optimization methods require specification of a superstructure which becomes a tedious and error-prone task for complex systems. Superstructure specification is avoided by the presented superstructure-free approach, which is shown to successfully solve the design task yielding a high-quality Pareto front of promising structural alternatives. The economic objective function avoids introducing infinite numbers of units (e.g., turbine, reheater and feedwater preheater) as favored by pure thermodynamic optimization. The number of feasible solutions found per number of mutation tries is still high even after many generations but declines after introducing highly-nonlinear cost functions leading to challenging MINLP problems. The identified Pareto-optimal solutions tend to employ more units than found in modern power plants indicating the need for cost functions to reflect current industrial practice. In summary, the multi-objective superstructure-free synthesis framework is a robust approach for very complex problems in the synthesis of thermal power plants. - Highlights: • A generalized multi-objective superstructure-free synthesis framework for thermal power plants is presented. • The superstructure-free synthesis framework is comprehensively evaluated by complex bi-objective synthesis problems. • The proposed framework is effective to explore the structural design space even for complex problems.

Template-free synthesis of two-dimensional titania/titanate nanosheets as electrodes for high-performance supercapacitor applications

Science.gov (United States)

Barai, Hasi Rani; Rahman, Md. Mahbubur; Joo, Sang Woo

2017-12-01

Template-free two-dimensional (2D) titania/titanate nanosheets on Ti metal foil (TiNS/Ti) is prepared by a hydrothermal method at 150 °C assisted by KOH(aq.),followed by sintering at 500 °C. A single thin layer of TiNS is grown with 2D morphology when using low concentrations of KOH(aq.) (0.25 and 0.5 M). However, the morphology is transformed to 1D when using a high concentration of KOH(aq.). The TiNS is a mixture of rutile TiO2 and K-titanate (K2Ti3O7 and K2Ti2O5) with the formation of Ti3+ interstitials. The optimized TiNS/Ti electrode exhibits quasi-rectangular cyclic voltammograms (CVs) in a wide potential range. The specific capacitance (Cs) are 6.8 × 103 and 4.7 × 103 μF/cm2 according to the CV (scan rate, 5 mV/s) and charge-discharge measurements (CD, current density, 50 μA/cm2), respectively. These values are much higher than those reported for pure 0D and 1D TiO2 nanostructures.The higher Cs for the TiNS/Ti electrode can be ascribed to the increased rate of K+ intercalation and de-intercalation during charging and discharging, as well as enhanced conductivity enable by the K in the crystal lattice (10.30%) and Ti3+ interstitials (5.2%), respectively. The TiNS/Ti electrode shows excellent stability with the Cs retention of 89% even after 5000 CD cycles.

Synthesis of templated carbons starting from clay and clay-derived zeolites for hydrogen storage applications

CSIR Research Space (South Africa)

Musyoka, Nicholas M

2014-10-01

Full Text Available 57 58 59 60 For Peer Review 1 Synthesis of templated carbons starting from clay and clay-derived zeolites for hydrogen storage applications N. M. Musyoka1*, J. Ren1, H. W. Langmi1, D. E. C. Rogers1, B. C. North1, M. Mathe1 and D. Bessarabov2... clear (filtered) extract of cloisite clay, SNC for zeolite from unfiltered cloisite clay extract and SBC for zeolite from unfiltered South African bentonite clay extract. Furfuryl alcohol (Sigma Aldrich, C5H6O2, 98%) and Ethylene gas were used...

Zigzag-shaped nickel nanowires via organometallic template-free route

Energy Technology Data Exchange (ETDEWEB)

Shviro, Meital; Paszternak, Andras [Bar Ilan Institute of Nanotechnology and Advanced Materials (BINA), Bar Ilan University, Department of Chemistry (Israel); Chelly, Avraham [Bar Ilan Institute of Nanotechnology and Advanced Materials (BINA), Bar Ilan University, Department of Engineering (Israel); Zitoun, David, E-mail: david.zitoun@biu.ac.il [Bar Ilan Institute of Nanotechnology and Advanced Materials (BINA), Bar Ilan University, Department of Chemistry (Israel)

2013-08-15

In this manuscript, the formation of nickel nanowires of 10-20 nm in diameter (average size: several tens to hundreds of {mu}m long and 1.0-1.5 {mu}m wide) at low temperature is found to be driven by dewetting of liquid organometallic precursors during spin-coating process and by self-assembly of Ni clusters. Elaboration of metallic thin films by low-temperature deposition technique makes the preparation process compatible with most of the substrates. The use of iron and cobalt precursor shows that the process could be extended to other metallic systems. In this work, AFM and SEM are used to follow the assembly of Ni clusters into straight or zigzag lines. The formation of zigzag structure is specific to the Ni precursor at appropriate preparation parameters. This template-free process allows a control of anisotropic structures with homogeneous sizes and angles on the standard Si/SiO{sub 2} surface.

Phase controlled solvothermal synthesis of Cu{sub 2}ZnSnS{sub 4}, Cu{sub 2}ZnSn(S,Se){sub 4} and Cu{sub 2}ZnSnSe{sub 4} Nanocrystals: The effect of Se and S sources on phase purity

Energy Technology Data Exchange (ETDEWEB)

Pal, Mou [Instituto de Energías Renovables, Universidad Nacional Autónoma de México, 62580 Temixco, Morelos (Mexico); Instituto de Física, BUAP, Av. San Claudio y Blvd. 18 Sur Col. San Manuel, Ciudad Universitaria, C.P. 72570, Puebla (Mexico); Mathews, N.R. [Instituto de Energías Renovables, Universidad Nacional Autónoma de México, 62580 Temixco, Morelos (Mexico); Paraguay-Delgado, F. [Departamento de Materiales Nanoestructurados, Centro de Investigación en Materiales Avanzados (CIMAV), Chihuahua (Mexico); Mathew, X., E-mail: xm@ier.unam.mx [Instituto de Energías Renovables, Universidad Nacional Autónoma de México, 62580 Temixco, Morelos (Mexico)

2015-09-15

In this study, we have reported the synthesis of Cu{sub 2}ZnSnSe{sub 4} (CZTSe), Cu{sub 2}ZnSnS{sub 4} (CZTS) and Cu{sub 2}ZnSn(S,Se){sub 4} (CZTSSe) nanocrystals with tunable band gap and composition obtained by solvothermal method. The crystalline structure, composition, morphology and optical properties of the nanoparticles were characterized by X-ray diffraction (XRD), Raman scattering, energy dispersive X-ray spectroscopy, transmission electron microscopy and diffuse reflectance (DR) spectroscopy. While the XRD patterns of CZTS and CZTSe nanoparticles prepared with elemental S/Se powder revealed the presence of phase pure nanoparticles, the CZTSSe nanoparticles obtained using a mixture of S and Se, were found to contain many secondary phases under the same synthesis protocol. Formation of impurity phases in CZTSSe sample, can be avoided by using a mixture of 1-dodecanethiol (DT; CH{sub 3}(CH{sub 2}){sub 11}SH)/oleylamine (OLA) instead of S powder and following the same experimental procedure. The incorporation of S in CZTSe nanocrystals prepared in presence of DDT/OLA mixture was confirmed through structural and optical characterizations. The optical properties of the quaternary chalcogenide nanocrystals were found to vary with the chemical composition of the material. - Highlights: • Solvothermal synthesis of CZTS, CZTSSe and CZTSe nanocrystals and discussion on possible formation mechanism. • Use of dodecanethiol/oleylamine mixture to synthesize phase-pure CZTSSe nanocrystals. • Formation of impurity phases can be controlled with proper S and Se sources.

Highly tailorable thiol-ene based emulsion-templated monoliths

DEFF Research Database (Denmark)

Lafleur, J. P.; Kutter, J. P.

2014-01-01

The attractive surface properties of thiol-ene polymers combined with their ease of processing make them ideal substrates in many bioanalytical applications. We report the synthesis of highly tailorable emulsion-templated porous polymers and beads in microfluidic devices based on off-stoichiometr......The attractive surface properties of thiol-ene polymers combined with their ease of processing make them ideal substrates in many bioanalytical applications. We report the synthesis of highly tailorable emulsion-templated porous polymers and beads in microfluidic devices based on off......-stoichiometry thiolene chemistry. The method allows monolith synthesis and anchoring inside thiol-ene microchannels in a single step. Variations in the monomer stoichiometric ratios and/or amount of porogen used allow for the creation of extremely varied polymer morphologies, from foam-like materials to dense networks...

Progress on Synthesis of Hollow Nanostructure by Soft-templates%利用软模板法合成中空纳米结构的研究进展

Institute of Scientific and Technical Information of China (English)

王轶男; 韩晓军

2017-01-01

Hollow nanostructures possess the properties of high loading, low density and large specific surface area, therefore they find a lot of applications in many fields.The synthesis of hollow nanostructure by soft template method has the advantages of simplicity and structure controllability.At present, the most commonly used templates include microemulsion templates, micelle/vesicle templates and bubble templates.The hollow nanostructure is obtained by nanoparticle assembly on these soft templates via electrostatic adsorption, hydrogen bonding and interfacial reaction.The progresses on synthesis of hollow nanostructures by soft template are summarized and perspected.%中空纳米材料具有高负载、低密度、和比表面积大等特点,有着广泛应用. 软模板合成中空纳米结构具有简单易行和结构可控等优点. 目前,采用最多的软模板主要有微乳液、胶束/囊泡模板和气泡软模板,通过静电吸附、氢键和界面反应等方法使纳米粒子沉积在模板表面便可得到中空结构. 本文总结并展望了利用软模板法合成中空纳米结构的研究进展.

Mesoporous carbon prepared from carbohydrate as hard template for hierarchical zeolites

DEFF Research Database (Denmark)

Egeblad, Kresten; Christensen, Claus H.

2007-01-01

treatment of a mixture of sucrose and ammonia followed by carbonization of the mixture in N-2 at high temperatures. The porous carbon produced by this method was subsequently applied as a hard template in the synthesis of mesoporous silicalite-1 and removed by combustion after synthesis. X-ray diffraction......A mesoporous carbon prepared from sucrose was successfully employed as a hard template to produce hierarchical silicalite-1, thus providing a very simple and inexpensive route to desirable zeolite catalysts from widely available raw materials. The porous carbon was prepared by hydrothermal...... the porous carbon template as well as the mesoporous zeolite single-crystal material....

Review of Research on Template Methods in Preparation of Nanomaterials

Directory of Open Access Journals (Sweden)

Yadian Xie

2016-01-01

Full Text Available The nanomaterials have been widely used in various fields, such as photonics, catalysis, and adsorption, because of their unique physical and chemical properties. Therefore, their production methods are of utmost importance. Compared with traditional synthetic methods, the template method can effectively control the morphology, particle size, and structure during the preparation of nanomaterials, which is an effective method for their synthesis. The key for the template method is to choose different templates, which are divided into hard template and soft template according to their different structures. In this paper, the effects of different types of templates on the morphology of nanomaterials during their preparation are investigated from two aspects: hard template and soft template, combined with the mechanism of action.

Structure-directing effects of ionic liquids in the ionothermal synthesis of metal–organic frameworks

Directory of Open Access Journals (Sweden)

Thomas P. Vaid

2017-07-01

Full Text Available Traditional synthesis of metal–organic frameworks (MOFs involves the reaction of a metal-containing precursor with an organic linker in an organic solvent at an elevated temperature, in what is termed a `solvothermal' reaction. More recently, many examples have been reported of MOF synthesis in ionic liquids (ILs, rather than an organic solvent, in `ionothermal' reactions. The high concentration of both cations and anions in an ionic liquid allows for the formation of new MOF structures in which the IL cation or anion or both are incorporated into the MOF. Most commonly, the IL cation is included in the open cavities of the MOF, countering the anionic charge of the MOF framework itself and acting as a template around which the MOF structure forms. Ionic liquids can also serve other structure-directing roles, for example, when an IL containing a single enantiomer of a chiral anion leads to a homochiral MOF, even though the IL anion is not itself incorporated into the MOF. A comprehensive review of ionothermal syntheses of MOFs, and the structure-directing effects of the ILs, is given.

Zeolite-templated carbon replica: a Grand Canonical Monte-Carlo simulation study

International Nuclear Information System (INIS)

Thomas Roussel; Roland J M Pellenq; Christophe Bichara; Roger Gadiou; Antoine Didion; Cathie Vix Guterl; Fabrice Gaslain; Julien Parmentier; Valentin Valtchev; Joel Patarin

2005-01-01

Microporous carbon materials are interesting for several applications such as hydrogen storage, catalysis or electrical double layer capacitors. The development of the negative templating method to obtain carbon replicas from ordered templates, has lead to the synthesis of several new materials which have interesting textural properties, attractive for energy storage. Among the possible templates, zeolites can be used to obtain highly microporous carbon materials. Nevertheless, the phenomena involved in the replica synthesis are not fully understood, and the relationships between the structure of the template, the carbon precursor and the resulting carbon material need to be investigated. Experimental results for carbon zeolite-templated nano-structures can be found in a series of papers; see for instance ref. [1] in which Wang et al describe a route to ultra-small Single Wall Carbon Nano-tubes (SWNTs) using the porosity of zeolite AlPO 4 -5. After matrix removal, the resulting structure is a free-standing bundle of 4 Angstroms large nano-tubes. However, it is highly desirable to obtain an ordered porous carbon structure that forms a real 3D network to be used for instance in gas storage applications. Carbon replica of faujasite and EMT zeolites can have these properties since these zeolites have a 3D porous network made of 10 Angstroms cages connected to each other through 7 Angstroms large windows. The first step of this study was to generate a theoretical carbon replica structure of various zeolites (faujasite, EMT, AlPO 4 -5, silicalite). For this purpose, we used the Grand Canonical Monte-Carlo (GCMC) technique in which the carbon-carbon interactions were described within the frame of a newly developed Tight Binding approach and the carbon-zeolite interactions assumed to be characteristic of physi-sorption. The intrinsic stability of the subsequent carbon nano-structures was then investigated after mimicking the removal of the inorganic phase by switching

Solvothermal synthesis of uranium(VI) phases with aromatic carboxylate ligands: A dinuclear complex with 4-hydroxybenzoic acid and a 3D framework with terephthalic acid

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yingjie, E-mail: yzx@ansto.gov.au [Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Karatchevtseva, Inna [Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Bhadbhade, Mohan [Mark Wainwright Analytical Centre, University of New South Wales, Kensington, NSW 2052 (Australia); Tran, Toan Trong; Aharonovich, Igor [School of Physics and Advanced Materials, University of Technology Sydney, Ultimo, NSW 2007 (Australia); Fanna, Daniel J.; Shepherd, Nicholas D. [School of Science and Health, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751 (Australia); Lu, Kim [Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Li, Feng [School of Science and Health, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751 (Australia); Lumpkin, Gregory R. [Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia)

2016-02-15

With the coordination of dimethylformamide (DMF), two new uranium(VI) complexes with either 4-hydroxybenzoic acid (H{sub 2}phb) or terephthalic acid (H{sub 2}tph) have been synthesized under solvothermal conditions and structurally characterized. [(UO{sub 2}){sub 2}(Hphb){sub 2}(phb)(DMF)(H{sub 2}O){sub 3}]·4H{sub 2}O (1) has a dinuclear structure constructed with both pentagonal and hexagonal bipyramidal uranium polyhedra linked through a µ{sub 2}-bridging ligand via both chelating carboxylate arm and alcohol oxygen bonding, first observation of such a coordination mode of 4-hydroxybenzoate for 5 f ions. [(UO{sub 2})(tph)(DMF)] (2) has a three-dimensional (3D) framework built with pentagonal bipyramidal uranium polyhedra linked with µ{sub 4}-terephthalate ligands. The 3D channeled structure is facilitated by the unique carboxylate bonding with nearly linear C–O–U angles and the coordination of DMF molecules. The presence of phb ligands in different coordination modes, uranyl ions in diverse environments and DMF in complex 1, and tph ligand, DMF and uranyl ion in complex 2 has been confirmed by Raman spectroscopy. In addition, their thermal stability and photoluminescence properties have been investigated. - Graphical abstract: With the coordination of dimethylformamide, two new uranyl complexes with either 4-hydroxybenzoate or terephthalate have been synthesized under solvothermal conditions and structurally characterized. - Highlights: • Solvent facilitates the synthesis of two new uranium(VI) complexes. • A dinuclear complex with both penta- and hexagonal bipyramidal uranium polyhedral. • A unique µ{sub 2}-bridging mode of 4-hydroxybenzoate via alcohol oxygen for 5 f ions. • A 3D framework with uranium polyhedra and µ{sub 4}-terephthalate ligands. • Vibration modes and photoluminescence properties are reported.

Solvothermal synthesis of Zinc sulfide decorated Graphene (ZnS/G) nanocomposites for novel Supercapacitor electrodes

International Nuclear Information System (INIS)

Ramachandran, Rajendran; Saranya, Murugan; Kollu, Pratap; Raghupathy, Bala P.C.; Jeong, Soon Kwan; Grace, Andrews Nirmala

2015-01-01

Highlights: • ZnS/G nanocomposites were prepared by a simple solvothermal process. • Electrochemical measurements were carried out in 6 M KOH electrolyte. • Cyclic voltammetry showed the excellent capacitive behavior of the composites. • A specific capacitance of 197.1 F/g was observed for ZnS/G-60 nanocomposites. - Abstract: Zinc sulfide decorated graphene nanocomposites are synthesized by a facile solvothermal approach and the prepared composites are analyzed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), High Resolution Transmission electron microscopy (HRTEM), Fourier transform infrared (FTIR), Ultraviolet visible spectroscopy (UV), Photoluminescence spectroscopy (PL) and Raman spectrum. Results show the effective reduction of graphene oxide (GO) to graphene and decoration of ZnS nanoparticles on graphene sheets. Towards supercapacitor applications, the electrochemical measurements of different electrodes are performed in 6 M KOH electrolyte. A series of composites with different loadings of graphene is synthesized and tested for its electrochemical properties. The specific capacitance of the electrodes are evaluated from cyclic voltammetry (CV) studies and a maximum specific capacitance of 197.1 F/g is achieved in ZnS/G-60 electrode (60 indicates the weight ratio of GO) at scan rate of 5 mV s"−"1. A capacitance retention of about 94.1% is observed even after 1000 cycles for ZnS/G-60 electrode, suggesting the long time cyclic stability of the composite electrode. Galvanostatic charge–discharge curves show the highly reversible process of ZnS/G-60 electrode. Electrochemical Impedance Spectrum (EIS) shows a high conductivity of composite electrode suggesting that the composites are good candidates for energy storage.

Structural and Morphological Tuning of LiCoPO4 Materials Synthesized by Solvo-Thermal Methods for Li-Cell Applications

Directory of Open Access Journals (Sweden)

Jessica Manzi

2015-12-01

Full Text Available Olivine-type lithium metal phosphates (LiMPO4 are promising cathode materials for lithium-ion batteries. LiFePO4 (LFP is commonly used in commercial Li-ion cells but the Fe3+/Fe2+ couple can be usefully substituted with Mn3+/Mn2+, Co3+/Co2+, or Ni3+/Ni2+, in order to obtain higher redox potentials. In this communication we report a systematic analysis of the synthesis condition of LiCoPO4 (LCP using a solvo-thermal route at low temperature, the latter being a valuable candidate to overcome the theoretical performances of LFP. In fact, LCP shows higher working potential (4.8 V vs. 3.6 V compared to LFP and similar theoretical capacity (167 mAh·g−1. Our goal is to show the effect of the synthesis condition of the ability of LCP to reversibly cycle lithium in electrochemical cells. LCP samples have been prepared through a solvo-thermal method in aqueous-non aqueous solvent blends. Different Co2+ salts have been used to study the effect of the anion on the crystal growth as well as the effect of solution acidity, temperature and reaction time. Materials properties have been characterized by Fast-Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopies. The correlation between structure/morphology and electrochemical performances has been investigated by galvanostatic charge-discharge cycles.

Solvothermal Synthesis of One-Dimensional Transition Metal Doped ZnO Nanocrystals and Their Applications in Smart Window Devices

OpenAIRE

Šutka, A; Timusk, M; Kisand, V; Saal, K; Joost, U; Lõhmus, R

2015-01-01

Oxide semiconductor nanowire (NW) suspension based devices have been attracted growing interest in smart window applications due to their great controllability of light transmittance, simplicity and long term stability. Recently, we demonstrated smart window device using the suspension of electrospun TiO2 or solvothermally synthesized ZnO NWs in viscous polydimethylsiloxane (PDMS) matrix. The operating principle of the oxide semiconductor NW and PDMS device is based on the alterable orientati...

Carbon-coated SnO2 nanotubes: template-engaged synthesis and their application in lithium-ion batteries

Science.gov (United States)

Wu, Ping; Du, Ning; Zhang, Hui; Yu, Jingxue; Qi, Yue; Yang, Deren

2011-02-01

This paper reports the synthesis of carbon-coated SnO2 (SnO2-C) nanotubes through a simple glucose hydrothermal and subsequent carbonization approach by using Sn nanorods as sacrificial templates. The as-synthesized SnO2-C nanotubes have been applied as anode materials for lithium-ion batteries, which exhibit improved cyclic performance compared to pure SnO2 nanotubes. The hollow nanostructure, together with the carbon matrix which has good buffering effect and high electronic conductivity, can be responsible for the improved cyclic performance.

Computer-designed surgical guide template compared with free-hand operation for mesiodens extraction in premaxilla using “trapdoor” method

Science.gov (United States)

Hu, Ying Kai; Xie, Qian Yang; Yang, Chi; Xu, Guang Zhou

2017-01-01

Abstract The aim of this study was to introduce a novel method of mesiodens extraction using a vascularized pedicled bone flap by piezosurgery and to compare the differences between a computer-aided design surgical guide template and free-hand operation. A total of 8 patients with mesiodens, 4 with a surgical guide (group I), and 4 without it (group II) were included in the study. The surgical design was to construct a trapdoor pedicle on the superior mucoperiosteal attachment with application of piezosurgery. The bone lid was repositioned after mesiodens extraction. Group I patients underwent surgeries based on the preoperative planning with surgical guide templates, while group II patients underwent free-hand operation. The outcome variables were success rate, intraoperative time, anterior nasal spine (ANS) position, changes of nasolabial angle (NLA), and major complications. Data from the 2 groups were compared by SPSS 17.0, using Wilcoxon test. The operative time was significantly shorter in group I patients. All the mesiodentes were extracted successfully and no obvious differences of preoperative and postoperative ANS position and NLA value were found in both groups. The patients were all recovered uneventfully. Surgical guide templates can enhance clinical accuracy and reduce operative time by facilitating accurate osteotomies. PMID:28658139

Template synthesis of indium nanowires using anodic aluminum oxide membranes.

Science.gov (United States)

Chen, Feng; Kitai, Adrian H

2008-09-01

Indium nanowires with diameters approximately 300 nm have been synthesized by a hydraulic pressure technique using anodic aluminum oxide (AAO) templates. The indium melt is injected into the AAO template and solidified to form nanostructures. The nanowires are dense, continuous and uniformly run through the entire approximately 60 microm thickness of the AAO template. X-ray diffraction (XRD) reveals that the nanowires are polycrystalline with a preferred orientation. SEM is performed to characterize the morphology of the nanowires.

Two-dimensional collagen-graphene as colloidal templates for biocompatible inorganic nanomaterial synthesis

Science.gov (United States)

Kumari, Divya; Sheikh, Lubna; Bhattacharya, Soumya; Webster, Thomas J; Nayar, Suprabha

2017-01-01

In this study, natural graphite was first converted to collagen-graphene composites and then used as templates for the synthesis of nanoparticles of silver, iron oxide, and hydroxyapatite. X-ray diffraction did not show any diffraction peaks of graphene in the composites after inorganic nucleation, compared to the naked composite which showed (002) and (004) peaks. Scanning electron micrographs showed lateral gluing/docking of these composites, possibly driven by an electrostatic attraction between the positive layers of one stack and negative layers of another, which became distorted after inorganic nucleation. Docking resulted in single layer-like characteristics in certain places, as seen under transmission electron microscopy, but sp2/sp3 ratios from Raman analysis inferred three-layer composite formation. Strain-induced folding of these layers into uniform clusters at the point of critical nucleation, revealed beautiful microstructures under scanning electron microscopy. Lastly, cell viability studies using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays showed the highest cell viability for the collagen-graphene-hydroxyapatite composites. In this manner, this study provided – to the field of nanomedicine – a new process for the synthesis of several nanoparticles (with low toxicity) of high interest for numerous medical applications. PMID:28553102

Nucleic Acid Templated Reactions for Chemical Biology.

Science.gov (United States)

Di Pisa, Margherita; Seitz, Oliver

2017-06-21

Nucleic acid directed bioorthogonal reactions offer the fascinating opportunity to unveil and redirect a plethora of intracellular mechanisms. Nano- to picomolar amounts of specific RNA molecules serve as templates and catalyze the selective formation of molecules that 1) exert biological effects, or 2) provide measurable signals for RNA detection. Turnover of reactants on the template is a valuable asset when concentrations of RNA templates are low. The idea is to use RNA-templated reactions to fully control the biodistribution of drugs and to push the detection limits of DNA or RNA analytes to extraordinary sensitivities. Herein we review recent and instructive examples of conditional synthesis or release of compounds for in cellulo protein interference and intracellular nucleic acid imaging. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Evolvement of soft templates in surfactant/cosurfactant system for shape control of ZnSe nanocrystals

International Nuclear Information System (INIS)

Hou Bo; Liu Yongjun; Li Yanjuan; Yuan Bo; Jia Mingfen; Jiang Fengzhi

2012-01-01

Highlights: ► Soft templates were found in the shape control synthesis of ZnSe nanocrystals. ► Micelle formation model in the soft templates system was proposed and proved. ► Different shapes of ZnSe nanocrystals were prepared and explained by proposed model. - Abstract: The evolution of soft templates in the synthesis of ZnSe nanocrystals realized through a surfactant/cosurfactant system was investigated and a micelle formation process model was proposed. Through freeze-fracture electron microscopy, it was proven that template micelles were formed in the zinc precursors. Furthermore, it was found that a long stirring period was essential for achieving the lowest energy state of the soft templates which were used for synthesizing monodisperse ZnSe quantum dots.

Room temperature synthesis and characterization of ultralong Cd(OH)2 nanowires: a simple and template-free chemical route

International Nuclear Information System (INIS)

Sahraei, R.; Daneshfar, A.; Roushani, M.; Mihandoost, A.; Nabiyouni, G.; Majles Ara, M.H.

2012-01-01

Ultralong Cd(OH) 2 nanowires were fabricated in high yield by a convenient chemical method using alkali medium at room temperature without using any templates. The preparation conditions induce a unilateral growth of nanowires, despite the absence of any template. The length of the nanowires reached several hundreds of micrometers, giving an aspect ratio of a few thousands. The X-ray diffraction shows that the Cd(OH) 2 nanostructures crystallized in the wurtzite structure without any special orientation. The photoluminescence spectrum of Cd(OH) 2 nanostructures appears as two emission bands: one related to green emission at 475-510 nm, and the other related to deep level emission at 510-540 nm. Also the formation mechanisms of the nanowires are presented. The growth mechanism involves the irreversible and specifically oriented self-assembly of primary nanocrystals and results in the formation of the nanowires. (orig.)

Templated Synthesis of Magnetic Nanoparticles through the Self-Assembly of Polymers and Surfactants

Directory of Open Access Journals (Sweden)

Vo Thu An Nguyen

2014-08-01

Full Text Available The synthesis of superparamagnetic nanoparticles (NPs for various technological applications continues to be an interesting research topic. The successful application of superparamagnetic NPs to each specific area typically depends on the achievement of high magnetization for the nanocrystals obtained, which is determined by their average size and size distribution. The size dispersity of magnetic NPs (MNPs is markedly improved when, during the synthesis, the nucleation and growth steps of the reaction are well-separated. Tuning the nucleation process with the assistance of a hosting medium that encapsulates the precursors (such as self-assembled micelles, dispersing them in discrete compartments, improves control over particle formation. These inorganic-organic hybrids inherit properties from both the organic and the inorganic materials, while the organic component can also bring a specific functionality to the particles or prevent their aggregation in water. The general concept of interest in this review is that the shape and size of the synthesized MNPs can be controlled to some extent by the geometry and the size of the organic templates used, which thus can be considered as molds at the nanometer scale, for both porous continuous matrices and suspensions.

A template-free sol-gel technique for controlled growth of ZnO nanorod arrays

International Nuclear Information System (INIS)

Huang, N.; Zhu, M.W.; Gao, L.J.; Gong, J.; Sun, C.; Jiang, X.

2011-01-01

The growth of ZnO nanorod arrays via a template-free sol-gel process was investigated. The nanorod is single-crystalline wurtzite structure with [0 0 0 1] growth direction determined by the transmission electron microscope. The aligned ZnO arrays were obtained directly on the glass substrates by adjusting the temperatures and the withdrawal speeds, without seed-layer or template assistant. A thicker oriented ZnO nanorod arrays was obtained at proper experimental conditions by adding dip-coating layers. Room temperature photoluminescence spectrum exhibits an intensive UV emission with a weak broad green emission as well as a blue double-peak emission located at 451 and 468 nm, respectively. Further investigation results show that the difference in the alignment of nanorods ascribes to the different orientations of the nanoparticles-packed film formed prior to nanorods on the substrate. Well ordered ZnO nanorods are formed from this film with good c-axis orientation. Our study is expected to pave a way for direct growth of oriented nanorods by low-cost solution approaches.

Template-Free Synthesis of Hollow-Structured Co ₃ O ₄ Nanoparticles as High-Performance Anodes for Lithium-Ion Batteries

Energy Technology Data Exchange (ETDEWEB)

Wang, Deli; Yu, Yingchao; He, Huan; Wang, Jie; Zhou, Weidong; Abruña, Hector D.

2015-02-24

We have developed a template-free procedure to synthesize Co3O4 hollow-structured nanoparticles on a Vulcan XC-72 carbon support. The material was synthesized via an impregnation–reduction method followed by air oxidation. In contrast to spherical particles, the hollow-structured Co3O4 nanoparticles exhibited excellent lithium storage capacity, rate capability, and cycling stability when used as the anode material in lithium-ion batteries. Electrochemical testing showed that the hollow-structured Co3O4 particles delivered a stable reversible capacity of about 880 mAh/g (near the theoretical capacity of 890 mAh/g) at a current density of 50 mA/g after 50 cycles. The superior electrochemical performance is attributed to its unique hollow structure, which combines nano- and microscale properties that facilitate electron transfer and enhance structural robustness.

GRINDING SOLVENT-FREE PAAL-KNORR PYRROLE SYNTHESIS ...

African Journals Online (AJOL)

Paal-Knorr pyrrole synthesis on smectites as recyclable and green catalysts. Bull. Chem. Soc. .... 1-Propyl-2,5-dimethyl-1H-pyrrole (8a). Oil (reported as oil .... of pyrroles catalyzed by zirconium chloride under solvent-free conditions . Ultrason.

Applications of cell-free protein synthesis in synthetic biology: Interfacing bio-machinery with synthetic environments.

Science.gov (United States)

Lee, Kyung-Ho; Kim, Dong-Myung

2013-11-01

Synthetic biology is built on the synthesis, engineering, and assembly of biological parts. Proteins are the first components considered for the construction of systems with designed biological functions because proteins carry out most of the biological functions and chemical reactions inside cells. Protein synthesis is considered to comprise the most basic levels of the hierarchical structure of synthetic biology. Cell-free protein synthesis has emerged as a powerful technology that can potentially transform the concept of bioprocesses. With the ability to harness the synthetic power of biology without many of the constraints of cell-based systems, cell-free protein synthesis enables the rapid creation of protein molecules from diverse sources of genetic information. Cell-free protein synthesis is virtually free from the intrinsic constraints of cell-based methods and offers greater flexibility in system design and manipulability of biological synthetic machinery. Among its potential applications, cell-free protein synthesis can be combined with various man-made devices for rapid functional analysis of genomic sequences. This review covers recent efforts to integrate cell-free protein synthesis with various reaction devices and analytical platforms. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evolvement of soft templates in surfactant/cosurfactant system for shape control of ZnSe nanocrystals

Energy Technology Data Exchange (ETDEWEB)

Hou Bo [Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming 650091 (China); Liu Yongjun [Advanced Analysis and Measurement Center, Yunnan University, Kunming 650091 (China); Li Yanjuan [Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming 650091 (China); Yuan Bo [Advanced Analysis and Measurement Center, Yunnan University, Kunming 650091 (China); Jia Mingfen [Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming 650091 (China); Jiang Fengzhi, E-mail: fengzhij@ynu.edu.cn [Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming 650091 (China); Advanced Analysis and Measurement Center, Yunnan University, Kunming 650091 (China)

2012-03-25

Highlights: Black-Right-Pointing-Pointer Soft templates were found in the shape control synthesis of ZnSe nanocrystals. Black-Right-Pointing-Pointer Micelle formation model in the soft templates system was proposed and proved. Black-Right-Pointing-Pointer Different shapes of ZnSe nanocrystals were prepared and explained by proposed model. - Abstract: The evolution of soft templates in the synthesis of ZnSe nanocrystals realized through a surfactant/cosurfactant system was investigated and a micelle formation process model was proposed. Through freeze-fracture electron microscopy, it was proven that template micelles were formed in the zinc precursors. Furthermore, it was found that a long stirring period was essential for achieving the lowest energy state of the soft templates which were used for synthesizing monodisperse ZnSe quantum dots.

Preparation of ubiquitin-conjugated proteins using an insect cell-free protein synthesis system.

Science.gov (United States)

Suzuki, Takashi; Ezure, Toru; Ando, Eiji; Nishimura, Osamu; Utsumi, Toshihiko; Tsunasawa, Susumu

2010-01-01

Ubiquitination is one of the most significant posttranslational modifications (PTMs). To evaluate the ability of an insect cell-free protein synthesis system to carry out ubiquitin (Ub) conjugation to in vitro translated proteins, poly-Ub chain formation was studied in an insect cell-free protein synthesis system. Poly-Ub was generated in the presence of Ub aldehyde (UA), a de-ubiquitinating enzyme inhibitor. In vitro ubiquitination of the p53 tumor suppressor protein was also analyzed, and p53 was poly-ubiquitinated when Ub, UA, and Mdm2, an E3 Ub ligase (E3) for p53, were added to the in vitro reaction mixture. These results suggest that the insect cell-free protein synthesis system contains enzymatic activities capable of carrying out ubiquitination. CBB-detectable ubiquitinated p53 was easily purified from the insect cell-free protein synthesis system, allowing analysis of the Ub-conjugated proteins by mass spectrometry (MS). Lys 305 of p53 was identified as one of the Ub acceptor sites using this strategy. Thus, we conclude that the insect cell-free protein synthesis system is a powerful tool for studying various PTMs of eukaryotic proteins including ubiqutination presented here.

A flexible, bolaamphiphilic template for mesoporous silicas.

Science.gov (United States)

Yuen, Alexander K L; Heinroth, Falk; Ward, Antony J; Masters, Anthony F; Maschmeyer, Thomas

2013-08-28

A novel symmetrical bolaamphiphile, containing two N-methylimidazolium head-groups bridged by a 32-methylene linker, was synthesized and characterized. A variety of mesoporous silicas was prepared using the bolaamphiphile as a "soft template". The effects of absolute surfactant concentration and synthesis conditions upon the morphologies of these silicas were investigated. For a given surfactant concentration, particle morphology; pore size; and pore ordering were modified through control of the template to silica-precursor ratio and synthesis conditions. Observed morphologies included: lenticular core-shell nanoparticles and decorticated globules, truncated hexagonal plates, and sheets. In all cases the mesopores are aligned along the shortest axis of the nanomaterial. Decorticated materials displayed surface areas of up to 1200 m(2) g(-1) and pore diameters (D(BJH)) of 24-28 Å. Small-angle X-ray diffraction and transmission electron microscopy measurements revealed that the majority of the materials has elliptical pores arranged in rectangular lattices (c2mm). Adoption of this symmetry group is a result of the template aggregate deformation from a regular hexagonal phase of cylindrical rods to a ribbon phase under the synthetic conditions.

Synthesis and characterization of CoPt nanoparticles prepared by room temperature chemical reduction with PAMAM dendrimer as template.

Science.gov (United States)

Wan, Haiying; Shi, Shifan; Bai, Litao; Shamsuzzoha, Mohammad; Harrell, J W; Street, Shane C

2010-08-01

We describe an approach to synthesize monodisperse CoPt nanoparticles with dendrimer as template by a simple chemical reduction method in aqueous solution using NaBH4 as reducing agent at room temperature. The as-made CoPt nanoparticles buried in the dendrimer matrix have the chemically disordered fcc structure and can be transformed to the fct phase after annealing at 700 degrees C. This is the first report of dendrimer-mediated room temperature synthesis of monodisperse magnetic nanoparticles in aqueous solution.

Solvothermal preparation and fluorescent properties of color-tunable InP/ZnS quantum dots

Energy Technology Data Exchange (ETDEWEB)

Lee, Ju Chul; Jang, Eun-Pyo [Department of Materials Science and Engineering, Hongik University, Seoul 121-791 (Korea, Republic of); Jang, Dong Seon; Choi, Yoonyoung; Choi, Moongoo [Materials and Devices Laboratory, LGE Advanced Research Institute, LG Electronics, Seoul 137-724 (Korea, Republic of); Yang, Heesun, E-mail: hyang@hongik.ac.kr [Department of Materials Science and Engineering, Hongik University, Seoul 121-791 (Korea, Republic of)

2013-02-15

This work reports on the solvothermal preparation and optical properties of InP core and InP/ZnS core/shell quantum dots (QDs). InP QDs are synthesized using a phosphorus (P) source of tris(dimethylamino)phosphine (P(N(CH{sub 3}){sub 2}){sub 3}) under the solvothermal conditions in the range of reaction temperature of 120-180 Degree-Sign C and reaction time of 12 h-1 week to tune their size. ZnS shelling is also solvothermally performed by varying the shell growth temperature from 180 to 220 Degree-Sign C for 6 h, and then respective InP and InP/ZnS QDs are subjected to the size-sorting procedure. Effects of the shelling temperature on the fluorescent attributes (emission peak wavelength, bandwidth, and quantum yield) of the resulting size-sorted InP/ZnS QD fractions are investigated. The qualitative information on the shell thickness as a function of shelling temperature is furthermore provided by x-ray diffraction and x-ray photoelectron spectroscopy. - Highlights: Black-Right-Pointing-Pointer InP/ZnS core/shell QDs are prepared using a P source of P(N(CH{sub 3}){sub 2}){sub 3} by a stepwise solvothermal approach. Black-Right-Pointing-Pointer Widely emission-tuable InP/ZnS QDs are realized by varying the solvothermal condition for core QD growth. Black-Right-Pointing-Pointer Effects of ZnS shelling temperature on fluorescent properties of InP/ZnS QDs are investigated.

Solvothermal preparation and fluorescent properties of color-tunable InP/ZnS quantum dots

International Nuclear Information System (INIS)

Lee, Ju Chul; Jang, Eun-Pyo; Jang, Dong Seon; Choi, Yoonyoung; Choi, Moongoo; Yang, Heesun

2013-01-01

This work reports on the solvothermal preparation and optical properties of InP core and InP/ZnS core/shell quantum dots (QDs). InP QDs are synthesized using a phosphorus (P) source of tris(dimethylamino)phosphine (P(N(CH 3 ) 2 ) 3 ) under the solvothermal conditions in the range of reaction temperature of 120–180 °C and reaction time of 12 h−1 week to tune their size. ZnS shelling is also solvothermally performed by varying the shell growth temperature from 180 to 220 °C for 6 h, and then respective InP and InP/ZnS QDs are subjected to the size-sorting procedure. Effects of the shelling temperature on the fluorescent attributes (emission peak wavelength, bandwidth, and quantum yield) of the resulting size-sorted InP/ZnS QD fractions are investigated. The qualitative information on the shell thickness as a function of shelling temperature is furthermore provided by x-ray diffraction and x-ray photoelectron spectroscopy. - Highlights: ► InP/ZnS core/shell QDs are prepared using a P source of P(N(CH 3 ) 2 ) 3 by a stepwise solvothermal approach. ► Widely emission-tuable InP/ZnS QDs are realized by varying the solvothermal condition for core QD growth. ► Effects of ZnS shelling temperature on fluorescent properties of InP/ZnS QDs are investigated.

Synthesis of non-siliceous mesoporous oxides.

Science.gov (United States)

Gu, Dong; Schüth, Ferdi

2014-01-07

Mesoporous non-siliceous oxides have attracted great interest due to their unique properties and potential applications. Since the discovery of mesoporous silicates in 1990s, organic-inorganic assembly processes by using surfactants or block copolymers as soft templates have been considered as a feasible path for creating mesopores in metal oxides. However, the harsh sol-gel conditions and low thermal stabilities have limited the expansion of this method to various metal oxide species. Nanocasting, using ordered mesoporous silica or carbon as a hard template, has provided possibilities for preparing novel mesoporous materials with new structures, compositions and high thermal stabilities. This review concerns the synthesis, composition, and parameter control of mesoporous non-siliceous oxides. Four synthesis routes, i.e. soft-templating (surfactants or block copolymers as templates), hard-templating (mesoporous silicas or carbons as sacrificial templates), colloidal crystal templating (3-D ordered colloidal particles as a template), and super lattice routes, are summarized in this review. Mesoporous metal oxides with different compositions have different properties. Non-siliceous mesoporous oxides are comprehensively described, including a discussion of constituting elements, synthesis, and structures. General aspects concerning pore size control, atomic scale crystallinity, and phase control are also reviewed.

Sites of termination of in vitro DNA synthesis on psoralen phototreated single-stranded templates

International Nuclear Information System (INIS)

Piette, J.; Hearst, J.

1985-01-01

Single-stranded DNA has been photochemically induced to react with 4'-hydroxymethyl-4,5',8-trimethylpsoralen (HMT) and used as substrate for DNA replication with E. coli DNA polymerase I large fragment. By using the dideoxy sequencing procedure, it is possible to map the termination sites on the template photoreacted with HMT. These sites occur at the nucleotides preceding each thymine residue (and a few cytosine residues), emphasizing the fact that in a single-stranded stretch of DNA, HMT reacts with each thymine residue without any specificity regarding the flanking base sequence of the thymine residues. In addition, termination of DNA synthesis due to psoralen-adducted thymine is not influenced by the efficiency of the 3'-5' exonuclease proof-reading activity of the DNA polymerase. (author)

Synthesis of polymer nanostructures via the use of surfactant surface aggregates as templates

Science.gov (United States)

Marquez, Maricel

The subject of this work is the synthesis of polymer nanostructures via the use of surfactant surface aggregates as templates, also termed Template Assisted Admicellar Polymerization (TAAP). The first chapter reviews some of the most current nanopatterning techniques (including both top-down and bottom-up approaches), with particular emphasis on the fabrication of organic and inorganic patterned nanostructures via particle lithography. In chapter 2, highly ordered hexagonal arrays of latex spheres were prepared on highly ordered pyrolytic graphite (HOPG) from a variation of the Langmuir Blodgett technique, using an anionic surfactant (SDS), and a low molecular weight (ca. 10000) polyacrylamide as spreading agents. When a nonionic polyethoxylated (EO = 9) surfactant was used as the spreading agent, no ordered arrays were observed. Based on the correlation found between the surface tension in the presence of the latex particles and the critical concentration at which hexagonal arrangements of latex spheres occurs; a model was proposed to explain the role of the spreading agent in forming stable monolayers at the air/liquid interface, which in turn are necessary for the formation of well-ordered monolayers on a solid substrate from the LB technique. According to this model, solid-like regions of small numbers of latex spheres form at the liquid-air interface, which are then transferred to the substrate. These ordered regions then act as nuclei for the formation of 2D arrays of latex spheres on the surface upon water evaporation. The role of other factors such as relative humidity, substrate and solvent choice, and pulling vs. compression speed were also found to affect the quality of the monolayers formed. Finally, a simple, easy to automate, yet effective surface tension method was proposed to predict the optimal conditions for the formation of ordered monolayers using a variation of the LB deposition method from any monodisperse set of spheres. In chapter 3, a novel

A template-free method for stable CuO hollow microspheres fabricated from a metal organic framework (HKUST-1).

Science.gov (United States)

Zhang, Suoying; Liu, Hong; Liu, Pengfei; Yang, Zhuhong; Feng, Xin; Huo, Fengwei; Lu, Xiaohua

2015-06-07

Uniform CuO hollow microspheres were successfully achieved from a non-uniform metal organic framework by using a template-free method. The process mechanism has been revealed to be spherical aggregation and Ostwald ripening. When tested in CO oxidation and heat treatment, these assembled microspheres exhibited an excellent catalytic performance and show a much better stability than the inherited hollow structure from MOFs.

Protecting-Group-Free Synthesis of 2-Deoxy-Aza-Sugars

Directory of Open Access Journals (Sweden)

Mattie Simon Maria Timmer

2009-12-01

Full Text Available The protecting-group-free asymmetric synthesis of 1,2,4-trideoxy-1,4-imino-L-xylitol is readily achieved in five steps from 2-deoxy-D-ribose and with an overall yield of 48%. Key in this synthesis is the application of our recently developed Vasella-reductive amination and carbamate annulation methodologies to the synthesis of 2-deoxy-aza-sugars. The carbamate annulation occurred with excellent yield and diastereoselectively (>20:1 d.r., in favour of the 3,4-cis isomer.

Microwave-assisted silica-promoted solvent-free synthesis of ...

Indian Academy of Sciences (India)

method using microwave irradiation with an excellent yield. The newly ... Table 1. Silica promoted microwave-assisted solvent-free synthesis of quinazolinone ... Time (min). Yield (%)a ..... thanks SC/ST cell of Bangalore University for research.

A facile template method to synthesize significantly improved LiNi0.5Mn1.5O4 using corn stalk as a bio-template

International Nuclear Information System (INIS)

Liu, Guiyang; Kong, Xin; Sun, Hongyan; Wang, Baosen; Yi, Zhongzhou; Wang, Quanbiao

2014-01-01

In order to simplify the template method for the synthesis of cathode materials for lithium ion batteries, a facile template method using plant stalks as bio-templates has been introduced. Based on this method, LiNi 0.5 Mn 1.5 O 4 spinel with a significantly improved electrochemical performance has been synthesized using corn stalk as a template. X-ray diffraction (XRD), Fourier transform infrared pectroscopy (FTIR) and scanning electron microscope (SEM) have been used to investigate the phase composition and micro-morphologies of the products. Charge-discharge measurements in lithium cells, cyclic voltammetry (CV) and Electrochemical impedance spectroscopy (EIS) have been used to study the electrochemical performance of the products. The results indicate that the templated product exhibits higher crystallinity than that of non-templated product. Both of the templated product and the non-templated product are combination of the ordered space group P4 3 32 and the disordered Fd-3 m. The specific BET surface area of the templated product is about twice larger than that of the non-templated product. Moreover, the electrochemical performances of the templated product including specific capacity, cycling stability and rate capability are significantly improved as compared with the non-templated product, due to its higher crystallinity, larger Li + diffusion coefficient and lower charge transfer resistance

Minute-made and low carbon fingerprint microwave synthesis of high quality templated mesoporous silica

KAUST Repository

Chaignon, J.; Bouizi, Y.; Davin, L.; Calin, N.; Albela, B.; Bonneviot, L.

2015-01-01

© The Royal Society of Chemistry 2015. Hexagonal mesostructured templated silicas were produced in less than 10 minutes using an ultra-fast microwave assisted hydrothermal synthesis. Typically, 10 g can be prepared at once in a commercial microwave device usually devoted to analytical digestion. Undesired alcohol side-products were avoided using inexpensive water colloidal silica instead of silicon alkoxides as the silicon source. In comparison with classical heating activation, the absence of pore expansion and pore wall thickening even for synthesis temperatures as high as 190 °C evidenced that heat transfer and diffusion of matter had no time to take place. Comparison between the chemically extracted and calcined samples shows that the structure was better stabilized for autoclaving above 150 °C. However, a fast temperature ramping and final temperatures above 180 °C were required to sear structures of the highest quality comparable to that of the best conventional methods. This is rationalized by assuming a sequential flake-by-flake assembly of the pore-wall at the micelle palisade. Notably, tosylate counterions yielded better structural characteristics than bromide counterions and allowed better opportunities for surfactant recycling.

Green synthesis of graphitic carbon nitride nanodots using sodium chloride template

Energy Technology Data Exchange (ETDEWEB)

Yuan, Bo [National University of Defense Technology, College of Science (China); Zou, Xianshuai; Yan, Tingnan; Fei, Junjie [Xiangtan University, College of Chemistry (China); Chu, Zengyong, E-mail: chuzy@nudt.edu.cn [National University of Defense Technology, College of Science (China)

2016-05-15

Graphitic carbon nitride (g-C{sub 3}N{sub 4}) nanodots are simply prepared by a thermal treatment of dicyandiamide (DCDA) confined within NaCl templates. Cyano groups are introduced to the nanodots due to the catalytic effect of NaCl. NaCl could facilitate the polymerization of DCDA at lower temperatures, but will promote the decomposition when the temperature is above 550 °C. Thermal treatment at 600 °C for 30 min is the optimal condition for the scalable synthesis of g-C{sub 3}N{sub 4} nanodots with an average diameter of ~9 nm. g-C{sub 3}N{sub 4} nanodots have a higher band gap of 3.1 eV, which can emit bright blue light due to the decreased diameter, the introduction of cyano groups, and the incorporation of some sodium ions. The residue sodium ions and the cyano groups might lead to the local distortion of the graphitic crystals, or act as recombination centers for the enhanced photoluminescence.Graphical Abstract.

Synthesis and characterization of Na(Gd0.5Lu0.5)F4: Nd3+,a core-shell free multifunctional contrast agent.

Science.gov (United States)

Mimun, L Christopher; Ajithkumar, G; Rightsell, Chris; Langloss, Brian W; Therien, Michael J; Sardar, Dhiraj K

2017-02-25

Compared to conventional core-shell structures, core-shell free nanoparticles with multiple functionalities offer several advantages such as minimal synthetic complexity and low production cost. In this paper, we present the synthesis and characterization of Nd 3+ doped Na(Gd 0.5 Lu 0.5 )F 4 as a core-shell free nanoparticle system with three functionalities. Nanocrystals with 20 nm diameter, high crystallinity and a narrow particle size distributions were synthesized by the solvothermal method and characterized by various analytical techniques to understand their phase and morphology. Fluorescence characteristics under near infrared (NIR) excitation at 808 nm as well as X-ray excitation were studied to explore their potential in NIR optical and X-ray imaging. At 1.0 mol% Nd concentration, we observed a quantum yield of 25% at 1064 nm emission with 13 W/cm 2 excitation power density which is sufficiently enough for imaging applications. Under 130 kVp (5 mA) power of X-ray excitation, Nd 3+ doped Na(Gd 0.5 Lu 0.5 )F 4 shows the characteristic emission bands of Gd 3+ and Nd 3+ with the strongest emission peak at 1064 nm due to Nd 3+ . Furthermore, magnetization measurements show that the nanocrystals are paramagnetic in nature with a calculated magnetic moment per particle of ~570 μB at 2T. These preliminary results support the suitability of the present nanophosphor as a multimodal contrast agent with three imaging features viz. optical, magnetic and X-ray.

Synthesis of boron nitride nanotubes with SiC nanowire as template

International Nuclear Information System (INIS)

Zhong, B.; Song, L.; Huang, X.X.; Wen, G.W.; Xia, L.

2011-01-01

Highlights: → Boron nitride nanotubes (BNNTs) have been fabricated using SiC nanowires as template. → SiC nanowires could be effectively etched out by the vapors decomposed from ammonia borane, leading to the formation of BNNTs. → A template self-sacrificing mechanism is responsible for the formation of BNNTs. -- Abstract: A novel template method for the preparation of boron nitride nanotubes (BNNTs) using SiC nanowire as template and ammonia borane as precursor is reported. We find out that the SiC nanowires could be effectively etched out by the vapors decomposed from ammonia borane, leading to the formation of BNNTs. The as-prepared products are well characterized by means of complementary analytical techniques. A possible formation mechanism is disclosed. The method developed here paves the way for large scale production of BNNTs.

Surfactant and template free synthesis of porous ZnS nanoparticles

International Nuclear Information System (INIS)

Akhtar, Muhammad Saeed; Riaz, Saira; Mehmood, Rana Farhat; Ahmad, Khuram Shahzad; Alghamdi, Yousef; Malik, Mohammad Azad; Naseem, Shahzad

2017-01-01

ZnS thin films composed of porous nanoparticles have been deposited on to glass substrates by combining three simple synthesis methodologies i.e. chemical bath deposition, co-precipitation and spin coating. The XRD results reveal the cubic phase of ZnS thin films crystallized at nano scale. The crystallite size estimated by Scherrer formula was 3.4 nm. The morphology of the samples was analyzed through scanning electron microscopy (SEM) and is evident that thin films are composed of porous nanoparticles with an average size of 150 nm and pores of 40 nm on almost every grain. Crystallinity, phase and morphology were further confirmed via transmission electron microscopy (TEM). The stoichiometry and phase purity of thin films were determined by energy dispersive X-ray (EDX) spectrum and X-ray photoelectron spectroscopy (XPS) analysis, respectively. The surface topography and homogeneity of thin films were analyzed by atomic force microscopy (AFM) and obtained root mean square roughness (4.0326 nm) reveals the morphologically homogeneous growth of ZnS on glass substrates. The UV–Vis spectroscopy and photoluminescence (PL) were carried out to estimate the band gap and observe the emission spectra in order to speculate the viability of ZnS porous nanoparticles in optoelectronic devices and sensors. - Highlights: • ZnS thin films composed of porous nanoparticles have been deposited. • Methodology is based on a combination of three techniques. • Cubic phase ZnS nanoparticles deposited onto glass substrates. • Films characterized by UV/Vis, PL, XRD, SEM, TEM, AFM and XPS.

Surfactant and template free synthesis of porous ZnS nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Akhtar, Muhammad Saeed [Division of Science and Technology, University of Education, College Road Township, Lahore (Pakistan); Schools of Materials, The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Riaz, Saira [Centre of Excellence in Solid State Physics, University of the Punjab, Lahore-54590 (Pakistan); Mehmood, Rana Farhat [University of Education, Lahore, D.G. Khan Campus, Kangan Road, Dera Ghazi Khan (Pakistan); Ahmad, Khuram Shahzad [Environmental Sciences Department, Fatima Jinnah Women University, The Mall, Rawalpindi (Pakistan); Alghamdi, Yousef [Department of Chemistry, Faculty of Science & Art –Rabigh, King Abdulaziz University, Jeddah (Saudi Arabia); Malik, Mohammad Azad, E-mail: Azad.malik@manchester.ac.uk [Schools of Materials, The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Department of Chemistry, University of Zululand, Private Bag X1001, Kwa-Dlangezwa, 3886 (South Africa); Naseem, Shahzad [Centre of Excellence in Solid State Physics, University of the Punjab, Lahore-54590 (Pakistan)

2017-03-01

ZnS thin films composed of porous nanoparticles have been deposited on to glass substrates by combining three simple synthesis methodologies i.e. chemical bath deposition, co-precipitation and spin coating. The XRD results reveal the cubic phase of ZnS thin films crystallized at nano scale. The crystallite size estimated by Scherrer formula was 3.4 nm. The morphology of the samples was analyzed through scanning electron microscopy (SEM) and is evident that thin films are composed of porous nanoparticles with an average size of 150 nm and pores of 40 nm on almost every grain. Crystallinity, phase and morphology were further confirmed via transmission electron microscopy (TEM). The stoichiometry and phase purity of thin films were determined by energy dispersive X-ray (EDX) spectrum and X-ray photoelectron spectroscopy (XPS) analysis, respectively. The surface topography and homogeneity of thin films were analyzed by atomic force microscopy (AFM) and obtained root mean square roughness (4.0326 nm) reveals the morphologically homogeneous growth of ZnS on glass substrates. The UV–Vis spectroscopy and photoluminescence (PL) were carried out to estimate the band gap and observe the emission spectra in order to speculate the viability of ZnS porous nanoparticles in optoelectronic devices and sensors. - Highlights: • ZnS thin films composed of porous nanoparticles have been deposited. • Methodology is based on a combination of three techniques. • Cubic phase ZnS nanoparticles deposited onto glass substrates. • Films characterized by UV/Vis, PL, XRD, SEM, TEM, AFM and XPS.

Soft plasma processing of organic nanowires: a route for the fabrication of 1D organic heterostructures and the template synthesis of inorganic 1D nanostructures.

Science.gov (United States)

Alcaire, Maria; Sanchez-Valencia, Juan R; Aparicio, Francisco J; Saghi, Zineb; Gonzalez-Gonzalez, Juan C; Barranco, Angel; Zian, Youssef Oulad; Gonzalez-Elipe, Agustin R; Midgley, Paul; Espinos, Juan P; Groening, Pierangelo; Borras, Ana

2011-11-01

Hierarchical (branched) and hybrid metal-NPs/organic supported NWs are fabricated through controlled plasma processing of metalloporphyrin, metallophthalocyanine and perylene nanowires. The procedure is also applied for the development of a general template route for the synthesis of supported metal and metal oxide nanowires.

Synthesis of nano γ-alumina by the solvothermal technique

International Nuclear Information System (INIS)

Meor Yusoff Meor Sulaiman; Masliana Muslimin

2006-01-01

The paper describes work done on synthesis of γ-alumina by using the solvo thermal technique. Synthesis of γ-alumina involves the transition reactions of the aluminium hydroxide into alumina by a dehydroxylation process. As there are many forms of transition aluminas produced during this process, a x-ray diffraction (XRD) technique was used to identify γ-alumina and the other forms of alumina. After establishing the optimum conditions for the production of a single-phase γ-alumina, characteristic study on the product was performed. An important parameter in establishing nanosized powders is their crystallite size and analysis of the γ-alumina shows that it is a nanosized powder with a size of 28 nm. Other properties analysed include morphology, surface area and particle size. (Author)

Solvothermal Synthesis of Fe2O3 Loaded Activated Carbon as Electrode Materials for High-performance Electrochemical Capacitors

International Nuclear Information System (INIS)

Li, Ying; Kang, Litao; Bai, Gailing; Li, Peiyang; Deng, Jiachun; Liu, Xuguang; Yang, Yongzhen; Gao, Feng; Liang, Wei

2014-01-01

This article describes a facile solvothermal synthesis method to prepare Fe 2 O 3 /AC composites for electrochemical capacitors from Iron (III) chloride hexahydrate (FeCl 3 ·6H 2 O), activated carbon (AC, from petroleum coke), and four different precipitants (i.e., NaOH, CH 3 COONa, HMT, CO(NH 2 ) 2 ). X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDS) and Thermogravimetric (TG) analysis show that the products consisted of nanosized α-Fe 2 O 3 (weight ratios: 48.1, 47.9, 44.2, 44.3%) loaded onto AC particles (∼ 20 μm). Significantly, both kind and dosage of precipitants exhibit effects on the specific capacitances of Fe 2 O 3 /AC composites. The highest specific capacitance reaches up to 240 F g −1 (at a current density of 1 A g −1 in 6 M KOH aqueous electrolyte) when the molar ratio of CH 3 COONa: FeCl 3 is 9. On the other hand, the sample prepared with NaOH: FeCl 3 molar ratio being 1.5 exhibits excellent rate capability with specific capacitance of 215 F g −1 at 1 A g −1 , and 89.3, 82.3, 78.1, 72.6 and 65.1% capacity retention at 2, 5, 10, 20, and 40 A g −1 , respectively. These electrochemical performances are superior to other materials consisted of Fe 2 O 3 /carbon nanotube (CNT), graphene oxide (GO) or reduced graphene oxide (rGO) composites, demonstrating the great potential of Fe 2 O 3 /AC composites in the development of high-performance electrode materials for electrochemical capacitors

Preparation of Three-Dimensional Graphene Foams Using Powder Metallurgy Templates.

Science.gov (United States)

Sha, Junwei; Gao, Caitian; Lee, Seoung-Ki; Li, Yilun; Zhao, Naiqin; Tour, James M

2016-01-26

A simple and scalable method which combines traditional powder metallurgy and chemical vapor deposition is developed for the synthesis of mesoporous free-standing 3D graphene foams. The powder metallurgy templates for 3D graphene foams (PMT-GFs) consist of particle-like carbon shells which are connected by multilayered graphene that shows high specific surface area (1080 m(2) g(-1)), good crystallization, good electrical conductivity (13.8 S cm(-1)), and a mechanically robust structure. The PMT-GFs did not break under direct flushing with DI water, and they were able to recover after being compressed. These properties indicate promising applications of PMT-GFs for fields requiring 3D carbon frameworks such as in energy-based electrodes and mechanical dampening.

Solvothermal synthesis of tetravalent uranium with isophthalate or pyromellitate ligands

Energy Technology Data Exchange (ETDEWEB)

Falaise, Clement; Delille, Jason; Volkringer, Christophe; Loiseau, Thierry [Contribution from Unite de Catalyse et Chimie du Solide (UCCS) - UMR CNRS 8181, Universite de Lille, USTL-ENSCL, Villeneuve d' Ascq (France)

2015-06-15

Three new coordination polymers bearing tetravalent uranium have been isolated with the O-donor ligands such as isophthalate (1,3-bdc) or pyromellitate (btec). The compounds 1 and 3 have been solvothermally synthesized in N,N-dimethylformamide (DMF). The crystal structure of U(1,3-bdc){sub 2}(DMF) (1) is built up from discrete tricapped trigonal-primastic UO{sub 9} units, for which one carbonyl oxygen atom from DMF is bound to uranium. The connection of the UO{sub 9} units with the isophthalate linkers occurs in a chelating and bidentate fashion and gives rise to the formation of a 3D framework, delimiting narrow channels running along the [101] direction. Upon heating, the DMF molecules are removed, generating the second phase U(1,3-bdc){sub 2} (2) compound, closely related to 1. Indeed, the coordination environment of uranium is reduced to eight with a distorted square-antiprismatic geometry. This transition induces the relative shrinkage of the network (ΔV = 23 %). The structure of the compound U(btec)(DMF){sub 2} (3) also exhibits a 3D framework composed of an isolated bicapped square-antiprismatic UO{sub 10} unit, for which two carbonyl oxygen atoms from DMF are bonded to uranium. Pyromellitate ensures the connection of the UO{sub 10} units through the carboxylate arms in a chelating mode. This results in the formation of a network with diamond-shaped channels, developed along the c axis and encapsulating the DMF molecules. In contrast to 1, no stable phase is observed upon removing the DMF species by heating. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Effects of inherent/enhanced solid acidity and morphology of diatomite templates on the synthesis and porosity of hierarchically porous carbon.

Science.gov (United States)

Liu, Dong; Yuan, Peng; Tan, Daoyong; Liu, Hongmei; Fan, Mingde; Yuan, Aihua; Zhu, Jianxi; He, Hongping

2010-12-21

The inherent or enhanced solid acidity of raw or activated diatomite is found to have significant effects on the synthesis of hierarchically porous diatomite-templated carbon with high surface area and special porous structure. The solid acidity makes raw/activated diatomite a catalyst for the generation of porous carbon, and the porous parameters of the carbon products are strongly dependent on the solid acidity of diatomite templates. The morphology of diatomite also dramatically affects the textural structure of porous carbon. Two types of macroporous structures in the carbon product, the partially solid pillars and the ordered hollow tubes, derive from the replication of the central and the edge pores of diatom shell, respectively. The hierarchically porous carbon shows good capability for the adsorption of solvent naphtha and H(2), enabling potential applications in adsorption and gas storage.

Uranyl Sulfate Nanotubules Templated by N-phenylglycine

Directory of Open Access Journals (Sweden)

Oleg I. Siidra

2018-04-01

Full Text Available The synthesis, structure, and infrared spectroscopy properties of the new organically templated uranyl sulfate Na(phgH+7[(UO26(SO410](H2O3.5 (1, obtained at room temperature by evaporation from aqueous solution, are reported. Its structure contains unique uranyl sulfate [(UO26(SO410]8− nanotubules templated by protonated N-phenylglycine (C6H5NH2CH2COOH+. Their internal diameter is 1.4 nm. Each of the nanotubules is built from uranyl sulfate rings sharing common SO4 tetrahedra. The template plays an important role in the formation of the complex structure of 1. The aromatic rings are stacked parallel to each other due to the effect of π–π interaction with their side chains extending into the gaps between the nanotubules.

Hollow colloidal particles by emulsion templating, from synthesis to self-assembly

NARCIS (Netherlands)

Zoldesi, C.I.

2006-01-01

This research was focused on developing a new method to prepare hollow colloidal particles in the micrometer range, based on emulsion templating, characterization of both the templates and the resulting particles from physical and chemical viewpoint, and fabrication of materials based on such

Pending templates imprinted polymers-hypothesis, synthesis, adsorption, and chromatographic properties.

Science.gov (United States)

Yang, Chun; Luan, Xinjie; Zhao, Meifeng; Liu, Guofeng; Wang, Jian; Qu, Qishu; Hu, Xiaoya

2013-05-01

This is the first time when protein-imprinted polymers are prepared with "pending templates." The polymers were synthesized in the presence of a real sample (chicken egg white), rather than any known commercial proteins. Compared with a simultaneously synthesized nonimprinted control polymer, the polymers show higher adsorption capacity for abundant components (as "pending templates") in the original sample. Chromatography experiments indicated that the columns made of the imprinted polymers could retain abundant species (imprinted) and separate them from those not imprinted. Thus, the sample could be split into dimidiate subfractions with reduced complexities. "Pending template imprinting" suggests a new way to investigate molecular imprinting, especially to dissect, simplify, and analyze complicated samples through a series of polymers just imprinted by the samples per se. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and thermal characterization of CdS nano crystals in previously formed template of maleic anhydride-octene 1-vinyl butyl terpolymer

International Nuclear Information System (INIS)

Akbarov, O.H; Mammadova, R.E; Malikov, E.Y.

2008-01-01

Full text: Nano crystals have dimensions in the range 10100 nm. Crystals in this size range possess unique properties, which enable scientists to manufacture materials and devices capable of performing unimaginable tasks. For that reason synthesis of this semiconductor nano crystals is expedient. Many useful methods have been used for preparing sulphide semiconductor nano crystals, such as colloidal chemistry method, sol-gel method, inverse micelle method, in situ synthesis and assemble on polymer template. The most significant method is in situ synthesis and assemble of sulphide semiconductor nano crystals on polymer. Compared with other methods, the stability of nanoparticles is improved by the protection and confinement of the copolymer. Because of confinement and protection effects of template environmental risk is prevented in this method. On the base of this principles in situ synthesis of CdS nano crystals in maleic anhydride-octene 1-vinyl butyl terpolymer was realized in this scientific work. First of all in specific condition maleic anhydride, octene 1, and vinyl butyl ether were polymerized to form a terpolymer as the result of radical ter polymerization. In second step CdS nano crystals were synthesized in N,N-dimethylformamide solution of maleic anhydride-octene 1-vinyl butyl terpolymer through the reaction of thiourea with cadmium chloride. In this process CdCI 2 x 2.5H 2 O was dissolved in N,N-dimethylformamide solution of previously formed terpolymer and was heated in 90 0 C temperature for 4 hours with vigorous stirring. Then desired amount of thiourea in N,N-dimethylformamide was quickly injected into the reaction flask using a syringe. The reaction continued for another 1 hour, and a yellow clear solution was obtained, which indicated the formation of CdS nano crystals

Fast microwave-assisted solvothermal synthesis of metal nanoparticles (Pd, Ni, Sn) supported on sulfonated MWCNTs: Pd-based bimetallic catalysts for ethanol oxidation in alkaline medium

CSIR Research Space (South Africa)

Ramulifho, T

2012-01-01

Full Text Available The preparation of metal nanoparticles (Pd, Ni, Sn) supported on sulfonated multi-walled carbon nanotubes (SF-MWCNTs) using a very rapid microwave-assisted solvothermal strategy has been described. Electrocatalytic behaviour of the SF...

Facile preparation of porous carbon from coffee bean waste using low temperature solvothermal method

Science.gov (United States)

Baroroh, L. A. Al; Fitria, D.; Amal, M. I.; Wismogroho, A. S.; Widayatno, W. B.

2018-03-01

In this study, porous carbon made from coffee bean waste (CBW) was carbonized at 500 °C, 600 °C, and 700 °C to find effective temperature. It is verified from the IR spectrum that carbonization process at certain temperature can effectively break cellulose bonding and make aromatics functional group while preserving its carbon structure. The TG-DTA curve shows four stages of decomposition process and confirms most effective carbonization temperature. Activation process of as-carbonized CBW was carried out using solvothermal method in KOH and NH4OH steam environment at 200 °C with variation of 30%, 40%, and 50% solvothermal volume. Scanning electron micrographs reveals significant increase of porosity on the carbon surface and differences of structural pores between the variations. The results show the possible potential of utilizing low temperature-solvothermal method for nanoporous carbon material.

Review of Research on Template Methods in Preparation of Nanomaterials

OpenAIRE

Yadian Xie; Duygu Kocaefe; Chunying Chen; Yasar Kocaefe

2016-01-01

The nanomaterials have been widely used in various fields, such as photonics, catalysis, and adsorption, because of their unique physical and chemical properties. Therefore, their production methods are of utmost importance. Compared with traditional synthetic methods, the template method can effectively control the morphology, particle size, and structure during the preparation of nanomaterials, which is an effective method for their synthesis. The key for the template method is to choose di...

[Synthesis of hollow titania microspheres by using microfluidic droplet-template].

Science.gov (United States)

Ma, Jingyun; Jiang, Lei; Qin, Jianhu

2011-09-01

Droplet-based microfluidics is of great interest due to its particular characteristics compared with the conventional methods, such as reduced reagent consumption, rapid mixing, high-throughput, shape controlled, etc. A novel method using microfluidic droplet as soft template for the synthesis of hollow titania microspheres was developed. A typical polydimethylsiloxane (PDMS) microfluidic device containing "flow-focusing" geometry was used to generate water/oil (W/O) droplet. The mechanism for the hollow structure formation was based on the interfacial hydrolysis reaction between the continuous phase containing titanium butoxide precursor and the dispersed containing water. The continuous phase mixed with butanol was added in the downstream of the channel after the hydrolysis reaction. This step was used for drawing the water out of the microgels for further hydrolysis. The microgels obtained through a glass pipe integrated were washed, dried under vacuum and calcined after aging for a certain time. The fluorescence and scanning electron microscope (SEM) image of the microspheres indicated the hollow structure and the thickness of the shell. In addition, these microspheres with thin shell (about 2 microm) were apt to rupture and collapse. Droplet-based microfluidic offered a gentle and size-controllable manner to moderate this problem. Moreover, it has potential applications in photocatalysis combined with some modification realized on the chip simultaneously.

The Evolution of DNA-Templated Synthesis as a Tool for Materials Discovery.

Science.gov (United States)

O'Reilly, Rachel K; Turberfield, Andrew J; Wilks, Thomas R

2017-10-17

Precise control over reactivity and molecular structure is a fundamental goal of the chemical sciences. Billions of years of evolution by natural selection have resulted in chemical systems capable of information storage, self-replication, catalysis, capture and production of light, and even cognition. In all these cases, control over molecular structure is required to achieve a particular function: without structural control, function may be impaired, unpredictable, or impossible. The search for molecules with a desired function is often achieved by synthesizing a combinatorial library, which contains many or all possible combinations of a set of chemical building blocks (BBs), and then screening this library to identify "successful" structures. The largest libraries made by conventional synthesis are currently of the order of 10 8 distinct molecules. To put this in context, there are 10 13 ways of arranging the 21 proteinogenic amino acids in chains up to 10 units long. Given that we know that a number of these compounds have potent biological activity, it would be highly desirable to be able to search them all to identify leads for new drug molecules. Large libraries of oligonucleotides can be synthesized combinatorially and translated into peptides using systems based on biological replication such as mRNA display, with selected molecules identified by DNA sequencing; but these methods are limited to BBs that are compatible with cellular machinery. In order to search the vast tracts of chemical space beyond nucleic acids and natural peptides, an alternative approach is required. DNA-templated synthesis (DTS) could enable us to meet this challenge. DTS controls chemical product formation by using the specificity of DNA hybridization to bring selected reactants into close proximity, and is capable of the programmed synthesis of many distinct products in the same reaction vessel. By making use of dynamic, programmable DNA processes, it is possible to engineer a

Multi-template synthesis of hierarchically porous carbon spheres with potential application in supercapacitors

NARCIS (Netherlands)

Zhou, Weizheng; Lin, Zhixing; Tong, Gangsheng; Stoyanov, Simeon D.; Yan, Deyue; Mai, Yiyong; Zhu, Xinyuan

2016-01-01

A new and simple multi-template approach towards hierarchical porous carbon (HPC) materials was reported. HPC spheres were prepared by using hierarchical silica capsules (HSCs) as the hard template and triblock copolymer Pluronic P123 as the soft template. Three types of pores were tunably

Content of intrinsic disorder influences the outcome of cell-free protein synthesis.

Science.gov (United States)

Tokmakov, Alexander A; Kurotani, Atsushi; Ikeda, Mariko; Terazawa, Yumiko; Shirouzu, Mikako; Stefanov, Vasily; Sakurai, Tetsuya; Yokoyama, Shigeyuki

2015-09-11

Cell-free protein synthesis is used to produce proteins with various structural traits. Recent bioinformatics analyses indicate that more than half of eukaryotic proteins possess long intrinsically disordered regions. However, no systematic study concerning the connection between intrinsic disorder and expression success of cell-free protein synthesis has been presented until now. To address this issue, we examined correlations of the experimentally observed cell-free protein expression yields with the contents of intrinsic disorder bioinformatically predicted in the expressed sequences. This analysis revealed strong relationships between intrinsic disorder and protein amenability to heterologous cell-free expression. On the one hand, elevated disorder content was associated with the increased ratio of soluble expression. On the other hand, overall propensity for detectable protein expression decreased with disorder content. We further demonstrated that these tendencies are rooted in some distinct features of intrinsically disordered regions, such as low hydrophobicity, elevated surface accessibility and high abundance of sequence motifs for proteolytic degradation, including sites of ubiquitination and PEST sequences. Our findings suggest that identification of intrinsically disordered regions in the expressed amino acid sequences can be of practical use for predicting expression success and optimizing cell-free protein synthesis.

Controlling the anodizing conditions in preparation of an nanoporous anodic aluminium oxide template

Science.gov (United States)

Nazemi, Azadeh; Abolfazl, Seyed; Sadjadi, Seyed

2014-12-01

Porous anodic aluminium oxide (AAO) template is commonly used in the synthesis of one-dimensional nanostructures, such as nanowires and nanorods, due to its simple fabrication process. Controlling the anodizing conditions is important because of their direct influence on the size of AAO template pores; it affects the size of nanostructures that are fabricated in AAO template. In present study, several alumina templates were fabricated by a two-step electrochemical anodization in different conditions, such as the time of first process, its voltage, and electrolyte concentration. The effect of these factors on pore diameters of AAO templates was investigated using scanning electron microscopy (SEM).

Synthesis of platinum nanowheels using a bicellar template.

Science.gov (United States)

Song, Yujiang; Dorin, Rachel M; Garcia, Robert M; Jiang, Ying-Bing; Wang, Haorong; Li, Peng; Qiu, Yan; van Swol, Frank; Miller, James E; Shelnutt, John A

2008-09-24

Disk-like surfactant bicelles provide a unique meso-structured reaction environment for templating the wet-chemical reduction of platinum(II) salt by ascorbic acid to produce platinum nanowheels. The Pt wheels are 496 +/-55 nm in diameter and possess thickened centers and radial dendritic nanosheets (about 2-nm in thickness) culminating in flared dendritic rims. The structural features of the platinum wheels arise from confined growth of platinum within the bilayer that is also limited at edges of the bicelles. The size of CTAB/FC7 bicelles is observed to evolve with the addition of Pt(II) complex and ascorbic acid. Synthetic control is demonstrated by varying the reaction parameters including metal salt concentration, temperature, and total surfactant concentration. This study opens up opportunities for the use of other inhomogeneous soft templates for synthesizing metals, metal alloys, and possibly semiconductors with complex nanostructures.

A Continuous-Exchange Cell-Free Protein Synthesis System Based on Extracts from Cultured Insect Cells

Science.gov (United States)

Stech, Marlitt; Quast, Robert B.; Sachse, Rita; Schulze, Corina; Wüstenhagen, Doreen A.; Kubick, Stefan

2014-01-01

In this study, we present a novel technique for the synthesis of complex prokaryotic and eukaryotic proteins by using a continuous-exchange cell-free (CECF) protein synthesis system based on extracts from cultured insect cells. Our approach consists of two basic elements: First, protein synthesis is performed in insect cell lysates which harbor endogenous microsomal vesicles, enabling a translocation of de novo synthesized target proteins into the lumen of the insect vesicles or, in the case of membrane proteins, their embedding into a natural membrane scaffold. Second, cell-free reactions are performed in a two chamber dialysis device for 48 h. The combination of the eukaryotic cell-free translation system based on insect cell extracts and the CECF translation system results in significantly prolonged reaction life times and increased protein yields compared to conventional batch reactions. In this context, we demonstrate the synthesis of various representative model proteins, among them cytosolic proteins, pharmacological relevant membrane proteins and glycosylated proteins in an endotoxin-free environment. Furthermore, the cell-free system used in this study is well-suited for the synthesis of biologically active tissue-type-plasminogen activator, a complex eukaryotic protein harboring multiple disulfide bonds. PMID:24804975

A facile solvent-free Synthesis Route for the Assembly of Highly CO2 Selective and H2S tolerant NiSIFSIX Metal-Organic Framework

KAUST Repository

Eddaoudi, Mohamed; Shekhah, Osama; Belmabkhout, Youssef; Adil, Karim; Cairns, Amy J.; Bhatt, Prashant

2015-01-01

The development of materials for CO2 capture with high selectivity and high tolerance to H2S is of prime importance for various industrially relevant gas streams (e.g. natural gas and biogas upgrading as well as pre-combustion capture). Here, we report the successful fabrication of a MOF with combined exceptional CO2 capture properties and H2S tolerance, namely Ni SIFSIX based-MOF using both solvothermal and solvent-free methodologies.

A facile solvent-free Synthesis Route for the Assembly of Highly CO2 Selective and H2S tolerant NiSIFSIX Metal-Organic Framework

KAUST Repository

Eddaoudi, Mohamed

2015-07-06

The development of materials for CO2 capture with high selectivity and high tolerance to H2S is of prime importance for various industrially relevant gas streams (e.g. natural gas and biogas upgrading as well as pre-combustion capture). Here, we report the successful fabrication of a MOF with combined exceptional CO2 capture properties and H2S tolerance, namely Ni SIFSIX based-MOF using both solvothermal and solvent-free methodologies.

Self-Templated Stepwise Synthesis of Monodispersed Nanoscale Metalated Covalent Organic Polymers for In Vivo Bioimaging and Photothermal Therapy.

Science.gov (United States)

Shi, Yanshu; Deng, Xiaoran; Bao, Shouxin; Liu, Bei; Liu, Bin; Ma, Ping'an; Cheng, Ziyong; Pang, Maolin; Lin, Jun

2017-09-05

Size- and shape-controlled growth of nanoscale microporous organic polymers (MOPs) is a big challenge scientists are confronted with; meanwhile, rendering these materials for in vivo biomedical applications is still scarce. In this study, a monodispersed nanometalated covalent organic polymer (MCOP, M=Fe, Gd) with sizes around 120 nm was prepared by a self-templated two-step solution-phase synthesis method. The metal ions (Fe 3+ , Gd 3+ ) played important roles in generating a small particle size and in the functionalization of the products during the reaction with p-phenylenediamine (Pa). The resultant Fe-Pa complex was used as a template for the subsequent formation of MCOP following the Schiff base reaction with 1,3,5-triformylphloroglucinol (Tp). A high tumor suppression efficiency for this Pa-based COP is reported for the first time. This study demonstrates the potential use of MCOP as a photothermal agent for photothermal therapy (PTT) and also provides an alternative route to fabricate nano-sized MCOPs. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Selective Synthesis of Mesoporous and Nanorod CeVO4 without Template

International Nuclear Information System (INIS)

Zhu Ling; Li Qin; Li Jiayan; Liu Xiangdong; Meng Jian; Cao Xueqiang

2007-01-01

A simple and efficient method has been established for the selective synthesis of mesoporous and nanorod CeVO 4 with different precursors by sonochemical method. CeVO 4 nanorod can be simply synthesized by ultrasound irradiation of Ce(NO 3 ) 3 and NH 4 VO 3 in aqueous solution without any surfactant or template. While mesoporous CeVO 4 with high specific surface area can be prepared with Ce(NO 3 ) 3 , V 2 O 5 and NaOH in the same way. Mesoporous CeVO 4 has a specific surface area of 122 m 2 g -1 and an average pore size of 5.2 nm; CeVO 4 nanorods have a diameter of about 5 nm, and a length of 100-150 nm. The ultrasound irradiation and ammonia in the reactive solution are two key factors in the formation of such rod-like products. X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric (TG) and differential thermal analyses (DTA), UV/vis absorption spectroscopy and Brunauer-Emmett-Teller (BET) were applied for characterization of the as-prepared products

Template directed synthesis of plasmonic gold nanotubes with tunable IR absorbance.

Science.gov (United States)

Bridges, Colin R; Schon, Tyler B; DiCarmine, Paul M; Seferos, Dwight S

2013-04-01

A nearly parallel array of pores can be produced by anodizing aluminum foils in acidic environments. Applications of anodic aluminum oxide (AAO) membranes have been under development since the 1990's and have become a common method to template the synthesis of high aspect ratio nanostructures, mostly by electrochemical growth or pore-wetting. Recently, these membranes have become commercially available in a wide range of pore sizes and densities, leading to an extensive library of functional nanostructures being synthesized from AAO membranes. These include composite nanorods, nanowires and nanotubes made of metals, inorganic materials or polymers. Nanoporous membranes have been used to synthesize nanoparticle and nanotube arrays that perform well as refractive index sensors, plasmonic biosensors, or surface enhanced Raman spectroscopy (SERS) substrates, as well as a wide range of other fields such as photo-thermal heating, permselective transport, catalysis, microfluidics, and electrochemical sensing. Here, we report a novel procedure to prepare gold nanotubes in AAO membranes. Hollow nanostructures have potential application in plasmonic and SERS sensing, and we anticipate these gold nanotubes will allow for high sensitivity and strong plasmon signals, arising from decreased material dampening.

Template-free synthesis of hierarchical yolk-shell Co and N codoped porous carbon microspheres with enhanced performance for oxygen reduction reaction

Science.gov (United States)

Chao, Shujun; Cui, Qian; Wang, Kui; Bai, Zhengyu; Yang, Lin; Qiao, Jinli

2015-08-01

The structures and compositions of materials have important influences on their performance. Herein, hierarchically structured yolk-shell Co and N codoped porous carbon microspheres (YS-Co/N-PCMs) have been successfully synthesized by using low-cost melamine, formaldehyde and cobalt acetate as raw materials via a facile template-free hydrothermal method and a subsequent pyrolysis. The formation process of the yolk-shell precursor is systematically investigated, involving a morphological evolution process from solid microspheres, ultrathin and wrinkled shells wrap, to yolk-shell structure formation. More importantly, the unique structure combines the favorable features towards oxygen reduction reaction (ORR), such as high surface area, sufficient Co-Nx and graphitic N active sites and suitable pore structures. As a result, the YS-Co/N-PCMs catalyst shows high catalytic activity for ORR in alkaline media for fuel cells, which not only outperforms commercial Pt-based catalysts in terms of resistance to methanol crossover and long-time stability, but is also better than many non-precious metal doped carbon-based catalysts reported previously. In addition, the YS-Co/N-PCMs catalyst also has high catalytic activity toward oxygen evolution reaction (OER). Therefore, the YS-Co/N-PCMs catalyst may serve as a promising alternative to Pt/C catalyst for ORR and OER in alkaline media.

Unprecedented propane–SCR-NOx activity over template-free synthesized Al-rich Co-BEA* zeolite

Czech Academy of Sciences Publication Activity Database

Sazama, Petr; Mokrzycki, Lukasz; Wichterlová, Blanka; Vondrová, Alena; Pilař, Radim; Dědeček, Jiří; Sklenák, Štěpán; Tabor, Edyta

2015-01-01

Roč. 332, DEC 2015 (2015), s. 201-211 ISSN 0021-9517 R&D Projects: GA TA ČR(CZ) TH01021259; GA ČR GA15-13876S Institutional support: RVO:61388955 Keywords : beta zeolite * Al-rich BEA* * OSDA-free synthesis Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 7.354, year: 2015

LDH nanocages synthesized with MOF templates and their high performance as supercapacitors

Science.gov (United States)

Jiang, Zhen; Li, Zhengping; Qin, Zhenhua; Sun, Haiyan; Jiao, Xiuling; Chen, Dairong

2013-11-01

Layered double hydroxides (LDHs) are currently attracting intense research interest for their various applications. Three LDH hollow nano-polyhedra are synthesized with zeolitic imidazolate framework-67 (ZIF-67) nanocrystals as the templates. The nanocages well inherit the rhombic dodecahedral shape of the ZIF-67 templates, and the shell is composed of nanosheets assembled with an edge-to-face stacking. This is the first synthesis of the LDH non-spherical structures. And the mechanism of utilizing metal-organic framework (MOF) nanocrystals as templates is explored. Control of the simultaneous reactions, the precipitation of the shells and the template etching, is extremely crucial to the preparation of the perfect nanocages. And the Ni-Co LDH nanocages exhibit superior pseudocapacitance property due to their novel hierarchical and submicroscopic structures.Layered double hydroxides (LDHs) are currently attracting intense research interest for their various applications. Three LDH hollow nano-polyhedra are synthesized with zeolitic imidazolate framework-67 (ZIF-67) nanocrystals as the templates. The nanocages well inherit the rhombic dodecahedral shape of the ZIF-67 templates, and the shell is composed of nanosheets assembled with an edge-to-face stacking. This is the first synthesis of the LDH non-spherical structures. And the mechanism of utilizing metal-organic framework (MOF) nanocrystals as templates is explored. Control of the simultaneous reactions, the precipitation of the shells and the template etching, is extremely crucial to the preparation of the perfect nanocages. And the Ni-Co LDH nanocages exhibit superior pseudocapacitance property due to their novel hierarchical and submicroscopic structures. Electronic supplementary information (ESI) available: Experimental details, XRD, TEM, SEM, and XPS images. See DOI: 10.1039/c3nr03829g

Design of free patterns of nanocrystals with ad hoc features via templated dewetting

Energy Technology Data Exchange (ETDEWEB)

Aouassa, M.; Berbezier, I.; Favre, L.; Ronda, A. [IM2NP, CNRS, AMU, Marseille (France); Bollani, M.; Sordan, R. [LNES, Como (Italy); Delobbe, A.; Sudraud, P. [Orsay Physics, Fuveau (France)

2012-07-02

Design of monodisperse ultra-small nanocrystals (NCs) into large scale patterns with ad hoc features is demonstrated. The process makes use of solid state dewetting of a thin film templated through alloy liquid metal ion source focused ion beam (LMIS-FIB) nanopatterning. The solid state dewetting initiated at the edges of the patterns controllably creates the ordering of NCs with ad hoc placement and periodicity. The NC size is tuned by varying the nominal thickness of the film while their position results from the association of film retraction from the edges of the lay out and Rayleigh-like instability. The use of ultra-high resolution LMIS-FIB enables to produce monocrystalline NCs with size, periodicity, and placement tunable as well. It provides routes for the free design of nanostructures for generic applications in nanoelectronics.

Controlling macro- and mesostructures with hierarchical porosity through combined hard and soft templating.

Science.gov (United States)

Petkovich, Nicholas D; Stein, Andreas

2013-05-07

Rigid, porous objects and surfactants serve as powerful templates for the formation of mesoporous and macroporous materials. When both types of template are combined in a single synthesis, materials with intricate architectures and hierarchical porosity can be obtained. In this tutorial review, we explain how to conduct syntheses with both soft and hard templates; moreover, we describe methods to control the final structure present in the templated material. Much of the foundation for multiple templating lies in the study of materials made with only one type of template. To establish a foundation in this area, a description of hard and soft templating is given, delving into the templates available and the steps required for effective templating. This leads into an extended discussion about materials templated with both hard and soft templates. Through the use of recent examples in the literature, we aim to show the diversity of structures possible through multiple templating and the advantages these structures can provide for a wide range of applications. An emphasis is placed on how various factors-such as the type of template, type of precursor, heat-treatment temperature, confinement within a small space, and template-template interactions-impact morphology.

A shortcut hydrothermal strategy for the synthesis of zinc nanowires

International Nuclear Information System (INIS)

Hu Jianqiang; Chen Zhiwu; Xie Jingsi; Yu Ying

2008-01-01

Synthesis of metal nanowires has opened many new possibilities for designing ideal building blocks for future nanodevices. In this work, zinc nanowires with lengths of micrometre magnitude were synthesized in high yield by a shortcut hydrothermal strategy. The synthesis involves a template-free, non-seed and catalyst-free solution-phase process to high-quality zinc nanowires, which is low-cost and proceeds at relatively short time. In this process, zinc nanowires were prepared through the reduction of zinc acetate with absolute ethanol in the presence of silver nitrate under hydrothermal atmosphere. The strategy suggests that silver ion plays a vital role in the synthesis of zinc nanowires, without which the substituted product is zinc oxide nanowires. X-ray diffraction and energy-dispersive x-ray spectroscopy measurements confirm the final formation of zinc nanowires and component transformation from zinc oxide nanowires in the introduction of silver ion. We believe that with the efficient synthesis, longer zinc nanowires can be fabricated and may find potential applications for superconductors and nanodevices. (fast track communication)

Biocatalytic synthesis of polymeric nanowires by micellar templates of ionic surfactants

Energy Technology Data Exchange (ETDEWEB)

Nazari, K., E-mail: nazarikh@ripi.ir [Research Institute of Petroleum Industry, NIOC, P.O. Box 14665-137, Tehran (Iran, Islamic Republic of); Chemistry Dept., Shahr Rey Islamic Azad University, P.O. Box 18735-334, Tehran (Iran, Islamic Republic of); Adhami, F.; Najjar-Safari, A.; Salmani, S. [Chemistry Dept., Shahr Rey Islamic Azad University, P.O. Box 18735-334, Tehran (Iran, Islamic Republic of); Mahmoudi, A. [Chemistry Dept., Karaj Islamic Azad University, Karaj (Iran, Islamic Republic of)

2011-07-15

Highlights: {yields} Soft-template production of polyguaiacol nanowire was done by peroxidase enzyme. {yields} Main advantage of this simple method is producing soluble encapsulated nanowires. {yields} Nanowire can be easily precipitated and separated by dilution with distilled water. {yields} Size tuned templates of sodium decyl sulfate (d = 2.7 nm) gave nanowires with d = 2-4 nm. {yields} Dried surfactant-coated wires recover freshly on specified and desired applications. -- Abstract: Micelle-templated polyguaiacol nanowires were successfully prepared via polymerization oxidation of guaiacol (o-methoxy phenol) by peroxidase enzyme in the presence of hydrogen peroxide at mild reaction conditions. The dimensions of the prepared nanowires were controlled by tuning the size and shape of the micelle structure via changing and controlling the type, chain length and molar concentrations of the ionic surfactant. The progress of the reaction and estimation of the size of soft micellar templates were followed by UV-Vis spectroscopy and dynamic light scattering (DLS). The resulting micelle encapsulated or purified polyguaiacol nanowires were characterized using transmission electron microscopy (TEM).

Biocatalytic synthesis of polymeric nanowires by micellar templates of ionic surfactants

International Nuclear Information System (INIS)

Nazari, K.; Adhami, F.; Najjar-Safari, A.; Salmani, S.; Mahmoudi, A.

2011-01-01

Highlights: → Soft-template production of polyguaiacol nanowire was done by peroxidase enzyme. → Main advantage of this simple method is producing soluble encapsulated nanowires. → Nanowire can be easily precipitated and separated by dilution with distilled water. → Size tuned templates of sodium decyl sulfate (d = 2.7 nm) gave nanowires with d = 2-4 nm. → Dried surfactant-coated wires recover freshly on specified and desired applications. -- Abstract: Micelle-templated polyguaiacol nanowires were successfully prepared via polymerization oxidation of guaiacol (o-methoxy phenol) by peroxidase enzyme in the presence of hydrogen peroxide at mild reaction conditions. The dimensions of the prepared nanowires were controlled by tuning the size and shape of the micelle structure via changing and controlling the type, chain length and molar concentrations of the ionic surfactant. The progress of the reaction and estimation of the size of soft micellar templates were followed by UV-Vis spectroscopy and dynamic light scattering (DLS). The resulting micelle encapsulated or purified polyguaiacol nanowires were characterized using transmission electron microscopy (TEM).

Size-controlled soft-template synthesis of carbon nanodots toward versatile photoactive materials.

Science.gov (United States)

Kwon, Woosung; Lee, Gyeongjin; Do, Sungan; Joo, Taiha; Rhee, Shi-Woo

2014-02-12

Size-controlled soft-template synthesis of carbon nanodots (CNDs) as novel photoactive materials is reported. The size of the CNDs can be controlled by regulating the amount of an emulsifier. As the size increases, the CNDs exhibit blue-shifted photoluminescence (PL) or so-called an inverse PL shift. Using time-correlated single photon counting, ultraviolet photoelectron spectroscopy, and low-temperature PL measurements, it is revealed that the CNDs are composed of sp² clusters with certain energy gaps and their oleylamine ligands act as auxochromes to reduce the energy gaps. This insight can provide a plausible explanation on the origin of the inverse PL shift which has been debatable over a past decade. To explore the potential of the CNDs as photoactive materials, several prototypes of CND-based optoelectronic devices, including multicolored light-emitting diodes and air-stable organic solar cells, are demonstrated. This study could shed light on future applications of the CNDs and further expedite the development of other related fields. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Heterometallic clusters arising from cubic Ni3M'O4 (M'=K and Na) entity: Solvothermal synthesis with/without the assistance of microwave

International Nuclear Information System (INIS)

Zhang Shuhua; Zhou Yanling; Sun Xiaojun; Wei, Lian-Qiang; Zeng Minghua; Liang Hong

2009-01-01

Solvothermal reaction assisted with microwave leads to the formation of two unique heterometallic cubic clusters [Ni 3 M'(L) 3 (OH)(CH 3 CN) 3 ] 2 .CH 3 CN (M'=K for 1 and M'=Na for 2, where L is an anion of 2-[(2-hydroxy-3-methoxy-benzylidene)-amino]-ethanesulfonate) with higher efficiency, yields and purity than those without it. The 6-metallacrown-3 [Ni 3 (OH)(L) 3 ] - groups exhibit interesting ion trapping and self-assembly of size-different Na + and K + through form recognition and coordination activity in 1 and 2. The magnetic studies for 1 and 2 suggest that the {Ni 3 M'O 4 } (M'=K and Na) cores both display dominant ferromagnetic interactions from the nature of the binding modes of μ 3 -O (oxidophenyl) and μ 3 -OH. - Graphical abstract: Solvothermal reaction assisted with microwave leads to two heterometallic cubic clusters with 6-metallacrown-3 structure [Ni 3 O 3 (OH)] - acting as a host for a K + or Na + ion. The {Ni 3 M'O 4 } (M'=K, Na) cores display dominant ferromagnetic interactions.

A facile template approach for the synthesis of mesoporous Fe3C/Fe-N-doped carbon catalysts for efficient and durable oxygen reduction reaction

Institute of Scientific and Technical Information of China (English)

Shuai Li; Bo Li; Liang Ma; Jia Yang; Hangxun Xu

2017-01-01

Facile synthetic approaches toward the development of efficient and durable nonprecious metal catalysts for the oxygen reduction reaction (ORR) are very important for commercializing advanced electrochemical devices such as fuel cells and metal-air batteries.Here we report a novel template approach to synthesize mesoporous Fe-N-doped carbon catalysts encapsulated with Fe3C nanoparticles.In this approach,the layer-structured FeOCl was first used as a template for the synthesis of a three-dimensional polypyrrole (PPy) structure.During the removal of the FeOCl template,the Fe3+ can be absorbed by PPy and then converted into Fe3C nanoparticles and Fe-N-C sites during the pyrolyzing process.As a result,the as-prepared catalysts could exhibit superior electrocatalytic ORR performance to the commercial Pt/C catalyst in alkaline solutions.Furthermore,the Zn-air battery assembled using the mesoporous carbon catalyst as the air electrode could surpass the commercial Pt/C catalyst in terms of the power density and energy density.

Two-dimensional collagen-graphene as colloidal templates for biocompatible inorganic nanomaterial synthesis

Directory of Open Access Journals (Sweden)

Kumari D

2017-05-01

Full Text Available Divya Kumari,1,* Lubna Sheikh,1,* Soumya Bhattacharya,1,* Thomas J Webster,2 Suprabha Nayar1 1Materials Science and Technology Division, CSIR-National Metallurgical Laboratory, Burmamines, Jamshedpur, India; 2Department of Chemical Engineering, Northeastern University, Boston, MA, USA *These authors contributed equally to this work Abstract: In this study, natural graphite was first converted to collagen-graphene composites and then used as templates for the synthesis of nanoparticles of silver, iron oxide, and hydroxyapatite. X-ray diffraction did not show any diffraction peaks of graphene in the composites after inorganic nucleation, compared to the naked composite which showed (002 and (004 peaks. Scanning electron micrographs showed lateral gluing/docking of these composites, possibly driven by an electrostatic attraction between the positive layers of one stack and negative layers of another, which became distorted after inorganic nucleation. Docking resulted in single layer-like characteristics in certain places, as seen under transmission electron microscopy, but sp2/sp3 ratios from Raman analysis inferred three-layer composite formation. Strain-induced folding of these layers into uniform clusters at the point of critical nucleation, revealed beautiful microstructures under scanning electron microscopy. Lastly, cell viability studies using 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assays showed the highest cell viability for the collagen-graphene-hydroxyapatite composites. In this manner, this study provided – to the field of nanomedicine – a new process for the synthesis of several nanoparticles (with low toxicity of high interest for numerous medical applications. Keywords: composites, graphene, collagen, lateral gluing, and inorganic nanoparticles

Tailored Polymer-Supported Templates in Dynamic Combinatorial Libraries : Simultaneous Selection, Amplification and Isolation of Synthetic Receptors

NARCIS (Netherlands)

Besenius, Pol; Cormack, Peter A.G.; Liu, Jingyuan; Otto, Sijbren; Sanders, Jeremy K.M.; Sherrington, David C.

2008-01-01

The thermodynamically controlled synthesis and isolation of macrocyclic receptors from dynamic combinatorial libraries has been achieved in a single step using a polymer-supported template. The templates were cinchona alkaloids which show interesting enantio- and diastereoselective molecular

Vertically Free-Standing Ordered Pb(Zr0.52Ti0.48)O3 Nanocup Arrays by Template-Assisted Ion Beam Etching

Science.gov (United States)

Zhang, Xiaoyan; Tang, Dan; Huang, Kangrong; Hu, Die; Zhang, Fengyuan; Gao, Xingsen; Lu, Xubing; Zhou, Guofu; Zhang, Zhang; Liu, Junming

2016-04-01

In this report, vertically free-standing lead zirconate titanate Pb(Zr0.52Ti0.48)O3 (PZT) nanocup arrays with good ordering and high density (1.3 × 1010 cm-2) were demonstrated. By a template-assisted ion beam etching (IBE) strategy, the PZT formed in the pore-through anodic aluminum oxide (AAO) membrane on the Pt/Si substrate was with a cup-like nanostructure. The mean diameter and height of the PZT nanocups (NCs) was about 80 and 100 nm, respectively, and the wall thickness of NCs was about 20 nm with a hole depth of about 80 nm. Uppermost, the nanocup structure with low aspect ratio realized vertically free-standing arrays when losing the mechanical support from templates, avoiding the collapse or bundling when compared to the typical nanotube arrays. X-ray diffraction (XRD) and Raman spectrum revealed that the as-prepared PZT NCs were in a perovskite phase. By the vertical piezoresponse force microscopy (VPFM) measurements, the vertically free-standing ordered ferroelectric PZT NCs showed well-defined ring-like piezoresponse phase and hysteresis loops, which indicated that the high-density PZT nanocup arrays could have potential applications in ultra-high non-volatile ferroelectric memories (NV-FRAM) or other nanoelectronic devices.

An Intrinsically Disordered Peptide from Ebola Virus VP35 Controls Viral RNA Synthesis by Modulating Nucleoprotein-RNA Interactions

Directory of Open Access Journals (Sweden)

Daisy W. Leung

2015-04-01

Full Text Available During viral RNA synthesis, Ebola virus (EBOV nucleoprotein (NP alternates between an RNA-template-bound form and a template-free form to provide the viral polymerase access to the RNA template. In addition, newly synthesized NP must be prevented from indiscriminately binding to noncognate RNAs. Here, we investigate the molecular bases for these critical processes. We identify an intrinsically disordered peptide derived from EBOV VP35 (NPBP, residues 20–48 that binds NP with high affinity and specificity, inhibits NP oligomerization, and releases RNA from NP-RNA complexes in vitro. The structure of the NPBP/ΔNPNTD complex, solved to 3.7 Å resolution, reveals how NPBP peptide occludes a large surface area that is important for NP-NP and NP-RNA interactions and for viral RNA synthesis. Together, our results identify a highly conserved viral interface that is important for EBOV replication and can be targeted for therapeutic development.

An Intrinsically Disordered Peptide from Ebola Virus VP35 Controls Viral RNA Synthesis by Modulating Nucleoprotein-RNA Interactions.

Science.gov (United States)

Leung, Daisy W; Borek, Dominika; Luthra, Priya; Binning, Jennifer M; Anantpadma, Manu; Liu, Gai; Harvey, Ian B; Su, Zhaoming; Endlich-Frazier, Ariel; Pan, Juanli; Shabman, Reed S; Chiu, Wah; Davey, Robert A; Otwinowski, Zbyszek; Basler, Christopher F; Amarasinghe, Gaya K

2015-04-21

During viral RNA synthesis, Ebola virus (EBOV) nucleoprotein (NP) alternates between an RNA-template-bound form and a template-free form to provide the viral polymerase access to the RNA template. In addition, newly synthesized NP must be prevented from indiscriminately binding to noncognate RNAs. Here, we investigate the molecular bases for these critical processes. We identify an intrinsically disordered peptide derived from EBOV VP35 (NPBP, residues 20-48) that binds NP with high affinity and specificity, inhibits NP oligomerization, and releases RNA from NP-RNA complexes in vitro. The structure of the NPBP/ΔNPNTD complex, solved to 3.7 Å resolution, reveals how NPBP peptide occludes a large surface area that is important for NP-NP and NP-RNA interactions and for viral RNA synthesis. Together, our results identify a highly conserved viral interface that is important for EBOV replication and can be targeted for therapeutic development. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

A de novo designed monomeric, compact three helix bundle protein on a carbohydrate template

DEFF Research Database (Denmark)

Malik, Leila; Nygård, Jesper; Christensen, Niels Johan

2015-01-01

De novo design and chemical synthesis of proteins and of other artificial structures, which mimic them, is a central strategy for understanding protein folding and for accessing proteins with novel functions. We have previously described carbohydrates as templates for the assembly of artificial...... the template could facilitate protein folding. Here we report the design and synthesis of 3-helix bundle carboproteins on deoxy-hexopyranosides. The carboproteins were analyzed by CD, AUC, SAXS, and NMR, which revealed the formation of the first compact, and folded monomeric carboprotein distinctly different...

Synthesis of copper telluride nanowires using template-based ...

Indian Academy of Sciences (India)

Anodized alu- minum oxide foil (AAO) acts as template and electrodeposi- tion is conducted in a ... the nanopores were perpendicular to the AAO membrane sur- face and were uniform in ... Aluminium oxide 0·02–0·2. 13, 21, 47. 60. 105. –.

Solvent-free directed patterning of a highly ordered liquid crystalline organic semiconductor via template-assisted self-assembly for organic transistors.

Science.gov (United States)

Kim, Aryeon; Jang, Kwang-Suk; Kim, Jinsoo; Won, Jong Chan; Yi, Mi Hye; Kim, Hanim; Yoon, Dong Ki; Shin, Tae Joo; Lee, Myong-Hoon; Ka, Jae-Won; Kim, Yun Ho

2013-11-20

Highly ordered organic semiconductor micropatterns of the liquid-crystalline small molecule 2,7-didecylbenzothienobenzothiophene (C10 -BTBT) are fabricated using a simple method based on template-assisted self-assembly (TASA). The liquid crystallinity of C10 -BTBT allows solvent-free fabrication of high-performance printed organic field-effect transistors (OFETs). © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Self-template synthesis of double shelled ZnS-NiS1.97 hollow spheres for electrochemical energy storage

Science.gov (United States)

Wei, Chengzhen; Ru, Qinglong; Kang, Xiaoting; Hou, Haiyan; Cheng, Cheng; Zhang, Daojun

2018-03-01

In this work, double shelled ZnS-NiS1.97 hollow spheres have been achieved via a simple self-template route, which involves the synthesis of Zn-Ni solid spheres precursors as the self-template and then transformation into double shelled ZnS-NiS1.97 hollow spheres by sulfidation treatment. The as-prepared double shelled ZnS-NiS1.97 hollow spheres possess a high surface area (105.26 m2 g-1) and porous structures. Benefiting from the combined characteristics of novel structures, multi-component, high surface area and porous. When applied as electrode materials for supercapacitors, the double shelled ZnS-NiS1.97hollow spheres deliver a large specific capacitance of 696.8C g-1 at 5.0 A g-1 and a remarkable long lifespan cycling stability (less 5.5% loss after 6000 cycles). Moreover, an asymmetric supercapacitor (ASC) was assembled by utilizing ZnS-NiS1.97 (positive electrode) and activated carbon (negative electrode) as electrode materials. The as-assembled device possesses an energy density of 36 W h kg-1, which can be yet retained 25.6 W h kg-1 even at a power density of 2173.8 W Kg-1, indicating its promising applications in electrochemical energy storage. More importantly, the self-template route is a simple and versatile strategy for the preparation of metal sulfides electrode materials with desired structures, chemical compositions and electrochemical performances.

Cell-free protein synthesis: applications in proteomics and biotechnology.

Science.gov (United States)

He, Mingyue

2008-01-01

Protein production is one of the key steps in biotechnology and functional proteomics. Expression of proteins in heterologous hosts (such as in E. coli) is generally lengthy and costly. Cell-free protein synthesis is thus emerging as an attractive alternative. In addition to the simplicity and speed for protein production, cell-free expression allows generation of functional proteins that are difficult to produce by in vivo systems. Recent exploitation of cell-free systems enables novel development of technologies for rapid discovery of proteins with desirable properties from very large libraries. This article reviews the recent development in cell-free systems and their application in the large scale protein analysis.

Escherichia coli cell-free protein synthesis and isotope labeling of mammalian proteins.

Science.gov (United States)

Terada, Takaho; Yokoyama, Shigeyuki

2015-01-01

This chapter describes the cell-free protein synthesis method, using an Escherichia coli cell extract. This is a cost-effective method for milligram-scale protein production and is particularly useful for the production of mammalian proteins, protein complexes, and membrane proteins that are difficult to synthesize by recombinant expression methods, using E. coli and eukaryotic cells. By adjusting the conditions of the cell-free method, zinc-binding proteins, disulfide-bonded proteins, ligand-bound proteins, etc., may also be produced. Stable isotope labeling of proteins can be accomplished by the cell-free method, simply by using stable isotope-labeled amino acid(s) in the cell-free reaction. Moreover, the cell-free protein synthesis method facilitates the avoidance of stable isotope scrambling and dilution over the recombinant expression methods and is therefore advantageous for amino acid-selective stable isotope labeling. Site-specific stable isotope labeling is also possible with a tRNA molecule specific to the UAG codon. By the cell-free protein synthesis method, coupled transcription-translation is performed from a plasmid vector or a PCR-amplified DNA fragment encoding the protein. A milligram quantity of protein can be produced with a milliliter-scale reaction solution in the dialysis mode. More than a thousand solution structures have been determined by NMR spectroscopy for uniformly labeled samples of human and mouse functional domain proteins, produced by the cell-free method. Here, we describe the practical aspects of mammalian protein production by the cell-free method for NMR spectroscopy. © 2015 Elsevier Inc. All rights reserved.

View-Invariant Gait Recognition Through Genetic Template Segmentation

Science.gov (United States)

Isaac, Ebenezer R. H. P.; Elias, Susan; Rajagopalan, Srinivasan; Easwarakumar, K. S.

2017-08-01

Template-based model-free approach provides by far the most successful solution to the gait recognition problem in literature. Recent work discusses how isolating the head and leg portion of the template increase the performance of a gait recognition system making it robust against covariates like clothing and carrying conditions. However, most involve a manual definition of the boundaries. The method we propose, the genetic template segmentation (GTS), employs the genetic algorithm to automate the boundary selection process. This method was tested on the GEI, GEnI and AEI templates. GEI seems to exhibit the best result when segmented with our approach. Experimental results depict that our approach significantly outperforms the existing implementations of view-invariant gait recognition.

A combined salt-hard templating approach for synthesis of multi-modal porous carbons used for probing the simultaneous effects of porosity and electrode engineering on EDLC performance

KAUST Repository

Bhandari, Nidhi; Dua, Rubal; Esté vez, Luis Antonio; Sahore, Ritu; Giannelis, Emmanuel P.

2015-01-01

), resulting in high pore volume (∼3.9 cm3/g) while the salt template, zinc chloride, generates borderline-mesopores (∼2 nm), thus imparting high surface area (∼2100 m2/g). The versatility of the proposed synthesis technique is demonstrated using: (i) dual salt

Template-Assisted Wet-Combustion Synthesis of Fibrous Nickel-Based Catalyst for Carbon Dioxide Methanation and Methane Steam Reforming.

Science.gov (United States)

Aghayan, M; Potemkin, D I; Rubio-Marcos, F; Uskov, S I; Snytnikov, P V; Hussainova, I

2017-12-20

Efficient capture and recycling of CO 2 enable not only prevention of global warming but also the supply of useful low-carbon fuels. The catalytic conversion of CO 2 into an organic compound is a promising recycling approach which opens new concepts and opportunities for catalytic and industrial development. Here we report about template-assisted wet-combustion synthesis of a one-dimensional nickel-based catalyst for carbon dioxide methanation and methane steam reforming. Because of a high temperature achieved in a short time during reaction and a large amount of evolved gases, the wet-combustion synthesis yields homogeneously precipitated nanoparticles of NiO with average particle size of 4 nm on alumina nanofibers covered with a NiAl 2 O 4 nanolayer. The as-synthesized core-shell structured fibers exhibit outstanding activity in steam reforming of methane and sufficient activity in carbon dioxide methanation with 100% selectivity toward methane formation. The as-synthesized catalyst shows stable operation under the reaction conditions for at least 50 h.

Templated synthesis of nickel nanoparticles: Toward heterostructured nanocomposites for efficient hydrogen storage

Energy Technology Data Exchange (ETDEWEB)

Nelson, Nicholas Cole [Iowa State Univ., Ames, IA (United States)

2013-01-01

The world is currently facing an energy and environmental crisis for which new technologies are needed. Development of cost-competitive materials for catalysis and hydrogen storage on-board motor vehicles is crucial to lead subsequent generations into a more sustainable and energy independent future. This thesis presents work toward the scalable synthesis of bimetallic heterostructures that can enable hydrogen to compete with carbonaceous fuels by meeting the necessary gravimetric and volumetric energy densities and by enhancing hydrogen sorption/desorption kinetics near ambient temperatures and pressures. Utilizing the well-known phenomenon of hydrogen spillover, these bimetallic heterostructures could work by lowering the activation energy for hydrogenation and dehydrogenation of metals. Herein, we report a novel method for the scalable synthesis of silica templated zero-valent nickel particles (Ni$\\subset$ SiO₂) that hold promise for the synthesis of nickel nanorods for use in bimetallic heterostructures for hydrogen storage. Our synthesis proceeds by chemical reduction of a nickel-hydrazine complex with sodium borohydride followed by calcination under hydrogen gas to yield silica encapsulated nickel particles. Transmission electron microscopy and powder X-ray diffraction were used to characterize the general morphology of the resultant nanocapsules as well as the crystalline phases of the incorporated Ni⁰ nanocrystals. The structures display strong magnetic behavior at room temperature and preliminary data suggests nickel particle size can be controlled by varying the amount of nickel precursor used in the synthesis. Calcination under different environments and TEM analysis provides evidence for an atomic migration mechanism of particle formation. Ni$\\subset$SiO₂ nanocapsules were used as seeds to induce heterogeneous nucleation and subsequent growth within the nanocapsule via electroless nickel plating. Nickel nanoparticle

Positron annihilation spectroscopic studies of solvothermally synthesized ZnO nanobipyramids and nanoparticles

Science.gov (United States)

Ghoshal, Tandra; Biswas, Subhajit; Kar, Soumitra; Chaudhuri, Subhadra; Nambissan, P. M. G.

2008-02-01

Zinc oxide (ZnO) samples in the form of hexagonal-based bipyramids and particles of nanometer dimensions were synthesized through solvothermal route and characterized by x-ray diffraction and transmission electron microscopy. Positron annihilation experiments were performed to study the structural defects such as vacancies and surfaces in these nanosystems. From coincidence Doppler broadening measurements, the positron trapping sites were identified as Zn vacancies or Zn-O-Zn trivacancy clusters. The positron lifetimes, their relative intensities, and the Doppler broadened lineshape parameter S all showed characteristic changes across the nanobipyramid size corresponding to the thermal diffusion length of positrons. In large nanobipyramids, vacancies within the crystallites also trapped positrons and the effects of agglomeration of such vacancies due to increased temperatures of synthesis were reflected in the variation of the annihilation parameters with their base diameters. The sizes of the nanoparticles used were all in the limit of thermal diffusion length of positrons and the annihilation characteristics were in accordance with the decreasing contribution from surfaces with increasing particle size.

Zeolite-templated carbon replica: a grand canonical Monte-Carlo simulation study

International Nuclear Information System (INIS)

Roussel, Th.; Pellenq, R.J.M.; Bichara, Ch.; Gadiou, R.; Didion, A.; Vix-Guterl, C.; Gaslain, F.; Parmentier, J.; Valtchev, V.; Patarin, J.

2005-01-01

Microporous carbon materials are interesting for several applications such as hydrogen storage, catalysis or electrical double layer capacitors. The development of the negative templating method to obtain carbon replicas from ordered templates, has lead to the synthesis of several new materials which have interesting textural properties, attractive for energy storage. Among the possible templates, zeolites can be used to obtain highly microporous carbon materials. Nevertheless, the phenomena involved in the replica synthesis are not fully understood, and the relationships between the structure of the template, the carbon precursor and the resulting carbon material need to be investigated. Experimental results for carbon zeolite-templated nano-structures can be found in a series of papers; see for instance ref. [1] in which Wang et al describe a route to ultra-small Single Wall Carbon Nano-tubes (SWNTs) using the porosity of zeolite AlPO 4 -5. After matrix removal, the resulting structure is a free-standing bundle of 4 Angstroms large nano-tubes. However, it is highly desirable to obtain an ordered porous carbon structure that forms a real 3D network to be used for instance in gas storage applications. Carbon replica of faujasite and EMT zeolites can have these properties since these zeolites have a 3D porous network made of 10 Angstroms cages connected to each other through 7 Angstroms large windows. The first step of this study was to generate a theoretical carbon replica structure of various zeolites (faujasite, EMT, AlPO 4 -5, silicalite). For this purpose, we used the Grand Canonical Monte-Carlo (GCMC) technique in which the carbon-carbon interactions were described within the frame of a newly developed Tight Binding approach and the carbon-zeolite interactions assumed to be characteristic of physisorption. The intrinsic stability of the subsequent carbon nano-structures was then investigated after mimicking the removal of the inorganic phase by switching

From Extraction of Local Structures of Protein Energy Landscapes to Improved Decoy Selection in Template-Free Protein Structure Prediction.

Science.gov (United States)

Akhter, Nasrin; Shehu, Amarda

2018-01-19

Due to the essential role that the three-dimensional conformation of a protein plays in regulating interactions with molecular partners, wet and dry laboratories seek biologically-active conformations of a protein to decode its function. Computational approaches are gaining prominence due to the labor and cost demands of wet laboratory investigations. Template-free methods can now compute thousands of conformations known as decoys, but selecting native conformations from the generated decoys remains challenging. Repeatedly, research has shown that the protein energy functions whose minima are sought in the generation of decoys are unreliable indicators of nativeness. The prevalent approach ignores energy altogether and clusters decoys by conformational similarity. Complementary recent efforts design protein-specific scoring functions or train machine learning models on labeled decoys. In this paper, we show that an informative consideration of energy can be carried out under the energy landscape view. Specifically, we leverage local structures known as basins in the energy landscape probed by a template-free method. We propose and compare various strategies of basin-based decoy selection that we demonstrate are superior to clustering-based strategies. The presented results point to further directions of research for improving decoy selection, including the ability to properly consider the multiplicity of native conformations of proteins.

From Extraction of Local Structures of Protein Energy Landscapes to Improved Decoy Selection in Template-Free Protein Structure Prediction

Directory of Open Access Journals (Sweden)

Nasrin Akhter

2018-01-01

Full Text Available Due to the essential role that the three-dimensional conformation of a protein plays in regulating interactions with molecular partners, wet and dry laboratories seek biologically-active conformations of a protein to decode its function. Computational approaches are gaining prominence due to the labor and cost demands of wet laboratory investigations. Template-free methods can now compute thousands of conformations known as decoys, but selecting native conformations from the generated decoys remains challenging. Repeatedly, research has shown that the protein energy functions whose minima are sought in the generation of decoys are unreliable indicators of nativeness. The prevalent approach ignores energy altogether and clusters decoys by conformational similarity. Complementary recent efforts design protein-specific scoring functions or train machine learning models on labeled decoys. In this paper, we show that an informative consideration of energy can be carried out under the energy landscape view. Specifically, we leverage local structures known as basins in the energy landscape probed by a template-free method. We propose and compare various strategies of basin-based decoy selection that we demonstrate are superior to clustering-based strategies. The presented results point to further directions of research for improving decoy selection, including the ability to properly consider the multiplicity of native conformations of proteins.

Templated Atom-Precise Galvanic Synthesis and Structure Elucidation of a [Ag 24 Au(SR) 18 ] − Nanocluster

KAUST Repository

Bootharaju, Megalamane Siddaramappa

2015-11-27

Synthesis of atom-precise alloy nanoclusters with uniform composition is challenging when the alloying atoms are similar in size (for example, Ag and Au). A galvanic exchange strategy has been devised to produce a compositionally uniform [Ag24Au(SR)18]- cluster (SR: thiolate) using a pure [Ag25(SR)18]- cluster as a template. Conversely, the direct synthesis of Ag24Au cluster leads to a mixture of [Ag25-xAux(SR)18]-, x=1-8. Mass spectrometry and crystallography of [Ag24Au(SR)18]- reveal the presence of the Au heteroatom at the Ag25 center, forming Ag24Au. The successful exchange of the central Ag of Ag25 with Au causes perturbations in the Ag25 crystal structure, which are reflected in the absorption, luminescence, and ambient stability of the particle. These properties are compared with those of Ag25 and Ag24Pd clusters with same ligand and structural framework, providing new insights into the modulation of cluster properties with dopants at the single-atom level.

Separations using biological carriers immobilized in porous polymeric and sol-gel template synthesized nanotubular membranes

Science.gov (United States)

Lakshmi, Brinda B.

1998-12-01

The overall goal of the dissertation was to use immobilized biological carriers in membranes to separate compounds as challenging as enantiomers. The membranes were prepared by a process called 'template synthesis'. Template synthesis has been used to synthesize semiconductor nanostructures and also membranes which do the enantioseparation by a process called facilitated transport. The immobilized proteins act as carriers facilitating the transport of the substrate molecules through the membrane. The apoenzymes are enzymes devoid of cofactor. Apoenzymes will possess the molecular recognition site for the substrate but will not catalyze the reaction. Apoenzymes immobilized in the pores of porous polycarbonate membrane was used as a carrier. The ends of the pores were closed with porous polypyrrole. Compounds as interesting as enantiomers were separated with these membranes. Template synthesis has been extended to the synthesis of many important semiconductor oxide naostructures like TiO2, SiO2, ZnO, Co3O4 and MnO2. These structures were made by dipping the alumina template membrane in the sol and heating. Ti0 2 tubules and fibers were obtained by this method. The fibers were used to study photocatalysis reaction of organic compounds in sunlight. Proteins were immobilized within the inner surface of the tubules using Sn chemistry. Bovine serum albumn (BSA) immobilized within the different diameter tubules showed varying degree of facilitation with phenylalanine. The membranes also show interesting switching of selectivity from L to D depending on the tube size and feed concentration.

Chondroitin sulfate template-mediated biomimetic synthesis of nano-flake hydroxyapatite

Science.gov (United States)

He, Dan; Xiao, Xiufeng; Liu, Fang; Liu, Rongfang

2008-11-01

By Ca(NO 3) 2·4H 2O and (NH 4) 3PO 4·3H 2O as reagents and chondroitin sulfate (ChS) as a template, nano-flake hydroxyapatite (HA) is synthesized using a biomimetic method according to the biomineralization theory. HA crystals obtained are characterized in crystalline phase, microstructure, chemical composition and morphology by X-ray diffraction (XRD), Fourier transform infrared spectroscope (FTIR), transmission electron microscopy (TEM) and elemental analysis respectively. UV-vis spectrum is adopted to investigate interactions between functional groups ChS and HA. The results show that HA crystal nucleation and growth take place in chemical interactions between HA crystals and ChS as a template. And elemental analysis indicates that obtained HA contains a small amount of ChS. Furthermore, ChS concentration significantly affects the morphology of HA crystals. Staple-fiber-like HA crystals can be obtained at a low concentration in ChS, and flake-like HA crystals synthesized at a high concentration (≥0.5 wt.%) of ChS as a template.

Chondroitin sulfate template-mediated biomimetic synthesis of nano-flake hydroxyapatite

Energy Technology Data Exchange (ETDEWEB)

He Dan; Xiao Xiufeng; Liu Fang [College of Chemistry and Materials Science, Fujian Normal University, Fuzhou 350007 (China); Liu Rongfang [College of Chemistry and Materials Science, Fujian Normal University, Fuzhou 350007 (China)], E-mail: rfliu@vip.sina.com

2008-11-15

By Ca(NO{sub 3}){sub 2}.4H{sub 2}O and (NH{sub 4}){sub 3}PO{sub 4}.3H{sub 2}O as reagents and chondroitin sulfate (ChS) as a template, nano-flake hydroxyapatite (HA) is synthesized using a biomimetic method according to the biomineralization theory. HA crystals obtained are characterized in crystalline phase, microstructure, chemical composition and morphology by X-ray diffraction (XRD), Fourier transform infrared spectroscope (FTIR), transmission electron microscopy (TEM) and elemental analysis respectively. UV-vis spectrum is adopted to investigate interactions between functional groups ChS and HA. The results show that HA crystal nucleation and growth take place in chemical interactions between HA crystals and ChS as a template. And elemental analysis indicates that obtained HA contains a small amount of ChS. Furthermore, ChS concentration significantly affects the morphology of HA crystals. Staple-fiber-like HA crystals can be obtained at a low concentration in ChS, and flake-like HA crystals synthesized at a high concentration ({>=}0.5 wt.%) of ChS as a template.

Green synthesis of CuInS2/ZnS core-shell quantum dots by facile solvothermal route with enhanced optical properties

Science.gov (United States)

Jindal, Shikha; Giripunje, Sushama M.; Kondawar, Subhash B.; Koinkar, Pankaj

2018-03-01

We report an eco-friendly green synthesis of highly luminescent CuInS2/ZnS core-shell quantum dots (QDs) with average particle size ∼ 3.9 nm via solvothermal process. The present study embodies the intensification of CuInS2/ZnS QDs properties by the shell growth on the CuInS2 QDs. The as-prepared CuInS2 core and CuInS2/ZnS core-shell QDs have been characterized using a range of optical and structural techniques. By adopting a low temperature growth of CuInS2 core and high temperature growth of CuInS2/ZnS core-shell growth, the tuning of absorption and photoluminescence emission spectra were observed. Optical absorption and photoluminescence spectroscopy probe the effect of ZnS passivation on the electronic structure of the CuInS2 dots. In addition, QDs have been scrutinized using ultra violet photoelectron spectroscopy (UPS) to explore their electronic band structure. The band level positions of CuInS2 and CuInS2/ZnS QDs suffices the demand of non-toxic acceptor material for electronic devices. The variation in electronic energy levels of CuInS2 core with the coating of wide band gap ZnS shell influence the removal of trap assisted recombination on the surface of the core. QDs exhibited tunable emission from red to orange region. These studies reveal the feasibility of QDs in photovoltaic and light emitting diodes.

In situ XAS of the solvothermal decomposition of dithiocarbamate complexes

NARCIS (Netherlands)

Islam, H.-U.; Roffey, A.; Hollingsworth, N.; Catlow, R.; Wolthers, M.; de Leeuw, N.H.; Bras, W.; Sankar, G.; Hogarth, G.

2012-01-01

An in situ XAS study of the solvothermal decomposition of iron and nickel dithiocarbamate complexes was performed in order to gain understanding of the decomposition mechanisms. This work has given insight into the steps involved in the decomposition, showing variation in reaction pathways between

Synthesis and characterization of the ternary telluroargentate K4[Ag18Te11

KAUST Repository

Davaasuren, Bambar; Dashjav, Enkhtsetseg; Rothenberger, Alexander

2014-01-01

The ternary potassium telluroargentate(I), K4[Ag18Te11], was prepared by solvothermal synthesis in ethylenediamine at 160 °C. It crystallizes in the cubic space group Fm3¯ m (no. 225) with the cell parameter a = 18.6589(6) Å. The crystal structure

Excellent electrochemical performances of cabbage-like polyaniline fabricated by template synthesis

Science.gov (United States)

Hu, Chenglong; Chen, Shaoyun; Wang, Yuan; Peng, Xianghong; Zhang, Weihong; Chen, Jian

2016-07-01

In this article, we explore a novel route to fabricate cabbage-like polyaniline (PANI) by in situ polymerization of aniline using the hydroxylated poly (methyl methacrylate) nanospheres (i.e. PMMAsbnd OHsbnd NS) as a template. A maximum specific capacitance of 584 F/g (the current density is 0.1 A/g) is achieved at 10 mV s-1 as well as a high stability of over 3000 cycles (the decrease in the SC is ∼9.1%), which suggests the potential application of the cabbage-like polyaniline in supercapacitors. The predominant electrochemical performances of the cabbage-like polyaniline can be attributed to their large surface area and larger-scale π-π conjugated system present in the quinoid structure of the PANI molecular chain, which can drastically facilitate electron diffusion and improve the utilization of the electroactive PANI during the charge/discharge processes. Accordingly, the facility of charge transfer can decrease resistance along with the PANI molecular chain to improve the electrochemical stability and achieve high-capacitance response characteristics. The present study introduces a new synthesis method for the development of various morphology of other conducting polymer, which may find potential applications in a variety of high-performance electrochemical devices.

Protein coated gold nanoparticles as template for the directed synthesis of highly fluorescent gold nanoclusters

Science.gov (United States)

Zhang, Lingyan; Han, Fei

2018-04-01

Bovine serum albumin (BSA) modified gold nanoparticles (AuNPs) was selected as template for the synthesis of AuNPs@gold nanoclusters (AuNCs) core/shell nanoparticles, in which BSA not only acted as dual functions agent for both anchoring and reducing Au3+ ions, but also was employed as a bridge between the AuNPs and AuNCs. Optical properties of AuNPs@AuNCs core/shell nanoparticles were studied using UV-visible and fluorescence spectroscopy. The prepared AuNPs@AuNCs core/shell nanoparticles exhibited sphere size uniformity with improved monodispersity, excellent fluorescence and fluorescent stability. Compared with AuNCs, AuNPs@AuNCs core/shell nanoparticles possessed large size and strong fluorescence intensity due to the effect of AuNPs as core. Moreover, the mechanism of the AuNPs induced fluorescence changes of the core/shell nanoparticles was first explored.

Solvothermal and electrochemical synthetic method of HKUST-1 and its methane storage capacity

Science.gov (United States)

Wahyu Lestari, Witri; Adreane, Marisa; Purnawan, Candra; Fansuri, Hamzah; Widiastuti, Nurul; Budi Rahardjo, Sentot

2016-02-01

A comparison synthetic strategy of Metal-Organic Frameworks, namely, Hongkong University of Techhnology-1 {HKUST-1[Cu3(BTC)]2} (BTC = 1,3,5-benzene-tri-carboxylate) through solvothermal and electrochemical method in ethanol:water (1:1) has been conducted. The obtained material was analyzed using powder X-ray diffraction, Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Thermo-Gravimetric Analysis (TGA) and Surface Area Analysis (SAA). While the voltage in the electrochemical method are varied, ranging from 12 to 15 Volt. The results show that at 15 V the texture of the material has the best degree of crystallinity and comparable with solvothermal product. This indicated from XRD data and supported by the SEM image to view the morphology. The thermal stability of the synthesized compounds is up to 320 °C. The shape of the nitrogen sorption isotherm of the compound corresponds to type I of the IUPAC adsorption isotherm classification for microporous materials with BET surface area of 629.2 and 324.3 m2/g (for solvothermal and electrochemical product respectively) and promising for gas storage application. Herein, the methane storage capacities of these compounds are also tested.

Fabrication of free-standing copper foils covered with highly-ordered copper nanowire arrays

Science.gov (United States)

Zaraska, Leszek; Sulka, Grzegorz D.; Jaskuła, Marian

2012-07-01

The through-hole nanoporous anodic aluminum oxide (AAO) membranes with relatively large surface area (ca. 2 cm2) were employed for fabrication of free-standing and mechanically stable copper foils covered with close-packed and highly-ordered copper nanowire arrays. The home-made AAO membranes with different pore diameters and interpore distances were fabricated via a two-step self-organized anodization of aluminum performed in sulfuric acid, oxalic acid and phosphoric acid followed by the pore opening/widening procedure. The direct current (DC) electrodeposition of copper was performed efficiently on both sides of AAO templates. The bottom side of the AAO templates was not insulated and consequently Cu nanowire arrays on thick Cu layers were obtained. The proposed template-assisted fabrication of free-standing copper nanowire array electrodes is a promising method for synthesis of nanostructured current collectors. The composition of Cu nanowires was confirmed by energy dispersive X-Ray spectroscopy (EDS) and X-ray diffraction (XRD) analyses. The structural features of nanowires were evaluated from field emission scanning electron microscopy (FE-SEM) images and compared with the characteristic parameters of anodic alumina membranes.

Fabrication of free-standing copper foils covered with highly-ordered copper nanowire arrays

International Nuclear Information System (INIS)

Zaraska, Leszek; Sulka, Grzegorz D.; Jaskuła, Marian

2012-01-01

The through-hole nanoporous anodic aluminum oxide (AAO) membranes with relatively large surface area (ca. 2 cm 2 ) were employed for fabrication of free-standing and mechanically stable copper foils covered with close-packed and highly-ordered copper nanowire arrays. The home-made AAO membranes with different pore diameters and interpore distances were fabricated via a two-step self-organized anodization of aluminum performed in sulfuric acid, oxalic acid and phosphoric acid followed by the pore opening/widening procedure. The direct current (DC) electrodeposition of copper was performed efficiently on both sides of AAO templates. The bottom side of the AAO templates was not insulated and consequently Cu nanowire arrays on thick Cu layers were obtained. The proposed template-assisted fabrication of free-standing copper nanowire array electrodes is a promising method for synthesis of nanostructured current collectors. The composition of Cu nanowires was confirmed by energy dispersive X-Ray spectroscopy (EDS) and X-ray diffraction (XRD) analyses. The structural features of nanowires were evaluated from field emission scanning electron microscopy (FE-SEM) images and compared with the characteristic parameters of anodic alumina membranes.

Nacre-Templated Synthesis of Highly Dispersible Carbon Nanomeshes for Layered Membranes with High-Flux Filtration and Sensing Properties.

Science.gov (United States)

Kong, Meng; Li, Mingjie; Shang, Ruoxu; Wu, Jingyu; Yan, Peisong; Xu, Dongmei; Li, Chaoxu

2018-01-24

Marine shells not only represent a rapidly accumulating type of fishery wastes but also offer a unique sort of hybrid nanomaterials produced greenly and massively in nature. The elaborate "brick and mortar" structures of nacre enabled the synthesis of carbon nanomeshes with <1 nm thickness, hierarchical porosity, and high specific surface area through pyrolysis, in which two-dimensional (2D) organic layers served as the carbonaceous precursor and aragonite platelets as the hard template. Mineral bridges within 2D organic layers templated the formation of mesh pores of 20-70 nm. In contrast to other hydrophobic carbon nanomaterials, these carbon nanomeshes showed super dispersibility in diverse solvents and thus processability for membranes through filtration, patterning, spray-coating, and ink-writing. The carbon membranes with layered structures were capable of serving not only for high-flux filtration and continuous flow absorption but also for electrochemical and strain sensing with high sensitivity. Thus, utilization of marine shells, on one hand, relieves the environmental concern of shellfish waste, on the other hand, offers a facile, green, low-cost, and massive approach to synthesize unique carbon nanomeshes alternative to graphene nanomeshes and applicable in environmental adsorption, filtration, wearable sensors, and flexible microelectronics.

Grinding solvent-free Paal-Knorr pyrrole synthesis on smectites as ...

African Journals Online (AJOL)

Journal Home > Vol 32, No 1 (2018) > ... An environmentally benign method for the synthesis of N-substituted pyrroles from one-pot solvent-free ... conditions make this protocol practical, environmentally friendly and economically attractive.

Controlled synthesis of multi-morphology Te crystals by a convenient Lewis acid/base-assisted solvothermal method

International Nuclear Information System (INIS)

Wu Xiaoping; Yuan Lin; Zhou Shaomin; Lou Shiyun; Wang Yongqiang; Gao Tao; Liu YuBiao; Shi Xiaojing

2012-01-01

This paper reports on the controlled growth of multi-morphology Te crystals by a convenient Lewis acid/base-assisted solvothermal method for the first time. The morphological transformation from one-dimension (1D) nanostructures to 2D hierarchical flowerlike microarchitecture has been observed. The nanorods and nanowires with a well-defined crystallographical structure and the hierarchical flowers microarchitecture were obtained by changing the Lewis acids/bases. Lewis acids/bases were found to be crucial for the formation of the products by not only acting as the pH regulator but also as the shape controller, owing to their hydrolysis in the solvent to in situ form H + /OH − and hydrates. The results suggest that this should be an effective approach to the control the growth of t-Te crystals with interesting multiple morphologies, which are of interest for both theoretical investigations and practical applications.

Shape-Evolution Control of hybrid perovskite CH3NH3PbI3 crystals via solvothermal synthesis

Science.gov (United States)

Zhang, Baohua; Guo, Fuqiang; Yang, Lianhong; Jia, Xiuling; Liu, Bin; Xie, Zili; Chen, Dunjun; Lu, Hai; Zhang, Rong; Zheng, Youdou

2017-02-01

We systematically synthesized CH3NH3PbI3 crystals using solvothermal process, and the reaction conditions such as concentration of the precursor, temperature, time, and lead source have been comprehensively investigated to obtain shape-controlled CH3NH3PbI3 crystals. The results showed that the CH3NH3PbI3 crystals exhibit tetragonal phase and the crystals change from nanoparticles to hopper-faced cuboids. Photoluminescence spectra of the crystals obtained with different lead sources show a blue shift due to the presence of defects in the crystals, and the peak intensity is very sensitive to the lead sources. Moreover, impurities (undesirable byproducts and excess components like HI or CH3NH2) presented during crystal growth can result in hopper growth.

Solvothermal synthesis of mesoporous magnetite nanoparticles for Cr(IV) ions uptake and microwave absorption

Energy Technology Data Exchange (ETDEWEB)

Shen, Peng; Zhang, Haitao, E-mail: htzhang@ipe.ac.cn; Zhang, Suojiang, E-mail: sjzhang@ipe.ac.cn; Yuan, Pei [Chinese Academy of Sciences, Beijing Key Laboratory of Ionic Liquids Clean Process Institute of Process Engineering, Key Laboratory of Green Process and Engineering, Institute of Process Engineering (China); Yang, Yang [China Building Materials Academy, State Key Laboratory of Green Building Materials (China); Zhang, Qiang; Zhang, Xixiang [King Abdullah University of Science and Technology, Physical Science and Engineering (Saudi Arabia)

2016-05-15

Colloidal mesoporous magnetite nanoparticles with tunable porosity were realized by a simple and scalable solvothermal route with the aid of AOT as ligands. AOT was used to induce the anisotropic crystal growth of smaller nanocrystals and restrain their tight aggregation so as to form more mesoscale pores. Morphologies and microstructures investigation by SEM and TEM revealed that the bigger nanoparticles were composed of smaller nanocrystals with an average size of 18 nm. A possible formation mechanism was proposed for the mesoporous nanoparticles. Study of nitrogen adsorption–desorption isotherm revealed that the Brunauer–Emmett–Teller (BET) specific surface area of mesoporous nanoparticles is up to 209 m{sup 2}/g, resulting from the slit-shaped pores created by the aggregation of polyhedral nanocrystals. Magnetic properties study indicated that the as-prepared nanoparticles are superparamagnetic at room temperature. Optimized mesoporous magnetite nanoparticles exhibit a maximum Cr(VI) ion sorption capacity of 12.9 mmol/g, and its absorption behavior followed a Freundlich model. Microwave absorption study indicated that porous nanoparticles own higher permeability values than that of solid nanoparticles, leading to a higher dielectric loss in the frequency range of 2–18 GHz.Graphical Abstract.

Facile Synthesis of Novel Networked Ultralong Cobalt Sulfide Nanotubes and Its Application in Supercapacitors.

Science.gov (United States)

Liu, Sangui; Mao, Cuiping; Niu, Yubin; Yi, Fenglian; Hou, Junke; Lu, Shiyu; Jiang, Jian; Xu, Maowen; Li, Changming

2015-11-25

Ultralong cobalt sulfide (CoS(1.097)) nanotube networks are synthesized by a simple one-step solvothermal method without any surfactant or template. A possible formation mechanism for the growth processes is proposed. Owing to the hollow structure and large specific area, the novel CoS(1.097) materials present outstanding electrochemical properties. Electrochemical measurements for supercapacitors show that the as-prepared ultralong CoS(1.097) nanotube networks exhibit high specific capacity, good capacity retention, and excellent Coulombic efficiency.

Cu(I)/Cu(II) templated functional pseudorotaxanes and rotaxanes

Indian Academy of Sciences (India)

Further, copper ions have shown promising template for ... ion-assisted synthesis of pseudorotaxanes, rotaxanes and their chemical or ... Two different approaches like threading and clipping methods are .... stoppers and the central complex, ligand exchange is fast, which ... verified by variable-concentration CVs. Figure 10.

A Comparative Study of Solvothermal and Sol-Gel-Derived Nanocrystalline Alumina Catalysts for Ethanol Dehydration

Directory of Open Access Journals (Sweden)

Mingkwan Wannaborworn

2015-01-01

Full Text Available The ethanol dehydration to ethylene over alumina catalysts prepared by solvothermal and sol-gel methods was investigated. Also, a commercial alumina was used for comparison purposes. The results showed that the catalytic activity depends on the properties of catalyst derived from different preparation methods and reaction temperature. The alumina synthesized by solvothermal method exhibited the highest activity. This can be attributed to the higher surface area and larger amount of acid site, especially the ratio of weak/strong acid strength as determined by N2 physisorption and NH3-TPD studies. The solvothermal-derived catalyst exhibited an excellent performance with complete ethanol conversion and 100% selectivity to ethylene at 350°C in comparison with other ones. In addition, we further studied the catalytic dehydration of alumina catalyst modified with Fe. The presence of 10 wt.% Fe decreased both conversion and ethylene selectivity. However, the acetaldehyde selectivity apparently increased. It was related to the dehydrogenation pathway that takes place on Fe species.

Synthesis of Mesoporous α-Fe2O3 Nanoparticles by Non-ionic Soft Template and Their Applications to Heavy Oil Upgrading

Science.gov (United States)

Park, Chulwoo; Jung, Jinhwan; Lee, Chul Wee; Cho, Joungmo

2016-12-01

This paper reports the synthetic route of 3-D network shape α-Fe2O3 from aqueous solutions of iron precursor using a non-ionic polymeric soft-template, Pluronic P123. During the synthesis of α-Fe2O3, particle sizes, crystal phases and morphologies were significantly influenced by pH, concentrations of precursor and template. The unique shape of worm-like hematite was obtained only when a starting solution was prepared by a weakly basic pH condition and a very specific composition of constituents. The synthesized nanocrystal at this condition had a narrow pore size distribution and high surface area compared to the bulk α-Fe2O3 or the one synthesized from lower pH conditions. The hydrocracking performance was tested over the synthesized iron oxide catalysts with different morphologies. The worm-like shape of iron oxide showed a superior performance, including overall yield of liquid fuel product and coke formation, over the hydrocracking of heavy petroleum oil.

Investigation on development of advanced materials by solvothermal technique; Sorubo thermal hanno riyo senshin zairyo kaihatsu ni kansuru chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

Solvothermal reaction is reaction under high temperature and high pressure, which is expected to fabricate new functional materials. In this study, the materials are classified into two fields, i.e., inorganic materials, metals and their composites and organic materials and their composites. The current status of R and D of production and processing technology in each field is surveyed and the prospect of it is discussed. For the inorganic materials, metals and their composites, it is explained that very fine metal oxide particles, complex oxides, single crystals, whiskers, compounds with layer structure, metastable compounds, ion conductors and catalysts with high ability could be produced only by controlling the solvothermal reactions in atomic order. For the organic materials and their composites, surveyed results of the solvothermal technique using non-aqueous solutions are mainly provided. The necessity of a national project for researches on the solvothermal reactions is proposed from the viewpoint of resource, environment and energy. 777 refs., 38 figs., 26 tabs.

Effect of template-induced surface species on electronic structure and photocatalytic activity of g-C{sub 3}N{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Shen, Yu; Guo, Xiaojuan; Bo, Xiangkun; Wang, Yongzheng [Key Lab of Mesoscopic Chemistry MOE, School of Chemistry & Chemical Engineering, Nanjing University, Nanjing 210023 (China); Guo, Xiangke [Key Lab of Mesoscopic Chemistry MOE, School of Chemistry & Chemical Engineering, Nanjing University, Nanjing 210023 (China); Hubei Key Laboratory for Processing and Application of Catalytic Materials, Huanggang Normal University, Huanggang 438000 (China); Xie, Mingjiang, E-mail: xiemingjiang@hotmail.com [Key Lab of Mesoscopic Chemistry MOE, School of Chemistry & Chemical Engineering, Nanjing University, Nanjing 210023 (China); Guo, Xuefeng, E-mail: guoxf@nju.edu.cn [Key Lab of Mesoscopic Chemistry MOE, School of Chemistry & Chemical Engineering, Nanjing University, Nanjing 210023 (China); Hubei Key Laboratory for Processing and Application of Catalytic Materials, Huanggang Normal University, Huanggang 438000 (China)

2017-02-28

Highlights: • The effect of template on the surface chemistry of g-C{sub 3}N{sub 4} were investigated. • Template induces more non-graphitic species (sp{sup 3}−C−C− and −NH{sub x}) on g-C{sub 3}N{sub 4}. • Non-graphitic species influence electronic structure and performance of g-C{sub 3}N{sub 4}. - Abstract: In view of the fact that the photocatalytic activity of graphitic carbon nitride (g-C{sub 3}N{sub 4}) is greatly influenced by its electronic structure, herein, effect of templates induced surface species variation on the electronic structure and photocatalytic activity of the templated g-C{sub 3}N{sub 4} was investigated. By mixing the precursor of cyanamide with different templates (SiO{sub 2}, Al{sub 2}O{sub 3} and template-free) in the preparation of graphitic carbon nitride (g-C{sub 3}N{sub 4}), carbon nitrides with different surface species were obtained. The obtained carbon nitride (g-C{sub 3}N{sub 4}-Si) templated by SiO{sub 2} nanoparticles exhibits enlarged band gap (3.26 eV) and enhanced photo-degradation ability towards Methyl Orange (MO) compared to that of bulk g-C{sub 3}N{sub 4} (2.67 eV) synthesized from direct condensation/carbonization of melamine and Al{sub 2}O{sub 3}-templated g-C{sub 3}N{sub 4}-Al (2.76 eV). Detailed characterizations confirm that the introduction of templates in the synthesis process resulted in more non-graphitic species (sp{sup 3}−C−C− and −NH{sub x}) on the surface of the derived carbon nitrides, exerting remarkable effect on the electronic structure and photocatalytic performance.

Improved electrochemical performance of Li4Ti5O12 with a variable amount of graphene as a conductive agent for rechargeable lithium-ion batteries by solvothermal method

International Nuclear Information System (INIS)

Rai, Alok Kumar; Gim, Jihyeon; Kang, Sung-Won; Mathew, Vinod; Anh, Ly Tuan; Kang, Jungwon; Song, Jinju; Paul, Baboo Joseph; Kim, Jaekook

2012-01-01

We report on the solvothermal preparation of pure Li 4 Ti 5 O 12 and Li 4 Ti 5 O 12 /graphene (15 wt% and 30 wt%) nanocomposites anode for high-performance lithium-ion batteries. Structure and morphology studies of the nanocomposites by X-ray diffraction, field-emission scanning electron microscopy and field-emission transmission electron microscopy reveal Li 4 Ti 5 O 12 nanoparticles embedded onto the graphene nanosheets. On comparison to pure spinel Li 4 Ti 5 O 12 , the electrochemical performances of the Li 4 Ti 5 O 12 /graphene nanocomposites indicate higher capacities and enhanced cycle performances within the voltage domain of 1.0–2.5 V, under current rates as high as 10.4 C. The production of phase pure Li 4 Ti 5 O 12 nanoparticles ensures the short ion-diffusion paths while the presence of graphene facilitates improved structural network and hence enhanced electronic transport in the prepared nanocomposites. These factors eventually amount to impressive electrochemical properties. Highlights: ► A simple polyol-based approach to obtain the graphene nanosheets. ► Li 4 Ti 5 O 12 /graphene nanocomposites synthesis by polyol-based solvothermal process. ► Low temperature solvothermal strategy is one-step process to control nanoparticle sizes. ► The nanoparticles are well anchored onto the graphene nanosheets in the nanocomposites. ► Li 4 Ti 5 O 12 /graphene nanocomposites exhibit impressive electrochemical performances.

Construction of optimal 3-node plate bending triangles by templates

Science.gov (United States)

Felippa, C. A.; Militello, C.

A finite element template is a parametrized algebraic form that reduces to specific finite elements by setting numerical values to the free parameters. The present study concerns Kirchhoff Plate-Bending Triangles (KPT) with 3 nodes and 9 degrees of freedom. A 37-parameter template is constructed using the Assumed Natural Deviatoric Strain (ANDES). Specialization of this template includes well known elements such as DKT and HCT. The question addressed here is: can these parameters be selected to produce high performance elements? The study is carried out by staged application of constraints on the free parameters. The first stage produces element families satisfying invariance and aspect ratio insensitivity conditions. Application of energy balance constraints produces specific elements. The performance of such elements in benchmark tests is presently under study.

Synthesis of hydroxyapatite particles in catanionic mixed surfactants template

International Nuclear Information System (INIS)

Tari, Nesa Esmaeilian; Kashani Motlagh, Mohammad M.; Sohrabi, Beheshteh

2011-01-01

Highlights: ►The mixture of cetyltrimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) with different ratio were used as the template for synthesizing HAP particles. ► The overall morphology of the obtained powders at anionic-rich region (SDS:CTAB, 99:1) solution is rod like with high regularity. ► In the presence of cationic rich region (SDS:CTAB, 1:99) the resulted particles was sheet like. ► The resulted HAP nano particles in the presence of SDS were rod like but their morphology was less oriented than anionic-rich region. - Abstract: Different morphologies of nano hydroxyapatite particles, Ca 10 (PO 4 ) 6 (OH) 2 (HAP) are prepared by precipitation method using CaCl 2 and H 3 PO 4 (water phase) and the mixture of cationic surfactant cetyltrimethyl ammonium bromide (CTAB) and anionic one sodium dodecyl sulfate (SDS) as template. The mixture of these surfactants in two regions of cationic-rich and anionic-rich form the various aggregations as template. The results show that by changing the ratio of cationic to anionic surfactant in the mixture the morphology of the nano HAP can be controlled. The nano structure of products is studied by the means of X-ray diffraction (XRD), Fourier transmission infrared spectrometer (FT-IR) and scanning electron microscopy (SEM). With this system we could synthesize nano particles of hydroxyapatite with high crystallinity and least agglomeration.

Synthesis of hydroxyapatite particles in catanionic mixed surfactants template

Energy Technology Data Exchange (ETDEWEB)

Tari, Nesa Esmaeilian [Department of Chemistry, Iran University of Science and Technology, Resalat Square, Hengam Street, Tehran (Iran, Islamic Republic of); Kashani Motlagh, Mohammad M., E-mail: M.Kashani@iust.ac.ir [Department of Chemistry, Iran University of Science and Technology, Resalat Square, Hengam Street, Tehran (Iran, Islamic Republic of); Sohrabi, Beheshteh [Department of Chemistry, Iran University of Science and Technology, Resalat Square, Hengam Street, Tehran (Iran, Islamic Republic of)

2011-12-15

Highlights: Black-Right-Pointing-Pointer The mixture of cetyltrimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) with different ratio were used as the template for synthesizing HAP particles. Black-Right-Pointing-Pointer The overall morphology of the obtained powders at anionic-rich region (SDS:CTAB, 99:1) solution is rod like with high regularity. Black-Right-Pointing-Pointer In the presence of cationic rich region (SDS:CTAB, 1:99) the resulted particles was sheet like. Black-Right-Pointing-Pointer The resulted HAP nano particles in the presence of SDS were rod like but their morphology was less oriented than anionic-rich region. - Abstract: Different morphologies of nano hydroxyapatite particles, Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2} (HAP) are prepared by precipitation method using CaCl{sub 2} and H{sub 3}PO{sub 4} (water phase) and the mixture of cationic surfactant cetyltrimethyl ammonium bromide (CTAB) and anionic one sodium dodecyl sulfate (SDS) as template. The mixture of these surfactants in two regions of cationic-rich and anionic-rich form the various aggregations as template. The results show that by changing the ratio of cationic to anionic surfactant in the mixture the morphology of the nano HAP can be controlled. The nano structure of products is studied by the means of X-ray diffraction (XRD), Fourier transmission infrared spectrometer (FT-IR) and scanning electron microscopy (SEM). With this system we could synthesize nano particles of hydroxyapatite with high crystallinity and least agglomeration.

Solvothermal Synthesis of Zn2SnO4 Nanocrystals and Their Photocatalytic Properties

Directory of Open Access Journals (Sweden)

Guang Sun

2014-01-01

Full Text Available Crystalline Zn2SnO4 nanoparticles were successfully synthesized via a simple solvothermal route by using Zn(CH3COO2·2H2O and SnCl4·5H2O as source materials, NaOH as mineralizing agent, and water and ethanol as mixed solvents. The used amount of NaOH was found to have an important influence on the formation of Zn2SnO4. When the molar ratio of OH− : Zn2+ : Sn4+ was set in the range from 4 : 2 : 1 to 8 : 2 : 1, Zn2SnO4 nanoparticles with different shape and size were obtained. However, when the molar ratio of OH− : Zn2+ : Sn4+ was set as 10 : 2 : 1, a mixture phase of ZnO and ZnSn(OH6 instead of Zn2SnO4 was obtained. Photodegradation measurements indicated that the Zn2SnO4 nanoparticles own better photocatalytic property to depredate methyl orange than the Zn2SnO4 nanopolyhedrons. The superior photocatalytic properties of Zn2SnO4 nanoparticles may be contributed to their small crystal size and high surface area.

The iron member of the CPO-27 coordination polymer series: Synthesis, characterization, and intriguing redox properties

DEFF Research Database (Denmark)

Märcz, Matthias; Johnsen, Rune; Dietzel, Pascal D.C.

2012-01-01

The microporous coordination polymer CPO-27-Fe was synthesized from iron salts and 2,5-dihydroxyterephthalic acid by microwave assisted solvothermal synthesis. The crystal structures of the as-synthesized compounds were determined by Rietveld refinement from powder X-ray diffraction data using...

Spore coat protein synthesis in cell-free systems from sporulating cells of Bacillus subtilis.

Science.gov (United States)

Nakayama, T; Munoz, L E; Sadaie, Y; Doi, R H

1978-09-01

Cell-free systems for protein synthesis were prepared from Bacillus subtilis 168 cells at several stages of sporulation. Immunological methods were used to determine whether spore coat protein could be synthesized in the cell-free systems prepared from sporulating cells. Spore coat protein synthesis first occurred in extracts from stage t2 cells. The proportion of spore coat protein to total proteins synthesized in the cell-free systems was 2.4 and 3.9% at stages t2 and t4, respectively. The sodium dodecyl sulfate-urea-polyacrylamide gel electrophoresis patterns of immunoprecipitates from the cell-free systems showed the complete synthesis of an apparent spore coat protein precursor (molecular weight, 25,000). A polypeptide of this weight was previously identified in studies in vivo (L.E. Munoz, Y. Sadaie, and R.H. Doi, J. Biol. Chem., in press). The synthesis in vitro of polysome-associated nascent spore coat polypeptides with varying molecular weights up to 23,000 was also detected. These results indicate that the spore coat protein may be synthesized as a precursor protein. The removal of proteases in the crude extracts by treatment with hemoglobin-Sepharose affinity techniques may be preventing the conversion of the large 25,000-dalton precursor to the 12,500-dalton mature spore coat protein.

Increasing the fidelity of noncanonical amino acid incorporation in cell-free protein synthesis.

Science.gov (United States)

Gan, Qinglei; Fan, Chenguang

2017-11-01

Cell-free protein synthesis provides a robust platform for co-translational incorporation of noncanonical amino acid (ncAA) into proteins to facilitate biological studies and biotechnological applications. Recently, eliminating the activity of release factor 1 has been shown to increase ncAA incorporation in response to amber codons. However, this approach could promote mis-incorporation of canonical amino acids by near cognate suppression. We performed a facile protocol to remove near cognate tRNA isoacceptors of the amber codon from total tRNAs, and used the phosphoserine (Sep) incorporation system as validation. By manipulating codon usage of target genes and tRNA species introduced into the cell-free protein synthesis system, we increased the fidelity of Sep incorporation at a specific position. By removing three near cognate tRNA isoacceptors of the amber stop codon [tRNA Lys , tRNA Tyr , and tRNA Gln (CUG)] from the total tRNA, the near cognate suppression decreased by 5-fold without impairing normal protein synthesis in the cell-free protein synthesis system. Mass spectrometry analyses indicated that the fidelity of ncAA incorporation was improved. Removal of near cognate tRNA isoacceptors of the amber codon could increase ncAA incorporation fidelity towards the amber stop codon in release factor deficiency systems. We provide a general strategy to improve fidelity of ncAA incorporation towards stop, quadruplet and sense codons in cell-free protein synthesis systems. This article is part of a Special Issue entitled "Biochemistry of Synthetic Biology - Recent Developments" Guest Editor: Dr. Ilka Heinemann and Dr. Patrick O'Donoghue. Copyright © 2016 Elsevier B.V. All rights reserved.

Solvothermal synthesis and good microwave absorbing properties for magnetic porous-Fe3O4/graphene nanocomposites

Directory of Open Access Journals (Sweden)

Xiaojun Zeng

2017-05-01

Full Text Available The magnetic porous-Fe3O4/graphene nanocomposites have been fabricated by a facile solvothermal method. The porous Fe3O4 nanospheres are embedded uniformly in the graphene oxide (GO sheets to form a 3D Fe3O4/GO nanocomposite network. The dielectric properties for the Fe3O4/GO composites can be greatly improved by the 7 wt% GO additions. Good impedance matching can be also obtained in these Fe3O4/GO composites, which is proved to dominate their excellent microwave absorbing properties including the minimum reflection loss (RL value of -43.7 dB at 6.8 GHz with a sample thickness of 5 mm and a broad absorption bandwidth of 5.92 GHz (below -10 dB. These porous-Fe3O4/GO composites also exhibit the good structural stability and low density, which shows their great potential application in high-performance electromagnetic microwave-absorbing materials.

Template-free synthesis of ordered ZnO@ZnS core-shell arrays for high performance supercapacitors.

Science.gov (United States)

Yan, Hailong; Li, Tong; Lu, Yang; Cheng, Jinbing; Peng, Tao; Xu, Jinyou; Yang, Linying; Hua, Xiangqiang; Liu, Yunxin; Luo, Yongsong

2016-11-28

In this article, ordered ZnO@ZnS core-shell structures have been produced on a stainless mesh by a two-step approach without using a template. ZnO nanorods fabricated by a chemical vapor method are transferred into a 50 ml autoclave for a second stage ion-exchange reaction followed by heating at 120 °C for 4-16 h. The ZnO core is prepared as the conducting channel and ZnS as the active material. Such unique architecture exhibits remarkable electrochemical performance with high capacitance and desirable cycle life. When evaluating as the electrode for supercapacitors, the ZnO@ZnS core-shell structure delivers a high specific capacitance of 603.8 F g -1 at a current density of 2 A g -1 , with 9.4% capacitance loss after cycling 3000 times. The fabrication strategy presented here is simple and cost-effective, which can open new avenues for large-scale applications of the novel materials in energy storage.

Synthesis of zeolite-templated carbons for hydrogen storage applications

CSIR Research Space (South Africa)

Musyoka, Nicholas M

2013-10-01

Full Text Available in this field. Of the various nanocasting strategies for carbonaceous materials, hard templates such as zeolites have been of key research interest due to the many attractive properties associated with the resulting carbon replicas. Some of these properties are...

Nucleic acid and nucleotide-mediated synthesis of inorganic nanoparticles

Science.gov (United States)

Berti, Lorenzo; Burley, Glenn A.

2008-02-01

Since the advent of practical methods for achieving DNA metallization, the use of nucleic acids as templates for the synthesis of inorganic nanoparticles (NPs) has become an active area of study. It is now widely recognized that nucleic acids have the ability to control the growth and morphology of inorganic NPs. These biopolymers are particularly appealing as templating agents as their ease of synthesis in conjunction with the possibility of screening nucleotide composition, sequence and length, provides the means to modulate the physico-chemical properties of the resulting NPs. Several synthetic procedures leading to NPs with interesting photophysical properties as well as studies aimed at rationalizing the mechanism of nucleic acid-templated NP synthesis are now being reported. This progress article will outline the current understanding of the nucleic acid-templated process and provides an up to date reference in this nascent field.

Ordered mesoporous crystalline gamma-Al2O3 with variable architecture and porosity from a single hard template.

Science.gov (United States)

Wu, Zhangxiong; Li, Qiang; Feng, Dan; Webley, Paul A; Zhao, Dongyuan

2010-09-01

In this paper, an efficient route is developed for controllable synthesis of ordered mesoporous alumina (OMA) materials with variable pore architectures and high mesoporosity, as well as crystalline framework. The route is based on the nanocasting pathway with bimodal mesoporous carbon as the hard template. In contrast to conventional reports, we first realize the possibility of creating two ordered mesopore architectures by using a single carbon hard template obtained from organic-organic self-assembly, which is also the first time such carbon materials are adopted to replicate ordered mesoporous materials. The mesopore architecture and surface property of the carbon template are rationally designed in order to obtain ordered alumina mesostructures. We found that the key factors rely on the unique bimodal mesopore architecture and surface functionalization of the carbon hard template. Namely, the bimodal mesopores (2.3 and 5.9 nm) and the surface functionalities make it possible to selectively load alumina into the small mesopores dominantly and/or with a layer of alumina coated on the inner surface of the large primary mesopores with different thicknesses until full loading is achieved. Thus, OMA materials with variable pore architectures (similar and reverse mesostructures relative to the carbon template) and controllable mesoporosity in a wide range are achieved. Meanwhile, in situ ammonia hydrolysis for conversion of the metal precursor to its hydroxide is helpful for easy crystallization (as low as approximately 500 degrees C). Well-crystallized alumina frameworks composed of gamma-Al(2)O(3) nanocrystals with sizes of 6-7 nm are obtained after burning out the carbon template at 600 degrees C, which is advantageous over soft-templated aluminas. The effects of synthesis factors are demonstrated and discussed relative to control experiments. Furthermore, our method is versatile enough to be used for general synthesis of other important but difficult

Structure of Hepatitis C Virus Polymerase in Complex with Primer-Template RNA

Energy Technology Data Exchange (ETDEWEB)

Mosley, Ralph T.; Edwards, Thomas E.; Murakami, Eisuke; Lam, Angela M.; Grice, Rena L.; Du, Jinfa; Sofia, Michael J.; Furman, Philip A.; Otto, Michael J. (Pharmasset); (Emerald)

2012-08-01

The replication of the hepatitis C viral (HCV) genome is accomplished by the NS5B RNA-dependent RNA polymerase (RdRp), for which mechanistic understanding and structure-guided drug design efforts have been hampered by its propensity to crystallize in a closed, polymerization-incompetent state. The removal of an autoinhibitory {beta}-hairpin loop from genotype 2a HCV NS5B increases de novo RNA synthesis by >100-fold, promotes RNA binding, and facilitated the determination of the first crystallographic structures of HCV polymerase in complex with RNA primer-template pairs. These crystal structures demonstrate the structural realignment required for primer-template recognition and elongation, provide new insights into HCV RNA synthesis at the molecular level, and may prove useful in the structure-based design of novel antiviral compounds. Additionally, our approach for obtaining the RNA primer-template-bound structure of HCV polymerase may be generally applicable to solving RNA-bound complexes for other viral RdRps that contain similar regulatory {beta}-hairpin loops, including bovine viral diarrhea virus, dengue virus, and West Nile virus.

Oriented growth of magnetite along the carbon nanotubes via covalently bonded method in a simple solvothermal system

Energy Technology Data Exchange (ETDEWEB)

Zhan Yingqing; Zhao Rui; Meng Fanbing; Lei Yajie; Zhong Jiachun; Yang Xulin [Research Branch of Functional Materials, Institute of Microelectronic and Solid State Electronic, University of Electronic Science and Technology of China, Chengdu 610054 (China); Liu Xiaobo, E-mail: liuxb@uestc.edu.cn [Research Branch of Functional Materials, Institute of Microelectronic and Solid State Electronic, University of Electronic Science and Technology of China, Chengdu 610054 (China)

2011-06-15

Highlights: > Novel CNTs/magnetite hybrid materials were prepared via covalently bonded method. > Stable interaction between nitriles and iron ion promoted the oriented growth of magnetite. > The hybrid material exhibited higher magnetism and electromagnetic properties - Abstract: A new type of CNTs/magnetite hybrid material was prepared via covalently bonded method in a simple solvothermal system using FeCl{sub 3} as iron source, ethylene glycol as the reducing agent, and 4-aminophenoxyphthalonitrile-grafted CNTs as templates. The magnetite nanoparticles, with the diameters of 70-80 nm, were self-assembled along the CNTs. The FTIR, UV-vis and DSC revealed that a stable covalent bond between nitriles group and iron ion promoted the oriented growth of magnetite nanoparticles along the CNTs, resulting in good dispersibility and solution storage stability. The magnetic properties measurements indicated that a higher saturated magnetization (70.7 emu g{sup -1}) existed in the CNTs/magnetite hybrid material, which further enhanced the electromagnetic properties. The magnetic loss was caused mainly by natural resonance, which is in good agreement with the Kittel equation results. The novel electromagnetic hybrid material is believed to have potential applications in the microwave absorbing performances.

Oriented growth of magnetite along the carbon nanotubes via covalently bonded method in a simple solvothermal system

International Nuclear Information System (INIS)

Zhan Yingqing; Zhao Rui; Meng Fanbing; Lei Yajie; Zhong Jiachun; Yang Xulin; Liu Xiaobo

2011-01-01

Highlights: → Novel CNTs/magnetite hybrid materials were prepared via covalently bonded method. → Stable interaction between nitriles and iron ion promoted the oriented growth of magnetite. → The hybrid material exhibited higher magnetism and electromagnetic properties - Abstract: A new type of CNTs/magnetite hybrid material was prepared via covalently bonded method in a simple solvothermal system using FeCl 3 as iron source, ethylene glycol as the reducing agent, and 4-aminophenoxyphthalonitrile-grafted CNTs as templates. The magnetite nanoparticles, with the diameters of 70-80 nm, were self-assembled along the CNTs. The FTIR, UV-vis and DSC revealed that a stable covalent bond between nitriles group and iron ion promoted the oriented growth of magnetite nanoparticles along the CNTs, resulting in good dispersibility and solution storage stability. The magnetic properties measurements indicated that a higher saturated magnetization (70.7 emu g -1 ) existed in the CNTs/magnetite hybrid material, which further enhanced the electromagnetic properties. The magnetic loss was caused mainly by natural resonance, which is in good agreement with the Kittel equation results. The novel electromagnetic hybrid material is believed to have potential applications in the microwave absorbing performances.

Templated green synthesis of plasmonic silver nanoparticles in onion epidermal cells suitable for surface-enhanced Raman and hyper-Raman scattering

DEFF Research Database (Denmark)

Palanco, Marta Espina; Mogensen, Klaus Bo; Guehlke, Marina

2016-01-01

We report fast and simple green synthesis of plasmonic silver nanoparticles in the epidermal cells of onions after incubation with AgNO3 solution. The biological environment supports the generation of silver nanostructures in two ways. The plant tissue delivers reducing chemicals for the initial...... for one-and two-photon-excited spectroscopy such as surface enhanced Raman scattering (SERS) and surface enhanced hyper-Raman scattering (SEHRS). Our studies demonstrate a templated green preparation of enhancing plasmonic nanoparticles and suggest a new route to deliver silver nanoparticles as basic...... building blocks of plasmonic nanosensors to plants by the uptake of solutions of metal salts....

Metal-organic framework templated synthesis of Fe{sub 2}O{sub 3}/TiO{sub 2} nanocomposite for hydrogen production

Energy Technology Data Exchange (ETDEWEB)

Krafft, Kathryn E. de; Wang, Cheng; Lin, Wenbin [University of North Carolina, Chapel Hill, NC (United States). Department of Chemistry

2012-04-17

A new metal-organic framework (MOF)-templated method has been developed for the synthesis of a metal oxide nanocomposite with interesting photophysical properties. Fe-containing nanoscale MOFs are coated with amorphous titania, then calcined to produce crystalline Fe{sub 2}O{sub 3}/TiO{sub 2} composite nanoparticles. This material enables photocatalytic hydrogen production from water using visible light, which cannot be achieved by either Fe{sub 2}O{sub 3} or TiO{sub 2} alone or a mixture of the two. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Solvothermal synthesis of Zn{sub 2}GeO{sub 4}:Mn{sup 2+} nanophosphor in water/diethylene glycol system

Energy Technology Data Exchange (ETDEWEB)

Takeshita, Satoru; Honda, Joji [Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan); Isobe, Tetsuhiko, E-mail: isobe@applc.keio.ac.jp [Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan); Sawayama, Tomohiro; Niikura, Seiji [SINLOIHI Company, Limited, 2-19-12 Dai, Kamakura 247-8550 (Japan)

2012-05-15

The influence of aging of the suspension containing the amorphous precusors on structural, compositional and photoluminescent properties is studied to understand the mechanism on the formation of Zn{sub 2}GeO{sub 4}:Mn{sup 2+} nanoparticles during the solvothermal reaction in the water/diethylene glycol mixed solvent. Aging at 200 Degree-Sign C for 20 min forms the crystalline Zn{sub 2}GeO{sub 4} nanorods and then they grow up to {approx} 50 nm in mean length after aging for 240 min. Their interplanar spacing of (410) increases with increasing the aging time. The photoluminescence intensity corresponding to the d-d transition of Mn{sup 2+} increases with increasing the aging time up to 120 min, and then decreases after aging for 240 min. The photoluminescence lifetime decreases with increasing the aging time, indicating the locally concentrated Mn{sup 2+} ions. These results reveal that Mn{sup 2+} ions gradually replace Zn{sup 2+} ions near surface through repeating dissolusion and precipitation processes during prolonged aging after the complete crystallization of Zn{sub 2}GeO{sub 4}. - Graphical abstract: TEM images of Zn{sub 2}GeO{sub 4}:Mn{sup 2+} nanoparticles aged at 200 Degree-Sign C for different aging times in the mixed solvent of water and diethylene glycol. Highlights: Black-Right-Pointing-Pointer Mechanism on formation of Zn{sub 2}GeO{sub 4}:Mn{sup 2+} nanophosphor under solvothermal condition. Black-Right-Pointing-Pointer Zn{sub 2}GeO{sub 4} nanorods crystallize via amorphous precursors. Black-Right-Pointing-Pointer Gradual substitution of Mn{sup 2+} during prolonged aging. Black-Right-Pointing-Pointer Such an inhomogeneous Mn{sup 2+} doping process results in concentration quenching.

Role of cellulose functionality in bio-inspired synthesis of nano bioactive glass.

Science.gov (United States)

Gupta, Nidhi; Santhiya, Deenan

2017-06-01

In search of abundant cheaper natural polymer for bio-inspired bioactive glass nanoparticles synthesis, cellulose and its derivatives have been considered as a template. Different templates explored in the present studies are pure cellulose, methyl cellulose and amine grafted cellulose. To the best of our knowledge, for the first time of the considered templates, pure cellulose and amine grafted cellulose results in in situ nano particulate composite formation while interestingly methyl cellulose proves to be an excellent sacrificial template for the synthesis of uniform bioglass nanoparticles of diameter in the range of 55nm. Further, viscoelastic measurements were carried out using dynamic mechanical analyzer. Herein, an attempt has been made to establish structure-mechanical relationship based on the templates. Moreover, in vitro bioactivity is also observed to be affected by the nature of the template molecule used for the synthesis of bioactive glass. Copyright © 2017 Elsevier B.V. All rights reserved.

Enzymatic primer-extension with glycerol-nucleoside triphosphates on DNA templates.

Directory of Open Access Journals (Sweden)

Jesse J Chen

Full Text Available BACKGROUND: Glycerol nucleic acid (GNA has an acyclic phosphoglycerol backbone repeat-unit, but forms stable duplexes based on Watson-Crick base-pairing. Because of its structural simplicity, GNA is of particular interest with respect to the possibility of evolving functional polymers by in vitro selection. Template-dependent GNA synthesis is essential to any GNA-based selection system. PRINCIPAL FINDINGS: In this study, we investigated the ability of various DNA polymerases to use glycerol-nucleoside triphosphates (gNTPs as substrates for GNA synthesis on DNA templates. Therminator DNA polymerase catalyzes quantitative primer-extension by the incorporation of two glyceronucleotides, with much less efficient extension up to five glyceronucleotides. Steady-state kinetic experiments suggested that GNA synthesis by Therminator was affected by both decreased catalytic rates and weakened substrate binding, especially for pyrimidines. In an attempt to improve pyrimidine incorporation by providing additional stacking interactions, we synthesized two new gNTP analogs with 5-propynyl substituted pyrimidine nucleobases. This led to more efficient incorporation of gC, but not gT. CONCLUSIONS: We suggest that directed evolution of Therminator might lead to mutants with improved substrate binding and catalytic efficiency.

Solvothermal synthesis of mesoporous magnetite nanoparticles for Cr(IV) ions uptake and microwave absorption

KAUST Repository

Shen, Peng; Zhang, Haitao; Zhang, Suojiang; Yuan, Pei; Yang, Yang; Zhang, Qiang; Zhang, Xixiang

2016-01-01

Abstract: Colloidal mesoporous magnetite nanoparticles with tunable porosity were realized by a simple and scalable solvothermal route with the aid of AOT as ligands. AOT was used to induce the anisotropic crystal growth of smaller nanocrystals and restrain their tight aggregation so as to form more mesoscale pores. Morphologies and microstructures investigation by SEM and TEM revealed that the bigger nanoparticles were composed of smaller nanocrystals with an average size of 18 nm. A possible formation mechanism was proposed for the mesoporous nanoparticles. Study of nitrogen adsorption–desorption isotherm revealed that the Brunauer–Emmett–Teller (BET) specific surface area of mesoporous nanoparticles is up to 209 m2/g, resulting from the slit-shaped pores created by the aggregation of polyhedral nanocrystals. Magnetic properties study indicated that the as-prepared nanoparticles are superparamagnetic at room temperature. Optimized mesoporous magnetite nanoparticles exhibit a maximum Cr(VI) ion sorption capacity of 12.9 mmol/g, and its absorption behavior followed a Freundlich model. Microwave absorption study indicated that porous nanoparticles own higher permeability values than that of solid nanoparticles, leading to a higher dielectric loss in the frequency range of 2–18 GHz. Graphical Abstract: [Figure not available: see fulltext.] © 2016, Springer Science+Business Media Dordrecht.

Facile solvothermal synthesis of a graphene nanosheet-bismuth oxide composite and its electrochemical characteristics

International Nuclear Information System (INIS)

Wang Huanwen; Hu Zhongai; Chang Yanqin; Chen Yanli; Lei Ziqiang; Zhang Ziyu; Yang Yuying

2010-01-01

This work demonstrates a novel and facile route for preparing graphene-based composites comprising of metal oxide nanoparticles and graphene. A graphene nanosheet-bismuth oxide composite as electrode materials of supercapacitors was firstly synthesized by thermally treating the graphene-bismuth composite, which was obtained through simultaneous solvothermal reduction of the colloidal dispersions of negatively charged graphene oxide sheets in N,N-dimethyl formamide (DMF) solution of bismuth cations at 180 o C. The morphology, composition, and microstructure of the composites together with pure graphite oxide, and graphene were characterized using powder X-ray diffraction (XRD), FT-IR, field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), thermogravimetry and differential thermogravimetry (TG-DTG). The electrochemical behaviors were measured by cyclic voltammogram (CV), galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS). The specific capacitance of 255 F g -1 (based on composite) is obtained at a specific current of 1 A g -1 as compared with 71 F g -1 for pure graphene. The loaded-bismuth oxide achieves a specific capacitance as high as 757 F g -1 even at 10 A g -1 . In addition, the graphene nanosheet-bismuth oxide composite electrode exhibits the excellent rate capability and well reversibility.

Solvothermal synthesis of mesoporous magnetite nanoparticles for Cr(IV) ions uptake and microwave absorption

KAUST Repository

Shen, Peng

2016-05-12

Abstract: Colloidal mesoporous magnetite nanoparticles with tunable porosity were realized by a simple and scalable solvothermal route with the aid of AOT as ligands. AOT was used to induce the anisotropic crystal growth of smaller nanocrystals and restrain their tight aggregation so as to form more mesoscale pores. Morphologies and microstructures investigation by SEM and TEM revealed that the bigger nanoparticles were composed of smaller nanocrystals with an average size of 18 nm. A possible formation mechanism was proposed for the mesoporous nanoparticles. Study of nitrogen adsorption–desorption isotherm revealed that the Brunauer–Emmett–Teller (BET) specific surface area of mesoporous nanoparticles is up to 209 m2/g, resulting from the slit-shaped pores created by the aggregation of polyhedral nanocrystals. Magnetic properties study indicated that the as-prepared nanoparticles are superparamagnetic at room temperature. Optimized mesoporous magnetite nanoparticles exhibit a maximum Cr(VI) ion sorption capacity of 12.9 mmol/g, and its absorption behavior followed a Freundlich model. Microwave absorption study indicated that porous nanoparticles own higher permeability values than that of solid nanoparticles, leading to a higher dielectric loss in the frequency range of 2–18 GHz. Graphical Abstract: [Figure not available: see fulltext.] © 2016, Springer Science+Business Media Dordrecht.

Facile solvothermal synthesis of a graphene nanosheet-bismuth oxide composite and its electrochemical characteristics

Energy Technology Data Exchange (ETDEWEB)

Wang Huanwen [Key Laboratory of Eco-Environment-Related Polymer Materials of Ministry of Education, Key Laboratory of Polymer Materials of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China); Hu Zhongai, E-mail: zhongai@nwnu.edu.c [Key Laboratory of Eco-Environment-Related Polymer Materials of Ministry of Education, Key Laboratory of Polymer Materials of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China); Chang Yanqin; Chen Yanli; Lei Ziqiang; Zhang Ziyu; Yang Yuying [Key Laboratory of Eco-Environment-Related Polymer Materials of Ministry of Education, Key Laboratory of Polymer Materials of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China)

2010-12-01

This work demonstrates a novel and facile route for preparing graphene-based composites comprising of metal oxide nanoparticles and graphene. A graphene nanosheet-bismuth oxide composite as electrode materials of supercapacitors was firstly synthesized by thermally treating the graphene-bismuth composite, which was obtained through simultaneous solvothermal reduction of the colloidal dispersions of negatively charged graphene oxide sheets in N,N-dimethyl formamide (DMF) solution of bismuth cations at 180 {sup o}C. The morphology, composition, and microstructure of the composites together with pure graphite oxide, and graphene were characterized using powder X-ray diffraction (XRD), FT-IR, field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), thermogravimetry and differential thermogravimetry (TG-DTG). The electrochemical behaviors were measured by cyclic voltammogram (CV), galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS). The specific capacitance of 255 F g{sup -1} (based on composite) is obtained at a specific current of 1 A g{sup -1} as compared with 71 F g{sup -1} for pure graphene. The loaded-bismuth oxide achieves a specific capacitance as high as 757 F g{sup -1} even at 10 A g{sup -1}. In addition, the graphene nanosheet-bismuth oxide composite electrode exhibits the excellent rate capability and well reversibility.

Synthesis of platinum nanowire networks using a soft template.

Science.gov (United States)

Song, Yujiang; Garcia, Robert M; Dorin, Rachel M; Wang, Haorong; Qiu, Yan; Coker, Eric N; Steen, William A; Miller, James E; Shelnutt, John A

2007-12-01

Platinum nanowire networks have been synthesized by chemical reduction of a platinum complex using sodium borohydride in the presence of a soft template formed by cetyltrimethylammonium bromide in a two-phase water-chloroform system. The interconnected polycrystalline nanowires possess the highest surface area (53 +/- 1 m2/g) and electroactive surface area (32.4 +/- 3.6 m2/g) reported for unsupported platinum nanomaterials; the high surface area results from the small average diameter of the nanowires (2.2 nm) and the 2-10 nm pores determined by nitrogen adsorption measurements. Synthetic control over the network was achieved simply by varying the stirring rate and reagent concentrations, in some cases leading to other types of nanostructures including wormlike platinum nanoparticles. Similarly, substitution of a palladium complex for platinum gives palladium nanowire networks. A mechanism of formation of the metal nanowire networks is proposed based on confined metal growth within a soft template consisting of a network of swollen inverse wormlike micelles.

In vitro synthesis of minus-strand RNA by an isolated cereal yellow dwarf virus RNA-dependent RNA polymerase requires VPg and a stem-loop structure at the 3' end of the virus RNA.

Science.gov (United States)

Osman, Toba A M; Coutts, Robert H A; Buck, Kenneth W

2006-11-01

Cereal yellow dwarf virus (CYDV) RNA has a 5'-terminal genome-linked protein (VPg). We have expressed the VPg region of the CYDV genome in bacteria and used the purified protein (bVPg) to raise an antiserum which was able to detect free VPg in extracts of CYDV-infected oat plants. A template-dependent RNA-dependent RNA polymerase (RdRp) has been produced from a CYDV membrane-bound RNA polymerase by treatment with BAL 31 nuclease. The RdRp was template specific, being able to utilize templates from CYDV plus- and minus-strand RNAs but not those of three unrelated viruses, Red clover necrotic mosaic virus, Cucumber mosaic virus, and Tobacco mosaic virus. RNA synthesis catalyzed by the RdRp required a 3'-terminal GU sequence and the presence of bVPg. Additionally, synthesis of minus-strand RNA on a plus-strand RNA template required the presence of a putative stem-loop structure near the 3' terminus of CYDV RNA. The base-paired stem, a single-nucleotide (A) bulge in the stem, and the sequence of a tetraloop were all required for the template activity. Evidence was produced showing that minus-strand synthesis in vitro was initiated by priming by bVPg at the 3' end of the template. The data are consistent with a model in which the RdRp binds to the stem-loop structure which positions the active site to recognize the 3'-terminal GU sequence for initiation of RNA synthesis by the addition of an A residue to VPg.

Solvothermal synthesis of carbon coated N-doped TiO{sub 2} nanostructures with enhanced visible light catalytic activity

Energy Technology Data Exchange (ETDEWEB)

Yan Xuemin, E-mail: yanzhangmm2002@163.com [College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou 434023 (China); Kang Jialing; Gao Lin; Xiong Lin; Mei Ping [College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou 434023 (China)

2013-01-15

Highlights: Black-Right-Pointing-Pointer Chitosan was used as carbon and nitrogen resource to modify TiO{sub 2} nanostructure. Black-Right-Pointing-Pointer Nanocomposites with mesostructure were obtained by one-step solvothermal method. Black-Right-Pointing-Pointer Carbon species were modified on the surface of TiO{sub 2}. Black-Right-Pointing-Pointer Nitrogen was doped into the anatase titania lattice. Black-Right-Pointing-Pointer CTS-TiO{sub 2} nanocomposites show superior visible light photocatalytic activity. - Abstract: Visible light-active carbon coated N-doped TiO{sub 2} nanostructures(CTS-TiO{sub 2}) were prepared by a facile one-step solvothermal method with chitosan as carbon and nitrogen resource at 180 Degree-Sign C. The as-prepared samples were characterized by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), N{sub 2} adsorption-desorption analysis, X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy. The CTS-TiO{sub 2} nanocomposites possess anatase phase of nanocrystalline structure with average particle size of about 5-7 nm. A wormhole mesostructure can be observed in the CTS-TiO{sub 2} nanocomposites due to the constituent agglomerated of nanoparticles. It has been evidenced that the nitrogen was doped into the anatase titania lattice and the carbon species were modified on the surface of TiO{sub 2}. The photocatalytic activities of the as-prepared photocatalysts were measured by the degradation of methylene blue (MB) under visible light irradiation at {lambda} {>=} 400 nm. The results show that CTS-TiO{sub 2} nanostructures display a higher visible light photocatalytic activity than pure TiO{sub 2}, commercial P25 and C-coated TiO{sub 2} (C-TiO{sub 2}) photocatalysts. The higher photocatalytic activity could be attributed to the band-gap narrowed by N-doping and the accelerated separation of the photo-generated electrons

Anion Exchange in II-VI Semiconducting Nanostructures via Atomic Templating.

Science.gov (United States)

Agarwal, Rahul; Krook, Nadia M; Ren, Ming-Liang; Tan, Liang Z; Liu, Wenjing; Rappe, Andrew M; Agarwal, Ritesh

2018-03-14

Controlled chemical transformation of nanostructures is a promising technique to obtain precisely designed novel materials, which are difficult to synthesize otherwise. We report high-temperature vapor-phase anion-exchange reactions to chemically transform II-VI semiconductor nanostructures (100-300 nm length scale) while retaining the single crystallinity, crystal structure, morphology, and even defect distribution of the parent material via atomic templating. The concept of atomic templating is employed to obtain kinetically controlled, thermodynamically metastable structural phases such as zincblende CdSe and CdS from zincblende CdTe upon complete chemical replacement of Te with Se or S. The underlying transformation mechanisms are explained through first-principles density functional theory calculations. Atomic templating is a unique path to independently tune materials' phase and composition at the nanoscale, allowing the synthesis of novel materials.

Large scale solvothermal synthesis and a strategy to obtain stable Langmuir–Blodgett film of CoFe2O4 nanoparticles

International Nuclear Information System (INIS)

Thampi, Arya; Babu, Keerthi; Verma, Seema

2013-01-01

Highlights: • Large scale, monodisperse CoFe 2 O 4 nanoparticles by solvothermal route. • LB technique to obtain stable film of CoFe 2 O 4 nanoparticles over a large area. • Hydrophobicity of substrate was enhanced utilizing LB films of cadmium arachidate. • P–A isotherm and AFM cross sectional height profile analysis confirms stability. • Large scale organization of nanoparticles for surface pressure higher than 15 mN/m. -- Abstract: Nearly monodisperse oleic acid coated cobalt ferrite nanoparticles were synthesized in large scale by a simple solvothermal method utilizing N-methyl 2-Pyrrolidone (NMP) as a high boiling solvent. The magnetic oxide was further investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and vibrating sample magnetometer (VSM). Langmuir–Blodgett (LB) technique is discussed to obtain a 2D assembly of oleic acid coated CoFe 2 O 4 nanoparticles over a large area. We describe a method to obtain stable, condensed three layers of cadmium arachidate on a piranha treated glass substrate. The hydrophobic surface thus obtained was subsequently used for forming a stable monolayer of oleic acid stabilized cobalt ferrite nanoparticles at the air–water interface. The stability of the LB films at the air–water interface was studied by pressure–area isotherm curves and atomic force microscopy (AFM) cross sectional height profile analysis. 2D organization of the magnetic nanoparticles at different surface pressures was studied by TEM. Preparation of large area LB films of CoFe 2 O 4 nanoparticles is reported for a surface pressure more than 15 mN/m

Surfactant assisted synthesis of lamellar nanostructured LiFePO4 at 388 K

International Nuclear Information System (INIS)

Liu Chao; Ma Dongxia; Ji Xiujie; Zhao Shanshan; Li Song

2011-01-01

Lamellar nanostructured lithium iron phosphate (Lα-LFP) was synthesized using anion surfactant sodium dodecyl sulphonate (SDS) as supermolecular template in water-ethanol media at 388 K under self-generated pressure. FeSO 4 , (NH 4 ) 2 HPO 4 and LiOH were used as Fe, P and Li sources, respectively. The inorganic phase was analyzed by X-ray diffraction (XRD). The morphology and the lamellar nanostructure were observed by field emitting scanning electron microscopy (FESEM). The results showed that the synthesized Lα-LFP presents not only the ordered lamellar microstructure accumulated by 20-40-nm thick LFP layers, but also the consequent self-assembled blocky particles of 0.5-1 μm. In contrast, template free LFP (TF-LFP) show a flake-shaped and mess-orientated microstructure. As a soft template, SDS played the roles of inducing the lamellar nanostructure, purifying the inorganic phase and decreasing the synthesis temperature.

Effect of Antimalarial Drugs on Plasmodia Cell-Free Protein Synthesis

Directory of Open Access Journals (Sweden)

Ana Ferreras

2002-04-01

Full Text Available A cell-free system from Plasmodium falciparum able to translate endogenous mRNA was used to determine the effect of artemisinin, chloroquine and primaquine on the protein synthesis mechanism of the parasite. The antimalarial drugs did not inhibit the incorporation of [³H] methionine into parasite proteins even at concentrations higher than the ones found to strongly inhibit the parasite growth. Results clearly indicate that these compounds do not have a direct effect on protein synthesis activity of P. falciparum coded by endogenous mRNA.

Challenges in TEM sample preparation of solvothermally grown CuInS2 films.

Science.gov (United States)

Frank, Anna; Changizi, Rasa; Scheu, Christina

2018-06-01

Transmission electron microscopy (TEM) is a widely used tool to characterize materials. The required samples need to be electron transparent which should be achieved without changing the microstructure. This work describes different TEM sample preparation techniques of nanostructured CuInS 2 thin films on fluorine-doped tin oxide substrates, synthesized solvothermally using l-cysteine as sulfur source. Focused ion beam lamellae, conventional cross section samples and scratch samples have been prepared and investigated. It was possible to prepare appropriate samples with each technique, however, each technique brings with it certain advantages and disadvantages. FIB preparation of solvothermally synthesized CuInS 2 suffers from two main drawbacks. First, the whole CuInS 2 layer displays a strongly increased Cu content caused by Cu migration and preferential removal of In. Further, electron diffraction shows the formation of an additional CuS phase after Ga + bombardment. Second, diffraction analysis is complicated by a strong contribution of crystalline Pt introduced during the FIB preparation and penetrating into the porous film surface. The conventional cross sectional CuInS 2 sample also shows a Cu signal enhancement which is caused by contribution of the brass tube material used for embedding. Additionally, Cu particles have been observed inside the CuInS 2 which have been sputtered on the film during preparation. Only the scratch samples allow an almost artefact-free and reliable elemental quantification using energy-dispersive X-ray spectroscopy. However, scratch samples suffer from the drawback that it is not possible to determine the layer thickness, which is possible for both cross sectional preparation techniques. Consequently, it is concluded that the type of sample preparation should be chosen dependent on the required information. A full characterization can only be achieved when the different techniques are combined. Copyright © 2018 Elsevier Ltd. All

The evolution of hierarchical porosity in self-templated nitrogen-doped carbons and its effect on oxygen reduction electrocatalysis

NARCIS (Netherlands)

Eisenberg, D.; Prinsen, P.; Geels, N.J.; Stroek, W.; Yan, N.; Hua, B.; Luo, J.-L.; Rothenberg, G.

2016-01-01

Pyrolitic self-templating synthesis is an effective method for creating hierarchically porous N-doped carbons. We study the evolution of microstructure in self-templated carbons derived from magnesium nitrilotriacetate, in the 600–1000 °C temperature range. The materials are characterised using N2

Zinc oxide hollow micro spheres and nano rods: Synthesis and applications in gas sensor

International Nuclear Information System (INIS)

Jamil, Saba; Janjua, Muhammad Ramzan Saeed Ashraf; Ahmad, Tauqeer; Mehmood, Tahir; Li, Songnan; Jing, Xiaoyan

2014-01-01

Zinc oxide nano rods and micro hollow spheres are successfully fabricated by adopting a simple solvo-thermal approach without employing any surfactant/template by keeping heating time as variable. The prepared products are characterized by using different instruments such as X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). In order to investigate the morphological dependence on the reaction time, analogous experiments with various reaction times are carried out. Depending upon heating time, different morphological forms have been identified such as hollow microsphere (4 μm to 5 μm) and nano rods with an average diameter of approximately 100 nm. The fabricated materials are also tested for ethanol gas sensor applications and zinc oxide hollow microsphere proven to be an efficient gas sensing materials. Nitrogen adsorption–desorption measurement was performed to understand better performance of zinc oxide micro hollow spheres as effective ethanol gas sensing material. - Graphical abstract: Graphical abstract is represented by zinc oxide sphere (prepared by simple solvothermal approach), its XRD pattern(characterization) and finally its application in gas sensing. - Highlights: • Zinc oxide spheres were prepared by using solvothermal method. • Detailed description of the morphology of microspheres assembled by nano rods. • Formation mechanism of zinc oxide spheres assembled by nano rods. • Zinc oxide spheres and nano rods displayed very good gas sensing ability

Imidazoline derivative templated synthesis of broccoli-like Bi2S3 and its electrocatalysis towards the direct electrochemistry of hemoglobin.

Science.gov (United States)

Chen, Xiaoqian; Wang, Qingxiang; Wang, Liheng; Gao, Feng; Wang, Wei; Hu, Zhengshui

2015-04-15

A broccoli-like bismuth sulfide (bBi2S3) was synthesized via a solvothermal method using a self-made imidazoline derivative of 2-undecyl-1-dithioureido-ethyl-imidazoline as the soft template. The morphology and chemical constitution of the product were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). Electrochemical characterization experiments show that the bBi2S3 has the higher specific surface area and standard heterogeneous electron transfer rate constant than the rod-like Bi2S3 (rBi2S3). Hemoglobin (Hb) was then chosen as a protein model to investigate the electrocatalytic property of the synthesized bBi2S3. The results show that Hb entrapped in the composite film of chitosan and bBi2S3 displays an excellent direct electrochemistry, and retains its biocatalytic activity toward the electro-reduction of hydrogen peroxide. The current response in the amperometry shows a linear response to H2O2 concentrations in the range from 0.4 to 4.8µM with high sensitivity (444µAmM(-1)) and low detection limit (0.096µM). The Michaelis-Menten constant (KM(app)) of the fabricated bioelectrode for H2O2 was determined as low as 1µM. These results demonstrate that the synthesized bBi2S3 offers a new path for the immobilization of redox-active protein and the construction of the third-generation biosensors. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis and catalytic activity of polysaccharide templated nanocrystalline sulfated zirconia

Energy Technology Data Exchange (ETDEWEB)

Sherly, K. B.; Rakesh, K. [Mahatma Gandhi University Regional Research Center in Chemistry, Department of Chemistry, Mar Athanasius College, Kothamangalam-686666, Kerala (India)

2014-01-28

Nanoscaled materials are of great interest due to their unique enhanced optical, electrical and magnetic properties. Sulfate-promoted zirconia has been shown to exhibit super acidic behavior and high activity for acid catalyzed reactions. Nanocrystalline zirconia was prepared in the presence of polysaccharide template by interaction between ZrOCl{sub 2}⋅8H{sub 2}O and chitosan template. The interaction was carried out in aqueous phase, followed by the removal of templates by calcination at optimum temperature and sulfation. The structural and textural features were characterized by powder XRD, TG, SEM and TEM. XRD patterns showed the peaks of the diffractogram were in agreement with the theoretical data of zirconia with the catalytically active tetragonal phase and average crystalline size of the particles was found to be 9 nm, which was confirmed by TEM. TPD using ammonia as probe, FTIR and BET surface area analysis were used for analyzing surface features like acidity and porosity. The BET surface area analysis showed the sample had moderately high surface area. FTIR was used to find the type species attached to the surface of zirconia. UV-DRS found the band gap of the zirconia was found to be 2.8 eV. The benzylation of o-xylene was carried out batchwise in atmospheric pressure and 433K temperature using sulfated zirconia as catalyst.

Sacrificial Template-Based Synthesis of Unified Hollow Porous Palladium Nanospheres for Formic Acid Electro-Oxidation

Directory of Open Access Journals (Sweden)

Xiaoyu Qiu

2015-06-01

Full Text Available Large scale syntheses of uniform metal nanoparticles with hollow porous structure have attracted much attention owning to their high surface area, abundant active sites and relatively efficient catalytic activity. Herein, we report a general method to synthesize hollow porous Pd nanospheres (Pd HPNSs by templating sacrificial SiO2 nanoparticles with the assistance of polyallylamine hydrochloride (PAH through layer-by-layer self-assembly. The chemically inert PAH is acting as an efficient stabilizer and complex agent to control the synthesis of Pd HPNSs, probably accounting for its long aliphatic alkyl chains, excellent coordination capability and good hydrophilic property. The physicochemical properties of Pd HPNSs are thoroughly characterized by various techniques, such as transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy. The growth mechanism of Pd HPNSs is studied based on the analysis of diverse experimental observations. The as-prepared Pd HPNSs exhibit clearly enhanced electrocatalytic activity and durability for the formic oxidation reaction (FAOR in acid medium compared with commercial Pd black.

Copper-indium-gallium-diselenide nanoparticles synthesized by a solvothermal method for solar cell application

Directory of Open Access Journals (Sweden)

Chiou Chuan-Sheng

2017-01-01

Full Text Available Chalcopyrite copper-indium-gallium-diselenide (CIGS nanoparticles are useful for photovoltaic applications. In this study, the synthesis of CIGS powder was examined, and the powder was successfully synthesized using a relatively simple and convenient elemental solvothermal route. From the reactions of elemental Cu, In, Se and Ga(NO33 powders in an autoclave with ethylenediamine as a solvent, spherical CIGS nanoparticles, with diameters ranging from 20-40 nm, were obtained using a temperature of 200°C for 36h. The structure, morphology, chemical composition and optical properties of the as-synthesized CIGS were characterized using X-ray diffraction, transmission electron microscopy, selected area electron diffraction, scanning electron microscopy, inductively coupled plasma-mass spectrometry. In this sample, the mole ratio of Cu:In:Ga:Se was equal to 0.89:0.71:0.29:2.01, and the optical band gap was found to be 1.18 eV. The solar cell obtained a power conversion efficiency of 5.62% under standard air mass 1.5 global illumination.

An efficient synthesis of quinolines under solvent-free conditions

Indian Academy of Sciences (India)

Unknown

An efficient synthesis of quinolines under solvent-free conditions. 201 was then irradiated with microwaves in a microwave oven (Samsung model# CE118KF) at 1050W (70% of total power) for 5 minutes (3 + 2 with an inter- mission of 5 minutes). The reaction mixture was cooled at room temperature and rendered basic (pH.

Solvothermal synthesis of V2O5/graphene nanocomposites for high performance lithium ion batteries

International Nuclear Information System (INIS)

Chen, Da; Yi, Ran; Chen, Shuru; Xu, Terrence; Gordin, Mikhail L.; Lv, Dongping; Wang, Donghai

2014-01-01

Highlights: • A homogeneous V 2 O 5 /graphene nanocomposite is successfully synthesized. • V 2 O 5 nanoparticles are highly encapsulated in the 2D graphene matrix. • V 2 O 5 /graphene nanocomposite shows much better performance than bare V 2 O 5 . - Abstract: In this work, V 2 O 5 /graphene nanocomposites have been synthesized by a facile solvothermal approach. The V 2 O 5 nanoparticles, around 20–40 nm in size, were encapsulated in the 2D graphene matrix. The reversible Li-cycling properties of V 2 O 5 /graphene have been evaluated by galvanostatic discharge–charge cycling, cyclic voltammetry, and impedance spectroscopy. Compared with the bare V 2 O 5 nanoparticles, the V 2 O 5 /graphene nanocomposites exhibited enhanced electrochemical performance with higher reversible capacity and improved cycling stability and rate capability. The graphene nanosheets act not only as an electronically conductive matrix to improve the electronic and ionic conductivity of the composite electrode, but also as a flexible buffer matrix to maintain the structural integrity of the composite electrodes by preventing particle agglomeration, thus leading to the improvement of the electrochemical performance of V 2 O 5

Controllable architecture of CdS and CuS by single-source precursor-mediated approach and their photocatalytic activity

International Nuclear Information System (INIS)

Sahoo, Ashish K.; Srivastava, Suneel K.

2013-01-01

The present work deals with the preparation of hexagonal CdS and CuS by solvothermal decomposition of the morpholine-4-carbdithioate (MCDT) complexes of Cd and Cu in a water/THF mixture at 140–180 °C for 24 h and characterization. Scanning electron microscopy, field emission scanning electron microscopy and high resolution transmission electron microscopy show that CdS exhibits a hierarchical star- and lotus flower-like morphology in the presence of disodium salt of ethylenediamine tetraaceticacid and sodium dodecyl benzene sulphonate as soft templates at 140 and 160 °C, respectively. However, Cu complex of MCDT forms CuS nanoparticles in the temperature range of 140–180 °C. On the contrary, CdS nanoparticles and CuS microparticles are formed in the absence of any template under the identical experimental conditions. Raman studies show the characteristic peak of CdS and CuS, irrespective of their size and morphology. Finally, CdS and CuS of varying morphology have successfully been used as catalysts in UV photocatalytic decomposition of methylene blue dye. These findings show that CdS lotus-like microflowers are more effective catalysts than hierarchical stars, though the latter is found to have better reusability.Graphical AbstractA simple soft template-assisted and single complex source precursor-mediated solvothermal synthesis of CdS and CuS with a diverse set of morphology has been reported. In addition, the morphology and application in photocatalysis are also discussed.

Controllable architecture of CdS and CuS by single-source precursor-mediated approach and their photocatalytic activity

Energy Technology Data Exchange (ETDEWEB)

Sahoo, Ashish K.; Srivastava, Suneel K., E-mail: sunil111954@yahoo.co.uk [Indian Institute of Technology Kharagpur, Department of Chemistry (India)

2013-04-15

The present work deals with the preparation of hexagonal CdS and CuS by solvothermal decomposition of the morpholine-4-carbdithioate (MCDT) complexes of Cd and Cu in a water/THF mixture at 140-180 Degree-Sign C for 24 h and characterization. Scanning electron microscopy, field emission scanning electron microscopy and high resolution transmission electron microscopy show that CdS exhibits a hierarchical star- and lotus flower-like morphology in the presence of disodium salt of ethylenediamine tetraaceticacid and sodium dodecyl benzene sulphonate as soft templates at 140 and 160 Degree-Sign C, respectively. However, Cu complex of MCDT forms CuS nanoparticles in the temperature range of 140-180 Degree-Sign C. On the contrary, CdS nanoparticles and CuS microparticles are formed in the absence of any template under the identical experimental conditions. Raman studies show the characteristic peak of CdS and CuS, irrespective of their size and morphology. Finally, CdS and CuS of varying morphology have successfully been used as catalysts in UV photocatalytic decomposition of methylene blue dye. These findings show that CdS lotus-like microflowers are more effective catalysts than hierarchical stars, though the latter is found to have better reusability.Graphical AbstractA simple soft template-assisted and single complex source precursor-mediated solvothermal synthesis of CdS and CuS with a diverse set of morphology has been reported. In addition, the morphology and application in photocatalysis are also discussed.

Template-mediated synthesis of periodic membranes for improved liquid-phase separations

International Nuclear Information System (INIS)

Groger, H.

1997-01-01

Solid/liquid separations of particulates in waste streams will benefit from design and development of ultrafiltration (UF) membranes with uniform, tailorable pore size and chemical, thermal, and mechanical stability. Such membranes will perform solid/liquid separations with high selectivity, permeance, lifetime, and low operating costs. Existing organic and inorganic membrane materials do not adequately meet all these requirements. An innovative solution to the need for improved inorganic membranes is the application of mesoporous ceramics with narrow pore-size distributions and tailorable pore size (1.5 to 10 nm) that have recently been shown to form with the use of organic surfactant molecules and surfactant assemblies as removable templates. This series of porous ceramics, designated MCM-41, consists of silica or aluminosilicates distinguished by periodic arrays of uniform channels. In this Phase I Small Business Innovation Research program, American Research Corporation of Virginia will demonstrate the use of supported MCM-41 thin films deposited by a proprietary technique, as UF membranes. Technical objectives include deposition in thin, defect-free periodic mesoporous MCM-41 membranes on porous supports; measurement of membrane separation factors, permeance, and fouling; and measurement of membrane lifetime as part of an engineering and economic analysis

Template-mediated synthesis of periodic membranes for improved liquid-phase separations

Energy Technology Data Exchange (ETDEWEB)

Groger, H. [American Research Corp. of Virginia, Radford, VA (United States)

1997-10-01

Solid/liquid separations of particulates in waste streams will benefit from design and development of ultrafiltration (UF) membranes with uniform, tailorable pore size and chemical, thermal, and mechanical stability. Such membranes will perform solid/liquid separations with high selectivity, permeance, lifetime, and low operating costs. Existing organic and inorganic membrane materials do not adequately meet all these requirements. An innovative solution to the need for improved inorganic membranes is the application of mesoporous ceramics with narrow pore-size distributions and tailorable pore size (1.5 to 10 nm) that have recently been shown to form with the use of organic surfactant molecules and surfactant assemblies as removable templates. This series of porous ceramics, designated MCM-41, consists of silica or aluminosilicates distinguished by periodic arrays of uniform channels. In this Phase I Small Business Innovation Research program, American Research Corporation of Virginia will demonstrate the use of supported MCM-41 thin films deposited by a proprietary technique, as UF membranes. Technical objectives include deposition in thin, defect-free periodic mesoporous MCM-41 membranes on porous supports; measurement of membrane separation factors, permeance, and fouling; and measurement of membrane lifetime as part of an engineering and economic analysis.

Surfactant-assisted sacrificial template-mediated synthesis ...

Indian Academy of Sciences (India)

Heena Khajuria

Lanthanide ion based nanomaterials have gained much attention due to their ... A number of studies on the synthesis .... cum Steady State Luminescence Spectrometer, Edinburgh ..... and their application in lithium-ion batteries Adv. Mater.

The synthesis of porous Co3O4 micro cuboid structures by solvothermal approach and investigation of its gas sensing properties and catalytic activity

International Nuclear Information System (INIS)

Jamil, Saba; Jing, Xiaoyan; Wang, Jun; Li, Songnan; Liu, Jingyuan; Zhang, Milin

2013-01-01

Graphical abstract: - Highlights: • Micro cuboid Co 3 O 4 particle prepared by solvothermal method. • Study of morphology of synthesized cuboids before and after calcinations. • Investigation of formation mechanism of porous Co 3 O 4 from cuboid CoCO 3 . • Investigation of gas sensing properties of porous Co 3 O 4 . • Study of catalytic activity of product. - Abstract: The cobalt carbonate cuboids are prepared by adopting a simple solvothermal approach by using diethylene glycol and water in specific ratio as solvent. The prepared cobalt carbonate is subjected to different instrumentation to investigate its morphology and other properties. It is clear from the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) that the product is distinct cuboid in shape with a size of approximately 3 μm from each face of the cube. Each particle of cuboid cobalt carbonate seems to comprise of layer by layer assembly of unit cells that consequently leads to a cuboid geometry. The cuboid cobalt carbonate was calcined at 700 °C in a furnace under argon atmosphere that decompose cobalt carbonate into porous Co 3 O 4 with the loosely packed arrangement of nano architectures. The gas sensing properties and catalytic activity of porous cuboids Co 3 O 4 are also investigated

Solvothermal preparation of ZnO nanorods as anode material for improved cycle life Zn/AgO batteries.

Directory of Open Access Journals (Sweden)

Shafiq Ullah

Full Text Available Nano materials with high surface area increase the kinetics and extent of the redox reactions, thus resulting in high power and energy densities. In this study high surface area zinc oxide nanorods have been synthesized by surfactant free ethylene glycol assisted solvothermal method. The nanorods thus prepared have diameters in the submicron range (300 ~ 500 nm with high aspect ratio. They have uniform geometry and well aligned direction. These nanorods are characterized by XRD, SEM, Specific Surface Area Analysis, solubility in alkaline medium, EDX analysis and galvanostatic charge/discharge studies in Zn/AgO batteries. The prepared zinc oxide nanorods have low solubility in alkaline medium with higher structural stability, which imparts the improved cycle life stability to Zn/AgO cells.

Mesoporous templated silicas: stability, pore size engineering and catalytic activation

International Nuclear Information System (INIS)

Vansant, Etienne

2003-01-01

The Laboratory of Adsorption and Catalysis has focused its research activities on the synthesis and activation of new porous materials. In the past few years, we have succeeded in developing easy and reproducible pathways to synthesize a huge variety of mesoporous crystalline materials. Points of interest in the synthesis of Mesoporous Templated Silicas are (i) stabilization of the structure, to withstand hydrothermal, thermal and mechanical pressure, (ii) pore size engineering to systematically control the pore size, pore volume and the ratio micro/mesopores and (iii) ease and reproducibility of the synthesis procedure, applying green principles, such as template recuperation. By carefully adapting the synthesis conditions and composition of the synthesis gel, using surfactants (long chain quaternary ammonium ions) and co-templates (long chain amines, alcohols or alkanes), the pore size of the obtained materials can be controlled from 1.5 to 7.0 nm, retaining the very narrow pore size distribution. Alternatively, materials with combined micro- and mesoporosity can be synthesized, using neutral surfactants (triblock copolymers). Hereby, the optimization of the SBA-15 and SBA-16 synthesis is being done in order to create mesoporous materials with microporous walls. The second research line is the controlled activation of MTS materials, by grafting or incorporation of catalytic active centers. We have developed for this purpose the Molecular Designed Dispersion method, which uses metal diketonate complexes as precursors. It is shown that in all cases the dispersion of the metal oxides on the surface is much better compared to the conventional grafting techniques. We have studied and published activation with V, Ti, Mo, Fe, Al and Cr species on different MTS materials. The structure and location of the active metal ion is the subject of an extensive spectroscopic investigation, using FT-IR, FT-Raman, UV-Vis DR coupled with selective chemisorption experiments and

Microwave-assisted solvothermal synthesis of flower-like Ag/AgBr/BiOBr microspheres and their high efficient photocatalytic degradation for p-nitrophenol

International Nuclear Information System (INIS)

Li, Tingting; Luo, Shenglian; Yang, Lixia

2013-01-01

Flower-like Ag/AgBr/BiOBr microspheres were successfully fabricated by the approach of microwave-assisted solvothermal and in situ photo-assisted reduction. A reactive ionic liquid 1-hexadecyl-3-methylimidazolium bromide ([C 16 mim]Br) was employed as Br source in the presence of surfactant polyvinylpyrrolidone (PVP). The photocatalytic activity of Ag/AgBr/BiOBr towards the decomposition of p-nitrophenol under visible light irradiation was evaluated. The results indicated that Ag/AgBr/BiOBr showed enhanced photocatalytic activity towards p-nitrophenol, comparing with P25, BiOBr and Ag/AgBr. More than 96% of p-nitrophenol was decomposed in 3.5 h under visible-light irradation. The excellent photocatalytic activity of flower-like Ag/AgBr/BiOBr microspheres can be attributed to the large specific surface area, strong visible-light absorption, suitable energy band structure and surface plasmon resonance effect of Ag nanoparticles. The possible photocatalytic mechanism was proposed based on the active species test and band gap structure analysis. - Graphical abstract: The photocatalytic reaction mechanisms of the as-prepared Ag/AgBr/BiOBr. Display Omitted - Highlights: • Successful synthesis of flower-like Ag/AgBr/BiOBr microspheres. • The Ag/AgBr/BiOBr showed much higher photocatalytic activity towards p-nitrophenol as compared to BiOBr and Ag/AgBr. • The reasons for the excellent photocatalytic activity are the large specific surface area, strong visible-light absorption and surface plasmon resonance effect of Ag nanoparticles. • The O 2 · − , Br 0 and photogenerated h + play key roles in the photocatalytic degradation process

Synthesis of functional nanomaterials via colloidal mask templating and glancing angle deposition (GLAD)”

DEFF Research Database (Denmark)

Dolatshahi-Pirouz, Alireza; Jensen, Thomas Bo; Vorup-Jensen, Thomas

2010-01-01

We present a simple method for the fabrication of separated brush-like networks with both improved optical and biological properties. The brush networks were fabricated by combing the glancing angle deposition (GLAD) technique with colloidal mask templating. By changing the deposition angle during...... indicate that localized surface plasmons are present on the GLAD templated surfaces while cell assays with monocyte cells showed an impaired attachment to the brush structures. Consequently, deposition by means of a colloidal mask templating is indeed a very tunable and suited technique for the fabrication...

Synthesis of in vitro Co1E1 transcripts with 5'-terminal ribonucleotides that exhibit noncomplementarity with the DNA template

International Nuclear Information System (INIS)

Parker, R.C.

1986-01-01

A region that forms the S1 nuclease site in Co1E1 DNA is shown to code for an in vitro transcript, called S1 RNA-B, which contains a 5'-terminal GTP residue that exhibits noncomplementarity with the template's DNA sequence. The synthesis of S1 RNA-B initiates four bases upstream from the start point for S1 RNA-C. The initial four bases in S1 RNA-B and S1 RNA-C are identical. The relative synthesis of S1 RNA-B to S1 RNA-C is sensitive to the concentration of GTP, a substrate that is required for elongation past the +4 position in S1 RNA-C. Dinucleotides that are expected to only initiate synthesis of S1 RNA-C yield two transcripts that appear to initiate from the S1 RNA-C and S1 RNA-B start sites. In vitro studies involving other Co1E1 transcripts, RNA-B and RNA-C, provide similar observations concerning the noncomplementary initiation phenomenon. A model involving transcriptional slippage is suggested to explain the noncomplementary initiation phenomenon. The model proposes that the cycling reaction of Escherichia coli RNA polymerase produces tetranucleotides that are transposed to nearby upstream sequences for priming transcription

A facile solvothermal synthesis of large-grain iron cubes and cuboids with enhanced performances

International Nuclear Information System (INIS)

Yang, Bai; Yang, Xueying; Li, Xiaopan; Cao, Ying; Yu, Ronghai

2016-01-01

The cubic and cuboid pure iron particles with particle size ranging from 500 nm to 2 μm have been fabricated using a solvothermal method in ethanol solution. The controlled morphology and size distribution can be easily tuned by adjusting the reaction temperatures. The morphologies of the as-synthesized iron particles can be transformed from cubes to cuboids with the reaction temperature increasing from 100 to 150 °C. Uniform particles with narrow size distribution and good dispersion can be obtained under 120 °C. These chemically synthesized Fe particles exhibit good air stability and very slight surface oxidation. High saturation magnetization of 208–211 A m 2 /kg and very low coercivity of 19–26 Oe can be achieved in these micron-level iron particles due to their high purity and small shape anisotropy. The relatively simple preparation process with low cost, good air stability and high saturation magnetization for these large-grain pure iron particles promise their great potential applications in complicated shape and miniaturized Fe-based composite magnetic components. - Highlights: • The micron-level cubic and cuboid pure iron particles have been prepared. • The morphologies of the large-grain iron particles can be tuned. • These iron particles show slight surface oxidation and good air stability. • These iron particles exhibit high saturation magnetization of 208–211 A m 2 kg −1 .

Novel multiform morphologies of hydroxyapatite: Synthesis and growth mechanism

Energy Technology Data Exchange (ETDEWEB)

Mary, I. Reeta [Department of Nanoscience and Technology, Bharathiar University, Coimbatore 641046 (India); Department of Physics, Government Arts College, Coimbatore 641018 (India); Sonia, S.; Viji, S.; Mangalaraj, D.; Viswanathan, C. [Department of Nanoscience and Technology, Bharathiar University, Coimbatore 641046 (India); Ponpandian, N., E-mail: ponpandian@buc.edu.in [Department of Nanoscience and Technology, Bharathiar University, Coimbatore 641046 (India)

2016-01-15

Graphical abstract: - Highlights: • Novel multiform morphologies of hydroxyapatite from nanoscale building blocks. • Facile hydro/solvothermal method under mild reaction conditions without the necessity of post-annealing treatment. • Growth mechanism by Ostwald ripening and self-assembly processes. - Abstract: Morphological evolution of materials becomes a prodigious challenge due to their key role in defining their functional properties and desired applications. Herein, we report the synthesis of hydroxyapatite (HAp) microstructures with multiform morphologies, such as spheres, cubes, hexagonal rods and nested bundles constructed from their respective nanoscale building blocks via a simple cost effective hydro/solvothermal method. A possible formation mechanism of diverse morphologies of HAp has been presented. Structural analysis based on X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy confirms the purity of the HAp microstructures. The multiform morphologies of HAp were corroborated by using Field emission scanning electron microscope (FESEM).

Microwave-Assisted Synthesis of Mesoporous Nano-Hydroxyapatite Using Surfactant Templates

Science.gov (United States)

Mesoporous nano-hydroxyapatite (n-HAP) was expeditiously synthesized using the pseudo sol-gel microwave-assisted protocol (30 min) in the presence of two novel templates, namely sodium lauryl ether sulfate (SLES) and linear alkylbenzenesulfonate (LABS). The cooperative self-assem...

Template-mediated, Hierarchical Engineering of Ordered Mesoporous Films and Powders

Science.gov (United States)

Tian, Zheng

techniques to various substrates for low-cost counter-electrodes in dye-sensitized solar cells, as we demonstrate, or as potential high-flux membranes for molecular separations. Inspired by 'one-pot' 'soft'-templating approaches, wherein the pore forming agent and replica precursor are co-assembled, we establish how 'hard'-templating can be carried out in an analogous fashion. Namely, we show how pre-formed silica nanoparticles can be co-assembled from aqueous solutions with a carbon source (glucose), leading to elucidation of a pseudo-phase behavior in which we identify an operating window for synthesis of hierarchically bi-continuous carbon films. Systematic study of the association of carbon precursors with the silica particles in combination with transient coating experiments reveals mechanistic insight into how silica-adsorbed carbon precursor modulates particle assembly and ultimately controls template particle d-spacing. We uncover a critical d-spacing defining the boundary between ordered and disordered mesoporosity within the resulting films. We ultimately extend this thin-film mechanistic insight to realize 'one'-pot, bi-continuous 3DOm carbon powders. Through a combination of X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and high-resolution transmission electron microscopy (HR-TEM), we elucidate novel synthesis-structure relations for template-mediated microstructuring of the 3DOm replica carbons. Attractive properties of the resulting bi-continuous porous carbons for applications, for example, as novel electrodes, include high surface areas, large mesopore volumes, and tunable graphitic content (i.e. >50%) and character. We specifically demonstrate their performance, in thin film form, as counter-electrodes in dye-sensitized solar cells. We also demonstrate how they can be exploited in powder form as high-performance supercapacitor electrodes exhibiting attractive retention and absolute capacitance. We conclude the thesis by demonstrating the

UV-initiated template copolymerization of AM and MAPTAC: Microblock structure, copolymerization mechanism, and flocculation performance.

Science.gov (United States)

Li, Xiang; Zheng, Huaili; Gao, Baoyu; Sun, Yongjun; Liu, Bingzhi; Zhao, Chuanliang

2017-01-01

Flocculation as the core technology of sludge pretreatment can improve the dewatering performance of sludge that enables to reduce the cost of sludge transportation and the subsequent disposal costs. Therefore, synthesis of high-efficiency and economic flocculant is remarkably desired in this field. This study presents a cationic polyacrylamide (CPAM) flocculant with microblock structure synthesized through ultraviolet (UV)-initiated template copolymerization by using acrylamide (AM) and methacrylamido propyl trimethyl ammonium chloride (MAPTAC) as monomers, sodium polyacrylate (PAAS) as template, and 2,2'-azobis [2-(2-imidazolin-2-yl) propane] dihydrochloride (VA-044) as photoinitiator. The microblock structure of the CPAM was observed through nuclear magnetic resonance ( 1 H NMR and 13 C NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM) analyses. Furthermore, thermogravimetric/differential scanning calorimetry (TG/DSC) analysis was used to evaluate its thermal decomposition property. The copolymerization mechanism was investigated through the determination of the binding constant M K and study on polymerization kinetics. Results showed that the copolymerization was conducted in accordance with the I (ZIP) template polymerization mechanism, and revealed the coexistence of bimolecular termination free-radical reaction and mono-radical termination in the polymerization process. Results of sludge dewatering tests indicated the superior flocculation performance of microblock flocculant than random distributed CPAM. The residual turbidity, filter cake moisture content, and specific resistance to filtration reached 9.37 NTU, 68.01%, and 6.24 (10 12  m kg -1 ), respectively, at 40 mg L -1 of template poly(AM-MAPTAC) and pH 6.0. Furthermore, all flocculant except commercial CPAM showed a wide scope of pH application. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sonochemical synthesis and photocatalytic activity of meso- and macro-porous TiO2 for oxidation of toluene

International Nuclear Information System (INIS)

Yang Liu; Yan Li; Wang Yuntao; Xie Lei; Zheng Jie; Li Xingguo

2008-01-01

Meso-and macro-porous TiO 2 were synthesized by ultrasonic induced solvothermal method. Octadecylamine as a soft template was used to direct the formation of porous structure. The as-prepared porous TiO 2 was characterized by low angle and wide angle X-ray diffraction, N 2 adsorption-desorption isotherms and BET surface area. The energy influence of ultrasound and heat and concentration of nitric acid for post extraction on formation of porous structure were investigated. The photocatalytic activities of TiO 2 were investigated by degrading toluene gas under UV light. The results revealed that proper energy facilitates the formation of porous structure and too low concentration of nitric acid cannot extract template from pores. The photocatalytic activities of TiO 2 with porous structure are higher than those of nonporous ones

Surfactant-free synthesis of octahedral ZnO/ZnFe2O4 heterostructure with ultrahigh and selective adsorption capacity of malachite green

Science.gov (United States)

Liu, Jue; Zeng, Min; Yu, Ronghai

2016-05-01

A new octahedral ZnO/ZnFe2O4 heterostructure has been fabricated through a facile surfactant-free solvothermal method followed by thermal treatment. It exhibits a record-high adsorption capacity (up to 4983.0 mg·g-1) of malachite green (MG), which is a potentially harmful dye in prevalence and should be removed from wastewater and other aqueous solutions before discharging into the environment. The octahedral ZnO/ZnFe2O4 heterostructure also demonstrates strong selective adsorption towards MG from two kinds of mixed solutions: MG/methyl orange (MO) and MG/rhodamine B (RhB) mixtures, indicating its promise in water treatment.

Synthesis of templated carbon from nanoclay and its zeolitic derivatives for hydrogen storage applications

CSIR Research Space (South Africa)

Musyoka, Nicholas M

2014-06-01

Full Text Available materials were thoroughly characterized using XRD, SEM, TGA, TEM, N2-BET and also tested for hydrogen storage capacity. The resulting templated carbons were found to be highly ordered and had mimicked the crystal morphology of the templating materials...

One-pot solvothermal synthesis of Co{sub 1−x}Mn{sub x}C{sub 2}O{sub 4} and their application as anode materials for lithium-ion batteries

Energy Technology Data Exchange (ETDEWEB)

Ang, Wei An Elijah [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Energy Research Institute @ NTU (ERI-N), Nanyang Technological University, 50 Nanyang Drive, Singapore 637553 (Singapore); Cheah, Yan Ling; Wong, Chui Ling [Energy Research Institute @ NTU (ERI-N), Nanyang Technological University, 50 Nanyang Drive, Singapore 637553 (Singapore); Hng, Huey Hoon [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Madhavi, Srinivasan, E-mail: madhavi@ntu.edu.sg [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Energy Research Institute @ NTU (ERI-N), Nanyang Technological University, 50 Nanyang Drive, Singapore 637553 (Singapore); TUM CREATE Center for Electromobility, 1 CREATE Way, #10-02 CREATE Tower, Singapore 138602 (Singapore)

2015-07-25

Graphical abstract: MnC{sub 2}O{sub 4} exhibited good cycling stability while CoC{sub 2}O{sub 4} showed severe capacity fading phenomenon after 40 cycles. Notably, mixed solid solution having Co{sub 0.52}Mn{sub 0.48}C{sub 2}O{sub 4} composition improved the specific reversible discharge capacity to a stable value of ∼1000 mA h g{sup −1} (1 C-rate). - Highlights: • Mixed metal oxalates are synthesized by solvothermal method for the first time. • We control morphologies by varying solvent mixtures and transition metal types. • Li/Co{sub 0.52}Mn{sub 0.48}C{sub 2}O{sub 4} is the best capacity and rate-performing cell in this study. • The positive synergistic effect is attributed to optimal Co:Mn mole ratio. • Properties of Co give high capacity values while Mn give good cycling stability. - Abstract: A facile one-pot solvothermal route has been developed to synthesize phase pure M{sub x}C{sub 2}O{sub 4}⋅2H{sub 2}O (M = Mn, Co; 0 < x ⩽ 1) microstructures without employing any hard/soft template and their electrochemical performance in lithium-ion batteries has been systematically investigated. Morphology, microstructure and composition of the synthesized materials are characterized by field emission-scanning electron microscopy, X-ray diffraction and energy-dispersive X-ray spectroscopy. Anhydrous micron-sized MnC{sub 2}O{sub 4} and CoC{sub 2}O{sub 4} exhibits specific reversible discharge capacity of ∼800 and 950 mA h g{sup −1} respectively, at 1 C-rate. MnC{sub 2}O{sub 4} exhibited good cycling stability while CoC{sub 2}O{sub 4} showed severe capacity fading phenomenon after 40 cycles, thereafter attaining 400–600 mA h g{sup −1} for all C-rates. Interestingly, mixed solid solution having Co{sub 0.52}Mn{sub 0.48}C{sub 2}O{sub 4} composition improved the specific reversible discharge capacity to a stable value of ∼1000 mA h g{sup −1} (1 C-rate), which is one of the highest reported values for such oxalates. The cycling stability of this

Novel synthesis strategy for composite hydrogel of collagen/hydroxyapatite-microsphere originating from conversion of CaCO3 templates.

Science.gov (United States)

Wei, Qingrong; Lu, Jian; Wang, Qiaoying; Fan, Hongsong; Zhang, Xingdong

2015-03-20

Inspired by coralline-derived hydroxyapatite, we designed a methodological route to synthesize carbonated-hydroxyapatite microspheres from the conversion of CaCO3 spherulite templates within a collagen matrix under mild conditions and thus constructed the composite hydrogel of collagen/hydroxyapatite-microspheres. Fourier transform infrared spectroscopy (FTIR) and x-ray diffraction (XRD) were employed to confirm the successful generation of the carbonated hydroxyapatite phase originating from CaCO3, and the ratios of calcium to phosphate were tracked over time. Variations in the weight portion of the components in the hybrid gels before and after the phase transformation of the CaCO3 templates were identified via thermogravimetric analysis (TGA). Scanning electron microscopy (SEM) shows these composite hydrogels have a unique multiscale microstructure consisting of a collagen nanofibril network and hydroxyapatite microspheres. The relationship between the hydroxyapatite nanocrystals and the collagen fibrils was revealed by transmission electron microscopy (TEM) in detail, and the selected area electron diffraction (SAED) pattern further confirmed the results of the XRD analyses which show the typical low crystallinity of the generated hydroxyapatite. This smart synthesis strategy achieved the simultaneous construction of microscale hydroxyapatite particles and collagen fibrillar hydrogel, and appears to provide a novel route to explore an advanced functional hydrogel materials with promising potentials for applications in bone tissue engineering and reconstruction medicine.

Synthesis and applications of one-dimensional nano-structured polyaniline: An overview

International Nuclear Information System (INIS)

Zhang Donghua; Wang Yangyong

2006-01-01

This paper summarizes and reviews the various synthesizing approaches of one-dimensional nano-structured polyaniline (PANI) and several potential applications of the nanomaterial. The synthesizing approaches can be generally categorized into template synthesis and non-template synthesis according to whether template(s), hard (physical template) or soft (chemical template), is (are) used or not. However, though the various approaches established, preparation of one-dimensional nano-structured PANI with controllable morphologies and sizes, especially well oriented arrays on a large scale is still a major challenge. Furthermore, the formation mechanisms of the nanostructures are still unclear. On the other hand, one-dimensional nano-structured PANI exhibits high surface area, high conductivity, as well as controllable chemical/physical properties and good environmental stability, rendering the nanomaterial promising candidate for application ranging from sensors, energy storage and flash welding to digital nonvolatile memory

Synthesis and characterization of ester and amide derivatives of titanium(IV) carboxymethylphosphonate

International Nuclear Information System (INIS)

Melánová, Klára; Beneš, Ludvík; Trchová, Miroslava; Svoboda, Jan; Zima, Vítězslav

2013-01-01

A set of layered ester and amide derivatives of titanium(IV) carboxymethylphosphonate was prepared by solvothermal treatment of amorphous titanium(IV) carboxymethylphosphonate with corresponding 1-alkanols, 1,ω-alkanediols, 1-aminoalkanes, 1,ω-diaminoalkanes and 1,ω-amino alcohols and characterized by powder X-ray diffraction, IR spectroscopy and thermogravimetric analysis. Whereas alkyl chains with one functional group form bilayers tilted to the layers, 1,ω-diaminoalkanes and most of 1,ω-alkanediols form bridges connecting the adjacent layers. In the case of amino alcohols, the alkyl chains form bilayer and either hydroxyl or amino group is used for bonding. This simple method for the synthesis of ester and amide derivatives does not require preparation of acid chloride derivative as a precursor or pre-intercalation with alkylamines and can be used also for the preparation of ester and amide derivatives of titanium carboxyethylphosphonate and zirconium carboxymethylphosphonate. - Graphical abstract: Ester and amide derivatives of layered titanium carboxymethylphosphonate were prepared by solvothermal treatment of amorphous solid with alkanol or alkylamine. - Highlights: • Ester and amide derivatives of titanium carboxymethylphosphonate. • Solvothermal treatment of amorphous solid with alkanol or alkylamine. • Ester and amide formation confirmed by IR spectroscopy

Heat capacity of a white-eucalyptus biocarbon template for SiC/Si ecoceramics

Science.gov (United States)

Parfen'eva, L. S.; Smirnov, B. I.; Smirnova, I. A.; Wlosewicz, D.; Misiorek, H.; Jezowski, A.; Mucha, J.; de Arellano-Lopez, A. R.; Martinez-Fernandez, J.; Varela-Feria, F. M.; Krivchikov, A. I.

2006-11-01

The heat capacity C p of a biocarbon template based on white eucalyptus wood is measured at a constant pressure in the temperature range T = 3.5 300 K. The phonon mean free path l for a white-eucalyptus biocarbon template is calculated from the measured dependence C p (T) and data available in the literature on the phonon thermal conductivity and velocity of sound. It is established that, in the range 100 300 K, the phonon mean free path l is nearly constant and equal to ˜13 Å. This value is close to the smallest size of graphite-like crystallites (˜12 Å), which was derived earlier from x-ray diffraction data for a quasi-amorphous biocarbon template.

The origin of polynucleotide-directed protein synthesis

Science.gov (United States)

Orgel, Leslie E.

1989-01-01

If protein synthesis evolved in an RNA world it was probably preceded by simpler processes by means of which interaction with amino acids conferred selective advantage on replicating RNA molecules. It is suggested that at first the simple attachment of amino acids to the 2'(3') termini of RNA templates favored initiation of replication at the end of the template rather than at internal positions. The second stage in the evolution of protein synthesis would probably have been the association of pairs of charged RNA adaptors in such a way as to favor noncoded formation of peptides. Only after this process had become efficient could coded synthesis have begun.

Solvothermal synthesis of Ni(HCO{sub 3}){sub 2}/graphene composites toward supercapacitors and the faradiac redox mechanism in KOH solution

Energy Technology Data Exchange (ETDEWEB)

Sun, Jinfeng [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100080 (China); Li, Zhangpeng [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Wang, Jinqing, E-mail: jqwang@licp.cas.cn [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Wang, Zhaofeng [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Niu, Lengyuan; Gong, Peiwei [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100080 (China); Liu, Xiaohong; Wang, Honggang [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Yang, Shengrong, E-mail: sryang@licp.cas.cn [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

2013-12-25

Highlights: •Ni(HCO{sub 3}){sub 2}/GS composites were prepared by a simple solvothermal method. •Ni(HCO{sub 3}){sub 2}/GS composites exhibited good supercapacitive performance. •Ni(HCO{sub 3}){sub 2}/GS2 presented the highest capacitance of 1200 F g{sup −1} at 4 A g{sup −1}. -- Abstract: In this work, a series of composites consisting of Ni(HCO{sub 3}){sub 2} and graphene nanosheets (GS) have been prepared by a facile solvothermal method, and then their application as electrode materials for supercapacitors has been investigated by cyclic voltammetry (CV) and galvanostatic charge–discharge tests. Morphological and structural analyses by field-emission scanning electron microscopy, high resolution transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy indicated that Ni(HCO{sub 3}){sub 2} particles deposited on the GS and formed a loosely packed microstructure, actualizing the successful combination of Ni(HCO{sub 3}){sub 2} particles with GS. Among the prepared composites, the sample of Ni(HCO{sub 3}){sub 2}/GS2 exhibited the highest capacitance of 1200 F g{sup −1} at a current density of 4 A g{sup −1}, illustrating that such composite is a promising candidate as electrode material for supercapacitors. Moreover, the Faradic redox mechanism of the Ni(HCO{sub 3}){sub 2}/GS composite was further studied in virtue of XRD analysis, which revealed that the Ni(HCO{sub 3}){sub 2} phase could be quickly transformed into Ni(OH){sub 2} phase by an electrochemically induced phase transformation process during the galvanostatic charge–discharge tests.

Synthesis of mesoporous cerium-zirconium mixed oxides by hydrothermal templating method

Institute of Scientific and Technical Information of China (English)

无

2008-01-01

Mesoporous cerium-zirconium mixed oxides were prepared by hydrothermal method using cetyl trimethyl ammonium bromide (CTAB) as template.The effects of amount of template,pH value of solution and hydrothermal temperature on mesostructure of samples were systematically investigated.The final products were characterized by XRD,TEM,FT-IR,and BET.The results indicate that all the cerium-zirconium mixed oxides present a meso-structure.At molar ratio of n(CTAB)/n((Ce)+(Zr))=0.15,pH value of 9,and hydrothermal temperature of 120 ℃,the samples obtained possess a specific surface area of 207.9 m2/g with pore diameter of 3.70 nm and pore volume of 0.19 cm3/g.

Synthesis of IV-VI Transition Metal Carbide and Nitride Nanoparticles Using a Reactive Mesoporous Template for Electrochemical Hydrogen Evolution Reaction

KAUST Repository

Alhajri, Nawal Saad

2016-01-01

content rather than nitride. In addition, the reactivity of the transition metals of group IV-VI with the reactive template was investigated under a flow of N2 at different temperatures in the range of 1023 to 1573 K while keeping the weight ratio constant at 1:1. The results show that Ti, V, Nb, Ta, and Cr reacted with mpg-C3N4 at 1023 K to form nitride phase with face centered cubic structure. The nitride phase destabilized at higher temperature ≥1223 K through the reaction with the remaining carbon residue originated from the decomposition of the template to form carbonitride and carbide phases. Whereas, Mo and W produce a hexagonal structure of carbide irrespective of the applying reaction temperature. The tendency to form transition metal nitrides and carbides at 1023 K was strongly driven by the free energy of formation. The observed trend indicates that the free energy of formation of nitride is relatively lower for group IV and V transition metals, whereas the carbide phase is thermodynamically more favorable for group VI, in particular for Mo and W. The thermal stability of nitride decreases at high temperature due to the evolution of nitrogen gas. The electrocatalytic activities of the produced nanoparticles were tested for hydrogen evolution reaction in acid media and the results demonstrated that molybdenum carbide nanoparticles exhibited the highest HER current with over potential of 100 mV vs. RHE, among the samples prepared in this study. This result is attributed to the sufficiently small particle size (8 nm on average) and accordingly high surface area (308 m2 g-1). Also, the graphitized carbon layer with a thickness of 1 nm on its surface formed by this synthesis provides excellent electron pathway to the catalyst which will improve the rate of electron transfer reaction.

Hydro- and solvothermally-prepared ZnO and its catalytic effect on photodegradation of reactive orange 16 dye

Directory of Open Access Journals (Sweden)

Simović Bojana

2014-01-01

Full Text Available In this work, zinc oxide powders were obtained by two different techniques: hydro- and solvothermal synthesis starting from Zn(NO32 and Zn(CH3COO2, respectively. The influence of synthetic procedure on the structural, microstructural, thermal and photocatalytic properties of the prepared ZnO powders was investigated. Both ZnO samples were further annealed at moderate conditions (300°C to avoid grain growth and to remove traces of impurities. In all four cases a single-phase hexagonal ZnO was confirmed by X-ray powder diffraction. The morphology of prepared ZnO powders was different and it varied from rounded nanograins to microrods. All prepared samples showed higher photocatalytic efficiency in degradation of textile azo-dye Reactive Orange 16(RO16 than the commercial ZnO. In addition, the non-annealed samples had better photocatalytic properties than the commercial Degussa P25 TiO2 powder. [Projekat Ministarstva nauke Republike Srbije, br. III45007, br. ON171032 i br. ON172013

Research Update: Facile synthesis of CoFe2O4 nano-hollow spheres for efficient bilirubin adsorption

Science.gov (United States)

Rakshit, Rupali; Pal, Monalisa; Chaudhuri, Arka; Mandal, Madhuri; Mandal, Kalyan

2015-11-01

Herein, we report an unprecedented bilirubin (BR) adsorption efficiency of CoFe2O4 (CFO) nanostructures in contrast to the commercially available activated carbon and resin which are generally used for haemoperfusion and haemodialysis. We have synthesized CFO nanoparticles of diameter 100 nm and a series of nano-hollow spheres of diameter 100, 160, 250, and 350 nm using a simple template free solvothermal technique through proper variation of reaction time and capping agent, oleylamine (OLA), respectively, and carried out SiO2 coating by employing Stöber method. The comparative BR adsorption study of CFO and SiO2 coated CFO nanostructures indicates that apart from porosity and hollow configuration of nanostructures, the electrostatic affinity between anionic carboxyl group of BR and cationic amine group of OLA plays a significant role in adsorbing BR. Finally, we demonstrate that the BR adsorption capacity of the nanostructures can be tailored by varying the morphology as well as size of the nanostructures. We believe that our developed magnetic nanostructures could be considered as a potential material towards therapeutic applications against hyperbilirubinemia.

Perl Template Toolkit

CERN Document Server

Chamberlain, Darren; Cross, David; Torkington, Nathan; Diaz, tatiana Apandi

2004-01-01

Among the many different approaches to "templating" with Perl--such as Embperl, Mason, HTML::Template, and hundreds of other lesser known systems--the Template Toolkit is widely recognized as one of the most versatile. Like other templating systems, the Template Toolkit allows programmers to embed Perl code and custom macros into HTML documents in order to create customized documents on the fly. But unlike the others, the Template Toolkit is as facile at producing HTML as it is at producing XML, PDF, or any other output format. And because it has its own simple templating language, templates

Synthesis of Upconverting Hydrogel Nanocomposites Using Thiol-Ene Click Chemistry: Template for the Formation of Dendrimer-Like Gold Nanoparticle Assemblies.

Science.gov (United States)

Meesaragandla, Brahmaiah; Mahalingam, Venkataramanan

2015-11-16

The synthesis of upconverting hydrogel nanocomposites by base-catalyzed thiol-ene click reaction between 10-undecenoic acid capped Yb(3+)/Er(3+)-doped NaYF4 nanoparticles and pentaerythritol tetrakis(3-mercaptopropionate) (PETMP) as tetrathiol monomer is reported. This synthetic strategy for nanocomposite gels is quite different from works where usually the preformed gels are mixed with the nanoparticles. Developing nanocomposites by surface modification of capping ligands would allow tuning and controlling of the separation of the nanoparticles inside the gel network. The hydrogel nanocomposites prepared by thiol-ene click reaction show strong enhancement in luminescence intensity compared to 10-undecenoic acid-capped Yb(3+)/Er(3+)-doped NaYF4 nanoparticles through the upconversion process (under 980 nm laser excitation). The hydrogel nanocomposites display strong swelling characteristics in water resulting in porous structures. Interestingly, the resulting nanocomposite gels act as templates for the synthesis of dendrimer-like Au nanostructures when HAuCl4 is reduced in the presence of the nanocomposite gels. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Solvothermal synthesis of size-tunable ZnFe{sub 2}O{sub 4} colloidal nanocrystal assemblies and their electrocatalytic activity towards hydrogen peroxide

Energy Technology Data Exchange (ETDEWEB)

Liu, Ruirui, E-mail: liurui1114@outlook.com; Lv, Meng, E-mail: lm199133@126.com; Wang, Qianbin, E-mail: material_wqb@163.com; Li, Hongliang, E-mail: lhl@qdu.edu.cn; Guo, Peizhi, E-mail: pzguo@qdu.edu.cn; Zhao, X.S., E-mail: chezxs@qdu.edu.cn

2017-02-15

Three ZnFe{sub 2}O{sub 4} colloidal nanocrystal assemblies (CNAs), namely CNA1, CNA2 and CNA3, have been synthesized solvothermally with the size of 560 nm, 460 nm and 330 nm and are formed by the self-assembly of primary nanocrystals with the crystallite sizes of 19.2 nm, 15.5 nm and 21.8 nm, respectively. It was found that CNA2 performed superparamagnetic behavior with a saturation magnetization value of 36.9 emu g{sup −1} while either CNA1 or CNA3 exhibited weak ferromagnetic with a small hysteresis loop and large saturation magnetization. Electrochemical sensing measurements toward the reduction of hydrogen peroxide showed that the peak currents of the CNAs in cyclic voltammograms showed a linear relationship with the concentration of hydrogen peroxide in the experimental conditions and the peak potentials were increased with the order of CNA3, CNA2 and CNA1. The formation mechanism of ZnFe{sub 2}O{sub 4} CNAs had been discussed based on the experimental data. The magnetism and electrocatalysis of the ZnFe{sub 2}O{sub 4} CNAs were supposed to be dependent on the size of primary nanoparticles and the structure of the CNAs. - Highlights: • Size-tunable ZnFe{sub 2}O{sub 4} colloidal nanocrystal assemblies were synthesized solvothermally. • Magnetic properties of ZnFe{sub 2}O{sub 4} assemblies are depended on the size and self-assembly of primary nanoparticles. • Electrocatalytic activity of ZnFe{sub 2}O{sub 4} assemblies is determined by their structure.

Protein-Templated Fragment Ligations-From Molecular Recognition to Drug Discovery.

Science.gov (United States)

Jaegle, Mike; Wong, Ee Lin; Tauber, Carolin; Nawrotzky, Eric; Arkona, Christoph; Rademann, Jörg

2017-06-19

Protein-templated fragment ligation is a novel concept to support drug discovery and can help to improve the efficacy of protein ligands. Protein-templated fragment ligations are chemical reactions between small molecules ("fragments") utilizing a protein's surface as a reaction vessel to catalyze the formation of a protein ligand with increased binding affinity. The approach exploits the molecular recognition of reactive small-molecule fragments by proteins both for ligand assembly and for the identification of bioactive fragment combinations. In this way, chemical synthesis and bioassay are integrated in one single step. This Review discusses the biophysical basis of reversible and irreversible fragment ligations and gives an overview of the available methods to detect protein-templated ligation products. The chemical scope and recent applications as well as future potential of the concept in drug discovery are reviewed. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Large-scale solvothermal synthesis of fluorescent carbon nanoparticles

International Nuclear Information System (INIS)

Ku, Kahoe; Park, Jinwoo; Kim, Nayon; Kim, Woong; Lee, Seung-Wook; Chung, Haegeun; Han, Chi-Hwan

2014-01-01

The large-scale production of high-quality carbon nanomaterials is highly desirable for a variety of applications. We demonstrate a novel synthetic route to the production of fluorescent carbon nanoparticles (CNPs) in large quantities via a single-step reaction. The simple heating of a mixture of benzaldehyde, ethanol and graphite oxide (GO) with residual sulfuric acid in an autoclave produced 7 g of CNPs with a quantum yield of 20%. The CNPs can be dispersed in various organic solvents; hence, they are easily incorporated into polymer composites in forms such as nanofibers and thin films. Additionally, we observed that the GO present during the CNP synthesis was reduced. The reduced GO (RGO) was sufficiently conductive (σ ≈ 282 S m −1 ) such that it could be used as an electrode material in a supercapacitor; in addition, it can provide excellent capacitive behavior and high-rate capability. This work will contribute greatly to the development of efficient synthetic routes to diverse carbon nanomaterials, including CNPs and RGO, that are suitable for a wide range of applications. (paper)

Hexagonal-layered Na{sub 0.7}MnO{sub 2.05} via solvothermal synthesis as an electrode material for aqueous Na-ion supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Hou, Yan; Tang, Hongwei; Li, Bao; Chang, Kun [Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan, 453007 (China); Chang, Zhaorong, E-mail: czr_56@163.com [Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan, 453007 (China); Yuan, Xiao-Zi; Wang, Haijiang [National Research Council of Canada, V6T 1W5, Vancouver, BC (Canada)

2016-03-01

The layered sodium manganese oxides Na{sub 0.7}MnO{sub 2.05} material was synthesized using Na{sub 2}CO{sub 3} and Mn{sub 3}O{sub 4} precursors via a solvothermal method at different temperatures. The X-ray diffraction (XRD) shows that the Na{sub 0.7}MnO{sub 2.05} sample has a high crystallinity with hexagonal crystal system. The electrochemical performance was characterized by cyclic voltammetry (CV), impedance measurements and galvanostatic charge–discharge tests in symmetric Na-ion supercapacitors with 1 mol L{sup −1} Na{sub 2}SO{sub 4} solution as electrolyte. The Na{sub 0.7}MnO{sub 2.05} material shows a high specific capacity of about 162.5 F g{sup −1} at a current density of 50 mA g{sup −1} and a high coulombic efficiency approaching 100%. Even at a current density of 200 mA g{sup −1}, the discharge capacity of the material can reach to 146 F g{sup −1}. This electrode material holds great promise for practical applications. - Highlights: • Novel electrode material for supercapacitor: hexagonal-layered Na{sub 0.7}MnO{sub 2.05}. • Na{sub 0.7}MnO{sub 2.05} is synthesized using Mn{sub 3}O{sub 4} precursors via solvothermal method. • Obtained Na{sub 0.7}MnO{sub 2.05} exhibits superior electrochemical performance.

Influence of temperature on the formation and encapsulation of gold nanoparticles using a temperature-sensitive template

Directory of Open Access Journals (Sweden)

Noel Peter Bengzon Tan

2015-12-01

Full Text Available This data article describes the synthesis of temperature-sensitive and amine-rich microgel particle as a dual reductant and template to generate smart gold/polymer nanocomposite particle. TEM images illustrate the influence of reaction temperature on the formation and in-site encapsulation of gold nanoparticles using the temperature-sensitive microgel template. Thermal stability of the resultant gold/polymer composite particles was also examined.

Solvothermally synthesized europium-doped CdS nanorods: applications as phosphors

International Nuclear Information System (INIS)

Kumar, Sunil; Jindal, Zinki; Kumari, Nitu; Verma, Narendra Kumar

2011-01-01

To exploit the photoluminescent behavior of CdS at nanoscale with different doping concentration of europium—a rare earth element, we report the synthesis of Eu-doped CdS nanorods by using low temperature solvothermal process by using ethylenediamine. The outcomes can have future applications as phosphors, photovoltaic cells, lasers, light emitting diodes, bio-imaging, and sensors. The doping was confirmed by electron dispersive spectroscopy supported by X-ray diffraction. From scanning electron microscopy and transmission electron microscopy analysis it was observed that the average diameter of the Cd 1−x Eu x S nanorods is about 10–12 nm having lengths in the range of 50–100 nm. UV–Visible spectroscopy study was carried out to determine the band gap of the nanorods and the absorbance peaks showed blue shift with respect to the bulk CdS. The blue shift was also observed as the doping concentration of Eu increases. From photoluminescence (PL) studies at λ ex = 450 nm, peaks at 528 and 540 nm were observed due to CdS, peak at 570 nm is due to defects related transitions, while the peak at 613 nm is due to Eu. As the doping concentration of Eu is increased the intensity of the luminescent peak at 613 nm is increased. Thermogravimetric analysis showed the nanorods are thermally stable up to 300 °C. The traces of impurities adsorbed on the nanorods were confirmed by Fourier transform infrared spectroscopy.

Synthesis of mesh-shaped calcia partially stabilized zirconia using eggshell membrane template as filler composite

Directory of Open Access Journals (Sweden)

Gema Gempita

2017-08-01

Full Text Available This experiment was conducted experimentally to synthesize Calcia Partially Stabilized Zirconia (Ca-PSZ by sol-gel method using eggshell membrane template as a composite filler. The eggshell membrane was used to produce a mesh shaped structure, which hopefully can improve the mechanical properties of the composite. Ca-PSZ filler was synthesized from ZrOCl2 precursor and Ca(NO32 stabilizer with a 24 hours immersion time. Ca-PSZ of synthesis then mixed with the resin matrix to test its composite hardness. The EDS characterization results suggested that the sample contained elements of zirconia, calcium, and oxygen. Whereas, the XRD characterization identified that crystal structures that formed in the sample were nano scale tetragonal. Characterization of SEM showed Ca-PSZ with mesh structured. The average composite hardness value was 15.79 VHN. The composites with Ca-PSZ-synthesized filler could be prepared and its hardness value was higher than the composite with Ca-PSZ filler in spherical particles, but the hardness was still below the composite on the market.

High quality self-separated GaN crystal grown on a novel nanoporous template by HVPE.

Science.gov (United States)

Huo, Qin; Shao, Yongliang; Wu, Yongzhong; Zhang, Baoguo; Hu, Haixiao; Hao, Xiaopeng

2018-02-16

In this study, a novel nanoporous template was obtained by a two-step etching process from MOCVD-GaN/Al 2 O 3 (MGA) with electrochemical etching sequentially followed by chemical wet etching. The twice-etched MOCVD-GaN/Al 2 O 3 (TEMGA) templates were utilized to grow GaN crystals by hydride vapor phase epitaxy (HVPE) method. The GaN crystals were separated spontaneously from the TEMGA template with the assistance of voids formed by the etched nanopores. Several techniques were utilized to characterize the quality of the free-standing GaN crystals obtained from the TEMGA template. Results showed that the quality of the as-obtained GaN crystals was improved obviously compared with those grown on the MGA. This convenient technique can be applied to grow high-quality free-standing GaN crystals.

Effect of Thymine Starvation on Messenger Ribonucleic Acid Synthesis in Escherichia coli

Science.gov (United States)

Luzzati, Denise

1966-01-01

Luzzati, Denise (Institut de Biologie Physico-Chimique, Paris, France). Effect of thymine starvation on messenger ribonucleic acid synthesis in Escherichia coli. J. Bacteriol. 92:1435–1446. 1966.—During the course of thymine starvation, the rate of synthesis of messenger ribonucleic acid (mRNA, the rapidly labeled fraction of the RNA which decays in the presence of dinitrophenol or which hybridizes with deoxyribonucleic acid) decreases exponentially, in parallel with the viability of the thymine-starved bacteria. The ability of cell-free extracts of starved bacteria to incorporate ribonucleoside triphosphates into RNA was determined; it was found to be inferior to that of extracts from control cells. The analysis of the properties of cell-free extracts of starved cells shows that their decreased RNA polymerase activity is the consequence of a modification of their deoxyribonucleic acid, the ability of which to serve as a template for RNA polymerase decreases during starvation. PMID:5332402

Synthesis and characterization of biomorphic CeO2 obtained by using egg shell membrane as template

Directory of Open Access Journals (Sweden)

Marija Prekajski

2014-06-01

Full Text Available A new technology based on bio-templating approach was proposed in this paper. Egg-shell membrane (ESM has been employed as a natural biotemplate. Fibrous oxide ceramics was prepared by wet impregnation of biological template with water solution of cerium nitrate. The template was derived from membranes of fresh chicken eggs. Repeated impregnation, pyrolysis and final calcination in the range of 600 to 1200 °C in air resulted in template burnout and consolidation of the oxide layers. At low temperatures, the obtained products had structure which corresponded to the negative replication of biological templates. Unique bio-morphic CeO2 microstructures with interwoven networks were synthesized and characterized by scanning electron microscope (SEM and X-ray diffraction (XRD, whereas low-temperature nitrogen adsorption (BET method was used in order to characterize porous properties.

Synthesis of Hollow Silica by Stober Method with Double Polymers as Templates

International Nuclear Information System (INIS)

Nguyen, Anhthu; Park, Chang Woo; Kim, Sang Hern

2014-01-01

The hollow SiO 2 spheres with uniform size were synthesized by a modified stoeber method under the control of polyelectrolytes (PSS and PAA) as templates. This synthetic route includes the formation of spherical colloid micelle in ethanol solution, hydrolysis of TEOS under control of ammonia, and the removal of polyelectrolyte by washing or calcination. Hollow silica spheres with controllable core diameters between 100 and 270 nm and wall thickness between 15 and 50 nm have been synthesized. The influence of template solution concentration and solvent and dispersant on the formation of silica hollow spheres is studied and reported in detail

Rational design of mesoporous metals and related nanomaterials by a soft-template approach.

Science.gov (United States)

Yamauchi, Yusuke; Kuroda, Kazuyuki

2008-04-07

We review recent developments in the preparation of mesoporous metals and related metal-based nanomaterials. Among the many types of mesoporous materials, mesoporous metals hold promise for a wide range of potential applications, such as in electronic devices, magnetic recording media, and metal catalysts, owing to their metallic frameworks. Mesoporous metals with highly ordered networks and narrow pore-size distributions have traditionally been produced by using mesoporous silica as a hard template. This method involves the formation of an original template followed by deposition of metals within the mesopores and subsequent removal of the template. Another synthetic method is the direct-template approach from lyotropic liquid crystals (LLCs) made of nonionic surfactants at high concentrations. Direct-template synthesis creates a novel avenue for the production of mesoporous metals as well as related metal-based nanomaterials. Many mesoporous metals have been prepared by the chemical or electrochemical reduction of metal salts dissolved in aqueous LLC domains. As a soft template, LLCs are more versatile and therefore more advantageous than hard templates. It is possible to produce various nanostructures (e.g., lamellar, 2D hexagonal (p6mm), and 3D cubic (Ia\\3d)), nanoparticles, and nanotubes simply by controlling the composition of the reaction bath.

Synthesis of functional polypyrrole/prussian blue and polypyrrole/Ag composite microtubes by using a reactive template

Energy Technology Data Exchange (ETDEWEB)

Feng Xiaomiao; Sun Zhengzong; Hou Wenhua; Zhu Junjie [Key Laboratory of Mesoscopic Chemistry, Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China)

2007-05-16

Polypyrrole (PPy)/PB and PPy/Ag composite microtubes were synthesized in one pot by using methyl orange (MO) as a reactive self-degraded template. In contrast to reported conventional template approaches, the MO template did not need to be removed after polymerization. The formation mechanism, structural characteristics, conductivity, and electrochemical properties of the obtained PPy/PB and PPy/Ag microtubes are reported.

Synthesis of functional polypyrrole/prussian blue and polypyrrole/Ag composite microtubes by using a reactive template

International Nuclear Information System (INIS)

Feng Xiaomiao; Sun Zhengzong; Hou Wenhua; Zhu Junjie

2007-01-01

Polypyrrole (PPy)/PB and PPy/Ag composite microtubes were synthesized in one pot by using methyl orange (MO) as a reactive self-degraded template. In contrast to reported conventional template approaches, the MO template did not need to be removed after polymerization. The formation mechanism, structural characteristics, conductivity, and electrochemical properties of the obtained PPy/PB and PPy/Ag microtubes are reported

Towards room temperature, direct, solvent free synthesis of tetraborohydrides

International Nuclear Information System (INIS)

Remhof, A; Yan, Y; Friedrichs, O; Kim, J W; Mauron, Ph; Borgschulte, A; Züttel, A; Wallacher, D; Buchsteiner, A; Hoser, A; Oh, K H; Cho, Y W

2012-01-01

Due to their high hydrogen content, tetraborohydrides are discussed as potential synthetic energy carriers. On the example of lithium borohydride LiBH 4 , we discuss current approaches of direct, solvent free synthesis based on gas solid reactions of the elements or binary hydrides and/or borides with gaseous H 2 or B 2 H 6 . The direct synthesis from the elements requires high temperature and high pressure (700°C, 150bar D 2 ). Using LiB or AlB 2 as boron source reduces the required temperature by more than 300 K. Reactive milling of LiD with B 2 H 6 leads to the formation of LiBD 4 already at room temperature. The reactive milling technique can also be applied to synthesize other borohydrides from their respective metal hydrides.

Template-assisted growth of nano structured functional materials

International Nuclear Information System (INIS)

Ying, K.K.; Nur Ubaidah Saidin; Khuan, N.I.; Suhaila Hani Ilias; Foo, C.T.

2012-01-01

Template-assisted growth is an important nano electrochemical deposition technique for synthesizing one-dimensional (1-D) nano structures with uniformly well-controlled shapes and sizes. A good template with well-defined dimensions is imperative for realizing this task. Porous anodic alumina (PAA) has been a favorable candidate for this purpose as it can be tailor-made with precise pore geometries, such as pore length and diameter as well as inter-pore distances, via the anodization of pure aluminium. This paper reports the fabrication of PAA templates and electrochemical synthesis of functional nano structures in the form of nano wires using PAA templates as scaffolds. Axial heterostructure and homogeneous nano wires formed by engineering materials configuration via composition and/ or layer thickness variations were fabricated for different functionalities. X-ray diffraction and imaging techniques were used to alucidate the microstructures, morphologies and chemical compositions of the nano wires produced. Due to their large surface area-to-volume ratios, and therefore high sensitivities, these functional nano structures have useful applications as critical components in nano sensor devices and various areas of nano technology. Potential applications include as hydrogen gas sensors in nuclear power plant for monitoring structural integrity of reactor components and containment building, as well as environmental monitoring of air pollution and leakages of toxic gases and chemicals. (Author)

Rapid synthesis of zeolitic imidazolate framework-8 (ZIF-8) nanocrystals in an aqueous system

KAUST Repository

Pan, Yichang; Liu, Yunyang; Zeng, Gaofeng; Zhao, Lan; Lai, Zhiping

2011-01-01

We report here the first example of ZIF materials synthesized in aqueous solution. The synthesis was performed at room temperature and typically took several minutes compared to hours and days in non-aqueous conditions. The obtained product were ZIF-8 nanocrystals having size of ∼85 nm and showed excellent thermal, hydrothermal and solvothermal stabilities. © 2011 The Royal Society of Chemistry.

Synthesis of protein in host-free reticulate bodies of Chlamydia psittaci and Chlamydia trachomatis

International Nuclear Information System (INIS)

Hatch, T.P.; Miceli, M.; Silverman, J.A.

1985-01-01

Synthesis of protein by the obligate intracellular parasitic bacteria Chlamydia psittaci (6BC) and Chlamydia trachomatis (serovar L2) isolated from host cells (host-free chlamydiae) was demonstrated for the first time. Incorporation of [ 35 S]methionine and [ 35 S]cysteine into trichloroacetic acid-precipitable material by reticulate bodies of chlamydiae persisted for 2 h and was dependent upon a exogenous source of ATP, an ATP-regenerating system, and potassium or sodium ions. Magnesium ions and amino acids stimulated synthesis; chloramphenicol, rifampin, oligomycin, and carbonyl cyanide p-trifluoromethoxyphenylhydrazone (a proton ionophore) inhibited incorporation. Ribonucleoside triphosphates (other than ATP) had little stimulatory effect. The optimum pH for host-free synthesis was between 7.0 and 7.5. The molecular weights of proteins synthesized by host-free reticulate bodies closely resembled the molecular weights of proteins synthesized by reticulate bodies in an intracellular environment, and included outer membrane proteins. Elementary bodies of chlamydiae were unable to synthesize protein even when incubated in the presence of 10 mM dithiothreitol, a reducing agent which converted the highly disulfide bond cross-linked major outer membrane protein to monomeric form

Preparation of tailored carbons with meso- and micro- porosity via template synthesis route

Directory of Open Access Journals (Sweden)

Howard. M. Williams

2009-02-01

Full Text Available A low cost templating approach to making non-ordered carbons with a tailored meso/micropore structure is described. A series of mesoporous carbons was prepared from polyfurfuryl alcohol and phenolic resin precursors by a templating route, using a variety of commercially available silica gels as the template material. Carbons were produced with mesopore volumes up to 1 cm3 g-1, mesopore sizes in the range of 4 nm to 8 nm and surface areas in the range of 300 to 700 m2 g-1. These mesoporous carbons were subsequently activated in CO2 to add controlled amounts of microporosity to produce carbons with both a micro and mesoporous structure. Significantly, the activation process did not appreciably change the mesopore size distribution of the carbons. By altering the activation time, it was possible to tailor the micropore: mesopore volume ratios within wide limits.

Solvothermal Synthesis of Hierarchical Colloidal Nanocrystal Assemblies of ZnFe₂O₄ and Their Application in Water Treatment.

Science.gov (United States)

Guo, Peizhi; Lv, Meng; Han, Guangting; Wen, Changna; Wang, Qianbin; Li, Hongliang; Zhao, Xiusong

2016-09-29

Hierarchical colloidal nanocrystal assemblies (CNAs) of ZnFe₂O₄ have been synthesized controllably by a solvothermal method. Hollow ZnFe₂O₄ spheres can be formed with the volume ratios of ethylene glycol to ethanol of 1:4 in the starting systems, while solid ZnFe₂O₄ CNAs are obtained by adjusting the volume proportion of ethylene glycol to ethanol from 1:2 to 2:1. Magnetometric measurement data showed that the ZnFe₂O₄ CNAs obtained with the volume ratios of 1:2 and 1:1 exhibited weak ferromagnetic behavior with high saturation magnetization values of 60.4 and 60.3 emu·g -1 , respectively. However, hollow spheres showed a saturation magnetization value of 52.0 emu·g -1 , but the highest coercivity among all the samples. It was found that hollow spheres displayed the best ability to adsorb Congo red dye among all the CNAs. The formation mechanisms of ZnFe₂O₄ CNAs, as well as the relationship between their structure, crystallite size, and properties were discussed based on the experimental results.

Effect of solvent medium on the structural, morphological and optical properties of ZnS nanoparticles synthesized by solvothermal route

Energy Technology Data Exchange (ETDEWEB)

Mendil, R., E-mail: radia.mendil@yahoo.fr [Laboratoire de Physique des Matériaux et des Nanomatériaux appliquée à l' Environnement, Université de Gabès, Faculté des Sciences de Gabès, Cité Erriadh Manara Zrig, 6072 Gabès (Tunisia); Ben Ayadi, Z. [Laboratoire de Physique des Matériaux et des Nanomatériaux appliquée à l' Environnement, Université de Gabès, Faculté des Sciences de Gabès, Cité Erriadh Manara Zrig, 6072 Gabès (Tunisia); Djessas, K. [Laboratoire Procédés, Matériaux et Energie Solaire (PROMES-CNRS), TECNOSUD, Rambla de la thermodynamique, 66100 Perpignan (France); Université de Perpignan Via Domitia, 52 avenue Paul Alduy, 68860, Perpignan Cedex9 (France)

2016-09-05

Different morphologies of ZnS have been synthesized by a facile solvothermal approach in a mixed solvent made of Ethylenediamine (EN) and distilled water. The effect of solvent medium on the structural, morphological and optical properties of ZnS nanoparticles were investigated. The formation mechanism of different morphologies was proposed based on the experiment results. The as-prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive spectrometer (EDS), Raman spectroscopy and UV-Vis-IR spectrophotometer. The results show that phase transformation is easily induced and there is a strong correlation between morphology and structure of the ZnS nanocrystals by changing the solvent. The results also show that we have successfully produced hexagonal phase ZnS nanorods with mixed solvent. The grain sizes in the range of 17–22 nm were obtained according to elaboration conditions. Raman spectra show the intense peak at 346 cm{sup −1}, which is a typical Raman peak of bulk ZnS crystal, no signature of secondary phases. The band gap of ZnS increased from 3.49 to 3.74 eV with an increase in the EN composition in the solvent, implying that the optical properties of these materials are clearly affected by the synthesis medium. - Highlights: • ZnS was prepared at low temperature using solvothermal method. • The phase transformation and shape evolution processes were studied. • The role of solvent (EN/W) has been discussed for formation of ZnS nanostructures with different morphology. • The properties and growth mechanism of ZnS nanoparticles were investigated. • Optical band gap of ZnS powder were investigated using UV vis spectroscopy.

Metal-organic framework templated electrodeposition of functional gold nanostructures

International Nuclear Information System (INIS)

Worrall, Stephen D.; Bissett, Mark A.; Hill, Patrick I.; Rooney, Aidan P.; Haigh, Sarah J.; Attfield, Martin P.; Dryfe, Robert A.W.

2016-01-01

Highlights: • Electrodeposition of anisotropic Au nanostructures templated by HKUST-1. • Au nanostructures replicate ∼1.4 nm pore spaces of HKUST-1. • Encapsulated Au nanostructures active as SERS substrate for 4-fluorothiophenol. - Abstract: Utilizing a pair of quick, scalable electrochemical processes, the permanently porous MOF HKUST-1 was electrochemically grown on a copper electrode and this HKUST-1-coated electrode was used to template electrodeposition of a gold nanostructure within the pore network of the MOF. Transmission electron microscopy demonstrates that a proportion of the gold nanostructures exhibit structural features replicating the pore space of this ∼1.4 nm maximum pore diameter MOF, as well as regions that are larger in size. Scanning electron microscopy shows that the electrodeposited gold nanostructure, produced under certain conditions of synthesis and template removal, is sufficiently inter-grown and mechanically robust to retain the octahedral morphology of the HKUST-1 template crystals. The functionality of the gold nanostructure within the crystalline HKUST-1 was demonstrated through the surface enhanced Raman spectroscopic (SERS) detection of 4-fluorothiophenol at concentrations as low as 1 μM. The reported process is confirmed as a viable electrodeposition method for obtaining functional, accessible metal nanostructures encapsulated within MOF crystals.

Template-directed synthesis of oligoguanylic acids - Metal ion catalysis

Science.gov (United States)

Bridson, P. K.; Fakhrai, H.; Lohrmann, R.; Orgel, L. E.; Van Roode, M.

1981-01-01

The effects of Zn(2+), Pb(2+) and other metal ions on the efficiency and stereo-selectivity of the template-directed oligomerization of guanosine 5'-phosphorimidazolide are investigated. Reactions were run in the presence of a polyC template in a 2,6-lutidine buffer, and products analyzed by high-performance liquid chromatography on an RPC-5 column. The presence of the Pb(2+) ion is found to lead to the formation of 2'-5' linked oligomers up to the 40-mer, while Zn(2+) favors the formation of predominantly 3'-5' linked oligomers up to the 35-mer. When amounts of uracil, cytidine or adenosine 5'-phosphorimidazole equal to those of the guanosine derivative are included in the reaction mixture, the incorrect base is incorporated into the oligomer about 10% of the time with a Pb(2+) catalyst, but less than 0.5% of the time with Zn(2+). The Sn(2+), Sb(3+) and Bi(3+) ions are also found to promote the formation of 2'-5' oligomers, although not as effectively as Pb(2+), while no metal ions other than Zn(2+) promote the formation of the 3'-5' oligomers. The results may be important for the understanding of the evolution of nucleic acid replication in the absence of enzymes.

Synthesis of mesoporous TiO(2-x)N(x) spheres by template free homogeneous co-precipitation method and their photo-catalytic activity under visible light illumination.

Science.gov (United States)

Parida, K M; Naik, Brundabana

2009-05-01

The article presents preparation, characterization and catalytic activity evaluation of an efficient nitrogen doped mesoporous titania sphere photo-catalyst for degradation of methylene blue (MB) and methyl orange (MO) under visible light illumination. Nitrogen doped titania was prepared by soft chemical route i.e. template free, slow and controlled homogeneous co-precipitation from titanium oxysulfate sulfuric acid complex hydrate, urea, ethanol and water. The molar composition of TiOSO(4) to urea was varied to prepare different atomic % nitrogen doped titania. Mesoporous anatase TiO(2-x)N(x) spheres with average crystallite size of 10 nm and formation of titanium oxynitride center were confirmed from HRTEM, XRD and XPS study. UV-vis DRS showed a strong absorption in the range of 400-500 nm which supports its use in visible spectrum of light. Nitrogen adsorption-desorption study supports the porous nature of the doped material. All the TiO(2-x)N(x) samples showed higher photo-catalytic activity than Degussa P(25) and undoped mesoporous titania. Sample containing around one atomic % nitrogen showed highest activity among the TiO(2-x)N(x) samples.

Soft-Template Construction of 3D Macroporous Polypyrrole Scaffolds.

Science.gov (United States)

Liu, Shaohua; Wang, Faxing; Dong, Renhao; Zhang, Tao; Zhang, Jian; Zheng, Zhikun; Mai, Yiyong; Feng, Xinliang

2017-04-01

A bottom-up approach toward 3D hierarchical macroporous polypyrrole aerogels is demonstrated via soft template-directed synthesis and self-assembly of ultrathin polypyrrole nanosheets in solution, which present interconnected macropores, ultrathin walls, and large specific surface areas, thereby exhibiting a high capacity, satisfactory rate capability, and excellent cycling stability for Na-ion storage. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Solvothermal synthesis, characterization and optical properties of ZnO, ZnO-MgO and ZnO-NiO, mixed oxide nanoparticles

International Nuclear Information System (INIS)

Aslani, Alireza; Arefi, Mohammad Reza; Babapoor, Aziz; Amiri, Asghar; Beyki-Shuraki, Khalil

2011-01-01

ZnO-MgO and ZnO-NiO mixed oxides nanoparticles were produced from a solution containing Zinc acetate, Mg and Ni nitrate by Solvothermal method. The calcination process of the ZnO-MgO and ZnO-NiO composites nanoparticles brought forth polycrystalline two-phase ZnO-MgO and ZnO-NiO nanoparticles of 40-80 nm in diameters. ZnO, MgO and NiO were crystallized into wuertzite and rock salt structures, respectively. The optical properties of ZnO-MgO and ZnO-NiO nanoparticles were obtained by solid state UV and solid state florescent. The XRD, SEM and Raman spectroscopies of these nanoparticles were analyzed.

Solvothermal synthesis, characterization and optical properties of ZnO, ZnO-MgO and ZnO-NiO, mixed oxide nanoparticles

Science.gov (United States)

Aslani, Alireza; Arefi, Mohammad Reza; Babapoor, Aziz; Amiri, Asghar; Beyki-Shuraki, Khalil

2011-03-01

ZnO-MgO and ZnO-NiO mixed oxides nanoparticles were produced from a solution containing Zinc acetate, Mg and Ni nitrate by Solvothermal method. The calcination process of the ZnO-MgO and ZnO-NiO composites nanoparticles brought forth polycrystalline two-phase ZnO-MgO and ZnO-NiO nanoparticles of 40-80 nm in diameters. ZnO, MgO and NiO were crystallized into würtzite and rock salt structures, respectively. The optical properties of ZnO-MgO and ZnO-NiO nanoparticles were obtained by solid state UV and solid state florescent. The XRD, SEM and Raman spectroscopies of these nanoparticles were analyzed.

Solvothermal synthesis, characterization and optical properties of ZnO, ZnO-MgO and ZnO-NiO, mixed oxide nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Aslani, Alireza, E-mail: a.aslani@vru.ac.ir [Department of Chemistry, Faculty of Science, Vali-E-Asr University of Rafsanjan, Rafsanjan, PO Box: 77176 (Iran, Islamic Republic of); Arefi, Mohammad Reza [Islamic Azad University, Yazd Brunch, Young researchers Club, Yazd (Iran, Islamic Republic of); Babapoor, Aziz [Department of Chemical Engineering, Ahar Branch, Islamic Azad University, Ahar, PO Box: 54516 (Iran, Islamic Republic of); Amiri, Asghar; Beyki-Shuraki, Khalil [Department of Chemistry, Faculty of Science, Vali-E-Asr University of Rafsanjan, Rafsanjan, PO Box: 77176 (Iran, Islamic Republic of)

2011-03-15

ZnO-MgO and ZnO-NiO mixed oxides nanoparticles were produced from a solution containing Zinc acetate, Mg and Ni nitrate by Solvothermal method. The calcination process of the ZnO-MgO and ZnO-NiO composites nanoparticles brought forth polycrystalline two-phase ZnO-MgO and ZnO-NiO nanoparticles of 40-80 nm in diameters. ZnO, MgO and NiO were crystallized into wuertzite and rock salt structures, respectively. The optical properties of ZnO-MgO and ZnO-NiO nanoparticles were obtained by solid state UV and solid state florescent. The XRD, SEM and Raman spectroscopies of these nanoparticles were analyzed.

Small-angle neutron scattering studies of the template-mediated crystallization of ZSM-5 type zeolite