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Electrochemical Deposition (electrochemical + deposition)
Selected AbstractsFabrication of Two-Dimensional Arrays of CdSe Pillars Using E-Beam Lithography and Electrochemical DepositionADVANCED MATERIALS, Issue 1 2003Y.-W. Su Two-dimensional arrays of high refractive index structures can be fabricated using a combination of e-beam lithography for pattern definition and electrochemical deposition for structure formation. The potential of this method is demonstrated for CdSe, where nanopillars, mushrooms (see Figure), walls, and crosses are prepared. Such arrays have potential in optical device applications such as photonic crystals and waveguides. [source] ChemInform Abstract: Electrochemical Deposition of Bi on GaAs(100).CHEMINFORM, Issue 7 2002P. M. Vereecken Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Electrochemical Deposition and Properties of Nanometer-structure Ce-doped Lead Dioxide Film ElectrodeCHINESE JOURNAL OF CHEMISTRY, Issue 1 2005Shi-Yun Al Abstract The effect of Ce(III) on the morphology and structure of deposited film of lead dioxide was studied by cyclic voltammetry (CV), X-ray diffractometry (XRD) and scanning tunneling microscopy (STM). The results indicated that the Ce-doped PbO2 film consisted of a mixture of , - and , -phase of PbO2. Ce doping changed the size of PbO2 crystal grains and made the crystallite size on the electrode surface in the nanometer range. Owing to the formation of nanometer-structured grains, the specific surface areas and activity sites of the electrode surface were increased, hence the catalytic activity of Ce-doped PbO2 electrode was evidently higher than that of undoped PbO2 electrode. [source] Solar Cells by Design: Photoelectrochemistry of TiO2 Nanorod Arrays Decorated with CdSeADVANCED FUNCTIONAL MATERIALS, Issue 12 2010Jin Ho Bang Abstract One-dimensional (1D) nanostructures of TiO2 are grown directly on transparent, conductive glass substrate using hydrothermal/solvothermal methods. When employed as a photoanode in photoelectrochemical cells, the vertically aligned TiO2 nanorod array exhibits slower charge recombination at electrolyte interface as compared to mesoscopic TiO2 particulate film. Electrochemical deposition of CdSe onto TiO2 nanorod array is carried out to extend absorption into visible light region. The role of CdSe-sensitized, 1D rutile TiO2 architecture in the solar cell design is discussed. [source] Electrochemical deposition of Pt nanoparticles on diamond substratesPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 9 2009Jingping Hu Abstract Platinum nanoparticles were deposited on polished smooth, as-grown large grain and small grain diamond substrates by a potentiostatic method. The influence of deposition potential and the morphology of BDD substrates were studied. A progressive nucleation along with spherical clusters was observed on smooth BDD electrode, accompanied with a heterogeneous segregation of platinum on diamond facets of higher electrochemical activities and a weak binding to the substrate. In contrast, an instantaneous nucleation was observed on as-grown small grain and large grain BDD electrodes, with a dendritic microstructure and a much larger specific active area. The platinum decorated as-grown smaller grain BDD electrodes show a much better electrochemical stability than the other electrodes investigated. [source] Electroreduction of Oxygen and Electrooxidation of Methanol at Carbon and Single Wall Carbon Nanotube Supported Platinum ElectrodesELECTROANALYSIS, Issue 10 2008Ahmad, Nozad Golikand Abstract The present research aimed at investigating the electrocatalytic properties and the electrochemical deposition of Pt nanoparticles on carbon powder, carbon nanotube and preparation of carbon and single wall carbon nanotube supported platinum electrodes. The Pt nanoparticles were synthesized by electroreduction of hexachloroplatinic acid in aqueous solution at ,200,mV. Electrocatalytic properties of the modified electrodes for oxygen reduction were investigated by cyclic voltammetry in O2 saturated solution containing 0.1,M HClO4. Methanol electrooxidation at the modified surfaces in 0.5,M HCLO4 was studied by cyclic voltammetry. The corresponding results showed that the Pt/SWCNT/GC electrode exhibits more improved catalytical activity than the Pt/C/GC electrode. [source] Preparation of Tip-Protected Poly(oxyphenylene) Coated Carbon-Fiber UltramicroelectrodesELECTROANALYSIS, Issue 23 2006El-Deen Abstract A high-yield, reliable, and reproducible method has been successfully developed to fabricate poly(oxyphenylene)-coated carbon fiber ultramicroelectrodes (POCF UMEs) with tip radii r<2,,m. During the insulation process, the tip of the electrochemically etched electrode is protected by inserting it into an inert polymer while the remainder of the electrode is insulated by electrochemical deposition of a 1,3,,m thick poly(oxyphenylene) film. Optimum conditions for poly(oxyphenylene) deposition are developed and the resulting carbon fiber UMEs showed good cyclic voltammetric behavior even after storage for more than one year. These UMEs were tested for use as amperometric scanning electrochemical microscopy (SECM) tips and successfully imaged Au/Kel-F and Al/SiCp metal matrix composites. [source] Direct electrochemical detection of glucose in human plasma on capillary electrophoresis microchipsELECTROPHORESIS, Issue 21-22 2004Yan Du Abstract We developed an electrochemical detector on a hybrid chip for the determination of glucose in human plasma. The microchip system described in this paper consists of a poly(dimethylsiloxane) (PDMS) layer containing separation and injection channels and an electrode plate. The copper microelectrode is fabricated by selective electroless deposition. The fabrication of the decoupler is performed by platinum electrochemical deposition on the metal film formed by electroless deposition. Factors influencing the performance, including detection potential, separation field strength, and buffer concentration, were studied. The electrodes exhibited good stability and durability in the analytical procedures. Under optimized detection conditions, glucose responded linearly from 10 ,M to 1 mM. Finally, glucose in human plasma from three healthy individuals and two diabetics was successfully determined, giving a good prospect for a new clinical diagnostic instrument. [source] Microstructural Engineering of Hydroxyapatite Membranes to Enhance Proton ConductivityADVANCED FUNCTIONAL MATERIALS, Issue 24 2009Dongxia Liu Abstract A new approach to enhancing proton conductivity of ceramics is demonstrated by aligning proton conductive pathways and eliminating resistive grain boundaries. Hydroxyapatite (HAP) membranes are synthesized by multistage crystallization onto palladium. The synthesis involves three steps: electrochemical deposition of HAP seeds, secondary hydrothermal crystallization onto the seed layer to promote c -axis growth normal to the substrate, and tertiary hydrothermal crystallization to promote a- axis growth to fill the gaps between the aligned crystals. The c -axis alignment with crystal domains spanning the membrane thickness significantly enhances proton conduction since protons are primarily transported along the c -axes of HAP crystals. The novel HAP membranes display proton conductivity almost four orders of magnitude higher than traditional sintered HAP ceramics. The HAP membranes on palladium hydrogen membrane substrates hold promise for use in intermediate-temperature fuel cells, chemical sensors, and other devices. The synthesis approach presented may also be applied to other ion-conducting membrane materials to enhance transport properties. [source] Fabrication of Two-Dimensional Arrays of CdSe Pillars Using E-Beam Lithography and Electrochemical DepositionADVANCED MATERIALS, Issue 1 2003Y.-W. Su Two-dimensional arrays of high refractive index structures can be fabricated using a combination of e-beam lithography for pattern definition and electrochemical deposition for structure formation. The potential of this method is demonstrated for CdSe, where nanopillars, mushrooms (see Figure), walls, and crosses are prepared. Such arrays have potential in optical device applications such as photonic crystals and waveguides. [source] Deposition of PtxRu1,x Catalysts for Methanol Oxidation in Micro Direct Methanol Fuel CellsISRAEL JOURNAL OF CHEMISTRY, Issue 3-4 2008William E. Mustain Platinum-ruthenium electrodes (PtxRu1-x) have been prepared by electrochemical and electroless deposition and investigated as catalysts for the oxidation of methanol in acidic solutions. PtxRu1-x deposits were electrochemically deposited from acidic chloride electrolytes at potentials between ,0.46 and 0.34 V (vs. NHE). The composition of the electrodeposit was estimated by energy dispersive X-ray spectroscopy and is a strong function of the electrode potential. An empirical model for the deposition process is presented and kinetic parameters are estimated and discussed. Also, the methanol oxidation activity of the PtxRu1-x catalysts was characterized by cyclic voltammetry in 1.0 M CH3OH, 1.0 M H2SO4 solutions. Electroless PtxRu1-x samples were prepared in a modified Leaman bath with hydrazine dihydrochloride as the reducing agent. The kinetic results for the electrochemical deposition of PtxRu1-x were directly applied and the deposition potential was estimated as approximately 0.40 V. [source] Activated carbon-polyethylenedioxythiophene composite electrodes for symmetrical supercapacitorsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2008M. Selvakumar Abstract A symmetrical (p/p) supercapacitor has been fabricated by making use of activated carbon (AC)-polyethylenedioxythiophene (PEDOT)-composite electrodes for the first time. The composite electrodes have been prepared via electrochemical deposition of ,-napthalenesulphonate doped PEDOT onto AC electrodes. The characteristics of the electrodes and the fabricated supercapacitor have been investigated using cyclic voltammetry (CV) and AC impedance spectroscopy. The electrodes show a maximum specific capacitance of 158 Fg,1 at a scan rate of 10 mV s,1. This indicates that the in situ electro-polymerization of ethylenedioxythiophene (EDOT) onto AC could improve the performance of carbon electrodes for use in supercapacitors. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008 [source] Synthesis and Seebeck coefficient of nanostructured phosphorus-alloyed bismuth telluride thick filmsPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 11 2008Jian Zhou Abstract Phosphorous-alloyed Bi2Te3 thick films have been prepared by electrochemical deposition. The average grain size of the films was calculated to be 14-26 nm based on Scherrer's equation. The effect of P on the Seebeck coefficient of thermoelectric P-alloyed Bi2Te3 thick film was investigated. The results show that P-alloyed thick film has n-type conductivity with the Seebeck coefficient of -35 ,V/K. The correlation between P site occupancy in the crystal and the Seebeck coefficient was discussed. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Microstructure of nanopores in AAO templates favoring the growth of nickel nanowires by electrodepositionPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 12 2007Jong-Hyun Jeong Abstract Morphology of periodical nanoscale pores in AAO templates has been studied in relation with anodizing process, focusing on the growth of nickel nanowires by electrochemical deposition. The AAO templates were prepared by a two-step anodization process. The high purity aluminum plates were anodized in oxalic acid aqueous solution with variation of cell voltage. The pore size and interpore distance both increase with the applied potential. During the post treatment of barrier thinning, small-size pores with split-up structure at the tips are observed due to current-limited anodizing process (decreasing cell potential). The rectifying properties of the barrier layer allow the pores to be filled by nickel by AC electrodeposition. The nickel nanowires array shows the ferromagnetic properties with a preferred magnetic orientation along the wire axis. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Preparation and Characterization of Codeposited Palladium-Nickel/Titanium Electrodes and Palladium-Nickel/Polymeric Pyrrole Film/Titanium ElectrodesCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 10 2008X. Hu Abstract Palladium-nickel/titanium (Pd-Ni/Ti) and palladium-nickel/polymeric pyrrole film/titanium (Pd-Ni/PPy/Ti) electrodes were prepared by electrochemical deposition. The electrochemical characteristics of the Pd-Ni/Ti and Pd-Ni/PPy/Ti electrodes were studied by means of cyclic voltammetry (CV) based on orthogonal experiments. CV studies on the electrodes were conducted in 0.5,mol/L sulfuric acid solution. Experimental results indicate that the hydrogen adsorption peak value of the Pd-Ni/PPy/Ti electrode seen at ca. ,500,mV is larger than that of Pd-Ni/Ti electrode. Scanning electron microscope (SEM) images indicate that polymeric pyrrole film, which formed on electrode can modify the electrode surface configuration significantly and provide the surface of the Pd-Ni/PPy/Ti electrode with more layers and a larger surface area. [source] Electrochemical Preparation and Characterization of Lanthanum Hexacyanoferrate Modified ElectrodeCHINESE JOURNAL OF CHEMISTRY, Issue 2 2005Wu Ping Abstract An electroactive polynuclear inorganic compound of rare earth metal hexacyanoferrate, lanthanum hexacyanoferrate (LaHCF), was prepared by electrochemical deposition on the surface of a glassy carbon electrode with a potential cycling procedure. The cyclic voltammogram of LaHCF exhibits a pair of well-defined redox peaks with the formal potential of 208 mV (vs. SCE) at a scan rate of 100 mV/s in 0.2 mol/L NaCl solution and the redox peak currents increase linearly with the square root of the scan rate up to 1000 mV/s. The effects of the concentration of supporting electrolyte on the electrochemical characteristics of LaHCF were studied by voltammetry. LaHCF was also characterizated by scanning electron microscope (SEM), FTIR and XPS techniques. [source] | ||||||||||||||||