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Journal

Chemistry

2006

Articles 1 - 18 of 18

Full-Text Articles in Nanoscience and Nanotechnology

Stm Tip-Induced Nanostructuring-Replacement Method To Construct Pt Surface Nanostructures, Jin-Gang Wang, Jing Tang, Zhao-Bin Chen, Bing-Wei Mao Nov 2006

Stm Tip-Induced Nanostructuring-Replacement Method To Construct Pt Surface Nanostructures, Jin-Gang Wang, Jing Tang, Zhao-Bin Chen, Bing-Wei Mao

Journal of Electrochemistry

STM tip-induced surface nanostructuring based on "Jump-to-contact" mechanism is a nanostructuring technique that has the highest resolution in aqueous solutions.However,for metals that have high cohesive energy,atoms would transfer from surface to tip instead,which limits the wide application of this technique.In this paper,we present a two-step Nanostructuring-Replacement method to construct metal nanoclusters that cannot be obtained directly via the "Jump-to-contact" mechanism.The method is demonstrated to construct Pt nanoclusters that are of great interest in catalysis and electrocatalysis but cannot be constructed via the "Jump-to-contact" mechanism.Since Cu is the most intensively studied and successful system in the tip-induced nanostructuring,it is utilized as …

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Preparation And Electrochemical Property Of Bam Boo-Shaped Silicon Nanotubes, Zeng-Tao Liu, Yan-Peng Fu, Chen Li, Yong Yang Nov 2006

Preparation And Electrochemical Property Of Bam Boo-Shaped Silicon Nanotubes, Zeng-Tao Liu, Yan-Peng Fu, Chen Li, Yong Yang

Journal of Electrochemistry

A novel 1D bamboo-shaped silicon nanotubes was synthesized by chemical vapor deposition with Au catalyst and their electrochemical properties were primarily studied.The results showed that these silicon nanotubes were amorphous with the length about tens micrometer and the diameter about one hundred nanometer.Cyclic voltammetry studies showed that Li ions could intercalate into such silicon nanotubes at two location,i.e.,from the conjoint location and the wall of the hole.Meanwhile,the bamboo-shaped structure could help release the expansion of volume,which is usually serious in the lithium batteries.

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Novel Electrochemical Method For Synthesis Of Nanostructured Materials Of Noble Metals Based On Poly(N-Vinylpyrrolidone) (Pvp), Wei Pan Nov 2006

Novel Electrochemical Method For Synthesis Of Nanostructured Materials Of Noble Metals Based On Poly(N-Vinylpyrrolidone) (Pvp), Wei Pan

Journal of Electrochemistry

Gold nanocrystals with controllable size were synthesized through a simple electroreduction method using poly(N-vinylpyrrolidone)(PVP) of different polymerization degree as both stabilizer and shape-controller for gold nanoclusters.Individual gold nanoparticles spontaneously assembled into the wire-and ring-shaped nanoparticle aggregates depending on the PVP's dynamic stretching and curling,and precursor nanoparticles grew into flat,single-crystalline nanoprisms with thickness of dozens of nanometers based on the oriented aggregation between particles.Besides,core-shell Au/Ag nanoparticles were conveniently synthesized through two-step electroreduction of noble metal ions in the presence of PVPK30.The electrochemical synthetic method based on PVP provides a new path for preparation of noble metal nanostructured materials with different shape …

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Phase-Transfer Technique For Polymer-Protected Noble Metal Nanoparticles, Xing-Li Feng Nov 2006

Phase-Transfer Technique For Polymer-Protected Noble Metal Nanoparticles, Xing-Li Feng

Journal of Electrochemistry

A novel phase-transfer method was developed based on the decrease of PVP's solubility in water with increasing temperature,by means of which PVP-protected gold,silver and platinum nanoparticles can be conveniently transferred from aqueous phase to 1-butanol phase.Monodispersed metal nanoparticles were electrochemically synthesized at first in the aqueous,and then 1-butanol of appropriate volume was added to the aqueous phase.Heating the oil-water mixture to 80 ℃ under vigorous stirring would make metal nanoparticles leave the aqueous phase and enter into the 1-butanol phase,with high phasetransfer efficiency and without aggregation between nanoparticles.An electrochemical method to synthesize metal nanoparticles in the oil-water mixtures was further …

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Preparation And Electrochemical Characterization Of Anatase Tio_2 Nanotubes, Bin Cao, Jin-Wei Xu, Ling-Hong Ding, Wei-Feng Zhang Nov 2006

Preparation And Electrochemical Characterization Of Anatase Tio_2 Nanotubes, Bin Cao, Jin-Wei Xu, Ling-Hong Ding, Wei-Feng Zhang

Journal of Electrochemistry

Titanium oxide nanotubes were prepared by hydrothermal treatment of anatase-type TiO_(2) powders and NaOH solution in an autoclave.Transmission Electron Microscopy and X-ray Diffraction showed that the product is anatase-type TiO_(2) nanotubes.The constant charge-discharge current and cyclic voltammetry exhibited the TiO_(2) nanotubes have a large initial lithium insertion capacity of 260 mA·h/g and good reversibility.This study indicates that TiO_(2) nanotubes might be a good negative electrode materical for second lithium battery in the future.

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Electrochemical Properties Of The Modified Carbon Nanotubes, Chun-An Ma Nov 2006

Electrochemical Properties Of The Modified Carbon Nanotubes, Chun-An Ma

Journal of Electrochemistry

Powder micro-electrodes were prepared from raw carbon nanotubes and carbon nanotubes modified by carboxyl.The electro-reduction properties of both the raw and open-ended carbon nanotubes in p-Nitrophenol solution were investigated.The FTIR spectrum result indicated that the functional groups are successfully fixed on the surface of the carbon nanotubes after nitric acid treatment.The cyclic voltammetry results show that the electrochemical activity of carboxyl-modified carbon nanotubes was improved.The mechanism of electro-(reduction) for the carbon nanotubes after acid treatment was discussed.

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Immobilization Of Cytochrome C On The Surface Of Single-Wall Carbon Nanotube And Its Direct Electron Transfer And Electrocatalysis, Ya-Jing Yin, Ya-Fen Lv, Ping Wu, Pan Du, Yan-Mao Shi, Chen-Xin Cai Aug 2006

Immobilization Of Cytochrome C On The Surface Of Single-Wall Carbon Nanotube And Its Direct Electron Transfer And Electrocatalysis, Ya-Jing Yin, Ya-Fen Lv, Ping Wu, Pan Du, Yan-Mao Shi, Chen-Xin Cai

Journal of Electrochemistry

Cytochrome c(Cyto c) was immobilized on the surface of the single-wall carbon nanotube(SWNT) by using the method of adsorption.Infrared spectroscopy indicated that the Cyto c remained in its original structure and did not undergo structural change after its immobilization on the SWNT.The direct electrochemistry of cyto c,which was adsorbed on the surface of the SWNT,was studied by cyclic voltammetry.The voltammetric results demonstrated that the SWNT had promoting effects on the direct electron transfer of Cyto c and also indicated that the immobilized Cyto c retained its bioelectrocatalytic activity to the reduction of H_(2)O_(2).This modified electrode might be used in development …

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Electrodeposition Of Nano-Sb-Zn Alloy In Acetamide-Urea-Nabr-Kbr Melt, Peng Liu, Xin-Ai Guo, Ye-Xiang Tong, Qi-Qin Yang Aug 2006

Electrodeposition Of Nano-Sb-Zn Alloy In Acetamide-Urea-Nabr-Kbr Melt, Peng Liu, Xin-Ai Guo, Ye-Xiang Tong, Qi-Qin Yang

Journal of Electrochemistry

The electroreduction of Zn(II) and Sb(III) in acetamide-urea-NaBr-KBr(343 K) were studied by cyclic volatmmetry.The reduction of Zn(II) or Sb(III) to the metals is an irreversible process.The transfer coefficient of Zn(II)+2e→Zn and Sb(III) +3e→Sb were calculated to be 0.231 and 0.319,the diffusion coefficient of Zn(II) and Sb(III) in the melt were determined as 1.70 10~(-6) and 3.21 10~(-6) cm~(2)· s~(-1) respectively.The Zn-Sb films with different Zn content from 29.67 at% to 97.34 at% were electrodeposited in acetamide-urea-NaBr-KBr melt at 343 K by controlling the deposition potential and the Zn(II)/Sb(III) molar ratio.The morphology of Zn-Sb film was observed by SEM.Zn-Sb film comprises …

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Investigation On The Resistance To Electrochemical Oxidation Of Carbon Nanotubes With Various Diameters, Yu-Yan Shao, Ge-Ping Yin, Yun-Zhi Gao, Peng-Fei Shi Aug 2006

Investigation On The Resistance To Electrochemical Oxidation Of Carbon Nanotubes With Various Diameters, Yu-Yan Shao, Ge-Ping Yin, Yun-Zhi Gao, Peng-Fei Shi

Journal of Electrochemistry

The resistance to electrochemical oxidation of multi-wall carbon nanotubes(CNT) with various diameters is investigated by applying a fixed potential of 1.2 V(RHE) for 120 h in 0.5 mol L~(-1) H_(2)SO_(4).The oxidation current of CNTs decreases with their diameters,but CNTs between 10~20 nm in diameter(D1020) shows the lowest oxidation current.XPS analysis shows that,after oxidation,the increase in surface oxygen for D1020 is the smallest,implying that the oxidation degree for D1020 is the lowest.The conclusion can be reached that CNTs between 10~20 nm in diameter are the most resistant to electrochemical oxidation.The difference in electrochemical stability of CNTs is attributed to the difference …

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Pre-Oxidative Amperometric Glucose Biosensor Incorporated With Carbon Nanotube And Pbo_(2), Hong-Lan Qi, Cheng-Xiao Zhang Aug 2006

Pre-Oxidative Amperometric Glucose Biosensor Incorporated With Carbon Nanotube And Pbo_(2), Hong-Lan Qi, Cheng-Xiao Zhang

Journal of Electrochemistry

A pre-oxidative amperometric glucose biosensor incorporated with carbon nanotube,ferrocenemonocarboxylic acid and PbO_(2) was designed.The interferences coming from reduced substances,such as ascoribic acid and urine acid were eliminated by PbO_(2).The oxidative current is linear at the potential of +0.40 V(vs.SCE) to the concentration of glucose in the range from 0.50 to 20 mmol·L~(-1),and the detection limit of glucose is 0.1 mol L~(-1).The relative standard deviation is 3.3% for seven successive assays at 5.0 mmol·L~(-1)glucose.This biosensors have been applied to determination of the glucose in serum with satisfying results.

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The Electrochemical Study On Self-Assembled Monolayers Of Sodium Stearate Surfactant On Oil/Water Interface, Li-Na Tang Aug 2006

The Electrochemical Study On Self-Assembled Monolayers Of Sodium Stearate Surfactant On Oil/Water Interface, Li-Na Tang

Journal of Electrochemistry

The self-assembled monolayers of sodium stearate surfactant on oil/water interface was investigated by CV with copper ion as probe.The self-assembling process includes four stages,and forms a stable assembly.The electrochemical oxidation of copper ion at assembled surface is a combine controlled process both surface and diffusion with regression equation as i_(p) = 9.214-3.889 v~(1/2) +0.5809v,r=0.9978,compared with the oil covered bared electrode,it is a complete surface controlled.

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Electrochemical Preparation And Application Of Nanomaterials, Peng Liu, Ye-Xiang Tong, Qi-Qin Yang May 2006

Electrochemical Preparation And Application Of Nanomaterials, Peng Liu, Ye-Xiang Tong, Qi-Qin Yang

Journal of Electrochemistry

Nano materials and nano technology receive great attention all over the world.While electrochemistry has already achieved a great application in industry and it has proved that electrochemistry will play an important role in the field,such as energy source,new materials,life sciences,information sciences,environment and nano sciences.In this paper,the recent developments of electrochemical techniques for the preparing nano materials,application of nano materials in the areas of electrodeposition,batteries,electrocatalysis,sensors are introduced in brief.

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Electrochemical Studies On Electrocatalytic Activity Of Au_(Core) Pt_(Shell)Nanoparticles To Methanol Oxidation, Fang Bao, Jian-Lin Yao, Ren-Ao Gu May 2006

Electrochemical Studies On Electrocatalytic Activity Of Au_(Core) Pt_(Shell)Nanoparticles To Methanol Oxidation, Fang Bao, Jian-Lin Yao, Ren-Ao Gu

Journal of Electrochemistry

Au_(core)Pt_(shell)nanoparticles with different thicknesses were prepared by using chemical reduction method,and characterized by ultraviolet-visible spectroscopy(UV-Vis),transmission electron microscopy(TEM) and cyclic voltammetry(CV).The electrocatalytic activity of Au_(core)Pt_(shell)nanoparticles with the mean diameter of 70~80 nm to methanol oxidation was investigated by cyclic voltammetry in the acid solution.The results revealed that the prepared core-shell nanoparticles were covered by Pt shell and exhibited the similar optical property and electrocatalytic activity with the normal Pt surface.Moreover,the electrocatalytic activity increased with the electrochemical sweep in the certain potential range.It might be contributed by the special loose structure of Pt shell rather than the increase of the real area.

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Special Photoelectrochemical Response Of Nano-Crystalline Tio_2 Electrode, Bi-Bo Lan, Jian-Zhang Zhou, Yan-Yan Xi, Hong-Xiang Chen, Guang-Hua Yao, Zhong-Hua Lin Feb 2006

Special Photoelectrochemical Response Of Nano-Crystalline Tio_2 Electrode, Bi-Bo Lan, Jian-Zhang Zhou, Yan-Yan Xi, Hong-Xiang Chen, Guang-Hua Yao, Zhong-Hua Lin

Journal of Electrochemistry

The nano-crystalline TiO_2 electrodes were prepared by spread method,electrodeposition and sol-gel method.The experimental results show that the nano-crystalline TiO_2 electrodes have special photoelectrochemical response-the photocrrent-potential curves appear peaks.The special photoelectrochemical behaviors of nano-(crystalline) TiO_2 electrodes are ascribed to nano-structure as well as special light induced redox reaction mechanism of nano-crystalline semiconductor electrodes.

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Electrocatalytic Oxidation Of Glucose On Nano Pt/C Electrode, Cui-Lian Chen Feb 2006

Electrocatalytic Oxidation Of Glucose On Nano Pt/C Electrode, Cui-Lian Chen

Journal of Electrochemistry

Nano Pt/C electrocatalysts were prepared by intermittent microwave heating method.The electrooxidation of glucose on smooth Pt and～Pt/C electrodes has been studied and compared.The results showed that the electrochemical properties on nano Pt/C were improved due to the reduction of the overpotential and the increase in the kinetic rate.The surface area would be significantly increased when the particle size of the catalyst was reduced to nano-scale,resulting in the increase in the activity.The enhancement in the resistance to poisoning could be explained that the oxygen-containing species are easier to react with poisoning species on nano Pt/C and re-active the electrode.

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Development On Hydriding/Dehydriding Kinetics Of Mg Nano-Materials For Hydrogen Storage, Wei Mo, Hong-Liang Sun, Hai-Chang Zhang, Hua-Bin Yang, Zuo-Xiang Zhou Feb 2006

Development On Hydriding/Dehydriding Kinetics Of Mg Nano-Materials For Hydrogen Storage, Wei Mo, Hong-Liang Sun, Hai-Chang Zhang, Hua-Bin Yang, Zuo-Xiang Zhou

Journal of Electrochemistry

The development of Mg nano-materials for hydrogen storage in the recent decade has been reviewed in this paper.It was shown the Mg nano-powders prepared by high-energy ball milling showed promising hydriding and dehydriding performance with the transition metal oxides and other types of hydrogen storage alloys(ABx)as the catalysts.

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Electrochemistry And Structures Of Silicon Surface, Gregory X.Zhang Feb 2006

Electrochemistry And Structures Of Silicon Surface, Gregory X.Zhang

Journal of Electrochemistry

Accurate control and fabrication of silicon surface structures from atomic scale to micrometer scale,which may be randomly associated with surface roughness or have well defined patterns,is critical for the per-formance and reliability of electronic devices.Electrochemical reactions of silicon in solutions involved in wetcleaning and etching of silicon wafer play an importantrole in determining the structures of silicon surface.Atre-mendous amount of researches have been done in the last several decades to understand and control a range ofcomplex electrochemical reactions at silicon/solution interface and their relations to the resulted surface struc-tures.The findings generated from these research efforts have been compiled and integrated …

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Electroless Nickel Plating On Carbon Nanotube With Non-Palladium Activation Procedure, Guang-Hui Hu, Hui-Huang Wu, Yangfang-Zu Yangfang-Zu Feb 2006

Electroless Nickel Plating On Carbon Nanotube With Non-Palladium Activation Procedure, Guang-Hui Hu, Hui-Huang Wu, Yangfang-Zu Yangfang-Zu

Journal of Electrochemistry

A new procedure of surface activation without using palladium salt was proposed for electroless nickel plating on carbon nanotubes.In the procedure,carbon nanotubes were oxidized by nitric acid and then neutralized with NaOH to create carboxyl surface groups which were used to adsorb Ni~(2+)ions,thereafter the adsorbed Ni~(2+)ions were chemically reduced into Ni nano-particles as a catalytic center for electroless nickel deposition,all these were further confirmed by infrared absorption spectra and electron microscopic observations.The results indicate that the procedure is feasible to electroless nickel plating on carbon nanotubes.The different morphology of deposits obtained from electroless plating was also discussed.

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