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Full-Text Articles in Materials Chemistry

Mesoporous Carbon For High Power Supercapacitors, Bin Xu, Lu Peng, Guo-Qing Wang, Gao-Ping Cao, Feng Wu, Yu-Sheng Yang Feb 2009

Mesoporous Carbon For High Power Supercapacitors, Bin Xu, Lu Peng, Guo-Qing Wang, Gao-Ping Cao, Feng Wu, Yu-Sheng Yang

Journal of Electrochemistry

Mesoporous carbon for supercapacitors was prepared from sucrose using nano-CaCO3 as template.The microstructure of the carbon was characterized with N2 adsorption and transmission electron microscopy(TEM) observation.The electrochemical performances were evaluated in 6mol·L-1 KOH aqueous electrolyte with galvanostatic charge/discharge,cyclic voltammetry,and ac impedance spectroscopy.The sucrose-based mesoporous carbon had a surface area of 606 m2/g and enriched mesopores in the range of 10~30 nm.The mesoporous carbon presented a specific capacitance of 125 F/g at a current density of 50 mA/g and outstanding excellent rate performance.As the current density increased to 20 000 mA/g,its capacitance remained at 88 F/g,much higher than the commercial capacitive …


Photoelectrochemical Properties Of Tio_2 Nanoparticles, Jie Qu, Ying Li, Qi-Wei Jiang, Xue-Ping Gao Feb 2009

Photoelectrochemical Properties Of Tio_2 Nanoparticles, Jie Qu, Ying Li, Qi-Wei Jiang, Xue-Ping Gao

Journal of Electrochemistry

The protonated titanate nanoparticles were obtained at room temperature and subsequently calcined at different temperatures(300 ℃,400 ℃,500 ℃,600 ℃ and 700 ℃) in air.The obtained products were characterized by XRD,TEM and UV-Vis.It is found that the grain sizes of TiO2 nanoparticles calcined at 300 ℃ were about 20 nm,and increased gradually with the temperature rise.Photoelectric performance was measured with I~V curve and electrochemical impedance spectroscopy(EIS).The TiO2 nanoparticles obtained at 500 ℃ showed the best photoelectrochemical properties with a photovoltaic conversion efficiency of 6.39%,which is much higher than those at other temperatures.In addition,it is also demonstrated that the charge transfer resistance …


Nano-Sn/Hard Carbon Composite As Anode Material For Lithium Ion Batteries, Bing-Kun Guo, Jie Shu, Kun Tang, Ying Bai, Zhao-Xiang Wang, Li-Quan Chen Feb 2009

Nano-Sn/Hard Carbon Composite As Anode Material For Lithium Ion Batteries, Bing-Kun Guo, Jie Shu, Kun Tang, Ying Bai, Zhao-Xiang Wang, Li-Quan Chen

Journal of Electrochemistry

The tin(Sn) nano particles were embedded into the mesopores of hard carbon spherules(HCS) to form a composite anode material for lithium ion batteries.The structure of the obtained composite was characterized by X-ray diffraction(XRD) while its electrochemical performances were evaluated with galvanostatic cycling.It is found that the embedding Sn nanoparticles into porous HCS not only result in a composite material with high lithium storage capacity and capacity retention,but also increase the initial coulombic efficiency of the composite.Based on the infrared spectroscopic analysis,the enhanced initial coulombic efficiency is attributed to the inductive decomposition of the ROCO2Li species in the solid electrolyte interphase(SEI) …


A Conducance Detection System Applying Constant Current Source For Ion Chromatography, Hua-Bin Chen, Wei-Xiong Huang, Rong-Zong Hu Feb 2009

A Conducance Detection System Applying Constant Current Source For Ion Chromatography, Hua-Bin Chen, Wei-Xiong Huang, Rong-Zong Hu

Journal of Electrochemistry

Being different from bipolar pulse technique,a new type conductivity detection circuit system applying constant current source for ion chromatography was designed which effectively reduces the complexity of bipolar pulse technique,accurately and intelligently completes the signal amplification,collection,processing and spectrum displaying.In this article the detection principle and the hardware of the system were described and the experimental results with accurate and reliable measurements were shown.


Synthesis,Characteristics And Electrochemical Performance Of Nano-Sized Snco/Graphite Composites As Anode For Lithium Ion Batteries, Jin-Shu Cai, Ling Huang, Fu-Sheng Ke, Shi-Gang Sun Feb 2009

Synthesis,Characteristics And Electrochemical Performance Of Nano-Sized Snco/Graphite Composites As Anode For Lithium Ion Batteries, Jin-Shu Cai, Ling Huang, Fu-Sheng Ke, Shi-Gang Sun

Journal of Electrochemistry

The nano-structural Sn-Co/graphite composites were prepared by chemical reduction of the alloy electroless deposition solution in graphite suspensions,and the composites were annealed at 500 ℃.The phase structure and surface morphology of the composites were measured by XRD、SEM and Raman.The results indicate that there were high dispersions and high loadings of Sn-Co nanoparticles on graphite by thermal treatment.Electrochemical lithium storage performance was studied preliminarily on the obtained samples.The graphite modified with the Sn-Co nanoparticles possessed a higher electrochemical reversible capacity than that of graphite during the charge and discharge process.The appetency between the Sn-Co nanoparticles and graphite can effectively reduce or …


Preparation And Performance Of The Thin-Film Libpon Electrolyte, Feng Wu, Ya-Dong Liu, Ren-Jie Chen, Shi Chen Feb 2009

Preparation And Performance Of The Thin-Film Libpon Electrolyte, Feng Wu, Ya-Dong Liu, Ren-Jie Chen, Shi Chen

Journal of Electrochemistry

The LiBPON thin-film electrolyte was prepared by magnetron sputtering,and the relationship between the performance and the deposition condition was investigated.As seen in the SEM images,the thin films are dense and uniform without cracks,and according to the XRD patterns they have an amorphous structure.The electrochemical performance of the electrolyte was characterized by electrochemical impedance spectroscopy(EIS).The ionic conductivities of the thin film decreased with the RF power,but increased with the N2 pressure.The an ionic conductivity of 3.5×10-6 S/cm at room temperature was found from the electrochemical measurement.While the deposition rate increased with the RF power,but decreased with the N2 pressure.Nitrogen incorporation can …


Silicon Nanowires As Anode Materials For Lithium Ion Batteries, Yan-Peng Fu, Hui-Xin Chen, Yong Yang Feb 2009

Silicon Nanowires As Anode Materials For Lithium Ion Batteries, Yan-Peng Fu, Hui-Xin Chen, Yong Yang

Journal of Electrochemistry

The SiNWs electrodes were fabricated by coating and direct growth methods,respectively.The structure,morphology and electrochemical performance of such materials were characterized by XRD,SEM and charge-discharge tests.The results show that the electrodes prepared by direct growth method had higher capacity,better battery life and also displayed and excellent cyclability at higher currents.During the process of lithiation,the initial crystalline Si transformed to amorphous LixSi,and the average diameter of the SiNWs increased.Despite the large volume changed,the SiNWs remained intact and did not break into smaller particles.


Preparation Of The Protic Ionic Liquid/Pvdf-Hfp Composite Membranes And Its Performance For Dmfc, Rui-Ying Miao, Jian-Ling Li, Yong Fang, Xin-Dong Wang Feb 2009

Preparation Of The Protic Ionic Liquid/Pvdf-Hfp Composite Membranes And Its Performance For Dmfc, Rui-Ying Miao, Jian-Ling Li, Yong Fang, Xin-Dong Wang

Journal of Electrochemistry

The protic ionic liquid(PIL) α-methyl pyridinium trifluoroacetate([α-MPyH]Tfa) was synthesized by acid & alkali neutralization.Then PIL/PVDF-HFP composite membranes were prepared by means of phase inversion method using acetone as solvent.The conductivities of the composite membrane increased with the temperature and reached 8×10-3 S/cm,1×10-2 S/cm and 3×10-2 S/cm at room-temperature,30 ℃ and 80 ℃,respectively,by electrochemical impedance method.The properties of the methanol-rejecting of the membranes were measured by chronoamperometry as well.The results indicate that the properties of methanol-resistance of the membranes before and after IL combination were equivalent approximately.


Preparation And Performance Of Co And La Co-Doped Li-Rich Lithium Manganate, Da-Qiao Zhou Feb 2009

Preparation And Performance Of Co And La Co-Doped Li-Rich Lithium Manganate, Da-Qiao Zhou

Journal of Electrochemistry

The cathode material of Li1.1Co0.02La0.01Mn2O4 was successfully synthesized by the method of co-precipitation followed by a solid state reaction.In the sintering temperature range of 700~850 ℃,X-ray diffraction(XRD) results showed a single phase of each material and the increase of crystallization degree,and scanning electron microscopic(SEM) images indicated that the particle size increased and the specific surface area decreased,respectively,with increasing the sintering temperature.Due to its lower polarization resistance,the Co and La co-doped lithium-rich lithium manganate(sintered at 800 ℃) positive electrodes showed the most promising electrochemical performance.The capacity retention after 50 cycles reached 98.5%.


Electrochemical Properties Of Functionalized Carbon Nanotubes And Their Applications In Analysis Of 6-Mercaptopurine, Bao-Yi Lu, Yan-Yan Lai, Hong Li Feb 2009

Electrochemical Properties Of Functionalized Carbon Nanotubes And Their Applications In Analysis Of 6-Mercaptopurine, Bao-Yi Lu, Yan-Yan Lai, Hong Li

Journal of Electrochemistry

The electrochemical behaviors and adsorption properties of single-walled carbon nanotubes such as SWNT,SWNT-COOH,and SWNT-OH and multi-walled carbon nanotubes including MWNT,MWNT-COOH,and MWNT-OH modified at a graphite electrode have been investigated by using [Fe(CN)6]3-anion and [Co(phen)3]3+ cation.It was shown that shows good redox reversibility of [Fe(CN)6]3-/4-reactions on the existed carbon nanotubes(CNT) modified electrode.Based on the strong adsorptive property of [Co(phen)3]3+ on the CNT surface,the [Co(phen)3]3+/CNT modified graphite electrode can be obtained by progressive potential sweeping and developed to monitor quantitatively 6-mercaptopurine(6-MP).The adsorption capacity of [Co(phen)3]3+ on the multi-walled carbon nanotubes is higher than that of single-walled carbon nanotubes.For the carbon nanotubes with …


Electrocatalytic Reduction Of Oxygen On Tungsten Carbide Electrode, Chun-An Ma, Yun Huang, Ying-Hong Zhu, Zhao-Yang Chen Feb 2009

Electrocatalytic Reduction Of Oxygen On Tungsten Carbide Electrode, Chun-An Ma, Yun Huang, Ying-Hong Zhu, Zhao-Yang Chen

Journal of Electrochemistry

Tungsten carbide(WC) catalysts were prepared by gas-solid reaction using ammonium metatungstate as precursors which were pretreated with spray drying sphere miniaturation,carbon monoxide as carrier gas and hydrogen as deoxidizing gas.The WC electrode was fabricated using WC catalyst powders and PTFE as binding agent,and characterized by XRD and SEM.Electrocatalyst behavior of WC for oxygen reduction reaction in the sulphuric acid solution was studied by steady-state voltammetry and cyclic voltammetry.The results show that the WC powders obtained were in spheric particles and the prepared WC electrode had a good electrocatalyst activity to the oxygen reduction reaction.The electrode reaction was controlled by adsorption.The …


The Electrochemical Performance Of Ncf-Sulfur Cathode, Chun-Rong Zhao, Zhong-Bao Yu, Wei-Kun Wang, Yu-Sheng Yang Feb 2009

The Electrochemical Performance Of Ncf-Sulfur Cathode, Chun-Rong Zhao, Zhong-Bao Yu, Wei-Kun Wang, Yu-Sheng Yang

Journal of Electrochemistry

The electrochemical performance of NCF-sulfur cathode,with different NCF contents,was investigated by constant current discharge,cyclic voltammetry and AC impedance methods.The morphologies of the cathodes were observed using scanning electron microscopy.The results indicate that the cycle life and rate capability of NCF-sulfur cathode increased.Better performance of sulfur cathode was obtained by 3% and 5% NCF conductive addition.When the current density was 0.4 mA/cm2,the 3%NCF-sulfur cathode had an initial capacity of 880 mAh/g and a reversible capacity of 630 mAh/g after 20 cycles.


Electrosynthesis Of 2,2-Dimethylolpropionic Acid, Hong-Yan Sun, Zhen-Hai Liang Feb 2009

Electrosynthesis Of 2,2-Dimethylolpropionic Acid, Hong-Yan Sun, Zhen-Hai Liang

Journal of Electrochemistry

The Ti/SnO2+Sb2O4/PbO2 electrode was prepared.The structure phase and valent state were characterized by means of XRD and XPS.The 2,2-dimethylolpropionic acid was synthesized on the Ti/SnO2+Sb2O4/PbO2 anode by direct electro-oxidation of 2,2-dimethylolpropionaldehyde.The product and crude material were analyzed by HPLC,the effects of the concentration of 2,2-dimethylolpropionaldehyde,pH,potential and reaction temperature were studied.The results showed that the optimum conditions were anode potential 1.8 V,pH=1,reaction temperature 15℃ and 2,2-dimethylolpropionaldehyde concentration 0.10mol/L.Under the optimum conditions,the selectivity of 36%,the current efficiency of 28% and the conversion of 58% were reached.The reported method provides a new route for the synthesis of 2,2-dimethylol propionic acid.


19~(Th) International Symposium Of Fine Chemistry And Functional Polymers (Fcfp-Xix) & Iupac 5~(Th) Internaitonal Symoposium On Novel Materials And Synthesis(Nms-V) Feb 2009

19~(Th) International Symposium Of Fine Chemistry And Functional Polymers (Fcfp-Xix) & Iupac 5~(Th) Internaitonal Symoposium On Novel Materials And Synthesis(Nms-V)

Journal of Electrochemistry

No abstract provided.


Effect Of Irco Intermediate Layer On Electrochemical Property Of Rutisn Anode, Yan Zhao, Gui-Chang Liu, Yong-Lan Liao, Wei-Guang Ji, Shu-Jun Song Feb 2009

Effect Of Irco Intermediate Layer On Electrochemical Property Of Rutisn Anode, Yan Zhao, Gui-Chang Liu, Yong-Lan Liao, Wei-Guang Ji, Shu-Jun Song

Journal of Electrochemistry

The Ti based-RuTiSn anodes with IrCo intermediate layer were prepared by thermal decomposition method.The electrochemical properties of Ti/RuTiSn anodes with different Ir-Co intermediate layers were studied.The surface and elements compositions of the anodes were charactered by scanning electron microscopy(SEM) and electronic probe microanalysis(EPMA).The effects of intermediate layer on the electro-catalytic activity and stability were assessed by chlorine evolution potentials、accelerated lifetime test and cyclic voltammetric curves(CV).It was concluded that the anode,which contained several Ir-Co intermediate layers,could hold not only high electro-catalytic activity but also the increased stability.The enhanced life was up to 480 h.


The Electrochemical Behavior And Determination Of Carbendazim On Iron Montmorillonite Modified Electrode, Xiao-Li Jiang, Rong Li, Xiao-Ying He, Jiang Li, Ying Li Feb 2009

The Electrochemical Behavior And Determination Of Carbendazim On Iron Montmorillonite Modified Electrode, Xiao-Li Jiang, Rong Li, Xiao-Ying He, Jiang Li, Ying Li

Journal of Electrochemistry

The FeCl3 modified clay electrode was made.The electrochemical behavior of carbendazim(BCM) on the modified electrode was studied by cyclic voltammetry.The impacts of pH,scan rate and dosages of modifier were discussed and the important kinetic parameters of the electrochemical process were determined.The results indicated that the process was controlled by diffusion.The effective area of FeMM-CMC/GCE(A)=0.027 cm2,the transfer electron numbers(n)=2 and the diffusion coefficient(D)=5.115×10-6cm2/s.Under the optimized conditions,a good linearity was found between the first order derivative of peak current and concentration of BCM in the range of 2.00×10-5~8.00×10-4mol/L,with i′p=-8.045×10-7-0.0237c,correlation coefficient R=-0.9965,and the detect limitation of 2.41×10-6 mol/L.The recovery of BCM was detected …


Preparation And Characterization Of Tin-Nickel Alloy Electromagnetic Shielding Fabric, Ke-Jing Chu, Wei Wang, Bin Sun, Mei-Fang Zhu Feb 2009

Preparation And Characterization Of Tin-Nickel Alloy Electromagnetic Shielding Fabric, Ke-Jing Chu, Wei Wang, Bin Sun, Mei-Fang Zhu

Journal of Electrochemistry

A soft electromagnetic shielding fabric was successfully prepared by electroplating tin-nickel alloy on the Cu-plated PET fabric in potassium pyrophosphate system.Results show that the different tin content and different colour can be obtained by changing the ratio of metals in bath.Better corrosion resistance and anti-tarnishing were achieved with the fabric consisting of 68.96% Sn.The tin-nickel alloy surface for the electromagnetic shielding fabric had excellent conductivity,softness,permeability and soft luster、non-sensitized to the human body.Thereby it has broad prospect in EMI field and shielding clothing.