检索结果-南通市图书馆

Ordered Mesoporous Carbon/snO_2 Composites as the Electrode Material for supercapacitors

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan university of Technology(Materials science) 2011年第3期26卷 407-411页

作者：刘萍徐菁利 College of chemistry and chemical engineering Shanghai University of Engineering Science

A series of composites as electrode materials for supercapacitors were prepared via incipient wetness impregnation method utilizing ordered mesoporous carbon （OMC） and tin （IV） oxide （snO2） with different *** structure and electrochemical properties of the OMC/snO2 composites were characterized by XRD,TEM and cyclic voltammetry （CV）.Pore characteristics were measured by nitrogen adsorption and desorption *** results show that the structure and electrochemical properties of the composites depend mainly on the loading amount of snO2 in the ordered mesoporous *** optimum amount of snCl4.added is found to be 4. % （1.54.g ethanol-based snCl4.5H2O added to 1 g OMC） of the saturated *** specific capacitance of the composite of optimum amount of snCl4.（200 F g-1） is nearly three times of that of the pristine snO2 （72 F g-1） at the scan rate of 5 mV s-1,and its specific capacitance is almost equal to that of the ordered mesoporous carbon （126 F g-1） at the scan rate of 200 mV ***,it has better specific volumetric energy density than OMC due to its higher ***,in the potential range of 0-0.9 V the composite electrode material exhibits a stable cycle life after 500 cycles.

关键词： supercapacitors composite tin oxide electrochemical properties

Influence of Thickness on the Properties of solution-derived LiMn_2O_4.Thin Films

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan university of Technology(Materials science) 2009年第5期24卷 706-710页

作者：吴显明 College of chemistry and chemical engineering Jishou University

LiMn2O4.thin films of different thickness were derived from solution deposition and heat treated by rapid thermal annealing. The phase identification and surface morphology were studied by X-ray diffraction and scanning electron microscopy. The electrochemical properties of the films were examined by galvanostatic charge-discharge experiments and electrochemical impedance spectroscopy. LiMn2O4.thin films of different thickness derived from solution deposition and rapid thermal annealing are homogeneous and crack free with the grain size between 20 nm and 50 nm. The specific capacity of these films is between 4. and 4. μAh· cm^2· μm^-1. The capacity decreases with the increase of discharge current density. The capacity loss per cycle increases from 0.012% to 0.16% after being cycled 50 times as the film thickness increases from 0.18 μm to 1.04.μm. The lithium diffusion coefficients of these films are in the same order of 10-11 cm^2· s^-1.

关键词： lithium manganese oxides thin films diffusion electrochemical properties

surface investigation on Upilex-s polymide film iradiated by vacuum ultraviolet radiation

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2007年第S1期26卷 168-174页

作者： LIU Yuyan1),GONG Xianyun2),WAN Zhimin3),and DU Xingwen4.1) Department of Applied chemistry,Harbin Institute of Technology,Harbin 150001,china 2) Department of Life science and chemistry,Harbin university,Harbin 150001,china 3) Analysis and Measurement Center,Harbin Institute of Technology,Harbin 150001,china 4. Center for Composite Materials,Harbin Institute of Technology,Harbin 150001,china Harbin Inst Technol Dept Appl Chem Harbin 150001 Peoples R China Harbin Univ Dept Life Sci & Chem Harbin 150001 Peoples R China Harbin Inst Technol Ctr Anal & Measurement Harbin 150001 Peoples R China Harbin Inst Technol Ctr Composite Mat Harbin 150001 Peoples R China

Vacuum ultraviolet radiation of Upilex-s polyimide film 25 μm thick was performed using a gas jet type of vacuum ultraviolet simulator which gives unfixed wavelength from 5 nm to 200 *** redeposited on the films were observed and the nanoparticles formed on the surface consist mainly of carbon *** in the composition and the chemical characteristics of film surface after radiation were identified by X-ray photoelectron spectroscopy(XPs).Relative O content in the radiated area was found to be higher,while N content was lower than in the pristine *** indicates that Upilex-s polyimide film releases N atoms as volatile *** the C1s,O1s envelopes were fitted using Multipak spectrum *** surface morphologies on iradiated area were examined by Atomic Force Microscope(AFM).Pieces of radiant products protrude from the eradiated surface,leading to considerable roughness for the iradiated *** the surface transmittance of Upilex-s film after radiation reduces.

关键词： vacuum ultraviolet radiation Upilex-s polyimide film

simultaneous Removal of COs and H_2s at Low Temperatures over Nanoparticle a-FeOOH Based Catalysts

在线全文

学校读者我要写书评

暂无评论

Journal of Natural Gas chemistry 2003年第1期12卷 37-42页

作者： Zhihua Gao, Chunhu Li, Kechang Xiestate Key Lab of C1 chemistry and Technology, Institute of Coal chemical engineering, Taiyuan university of Technology,Taiyuan 030024.{4. stt. Key Lab of C1 Chem./Technology Inst. of Coal Chemical Engineering Taiyuan University of Technology Taiyuan 030024 China

Catalysts using α-FeOOH nanoparticles as the active ingredient were testedby a microreactor-chromatography assessing apparatus at atmospheric pressure between 25 and 60 ℃with a gas hourly space velocity of 10,000 h^(-1), while the removal performance of H_2s withcatalysts was investigated using the thermal gravimetric method. The results show that the catalystsare highly active for COs hydrolysis at low temperatures (≤60 ℃) and high gas hourly spacevelocity, and the highest activity can reach 100%. The catalyst is particularly stable for 12 h, andno deactivation is observed. Nanoparticle α-FeOOH prepared using hydrated iron sulfate showshigher COs hydrolysis activity, and the optimum calcination temperature for the catalyst is 260 ℃.In addition, the catalysts can remove COs and H_2s simultaneously, and 60 ℃ is favorable for theremoval of H_2s. The compensation effect exists in nanoparticle-based catalysts.

关键词： nanoparticle α-FeOOH COs hydrolysis removal of H_2s compensationeffect

siO/CNTs:A new anode composition for lithium-ion battery

在线全文

学校读者我要写书评

暂无评论

science china chemistry 2009年第12期52卷 2047-2050页

作者： REN YuRong1,2,3?,QU MeiZhen1 & YU ZuoLong1 1 Chengdu Institute of Organic chemistry,Chinese Academy of sciences,Chengdu 61004.,china 2 College of chemistry,Jilin Normal university,siping 136000,china 3 Graduate university of Chinese Academy of sciences,Beijing 100039,china 1. Chengdu Institute of Organic chemistry Chinese Academy of Sciences Chengdu 610041 China 2. College of chemistry Jilin Normal University Siping 136000 China 3. Graduate university of Chinese Academy of sciences Beijing 100039 China

A new anode composition siO/CNTs (carbon nanotubes) has been prepared by chemical vapor deposition (CVD) method. The results of scanning electron microscopy (sEM) confirm that CNTs deposit on small siO particles,form a cage,and enwrap siO particles tightly. siO/CNTs anode composition exhibits an initial discharge and charge capacity of 1171 and 789 mAh/g,and maintains a reversible capacity of 500 mAh/g after 80 cycles. The improvement of the cyclic performance for siO/CNTs composition is related to the maintaining of the electric network during cycling,which benefits from a tight contact between CNTs and siO particles.

关键词： siO/CNTs CVD composition anode Li-ion battery

Recent studies on chemistry of novel μ-CO-containing butterfly Fe/E (E=s,se,Te) cluster salts

在线全文

学校读者我要写书评

暂无评论

science china chemistry 2009年第1期52卷 1-14页

作者： sONG LiCheng Department of chemistry, state Key Laboratory of Elemento-Organic chemistry, Nankai university, Tianjin 300071, china 1. Department of chemistry State Key Laboratory of Elemento-Organic Chemistry Nankai University Tianjin 300071 China

This article describes recent developments in chemical study on a series of butterfly-shaped μ-CO-containing Fe/E (E = s, se, Te) cluster salts. These salts include eleven novel cluster anions, which are the single butterfly one μ-CO-containing [(μ-RE)(μ-CO)Fe2(CO)6]- (A), the double butterfly two μ-CO-containing {[(μ-CO)Fe2(CO)6]2(μ-EZE-μ)}2- (B, E = s; C, E = se), the triple butterfly three μ-CO- containing {[(μ-CO)Fe2(CO)6]3[(μ-sCH2CH2)3N]}3- (D), {[(μ-CO)Fe2(CO)6]3[1,3,5-(μ-sCH2)3C6H3]}3- (E), {[(μ- CO)Fe2(CO)6]3[(μ-sCH2)3CMe]}3- (F), the double butterfly one μ-CO-containing {[(μ-CO)Fe2(CO)6] [Fe2(CO)6][(μ-sCH2)3CMe]} - (G) derived in situ from F, the quadruple butterfly four μ-CO-containing {[(μ- CO)Fe2(CO)6]4.1,2,4.5-(μ-sCH2)4.6H2]}4. (H), the triple butterfly two μ-CO-containing {[(μ-CO)Fe2(CO)6]2 [Fe2(CO)6][1,2,4.5-(μ-sCH2)4.6H2]}2- (I) derived in situ from H, the quadruple butterfly four μ-CO-con- taining {[(μ-CO)Fe2(CO)6]4.(μ-sCH2)4.]}4. (J), and the triple butterfly two μ-CO-containing {[(μ-CO)Fe2 (CO)6]2[Fe2(CO)6][(μ-sCH2)4.]}2- (K) derived in situ from J. This article describes not only the synthetic methods for formation of such anionic cluster (A-K) salts, but also their novel reactions leading to various new types of butterfly Fe/E cluster complexes. All these findings described in this article are important both theoretically and practically.

关键词： butterfly cluster synthesis structure reaction mechanism

chemical Extraction Preparation of Delithiated Cathode Materials of Li-ion Battery

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan university of Technology(Materials science) 2009年第6期24卷 863-866页

作者：闫时建 school of Materials science and engineering Taiyuan University of Science and Technology

A method of conventional chemical reaction to prepare delithiated cathode materials of Li-ion battery was introduced. The cathode material of Li-ion battery was mixed with oxidizing agent Na2s2O8 in water solution, and the solution was stirred continuously to make the chemical reaction proceed sufficiently, then the reaction product was filtered and finally the insoluble delithiated cathode material was obtained. A series of tests were conducted to verify the composition, crystal structure and electrochemical property of the delithiated cathode materials were all desirable. This method overcomes the shortcomings of battery charging preparation and chemical extraction preparation employing other oxidizing agents.

关键词： chemical extraction delithiated cathode material Li-ion battery

Microkinetics of H2s Removal by Zinc Oxide in the Presence of Moist Gas Atmosphere

在线全文

学校读者我要写书评

暂无评论

Journal of Natural Gas chemistry 2003年第1期12卷 43-48页

作者： Hulling Fan, Chunhu Li, Hanxian Guo, Kechang Xiestate Key Lab of C1 chemistry and Technology, Institute for chemical engineering of Coal, Taiyuan university of Technology, Taiyuan 030024.{4. state Key Lab of C1 chemistry and Technology Institute for Chemical Engineering of Coal Taiyuan University of Technology Taiyuan 030024 China

The microkinetics of H_2s removal by ZnO desulfurization in H_2O-CO_2-N_2,H_2O-CO-N_2 and H_2O-O_2-N_2 gas mixtures was studied by thermogravimetric analysis. Experimentswere carried out with 100-120 mesh ZnO powder at temperatures from 4.3 K to 563 K. The results showthat the kinetic behaviors of desulfurization could all be described by an improved shrinking-coremodel. The activation energies of the reaction and the diffusion in different gas atmosphere's wereestimated.

关键词： kinetics desulfurization improved shrinking-core model H_2s zincoxide

Catalytic Acylation of Anisole over some Zeolites

在线全文

学校读者我要写书评

暂无评论

chemical Research in Chinese Universities 2000年第3期16卷 191-197页

作者： ZHAO Zhen hua (College of chemistry and chemical Technology, Hunan Normal university, Changsha 4.0081, P. R. china) (Received sept. 22, 1999) Hunan Normal Univ Coll Chem & Chem Technol Changsha 410081 Peoples R China

Methoxyacetophenone(4. MAP) was synthesized by the acylation of anisole with acetic anhydride in the presence of HY zeolite. The addition of an appropriate amount of some solvent such as dichloromethane, chloroform, carbon disulfide or chlorobenzene to the reaction system can improve the yield of the acylated product to a certain extent. HY zeolite used can be recovered, and reused after being regenerated, obtaining almost the same yield of 4. MAP as the fresh zeolite.

关键词： Acylation HY zeolite Catalyst Anisole Acetic anhydride synthesis Aromatic ketone