球磨形成的Ni-Mo纳米晶复合镀层上的析氢反应

采用复合电镀的方法将不同球磨时间制备的高催化活性的纳米晶，Ｎｉ－Ｍｏ合金粉直接镀于电极表面，并用稳态极化曲线及交流阻抗技术测试了这些电极析氢的电化学活性，同时用Ｘ射线衍射，透射电镜及扫描电镜监测了Ｎｉ－Ｍｏ合金粉的物相结构，晶粒尺寸及复合电极表面的形貌，并初步探讨了这些复合电极的析氢机理，实验结果表明，球磨不仅可使镍钼粉合金化成为纳米晶，同时随着球磨时间的增加，纳米晶晶粒继续细化，电极的析氢催化活     

在纳米晶Co—Mo／Ni复合电极上的析氢反应

采用复合电镀的方法将不同球磨时间制备的高催化活性的纳米晶Ｃｏ－Ｍｏ合金粉直接镀在电极表面，用稳态极化曲线及交流阻抗技术测试了这些电极析氢的电化学活性，并用Ｘ射线衍射，透射电镜及Ｘ射线光电子能谱，扫描电镜监测了Ｃｏ－Ｍｏ合金粉的物相结构，晶粒尺寸和复合镀的成份，形貌，实验结果表明，Ｃｏ－Ｍｏ纳米晶合金粉有较高的析氢催化活性，球磨使钴钼粉合金化成为纳米晶，一方面增加了复合镀层的真实表面积，另一方面由于     

锂离子电池纳米结构正极材料LiV3O8的制备及性能

采用水热合成方法,在不同水热合成温度下制备了具有纳米结构的锂离子电池正极材料LiV3O8。并利用X射线衍射、透射电镜、恒流充放电、循环伏安以及电化学交流阻抗等测试手段对其结构、形貌和性能做了研究。结果表明,不同的水热合成温度影响到产物的结构、形貌和性能。随着水热温度的升高,粒子的直径随之增大,而形貌和尺寸的均一性则有所降低。电化学测试结果表明水热180℃得到产物的比容量较高,具有良好的电化学可逆性,而且随着水热温度的升高,材料的电荷转移电阻依次减小,有利于锂离子的嵌入与脱出,比容量也随之增加。可见材料的结构中存在一定的非晶缺陷,以及粒子具有一定范围内的尺寸分布,对材料的电化学性能有改善作用。     

在纳米晶Co－Mo／Ni复合电极上的析氢反应

采用复合电镀的方法将不同球磨时间制备的高催化活性的纳米晶Ｃｏ－Ｍｏ合金粉直接镀在电极表面,用稳态极化曲线及交流阻抗技术测试了这些电极析氢的电化学活性,并用Ｘ射线衍射、透射电镜及Ｘ射线光电子能谱、扫描电镜监测了Ｃｏ－ＭＯ合金粉的物相结构、晶粒尺寸和复合镀层的成份、形貌,实验结果表明,Ｃｏ－Ｍｏ纳米晶合金粉有较高的析氢催化活性。球磨使钴钼粉合金化成为纳米晶,一方面增加了复合镀层的真实表面积,另一方面由于纳米晶合金具有高比例的表面活性原子,致使析氢活化能降低,加快了析氢反应,研究表明在不太高温度下,电化学脱附的活化能和整个析氢反应的活化能一致。说明电化学脱附为速度控制步骤。     

石墨烯和铁氰化镍复合物的制备及对多巴胺的电催化性能研究

采用化学合成法制备了铁氰化镍纳米颗粒,并将其与热还原石墨烯机械混合从而合成了铁氰化镍-石墨烯复合材料。在扫描电镜和透射电镜上对合成的复合材料进行形貌结构表征。利用循环伏安和计时电流测试技术对石墨烯复合物的电化学性能进行了探讨。复合物修饰电极对多巴胺具有优异的电催化活性。在较宽的浓度区间,多巴胺的响应电流与多巴胺浓度呈较好的线性关系。该电极材料有望用作多巴胺等药物小分子的灵敏检测。     

碳纳米管/铜纳米结构电极材料在葡萄糖检测中的应用

利用电化学沉积法制备了碳纳米管/铜纳米结构电极材料, 采用扫描电子显微镜和电化学方法对电极表面的形貌和电化学性质进行了表征. 结果表明, 碳纳米管/铜纳米结构电极材料具有较大的电化学活性表面积、 高稳定性、 良好的导电性以及高葡萄糖电氧化活性, 有望用于葡萄糖的检测.     

钙钛矿型LaCoO3电化学储锂的形貌调制效应

采用不同方法制备了块状(Bulk)、 纳米球状(NPs)及三维有序多孔(3DPF)钙钛矿型LaCoO₃电极材料, 并考察了材料的形貌、 结构与电化学储锂之间的相关性. 结果表明, 不同形貌的电极材料均呈钙钛矿型晶体结构, 但电化学储锂性能却表现出巨大差异: 在500 mA/g的电流密度下, 块状、 纳米球状及三维有序多孔LaCoO₃电极经350次循环后放电比容量分别为157, 579和648 mA·h/g. 电化学性能的迥异主要归因于所制备的纳米及多孔结构使活性材料与电解液之间的接触面积增大, 反应活性位点明显增多, 传质电阻降低, 从而使电子传输和Li离子的嵌入/脱嵌过程得到显著改善.     

锂离子电池高比容量FeSn_2-C复合负极材料的合成与性能

Sn基合金负极材料具有高达990 mAh·g-1的理论比容量,但其也存在因脱嵌锂过程发生巨大的体积变化而导致循环性能较差的问题.本文以Sn、Fe、石墨为原料利用简易的高能球磨法成功制备了具有核壳结构的FeSn2-C复合物,系统研究了球磨时间、FeSn2相含量对材料物相结构及电化学性能的影响,并分析了电极的失效机理.研究表明,球磨时间的增加有利于FeSn2金属间化合物相的形成及材料颗粒的细化,进而有利于材料比容量的增加及循环性能的提升;FeSn2相含量的增加能够提高FeSn2-C材料的比容量,但会降低FeSn2-C电极的循环稳定性.经工艺优化及组分调节,球磨24 h合成的Sn20Fe10C70材料具有最优的电化学性能,材料的比容量在540mAh·g-1左右,并能稳定循环100次,是一种非常有发展前途的锂离子电池高比容量负极材料.     

溶剂热法合成不同形貌的Co3O4及其电容特性

采用溶剂热法以不同的钴盐在水-正丁醇体系中合成了不同形貌及尺寸的纳米Co3O4. 采用XRD和TEM对产物的物相和形貌进行表征. 结果表明, 通过改变反应体系中阴离子的种类, 可以控制产物Co3O4的形貌与晶粒尺寸. 通过循环伏安法、恒流充放电和交流阻抗法对Co3O4电极材料的电化学性能进行表征. 结果表明, Co3O4的形貌与晶粒尺寸对其电化学性能有显著影响. 在2 mol·L-1 KOH溶液中, 在-0.40 - 0.55 V (vs SCE)电位范围内, 由Co(NO3)2制备的球形Co3O4表现出更好的电容特性,单电极初始比容量达362.0 F·g-1, 经过400 次循环后比容量仍保持90%.     

Li2FeSiO4/C正极材料的固相合成及电化学性能

以偏硅酸锂、草酸亚铁为原料,通过机械球磨-固相烧结法制得了Li2FeSiO4/C正极材料.用X射线衍射(XRD)和扫描电子显微镜(SEM)表征观察材料的结构和形貌.恒流充放电测试电极电化学性能.结果表明,30oC下1.5~4.8 V电位范围,于10 mA·g-1电流密度恒流充放电测试,Li2FeSiO4/C电极首次放电容量达167 mAh·g-1,有良好的电化学性能.     

Preparation and electrochemical performances of carbon-coated nanoscale SnS for supercapacitors

Carbon-coated SnS as electrode materials for supercapacitor were synthesized by high-energy ball milling and following co-heating with polyvinyl alcohol. The morphology and structure of prepared carbon-coated SnS were studied by high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). Electrochemical investigation indicated that carbon-coated SnS presented preferable electrochemical performances than pristine SnS. In comparison to pristine SnS, carbon-coated SnS had better capacitive response in cyclic voltammetry and could deliver larger specific capacitance of 28.47 F/g in galvanostatical charge–discharge process. Enhanced conductivity of carbon-coated SnS revealed by Nyquist plots was considered to be responsible for its enhanced electrochemical performances.     

CTAB辅助微波水热合成花簇状SnS微球

以氯化亚锡(SnCl2.2H2O)和硫代乙酰胺(TAA)为前驱物,十六烷基三甲基溴化铵(CTAB)为表面活性剂,采用微波水热法控制合成花簇状SnS微球。采用XRD和FESEM等分析手段对制备的样品进行表征。结果表明:合成的产物为正交晶系的SnS微晶,且结晶性良好;SnS微晶是由长方形纳米片自组装而成的花簇状微球。通过改变CTAB用量,可以实现花簇状SnS微晶的形貌和尺寸的调控,并初步分析了其形成过程。利用紫外-可见吸收光谱分析,产物的光学带隙约为1.51 eV;室温光致发光光谱表明,产物在832 nm处具有近红外发光特性。     

Net-like SnS/carbon nanocomposite film anode material for lithium ion batteries

SnS particles with sizes of 5.0–6.5 nm were prepared by a facile method. Resorcinol–formaldehyde sol with addition of the as-prepared SnS nanoparticles was spin-coated on a copper foil to prepare net-like SnS/C composite thin-film electrode for lithium ion batteries after carbonization at 650 °C. The SnS/C nanocomposite thin-film electrode showed preferable first coulombic efficiency and excellent cycling stability. The discharge and charge capacities were respectively 542.3 and 531.3 mAh/g after 40 cycles. The attractive electrochemical performances were mainly ascribed to the ultra fine particle, which showed no evident aggregation in high-resolution TEM image, and the effects of 3-dimensional net-like carbon structure, which uniformly surrounded the SnS nanoparticles to guarantee the contact, acted as a buffer matrix to alleviate the volume expansion of Li–Sn alloy and provided enough paths for electrolyte to reach SnS active material during discharge–charge process.     

Electrochemical Performance of LiMn2O4/LiFePO4 Blend Cathodes for Lithium Ion Batteries

A series of LiMn₂O₄/LiFePO₄ blend cathodes was prepared by hand milling and ball milling in order to compensate the disadvantage of spinel LiMn₂O₄ and olivine LiFePO₄. The morphologies of the blends were studied by scanning electron microscopy, and their electrochemical properties were studied by charge-discharge cycling, cyclic voltammetry and electrochemical impedance spectroscopy. It is easy to obtain uniform LiMn₂O₄/LiFePO₄ blends by the hand milling technique, while significant particle agglomeration is caused by the ball milling technique. When the LiMn₂O₄:LiFePO₄ mass ratio is 1:1, the nano-sized LiFePO₄ powders not only uniformly cover the micron-sized LiMn₂O₄ particles but also effectively fill in the cavities of the LiMn₂O₄ space. Such morphology offers a good electrical contact and a high tap density, which leads to a high discharge capacity and good cycle stability.     

脉冲微波辅助化学还原合成Pt/C 催化剂及其电催化氧还原性能

采用脉冲微波辅助化学还原法制备了质子交换膜燃料电池(PEMFC)用Pt/C 催化剂. 通过透射电镜(TEM)和X射线衍射(XRD)等分析技术对催化剂的微观结构和形貌进行了表征, 并利用循环伏安(CV)、线性扫描(LSV)和恒电位测量等方法评价了催化剂催化氧还原性能. 在此基础上制备了膜电极(MEA)并组装成单电池, 考察了制备的Pt/C 催化剂作为阴极催化剂材料的电催化性能. 结果表明, 脉冲微波辅助化学还原法是一种制备PEMFC催化剂的有效方法, 溶液pH值和微波功率对Pt 颗粒直径和分散有重要影响. TEM和XRD结果显示, 当溶液pH值为10 且微波功率为2 kW时, Pt 纳米粒子较均匀地分散在碳载体上, 粒径分布在1.3-2.4 nm之间, 平均粒径为1.8 nm. CV、LSV和恒电位测试结果表明, 该催化剂电化学比表面积(ESA)为55.6 m²·g^-1, 具有良好的催化氧还原反应活性和稳定性. 单电池测试结果表明, 在溶液pH值为10条件下, 微波功率为2 kW时制备的催化剂作阴极催化剂时, 单电池最高功率密度为2.26 W·cm^-2·mg^-1, 高于微波功率为1 kW时的最高功率密度(2.15 W·cm^-2·mg^-1)和Johnson Matthey催化剂的最高功率密度(1.89 W·cm^-2·mg^-1).     

CoFe<Subscript>2</Subscript>O<Subscript>4</Subscript> nanoparticles structural and magnetic stability relative to ball milling

The combustion method has been utilized to generate cobalt spinel ferrite nanoparticles. The generated nanoparticles were ball milled for different times. Physical and chemical properties of the nanoparticles were characterized by X- ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscope (TEM), and vibrating sample magnetometer (VSM). Crystalline structure of the nanoparticles was stable after ball milling. FTIR showed that oxygen-metal bonding was stronger after ball milling. Moreover, the ball milled nanoparticles magnetically were harder than the nanoparticle without ball milling.     

Ball-milling MoS_2/carbon black hybrid material for catalyzing hydrogen evolution reaction in acidic medium

Replacing platinum for catalyzing hydrogen evolution reaction(HER) in acidic medium remains great challenges. Herein, we prepared few-layered Mo S2 by ball milling as an efficient catalyst for HER in acidic medium. The activity of as-prepared Mo S2 had a strong dependence on the ball milling time. Furthermore,Ketjen Black EC 300 J was added into the ball-milled Mo S2 followed by a second ball milling, and the resultant Mo S2/carbon black hybrid material showed a much higher HER activity than Mo S2 and carbon black alone.The enhanced activity of the Mo S2/carbon black hybrid material was attributed to the increased abundance of catalytic edge sites of Mo S2 and excellent electrical coupling to the underlying carbon network.     

ZnS/SnS/Ag2S photocatalyst with enhanced photocatalytic activity under visible light illumination towards wastewater treatment

Research on Chemical Intermediates - In this study, various compositions of ternary ZnS/SnS/Ag2S nanocatalysts were prepared for the first time through a wet chemical method. The as-prepared...