Carbon Nanotubes Supported Conducting Polymer Electrode for Supercapacitor

Supercapacitors (SCs) as portable systems and electric vehicles have aroused great interest due to their high power in short term. The composite materials of carbon nanotubes and conducting polymers have been considered for SC electrodes. Carbon nanotubes (CNTs), due to their outstanding electric properties and nanoscale texture, such as large specific area, low cost, and cycle stability, exhibit a large and stable double layer capacitance. However, the pure CNTs have low specific capacitance and relatively poor energy density, which limit the commercial application for SCs. On the other hand, conducting polymers have been intensively investigated as the electrode material in SCs. Higher electrical conductivity, larger pseudo‐capacitance, and faster doping/dedoping rate during charge/discharge process are their main advantages. The possible application of conducting polymers in SCs is dictated by their significant capacitance values and huge faradaic capacitance. They undergo a redox reaction to store charge in the bulk of the material and thereby increase the energy stored and reduce self‐discharge. But they are not ideal materials used alone as advanced capacitors materials, because of their low mechanical strength, poor electrical conductivity and low porosity

Transmission electron microscopy analysis of some transition metal compounds for energy storage and conversion

This work was preliminarily supported by the National Key Research Program of China (2016YFA0202604), the Natural Science Foundation of China (21476271), NSFC-RGC (21461162003) and Natural Science Foundation (2014KTSCX004 and 2014A030308012) of Guangdong Province, China.Recently, transition metal compounds (TMCs) have been employed as high-performance electrode materials for lithium ion batteries (LIBs) and supercapacitors (SCs) owing to their high specific capacities, high electrical conductivity, and high chemical and thermal stability. While the characterization of electrochemical properties of TMC anodes is well developed, new challenges arise in understanding the structure-property relationships. Transmission electron microscopy (TEM) is a powerful tool for studying microstructural characteristics. With TEM and related techniques, fundamental understanding of how the microstructures affect the properties of the TMC nanostructured anodes can be improved. In this article, the application of TEM in characterization of some typical TMC anode materials optimized through structural engineering, elemental doping, surface modification, defect-control engineering, morphological control, etc. is reviewed. Emphasis is given on analyzing the microstructures, including surface structures, various defects, local chemical compositions and valence states of transition metals, aimed at illustrating a structure-property relationship. The contribution and future development of the TEM techniques to elucidation of the electrochemical properties of the TMC anodes are highlighted.PostprintPeer reviewe

Acid Treatment Enables Suppression of Electron-Hole Recombination in Hematite for Photoelectrochemical Water Splitting

We report a new strategy for efficient suppression of electron-hole recombination in hematite photoanodes. Acid-treated hematite show substantially enhanced photocurrent density compared to untreated samples. Electrochemical impedance spectroscopy studies reveal that the enhanced photocurrent is partly due to improved efficiency of charge separation. Transient absorption spectroscopic studies coupled to electrochemical measurements indicate that in addition to improved bulk electrochemical properties, acid treated hematite has significantly decreased surface electron-hole recombination losses due to a greater yield of the trapped photoelectrons being extracted to the external circuit

Synthesis of Indium Nanowires by Galvanic Displacement and Their Optical Properties

<p>Abstract</p> <p>Single crystalline indium nanowires were prepared on Zn substrate which had been treated in concentrated sulphuric acid by galvanic displacement in the 0.002 mol L^&#8722;1In₂(SO₄)₃-0.002 mol L^&#8722;1SeO₂-0.02 mol L^&#8722;1SDS-0.01 mol L^&#8722;1citric acid aqueous solution. The typical diameter of indium nanowires is 30 nm and most of the nanowires are over 30 &#956;m in length. XRD, HRTEM, SAED and structural simulation clearly demonstrate that indium nanowires are single-crystalline with the tetragonal structure, the growth direction of the nanowires is along [100] facet. The UV-Vis absorption spectra showed that indium nanowires display typical transverse resonance of SPR properties. The surfactant (SDS) and the pretreatment of Zn substrate play an important role in the growth process. The mechanism of indium nanowires growth is the synergic effect of treated Zn substrate (hard template) and SDS (soft template).</p

Electrodeposition of Neodymium_Iron Group Alloy Films in( p _CH 3C 6H 4SO 3) 3Nd+DMF System

本世纪３０年代Ａｕｄｒｅｉｔｈ等人基于分离稀土元素的目的，在某些有机溶剂电解液中用汞阴极电沉积了个别的稀土汞齐［１］．１９５４年Ｍｏｅｌｅｒ等在乙二胺中电沉积了Ｙ、Ｌａ和Ｎｄ（稀土含量只有５０％左右）［２］．随着电子和信息技术的发展，稀土合金功能薄膜...Neodymium p _toluenesulfonate was prepared and applied to the electrodepositon of neodymium_iron group alloy films. This salt has high solubility in DMF and can be dehydrated easily. Cyclic voltammograms of Pt electrode in ( p _CH 3C 6H 4SO 3) 3Nd+MCl 2(M=Fe,Co,Ni)+DMF indicated that the neodymiun_iron group alloys can be elcetrodeposited from this medium, the Nd_Fe,Nd_Co and Nd_Ni films were obtained by electrolysis at constant potential. The Nd_Fe,Nd_Co and Nd_Ni films are amorphous in which the rare earth contents are in the range of 15 at%～60 at% as analyzed by XRD and EDS. The Nd content in the deposited film increases with the shift of cathode potential to the negative direction. The deposited Nd_Co film has good soft magnetic properites and its crystallization temperature was determined as 468.3 ℃.Author's Address: School of Chem. and Chem. Engin., Zhongshan University, Guangzhou 51027

Electrochemical Preparation of Rare Earth Functional Materials and Application of Rare Earth to Electrochemistry

电化学方法制备稀土材料及稀土在电化学中的应用①杨绮琴童叶翔（中山大学化学与化学工程学院广州５１０２７５）稀土元素内层４ｆ电子的数目从０向１４个逐个填满，造成它们之间在光学、磁学、电学性能上出现明显差异，衍生出种类繁多的高新材料．我国的稀土资源非常丰...The new progress and related mechanism of the electrochemical preparation of rare earth materials(magnets, magnetooptic materials, battery materials, luminescent devices, semiconductors, superconductors) and the application of rare earth to the electrochemical areas(e.g. electroplating,corrosion,electrosynthses) have introduced.作者联系地址：中山大学化学与化学工程学院Author's Address: School of Chem. and Chem. Engin., Zhongshan Univ., Guuangzhou 51027

A Palladium-Tin Modified Microband Electrode Array for Nitrate Determination

A microband electrode array modified with palladium-tin bimetallic composite has been developed for nitrate determination. The microband electrode array was fabricated by Micro Electro-Mechanical System (MEMS) technique. Palladium and tin were electrodeposited successively on the electrode, forming a double-layer structure. The effect of the Pd-Sn composite was investigated and its enhancement of catalytic activity and lifetime was revealed. The Pd-Sn modified electrode showed good linearity (R2 = 0.998) from 1 mg/L to 20 mg/L for nitrate determination with a sensitivity of 398 μA/(mg∙L−1∙cm2). The electrode exhibited a satisfying analytical performance after 60 days of storage, indicating a long lifetime. Good repeatability was also displayed by the Pd-Sn modified electrodes. The results provided an option for nitrate determination in water