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991.
992.
In this study, Al was electrodeposited on a platinum substrate at room temperature from an ionic liquid bath of EMIC containing AlCl3 using potentiostatic polarization (PP), galvanostatic polarization (GP), monopolar current pulse polarization (MCP) and bipolar current pulse polarization (BCP). Transition of current or potential during galvanostatic or pulse polarization revealed that the initial stage of the deposition process was controlled by a nucleation process depending on the polarization condition. For example, the average size of Al deposits decreased with increasing current density in the case of GP. FE-SEM observation showed that dense and compact Al deposits with a smooth surface were obtained by the current pulse method. Roughness factor evaluated from electrochemical impedance measurement confirmed the smooth surface of these deposits. Adhesion strength of Al deposits was greatly improved using BCP in which an anodic pulse was combined with a cathodic pulse for electrodeposition. In this study, the optimal parameters for BCP were found to be IC = −16.0 mA cm−2, IA = 1.0 mA cm−2, rC (duty ratio) = 0.5, and f = 2 Hz. The mechanisms of electrodeposition by these three methods are discussed. 相似文献
993.
Preparation of cost-effective Pt–Co electrodes by pulse electrodeposition for PEMFC electrocatalysts
Seunghee Woo In Kim Jae Kwang Lee Sungyool Bong Jaeyoung Lee Hasuck Kim 《Electrochimica acta》2011,(8):97
Low loading platinum–cobalt (Pt–Co) cathode catalyst on a Nafion(Na+)-bonded carbon layer is fabricated by using galvanostatic pulse technique to show the advantage of electrodeposition for high utilization of catalyst in proton exchange membrane fuel cell (PEMFC). We observed that Pt–Co catalysts evenly exist on the surface of carbon electrode and its thickness is about 5.8 μm, which is four times thinner than conventional Pt/C. Improved single cell power performance of Pt–Co cathode catalysts with a ratio of 3.2:1 compared with Pt/C is clearly presented. 相似文献
994.
995.
采用循环伏安法研究了氯化物体系中锌-钴合金电镀的电沉积过程,采用X-射线厚度和成分分析仪测量了锌-钴合金镀层的厚度和钴金属质量分数.试验表明,在氯化钾锌-钴合金电镀槽液可以电镀钴质量分数为0.2%~0.4%的锌-钴合金,钴添加剂的加入,能够使氢的析出电位负移,扩大了锌-钴合金沉积的电位区间范围. 相似文献
996.
通过循环伏安和计时电位等电化学测量方法研究了硝酸铀酰在亲水性离子液体--氯化1-丁基-3-甲基咪唑([BMIM]C1)中的电化学过程.结果表明,UO2+2在离子液体[BMIM]Cl中转移2个电子,一步还原为UO2.当扫描速率为10~100 mV/s、体系温度为353 K、UO2+2浓度为13.27 mmol/L时,电极... 相似文献
997.
Ai-min LIU Meng-xia GUO Zhong-ning SHI Yu-bao LIU Feng-guo LIU Xian-wei HU You-jian YANG Wen-ju TAO Zhao-wen WANG 《中国有色金属学会会刊》2021,31(3):832-841
Zinc chloride (ZnCl2) was dissolved in the 1,3-dimethyl-2-imidazolinone (DMI) solvent, and the metallic zinc coatings were obtained by electrodeposition in room-temperature ambient air. The conductivity (σ), viscosity (η), and density (ρ) of the DMI?ZnCl2 solvated ionic liquid at various temperatures (T) were measured and fitted. Furthermore, cyclic voltammetry was used to study the electrochemical behavior of Zn(II) in the DMI?ZnCl2 solvated ionic liquid, indicating that the reduction of Zn(II) on the tungsten electrode was a one-step two-electron transfer irreversible process. XRD and SEM?EDS analysis of the cathode product confirmed that the deposited coating was metallic zinc. Finally, the effects of deposition potential, temperature and duration on the morphology of zinc coatings were investigated. The results showed that a dense and uniform zinc coating was obtained by potentiostatic electro- deposition at ?2 V (vs Pt) and 353 K for 1 h. 相似文献
998.
999.
《中国有色金属学会会刊》2021,31(8):2522-2531
The density, conductivity, and viscosity of the 1,3-dimethyl-2-imidazolinone and lithium nitrate (DMI– LiNO3) solvated ionic liquid were measured as a function of temperature. Additionally, the electrochemical mechanism and electrodeposition of neodymium from the DMI–LiNO3 solvated ionic liquid were investigated. Cyclic voltammetry results indicate that the electrochemical reduction of Nd(III) is irreversible and proceeds via one-step with three-electron transfer, which is controlled by diffusion with a diffusion coefficient of 5.08×10−8 cm2/s. Energy- dispersive X-ray spectrometry and X-ray photoelectron spectroscopy data confirm that the electrodeposit obtained after electrodeposition at −4 V (vs Ag) using the DMI–LiNO3–Nd(CF3SO3)3 solvated ionic liquid contains metallic neodymium. 相似文献
1000.
将多组分活性材料组合成新的结构用作电极材料是提高超级电容器性能的一种有效措施。采用典型的两步水热法与电沉积法制备了FeCo2S4/Ni(OH)2复合纳米材料,并表征其物理及电化学性能。结果表明,FeCo2S4纳米花被电沉积上的Ni(OH)2纳米片包围,形成三维互连网状结构,有利于电极材料与电解液的充分接触。所得的FeCo2S4/Ni(OH)2复合电极材料显示出极高的比电容(当电流密度为1 A·g^-1时,比电容达1588.2 F·g^-1)、优异的倍率性能及循环稳定性。此外,以FeCo2S4/Ni(OH)2为正极、活性炭为负极组装了非对称超级电容器。结果显示,非对称超级电容器具有高能量密度及良好的循环稳定性。 相似文献