1-丁基-3-甲基咪唑醋酸盐和水混合电解液中三价铬电沉积铬的研究  

Electrochemical Deposition of Cr from Cr^(3+) in the Mixed Electrolyte of [BMIM]OAc/H_2O

作　　者：罗维[1] 钮东方[1] 杜荣斌 王钧伟 汪竹青 徐衡 张新胜[1] LUO Wei NIU Dong-fang DU Rong-bin WANG Jun-wei WANG Zhu-qing XU Heng ZHANG Xin-sheng(State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China Collaborative Innovation Center for Petrochemical New Materials, A nqing 246011, Anhui, China)

机构地区：[1]华东理工大学化学工程联合国家重点实验室,上海200237 [2]石油化工新材料协同创新中心,安徽安庆246011

出　　处：《电化学》2017年第3期332-339,共8页Journal of Electrochemistry

基　　金：安徽省石油化工新材料协同创新中心资助

摘　　要：本文在[BMIM]OAc-H_2O电解液中研究了Cr^(3+)的电沉积反应.经循环伏安研究表明,Cr^(3+)的还原属于受扩散控制的分步还原过程,即Cr^(3+)+e→Cr^(2+)和Cr^(2+)+2e→Cr^0.在40 ℃下通过Rendle-Sevcik方程计算得到Cr^(3+)的扩散系数为1.2×10^(-8)cm^2·s^(-1).采用计时电流法探讨了Cr的三维瞬时成核机理.对沉积的铬镀层进行了XRD和SEM表征,结果表明,经600 ℃氩气保护下煅烧后的镀层由Cr和Cr_2O_3纳米球状颗粒聚集而成,其平均粒径为0.48μm.对40oC、-3.0 V条件下所得镀层进行EDX检测,发现Cr与O的能级峰十分明显,其中Cr的质量分数为83.8%.通过在[BMIM]OAc、[BMIM]BF_4和[BMIM]PF_6三种离子液体体系中电镀得到的Cr镀层质量的比较,表明OAc^-的确有利于Cr的电沉积.The electrochemical reduction of trivalent chromium ion （Cr3＋） to Cr in 1-butyl-3-methylimidazolium acetate （[BMIM]OAc）-H2O mixed electrolyte was investigated. The cyclic voltammograms showed that the electroreduction of Cr3＋ in the mixed electrolyte occurred in a two-step process, namely, Cr3＋ ＋ e → Cr2＋ and Cr2＋ ＋ 2e→ Cr^0, controlled by the diffusion of Cr3＋ to the electrode. The diffusion coefficient of Cr3＋ was 1.2 ×10^-8 cm2· s-1 at 40 ℃obtained by Rendle-Sevcik equation. The chronoamperomograms of the Cr3＋ electrodeposition confirmed the three-dimensional instantaneous nucleation mechanism of Cr. The XRD and SEM characterizations on the Cr coating after calcining in argon atmosphere at 600℃ revealed that the coating was composed of Cr and chromium oxide （Cr2O3） nanoparticles with an average particle size of 0.48 μm. The elements of Cr and O were obviously detected from the coating obtained at 40 ℃ and -3.0 V by EDX and the mass fraction of Cr reached 83.8%. Comparison in the qualities of coating layers prepared by Cr electrodepositions in [BMIM]OAc, [BMIM]BF4 and [BMIM]PF6 electrolytes indicated that the OAc- was presented in favor of Cr3＋ reduction.

关 键 词：电沉积 1-丁基-3-甲基咪唑乙酸盐 三价铬 铬镀层 

分 类 号：TQ153[化学工程—电化学工业]