氯化胆碱-乙二醇低共熔溶剂中银的电沉积

Electrodeposition of silver in choline chloride-ethylene glycol deep eutectic solvents

低共熔溶剂(DES)是一种新型绿色溶剂,具有制备简单、电化学窗口宽和导电性好等优点.本文中对氯化胆碱-乙二醇(ChCl-EG)低共熔溶剂中Ag的电沉积行为进行研究,利用拉曼光谱和FTIR红外光谱表征了ChCl-EG低共熔溶剂的结构,采用循环伏安法和计时电流法研究了ChCl-EG低共熔溶剂中电沉积Ag的电化学行为及成核机理,利用XRD和SEM等检测手段分析了沉积产物的物相组成和微观形貌.结果表明:ChCl-EG低共熔溶剂加入AgNO_(3)后,Ag是以[AgCl_(2)]-形式存在的;Ag^(+)在ChCl-EG体系中的还原属于一步沉积,是受扩散控制的准可逆过程;根据Scharifker-Hills模型分析,Ag在ChCl-EG中的沉积符合三维瞬时形核;沉积产物表面光滑,并且呈不规则的短棒状结构.

The deep eutectic solvent(DES)is a new type of green solvent with the advantages of simple preparation,wide electrochemical window and high conductivity.In this paper,the electrochemical behavior of Ag in choline chloride-ethylene glycol(ChCl-EG)deep eutectic solvent was investigated.The structure of ChCl-EG deep eutectic solvent was characterized by Raman spectroscopy and FTIR infrared spectroscopy,and the electrochemical behavior and nucleation mechanism of Ag electrodeposited in ChCl-EG deep eutectic solvent were studied by cyclic voltammetry and chronoamperometry.The phase composition and micro-morphology of the deposited products were analyzed by XRD and SEM.The results show that Ag is present in the form of[AgCl_(2)]-after the addition of AgNO_(3) to the ChCl-EG deep eutectic solvent;the reduction of Ag^(+)in the ChCl-EG system is a one-step deposition and a quasi-reversible process controlled by diffusion;the deposition of Ag in ChCl-EG is consistent with three-dimensional transient nucleation according to the Scharifker-Hills model;the surface of the deposited product is smooth with an irregular short rod-like structure.