Preparation of copper–silver alloy with different morphologies by a electrodeposition method in 1-butyl-3-methylimidazolium chloride ionic liquid

Abstract

Electrodeposition of a copper–silver alloy based on a 1-butyl-3-methylimidazolium chloride (BMIC) ionic liquid was studied. The electrochemical behaviour of copper and silver ions was characterized by cyclic voltammogram. The morphologies and phase compositions of copper–silver alloy coating under different electrodeposition conditions were investigated by scanning electron microscopy and X-ray diffraction. The results show that copper–silver alloys with different micro-morphologies can be obtained under different potential conditions in BMIC. Co-deposition of the copper–silver alloy followed a two-step reduction process, the first step is the reduction of the cupric ion to the cuprous ion and the second step is the simultaneous reduction of the cuprous ion and the silver ion to form an alloy. A dendritic alloy can be obtained at − 0.60 V, a bract alloy can be obtained at − 0.80 V and a granular alloy can be obtained at − 1 V. The coating particle size at 60 ∘C was smaller than the particle size obtained at 40 ∘C. The Cu–Ag alloy prepared by electrodeposition in ionic liquids consists of single-phase copper and single-phase silver.