Formation of porous silver by electrochemical alloying/dealloying in a water-insensitive zinc chloride-1-ethyl-3-methyl imidazolium chloride ionic liquid.

ABSTRACT

This paper describes the formation of a porous silver surface by a convenient two-step process involving electrochemical formation of a binary silver-zinc alloy film on a silver surface followed by electrochemical etching of the zinc from the alloy. Both the deposition and the dealloying steps were performed in a single bath of low-temperature zinc chloride-1-ethyl-3-methylimidazolium chloride ionic liquid at temperatures below 150 degrees C without using any other corrosive acids or bases. The effects of the deposited zinc quantity, deposition potential, current, and temperature on the structures and morphologies of the porous silver film were examined. In comparison with conventional molecular electrolyte solutions, ionic liquids provide a more versatile environment for fabricating porous metals. Because the zinc(II) species consumed during the deposition step was recovered during the dealloying step, the ionic liquid is reusable.