The preparation of porous copper or copper-zinc surfaces by electrochemical formation of binary Cu-Zn alloys on Cu substrate and subsequent electrochemical etching of the zinc was investigated in a zinc chloride-1-ethyl-3-methylimidazolium chloride ionic liquid at 120 degrees C. Cyclic voltammetry and X-ray diffraction measurements suggested that phase transformation from gamma- to beta'-Cu-Zn alloy occurred during constant potential dealloying. Essentially all the Zn content in the Cu-Zn could be removed from the alloy with dealloying at a sufficiently positive potential. Dealloyed materials exhibited well-developed bicontinuous porous structure. The dependence of the surface morphology of the porous Cu film on several experimental parameters, including deposition current and charge, and anodizing potential and temperature, were examined. (c) 2007 The Electrochemical Society.