Formation of Nanoporous Gold Film on Ti by Anodization in Oxalic Acid

Abstract
A nanoporous gold (NPG) film was formed on a Ti sheet or sputter-deposited thin Ti film by the anodization of a thin gold film on the Ti substrates in oxalic acid. A remarkably low anodic current of the Ti sheet compared with that of the Al sheet indicates that Ti is a stable substrate for the NPG film formed by the anodization. It is also confirmed that the preanodization of the Ti sheet significantly improves the adhesion of the NPG film to Ti. By increasing the anodic potential, NPG film was formed on sputter-deposited thin Ti film with a thickness of 130 nm.