Anodic Fabrication of Nanoporous Gold Films from Pure Gold in Oxalic Acid Solution and Their Applications in Electrocatalysis and SERS

Abstract

Nanoporous gold films (NPGFs) with high roughness have been fabricated by strong anodization of pure gold substrates in an aqueous solution of oxalic acid (OA), a facile method similar to the recent work of Nishio and Masuda (Angew. Chem. Int. Ed., 50 (2011) 1). The influence of anodic step potential, anodic polarization time and OA concentration on the roughness factor (R) of NPGFs has been investigated. The fabrication might be mainly related to the formation of multilayer gold oxide and chemical reduction of gold oxide by OA. The as–prepared NPGF exhibits a high electrocatalytic activity toward the oxidation of ethanol, glucose and ascorbic acid as well as the reduction of hydrogen peroxide. Furthermore, the NPGF also shows strong surface enhanced Raman spectroscopy (SERS) effect.