Preparation of Au-Bi2O3 Nanocomposite by Anodic Electrodeposition Combined with Galvanic Replacement

Abstract

Nanocomposite films of Au-modified bismuth oxide (Au-Bi2O3) were synthesized via anodic electrodeposition of Bi combined with a galvanic replacement reaction. First, Bi2O3 was prepared by the anodic oxidation of pre-electrodeposited Bi films in 0.1 M NaOH electrolyte. The amount of metallic bismuth in Bi2O3 was tuned by controlling the oxidation time or deposition potential. Thus-prepared Bi-Bi2O3 composite was converted to Au-Bi2O3 by galvanically replacing metallic Bi with Au from an aqueous HAuCl4 solution. The photocatalytic activity of the Au-Bi2O3 nanocomposite for decomposition of methyl orange dye was superior to that of the bare Bi2O3 counterpart under UV as well as visible light illumination.