Synthesis of Au/ZnO Composite Nanorod Arrays via Electrodeposition Followed by Galvanic Replacement

Nanorod arrays of Au/ZnO were synthesized via electrodeposition combined with a galvanic replacement reaction. Thus ZnO nanorods were first electrodeposited on transparent conducting glass, and the co-deposited metallic zinc was then galvanically replaced with Au from an aqueous HAuCl4 solution resulting in Au/ZnO nanocomposite. Significantly the initial ZnO hexagonal nanorod array morphology was preserved in the Au/ZnO nanocomposite after galvanic replacement. The photocatalytic activity of the nanocomposite, as assessed by methyl orange dye decomposition, was better for Au/ZnO than for the parent ZnO-a trend attributable to the better visible light sensitivity of Au/ZnO relative to ZnO.