Synthesis and characterization of ZnO/Au and ZnO/AuAg mesoflower composites for photoelectrochemical water-splitting applications

Abstract

Photoelectrochemical (PEC) water splitting is among of the greatest assuring methods in producing hydrogen. One of the alternative semiconductor materials used as a photoanode for water-splitting applications is ZnO. However, this compound has several drawbacks that can be overcome by combining it with noble metal particles. In this study, ZnO nanorods (NRs) were synthesized using the hydrothermal method and then decorated with AuAg mesoflowers (MFs) synthesized by the wet chemical method. A linear sweep voltammogram (LSV) measurement under visible light and AM 1.5 G shows that the ZnO/AuAg MFs produced the highest photocurrent in the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) with the highest efficiency, of 0.034 % at a voltage of 0.874V vs reversible hydrogen electrode (RHE). The AuAg MFs may act as electron donors, injecting electrons into the ZnO conduction band to increase the photocurrent.