Abstract
Cu 2 O-decorated CdS nanostructures are developed as highly efficient photocatalysts for hydrogen evolution from visible-light driven photocatalytic water splitting. The type II heterojunctions formed at the Cu 2 O/CdS interfaces facilitate charge separation that promotes photocatalytic water splitting and thus markedly improves the hydrogen evolution efficiency. For Cu 2 O decorated CdS nanobeads (NB), a milli-molar level specific hydrogen evolution rate of 4.76 mmol/h g is achieved, 72 times that achieved by plain CdS NBs, under irradiation of a 400 W light source using a mixture of Na 2 S and NaSO 3 as the sacrificial reagent. The improvements in hydrogen evolution acquired from the Cu 2 O decoration for CdS NBs are much greater than those attained for CdS nanoparticles (NPs) and CdS nanowires (NWs). The success of using CdS NBs as the hosting base for Cu 2 O decoration is attributed to the much better exposed CdS surfaces after the treatment, enabling direct contact of CdS with the reactant solution for hydrogen evolution, while the Cu 2 O surfaces are also exposed to contact the sacrificial reagent for scavenging holes. Copyright © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.