Band engineering for building cascading charge transport channels in ternary CdS-based nanorod array photoanode toward efficient photoelectrochemical H2 generation

A novel CdS/CdSe/Cu 2 O nanorod array (NRA) photoelectrode with cascading charge transport channels was designed for the first time to remarkedly boot photoelectrochemical (PEC) hydrogen generation under visible light illumination with zero bias. This ternary photoelectrode was constructed by modifying CdS nanorod arrays with n-type CdSe and p-type Cu 2 O nanoparticles , successively. In this novel photoanode , CdSe and Cu 2 O with small band gap not merely highly heighten the visible light absorption capacity of CdS, but more importantly integrate with CdS to build cascading charge transport channels at the CdS/CdSe and CdSe/Cu 2 O interfaces, dramatically facilitating the separation and transport efficiency for photoexcited electron and hole pairs. The CdS/CdSe/Cu 2 O NRA photoelectrode gains an obvious hydrogen generation rate of 193.2 μmol·h −1 , 8.2 times higher than that of bare CdS NRA photoelectrode. The remarkably enhanced PEC hydrogen production for the CdS/CdSe/Cu 2 O NRA photoanode can be ascribed to effective solar energy utilization and charge carrier separation.