Efficient photocatalytic hydrogen evolution with high-crystallinity and noble metal-free red phosphorus-CdS nanorods

Abstract

The photocatalytic production of H2 by low-cost semiconductors is a promising approach to store solar energy. Photocatalysts with heterojunctions convert visible light into H2 faster because of more efficient charge separation. The morphology, the structure, and the crystallinity are additional factors to consider when developing a photocatalyst. Here, highly-crystalline CdS nanorod (NR) were synthesized by a facile one-pot process. Under visible light, pure CdS NR produced H2 2.1 times faster than conventional CdS nanoparticles (NP). CdS NR were then combined with the semiconductor red phosphorus (RPh). A CdS NR-based heterojunction photocatalyst with RPh5% had an excellent photocatalytic H2 evolution rate of 11.72 mmol g−1 h−1, which was 3.6 times higher than pure CdS NR. The apparent quantum efficiency of RPh5%/CdS NR was 19.57%. Furthermore, RPh5%/CdS NR exhibited a superior photogenerated charge separation efficiency and was stable with little photocorrosion compared to CdS NP showing the high potential of this heterojunction photocatalyst.