The photocatalytic production of H-2 by low-cost semiconductors is a promising approach to store solar energy. Photocatalysts with heterojunctions convert visible light into H-2 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 H-2 2.1 times faster than conventional CdS nano-particles (NP). CdS NR were then combined with the semiconductor red phosphorus (RPh). A CdS NR-based heterojunction photocatalyst with RPh5% had an excellent photocatalytic H-2 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. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.