An efficient Ni2P-CdS photocatalyst for photocatalytic hydrogen evolution was synthesized by phosphorizing beta-Ni(OH)(2 )nanosheet with exposed (001) facets on CdS nanorods. The obtained Ni2P-CdS composite displays an outstanding and stable photocatalytic hydrogen generation rate of 68.47 mmol g(-1)h(-1) in 10 vol% lactic acid under visible light irradiation, more than 17 times higher than that for pure CdS nanorods. The transient photocurrent response, EIS measurement, Mott-Schottky plots, acidic LSV measurement, and PL spectra have proved that Ni2P loading can significantly improve the separation of photo-excited electron-hole pairs in CdS nanorods and enhance the hydrogen evolution capability for CdS. These improvements are achieved by features of Ni2P such as the high capability of trapping photo-generated electrons from CdS, lifting the total Fermi level and lowering the hydrogen evolution overpotential of the composite. The results show that beta-Ni(OH)(2) precursor with a high exposure degree of (001) facet is contributed to the epitaxial formation of (001)-facet-exposed Ni2P co-catalyst on CdS nanorods, resulting in that the Fermi level and the hydrogen evolution overpotential of the composite can be further lifted and lowered. This study has provided a novel precursor-derived route to fabricate highperformance co-catalysts with highly exposed active facets on CdS nanorods for effective photocatalytic hydrogen evolution. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.