Visible-light photocatalytic water splitting for hydrogen evolution has attracted tremendous attention in past decades, but it still suffers from low solar-hydrogen conversion efficiency. In this paper, two-dimensional (2D) CdS was synthesized by the hydrothermal method, and 2D CoP nanosheets were synthesized by successive hydrothermal, oxidation and phosphodation process. Then 2D-2D CdS-CoP photocatalysts were formed by ultrasonically dispersing the mixed solution of CdS and CoP, and their heterostructure was confirmed by transmission electron microscopy, X-ray photoelectron spectroscopy, fluo- rescence spectrometer and so on. CdS-CoP with 2% CoP loading amounts exhibits a maximum photocatalytic performance of 56.3 mmolg(-1)h(-1) under visible light irradiation, which is 11.3 times as high as bare CdS. The enhanced photocatalytic performance of CdS-CoP should be due to the following two points: (1) high catalytic activity of CoP; (2) highly efficient separation and transfer of electron-hole pairs photogenerated in CdS due to the synthesized 2D-2D heterostructure. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.