Developing noble-metal-free photocatalysts highly flexible for separating the photogenerated electron-hole pairs is crucial for the solar-energy-driven photocatalysis, but still remains an open question. Herein, we fabricated two dimensional Co3S4 nanosheets with a thickness of about 10 nm, and applied the nanosheets to support CdS nanoparticles (similar to 5 nm) to form a noble-metal-free CdS/Co3S4 photocatalyst with a higher ability in charge separation. In the visible-light-driven photocatalytic H2O splitting, an enhanced H-2 evolution (1083.9 mu mol h(-1)) was achieved on CdS/Co3S4, as compared with those on the CdS-nanoparticle-loaded Co3S4 nanoparticles (775.5 mu mol h(-1)) and noble-metal-based CdS/Pt photocatalyst (566.3 mu mol h(-1)). The enhanced photocatalytic performance is the result of the multiple roles of the Co3S4 nanosheets in the photocatalytic reaction, including promoting electron-hole separation, providing catalytically active sites and suppressing the aggregation of the CdS nanoparticles responsible for light absorption.