Hydrogen production by photolysis of water by sunlight is an environmentally-friendly preparation technology for renewable energy. Graphitic carbon nitride (g-C3N4), despite with obvious catalytic effect, is still unsatisfactory for hydrogen production. In this work, phosphorus element is incorporated to tune g-C3N4's property through calcinating the mixture of g-C3N4 and NaH2PO2, sacrificial agent and co-catalyst also been supplied to help efficient photocatalytic hydrogen production. Phosphorus (P) doped g-C3N4 samples (PCN-S) were prepared, and their catalytic properties were studied. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and ultraviolet diffuse reflection (UV-DRS) were used to study their structures and morphologies. The results show that the reaction rate of PCN-S is 318 mu rnol.h(-1).g(-1) which is 2.98 times as high as pure carbon nitride nanosheets (CN) can do. Our study paves a new avenue, which is simple, environment-friendly and sustainable, to synthesize highly efficient P doping g-C3N4 nanosheets for solar energy conversion. (C) 2020 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.