Graphitic C 3 N 4 Decorated with CoP Co‐catalyst: Enhanced and Stable Photocatalytic H 2 Evolution Activity from Water under Visible‐light Irradiation

In this work, graphitic C 3 N 4 decorated with a CoP co‐catalyst (g‐C 3 N 4 /CoP) is reported for photocatalytic H 2 evolution reaction based on two‐step hydrothermal and phosphidation method. The structure of g‐C 3 N 4 /CoP is well confirmed by XRD, FTIR, TEM, XPS, and UV/Vis diffuse reflection spectra techniques. When the weight percentage of CoP loading is 3.4 wt % (g‐C 3 N 4 /CoP‐3.4 %), the highest H 2 evolution amount of 8.4×10 2  μmol g −1 is obtained, which is 1.1×10 3  times than that over pure g‐C 3 N 4 . This value also is comparable with that of g‐C 3 N 4 loaded by the same amount of Pt. In cycling experiments, g‐C 3 N 4 /CoP‐3.4 % shows a stable photocatalytic activity. In addition, g‐C 3 N 4 /CoP‐3.4 % is an efficient photocatalyst for H 2 evolution under irradiation with natural solar light. Based on comparative photoluminescence emission spectra, photoelectrochemical I –t curves, EIS Nyquist plots, and polarization curves between g‐C 3 N 4 /CoP‐3.4 % and pure g‐C 3 N 4 , it is concluded that the presence of the CoP co‐catalyst accelerates the separation and transfer of photogenerated electrons of g‐C 3 N 4 , thus resulting in improved photocatalytic activity in the H 2 evolution reaction.