In Situ Synthesis of Cu 3 P / P‐Doped g‐C 3 N 4 Tight 2D / 2D Heterojunction Boosting Photocatalytic H 2 Evolution

Heterojunction design in a two‐dimensional (2D) fashion has been deemed beneficial for improving the photocatalytic activity of g‐C 3 N 4 because of the promoted interfacial charge transfer, yet still facing challenges. Herein, we construct a novel 2D/2D Cu 3 P nanosheet/P‐doped g‐C 3 N 4 (PCN) nanosheet heterojunction photocatalyst (PCN/Cu 3 P) through a simple in‐situ phosphorization treatment of 2D/2D CuS/g‐C 3 N 4 composite for photocatalytic H 2 evolution. We demonstrate that the 2D lamellar structure of both CuS and g‐C 3 N 4 could be well reserved in the phosphorization process, while CuS and g‐C 3 N 4 in‐situ transformed into Cu 3 P and PCN, respectively, leading to the formation of PCN/Cu 3 P tight 2D/2D heterojunction. Owing to the large contact area provided by intimate face‐to‐face 2D/2D structure, the PCN/Cu 3 P photocatalyst exhibits significantly enhanced charge separation efficiency, thus achieving a boosted visible‐light‐driven photocatalytic behavior. The highest rate for H 2 evolution reaches 5.12 μmol·h –1 , nearly 24 times and 368 times higher than that of pristine PCN and g‐C 3 N 4 , respectively. This work represents an excellent example in elaborately constructing g‐C 3 N 4 ‐based 2D/2D heterostructure and could be extended to other photocatalyst/co‐catalyst system.