“…Hence, it is essential to develop new materials with broad light absorption to enhance the efficiency of water splitting. Compared with the most commonly used photoelectrode materials such as ZnO, − TiO 2 , − and BiVO 4 , − g-C 3 N 4 films are considered as promising photoelectrodes because of their high stability, appropriate band edge position, and tunable electronic band structure. , Various strategies have been explored to improve the PEC performance of g-C 3 N 4 via broadening its light absorption, including doping, surface modification, , and constructing heterojunction. , Recently, Liu et al designed a NiO and Co 3 O 4 comodified g-C 3 N 4 nanocomposite to enhance its PEC sensing under visible light, expanding the absorption edge from 457 to 494 nm . Zhang et al synthesized a Cu 2 O/g-C 3 N 4 heterojunction and enhanced the PEC water-splitting efficiency of g-C 3 N 4 under visible light irradiation …”