WC1-x-Coupled 3D Porous Defective g-C3N4 for Efficient Photocatalytic Overall Water Splitting

Constrained by the limited visible light harvesting and high photogenerated electron-hole pair recombination rate, pristine g-C3N4 typically possesses poor overall water splitting behavior under visible light. To achieve efficient overall water splitting of g-C3N4 without the assistance of precious metals, herein, a WC1-x-coupled 3D porous defect g-C3N4 is constructed through simple one-step pyrolysis. Due to the introduction of platinum-like WC1-x, the effective heterogenization of WC1-x/g-C3N4 greatly improves the charge separation. In the meanwhile, the 3D multiple microstructures established by the self-protocol of ultrathin 2D g-C3N4 nanosheets enhance the light absorption efficiency and optimize the separation of photoexcited carriers. Significantly, the generation of nitrogen defects is capable of bringing about an optimized band structure. Based on those modifications, a significant photocatalytic overall water splitting capacity under visible light is obtained without the sacrificial agent by the prepared 3D WC1-x/g-C3N4, in which the simultaneous evolution of H-2 and O-2 was up to 84.1 and 41.7 mu molh(-1)g(-1), respectively.