Highly Hydrophilic and Defective Carbon Nitride for Enhanced Photocatalytic Hydrogen Evolution

Graphitic carbon nitride (g-C₃N₄), as a kind of nonmetallic low-cost photocatalyst, has great potential in photocatalytic hydrogen (H₂) evolution, but its poor hydrophilicity and nonwetting extremely limit its H₂ evolution efficiency. Herein, highly hydrophilic and defective g-C₃N₄ photocatalysts (NH₃-CN-P as a representative example) have been fabricated on the basis of the strategy of joint phosphorus doping and ammonia stripping. The dopant of phosphorus prefers to occupy the C atoms bonded to -NH₂ groups in the g-C₃N₄ skeleton, which is conducive to the formation of N defects caused by the effects of electronegativity and charge balance. Moreover, ammonia stripping plays a dual role in exposing plentiful two-dimensional defective planar structure and implanting the hydrophilic groups on the surface. As expected, the photocatalytic H₂ evolution property of NH₃-CN-P reaches 11.31 mmol g^-1 h^-1, with an apparent quantum yield of 17.9% at 420 nm, outperforming the majority of the reported g-C₃N₄-based photocatalysts.