The Precision Defect Engineering with Nonmetallic Element Refilling Strategy in g-C₃N₄ for Enhanced Photocatalytic Hydrogen Production

Traditional defect engineering and doping strategies are considered effective means for improving H₂ evolution, but the uncontrollability of the modification process does not always lead to efficient activity. A defect-induced heteroatom refilling strategy is used here to synthesize heteroatoms introduced carbon nitride by precisely controlling the “introduction” sites on efficient N1 sites. Density functional theory calculations show that the refilling of B, P, and S sites have stronger H₂O adsorption and dissociation capacity than traditional doping, which makes it an optimal H₂ production path. The large internal electric field strength of heteroatom-refilled catalysts leads to fast electron transfer and the hydrogen production of the best sample is up to 20.9 mmol g⁻¹ h⁻¹. This work provides a reliable and clear insight into controlled defect engineering of photocatalysts and a universal modification strategy for typical heteroatom and co-catalyst systems for H₂ production.