Modulating charge transfer dynamics for g-C3N4 through a dimension and interface engineered transition metal phosphide co-catalyst for efficient visible-light photocatalytic hydrogen generation

Abstract

Transition metal phosphide (TMP) co-catalysts have been widely applied to modify graphitic carbon nitride (g-C₃N₄) for improving the photocatalytic activity, but it is still a great challenge to fabricate high performance and stable g-C₃N₄ based photocatalysts decorated with TMP co-catalysts by simple approaches. Herein, we report a facile and general strategy for the synthesis of TMP/g-C₃N₄ hybrid photocatalysts with high H₂ production performance under visible light irradiation. Among the as-prepared TMP/g-C₃N₄ hybrids, the CoP/g-C₃N₄ sample with an optimum mass content of 2.5 wt% delivers the highest photocatalytic H₂ evolution rate of 956.8 μmol g⁻¹ h⁻¹. DFT calculations and experimental results reveal that the superior catalytic activity could be predominantly attributed to the larger number of active sites and the enhanced photo-excited charge transfer dynamics benefitting from the synergistic effect of the ultrasmall particle size and the intimate contact interface between g-C₃N₄ and CoP. We anticipate that the protocol would provide a promising strategy for designing TMP co-catalyst based hybrid nanostructures aiming to optimize photocatalytic hydrogen generation efficiency.