Highly promoted hydrogen production enabled by interfacial P–N chemical bonds in copper phosphosulfide Z-scheme composite

Transition metal phosphosulfides (TMPSs) have shown great potential as efficient catalysts toward hydrogen evolution reaction (HER). To further understand and promote the catalytic activity at the phosphosulfide (PS) structures, the multifunctional role of TMPS needs to be explored. Herein, we report copper phosphosulfide (Cu₃P|S) coupled with graphene-like C₃N₄ (GL-C₃N₄) as an excellent HER photocatalyst with a hydrogen production rate of 8.78 mmol g⁻¹ h⁻¹ (20.22 mmol g⁻¹ h⁻¹ with 0.5 wt.% Pt). Systematic investigations on the interaction between Cu₃P|S and GL-C₃N₄ unveil that such impressive photocatalytic activity arises from the interfacial P–N chemical bond that constructs a Z-scheme heterostructure. Time-resolved photoluminescence analysis indicates a considerably suppressed recombination rate of photoexcited charge carriers at the interface, which facilitates electron transfer and enhances the reducibility of electrons in the conduction band of Cu₃P|S. This work provides new design strategies for employing TMPSs as photocatalysts for highly efficient HER and other photoreduction reactions.