Formation of interfacial P-Ni-P coordination to boost charge transfer of polymeric carbon nitride for enhanced photocatalytic activity of H2 evolution

Abstract

Constructing composite semiconductor photocatalysts with intimate interfacial contact is crucial for efficient charge separation and surface reaction kinetics towards enhancing hydrogen evolution via photocatalytic water splitting. In this work, an in-situ interfacial P-Ni-P coordination strategy for band modulation and interfacial engineering of the Ni2P/P-PCN system is reported based on interstitial doping P and coupled Ni2P cocatalysts. As a non-noble metal composite catalyst, Ni2P/P-PCN displayed a photocatalytic hydrogen evolution rate (HER) of 1250 μmol h−1 g−1, which was 1.4 times higher than that of Pt/P-PCN. The experimental characterization and theoretical calculation results showed that P dopant atoms at the P-PCN interface were coupled with Ni2P via interfacial P-Ni-P bonds. These acted as electron bridges that provided electron transfer channels at the interface, which greatly improved the interfacial compatibility between P-PCN and Ni2P. Combinedly, these effects promoted the rapid separation and transfer of photogenerated carriers. Thus, Ni2P/P-PCN can potentially replace Pt as a noble-metal-free cocatalyst for efficient synergistic HER under visible light irradiation.