Synergism between Surface Engineering and S-Scheme Heterojunctions for Efficient Photocatalytic H2 Evolution

The sulfur modification of photocatalysts can significantly improve their performance, with widespread applications in photoelectrocatalysis and pollutant purification. In this article, sulfurization of NiWO4(NWO) leads to the formation of NiS-modified NiWO4 (NWS), which exhibits superior light absorption and electron transfer capabilities. The introduction of graphdiyne (GDY) into NWS was used to construct an NWS/GDY with S-scheme heterojunction. Experiments have shown that NWS/GDY exhibits lower impedance and stronger photocurrent response, which is attributed to the strong interface coupling between NWS and GDY and the construction of NiS, which inhibits electron–hole recombination and promotes the transfer of photogenerated electrons. In hydrogen evolution experiments, NWS/GDY achieves hydrogen production of 213.51 μmol in 4 h. We utilize DFT calculations and in situ XPS analysis to deduce the mechanism of photocatalytic hydrogen evolution.