Modulation of catalyst interfacial electric field and charge transfer promotes NiS-modified CoWO 4 /ZnIn 2 S 4 S-scheme heterojunction for efficient photocatalytic hydrogen evolution

The strategic post-synthetic modification of engineered S-scheme heterojunctions represents a potent and manipulable approach to significantly enhance photocatalytic activity. This study details the synthesis of innovative photocatalysts via the deposition of NiS nanoparticles onto S-scheme heterojunctions of CoWO 4 / ZnIn 2 S 4 (CWO/ZIS-NiS), facilitated by solvothermal and photochemical methodologies. Under visible light irradiation, the hydrogen production rate of CWO/ZIS-NiS was 22.304 mmol g-1 h-1 , which 14.7 times higher than that of the ZnIn 2 S 4 . XPS, EPR, SPV and DFT calculations were used to analyze the charge transfer path and the reasons for the performance improvement of the catalyst. The construction of the S-scheme CoWO 4 /ZnIn 2 S 4 heterojunction, along with NiS modification to enhance the interfacial electric field (IEF) and act as a reaction center, was identified as the primary reason for the enhanced hydrogen production activity. This work provides guidance for the design of efficient photocatalytic systems using the synergistic effect between cocatalysts and Sscheme heterojunctions.