Plasmon-mediated dual S-scheme charge transfer in CuS/InS/BiS hollow polyhedrons for efficient Photothermal-Assisted photocatalysis.

Step-scheme (S-scheme) semiconductor junction has garnered considerable attention for its potential applications in photocatalytic energy conversion. However, the photocatalytic activity of S-scheme junctions is restricted by inadequate light absorption and low charge separation efficiency. Herein, a plasmon-mediated dual S-scheme junction is constructed by growing InS and BiS nanoparticles on CuS hollow polyhedrons, exhibiting efficient photothermal-assisted photocatalysis. Due to the unique hollow polyhedron structure, the plasmon resonance, and the bandgap excitation, the CuS/InS/BiS hybrids show broad light absorption. Meanwhile, the plasmon-mediated dual S-scheme charge transfer, including the injection of plasmon-induced hot electrons from CuS to InS and BiS as well as the transfer of plasmon-induced hot holes from the trap states of CuS to InS and BiS, enables the hybrids to have efficient charge separation. In addition, remarkable photothermal performance originates from the synergistic effect of plasmonic heating and lattice thermal vibration, which leads to a further increase in the local temperature and enhancement of charge transfer efficiency in the hybrids. As a result, the CuS/InS/BiS hybrids demonstrate outstanding performance in photothermal-assisted photocatalytic hydrogen generation, rivaling many similar photocatalysts. This work offers valuable insights for designing high-efficiency photocatalysts based on S-scheme junctions.