Preparation and Hydrogen Production Application of Core–Shell Heterojunction Photocatalyst (PbS/ZnO)@CuS

This study employed a hydrothermal method to coat CuS onto PbS quantum dots loaded with ZnO, resulting in a core-shell-structured (PbS/ZnO)@CuS hetero-structured photocatalyst. The sulfide coating enhanced the photocatalyst's absorption in the near-infrared to visible light range and effectively reduced electron-hole (h⁺) pair recombination during photocatalytic processes. Electron microscopy analysis confirmed the successful synthesis of this core-shell structure using polyvinylpyrrolidone (PVP); however, the spatial hindrance effect of PVP led to a disordered arrangement of the CuS lattice, facilitating electron-hole recombination. Comprehensive analyses using transmission electron microscopy (TEM), photoluminescence (PL), and Brunauer-Emmett-Teller (BET) methods revealed that the (PbS/ZnO)@CuS photocatalyst synthesized at a hydrothermal temperature of 170 °C exhibited optimal hydrogen production efficiency. After conducting a photocatalytic reaction for 5 h in a mixed aqueous solution containing 0.25 M Na₂S + Na₂SO₃ as a sacrificial agent, a hydrogen production rate of 3473 μmol·g^-1·h^-1 was achieved.