Au Nanoparticle and CdS Quantum Dot Codecoration of In₂O₃ Nanosheets for Improved H₂ Evolution Resulting from Efficient Light Harvesting and Charge Transfer

Au nanoparticle (NP)- and CdS quantum dot (QD)-codecorated In₂O₃ nanosheets, assembled into flowerlike structure (In₂O₃/Au/CdS), were synthesized to facilitate photocatalytic H₂ production. The optimized In₂O₃/Au₄/CdS-12 (4 wt % Au NPs and CdS QDs were deposited for 12 cycles) displays achieved a photocatalytic hydrogen generation ability of 17.23 μmol/h (10 mg of catalyst), which is 22.97, 5.08, and 5.05 times as high as that of pristine In₂O₃ (0.75 μmol/h), In₂O₃/Au₄ (3.39 μmol/h), and In₂O₃/CdS-12 (3.41 μmol/h), respectively. This significant improvement of H₂ generation rate can be attributed to the following factors: the heterojunction at the In₂O₃-CdS interface and the Schottky barrier at the interface between In₂O₃-Au and CdS-Au improves the migration and separation of charge carriers, and the surface plasma resonance (SPR) effect of noble metal Au NPs enhances the light harvesting capacity of In₂O₃ and boosts the generation of hot electrons, efficiently improving the utilization rate of sunlight.