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.