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 In 2 O 3 nanosheets, assembled into flowerlike structure (In 2 O 3 /Au/CdS), were synthesized to facilitate photocatalytic H 2 production. The optimized In 2 O 3 /Au 4 /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 In 2 O 3 (0.75 μmol/h), In 2 O 3 /Au 4 (3.39 μmol/h), and In 2 O 3 /CdS-12 (3.41 μmol/h), respectively. This significant improvement of H 2 generation rate can be attributed to the following factors: the heterojunction at the In 2 O 3 –CdS interface and the Schottky barrier at the interface between In 2 O 3 –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 In 2 O 3 and boosts the generation of hot electrons, efficiently improving the utilization rate of sunlight.