Infrared Light-Induced Anomalous Defect-Mediated Plasmonic Hot Electron Transfer for Enhanced Photocatalytic Hydrogen Evolution

Efficient utilization of infrared (IR) light, which occupies almost half of the solar energy, is an important but challenging task in solar-to-fuel transformation. Herein, we report the discovery of CuS@ZnS core@shell nanocrystals (CSNCs) with strong localized surface plasmon resonance (LSPR) characteristics in the IR light region showing enhanced photocatalytic activity in hydrogen evolution reaction (HER). A unique “plasmon-induced defect-mediated carrier transfer” (PIDCT) at the heterointerfaces of the CSNCs divulged by time-resolved transient spectroscopy enables producing a high quantum yield of 29.2%. The CuS@ZnS CSNCs exhibit high activity and stability in H₂ evolution under near-IR light irradiation. The HER rate of CuS@ZnS CSNCs at 26.9 μmol h^-1 g^-1 is significantly higher than those of CuS NCs (0.4 μmol h^-1 g^-1) and CuS/ZnS core/satellite heterostructured NCs (15.6 μmol h^-1 g^-1). The PIDCT may provide a viable strategy for the tuning of LSPR-generated carrier kinetics through controlling the defect engineering to improve photocatalytic performance.