Plasmon‐induced photothermal effect of sub‐10‐nm Cu nanoparticles enables boosted full‐spectrum solar H2 production

Distinguishing the contributions from localized surface plasmon resonance (LSPR)induced photothermal effect is a significant challenge in the study of solar hydrogen production. Herein, a well‐defined one‐dimensional Cu/TiO2 heterostructure with Cu size of 3–6 nm is designed to address such issue. Cu nanoparticles present notable LSPR absorption from visible to near‐infrared light, while no hydrogen is produced in the presence of simulated light with λ ≥ 700 nm. Interestingly, a remarkable improvement of hydrogen evolution under full‐spectrum light was observed which is almost twice of that under only ultraviolet–visible light irradiation, implying the critical yet auxiliary role of LSPR‐induced photothermal effect in promoting photocatalytic performance. Significantly, a notable reduction of the apparent activation energy and strengthened charge separation efficiency are observed due to the increased local temperature of catalyst surface caused by the plasmon‐induced photothermal effect. The kinetic and thermodynamic changes should be responsible for the enhanced hydrogen production.