Plasmonic metal nanostructures offer the unique ability to effectively enhance sunlight harvesting by localized surface plasmon resonance (LSPR), which can induce direct photocatalytic reactions. However, only metal nanoparticles with a relatively low magnitude of electromagnetic field enhancement usually require a high illumination intensity to ensure the catalytic performance, which greatly limits the solar photocatalytic efficiency. Herein, we designed plasmonic Au nanoparticle film with high electromagnetic field enhancement to achieve high-efficiency catalytic activity under low-power NIR light illumination. This work minimized the influence of the photothermal effect on the reaction by using a low illumination intensity and further revealed the main contribution of plasmon-excited hot electrons to the photochemical reaction. This study provides important insights into the study of the mechanism of LSPR in photocatalytic reactions and further improves the efficiency of solar energy utilization.
Keywords: NIR photocatalysis; electromagnetic field enhancement; hot electrons; localized surface plasmon resonance; low-power illumination.