The dual role of Au nanoparticles in the surface plasmon resonance enhanced photocatalyst Au/g-C3N4

Abstract

Gold nanoparticles (Au NPs) are widely utilized to broaden the light absorption of the photocatalysts due to their localized surface plasmon resonance (LSPR). However, the photocatalytic mechanism of Au/photocatalyst heterostructure involving charges transfer and reactive sites is still in dispute. Here, we synthesized a typical system Au/graphite carbon nitride (g-C3N4) and demonstrate that the role of Au NPs in the LSPR enhanced photocatalysis. Under visible light, the photoexcited electrons of g-C3N4 would transfer to Au NPs and reduce protons into hydrogen together with hot electrons of Au NPs. The hot holes of Au NPs would flow to g-C3N4 and oxidize triethanolamine. Therefore, the Au NPs play a dual role, plasma, and cocatalyst, in the LSPR enhanced photocatalyst. When λ > 420 nm, Au /g-C3N4 has hydrogen production of 159.9 μmol g−1 h−1. Our findings confirm the significance of metal plasma in photocatalytic reaction and benefit designing photocatalysts with boosting performance.