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

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.