Optimized hot electron injection from Cu nanoparticles to S-doped CN by the formed S-Cu bonds for an enhanced photocatalytic performance.

Low-cost and high-abundance Cu nanostructures are potential near-infrared (NIR) surface plasmonic resonance (SPR) photosensitizers for carbon nitride (CN) photocatalysts, but their low activity and stability need to be improved. In this article, doping S into CN (S-CN) creates anchoring sites for photo-deposited Cu nanoparticles (NPs), and the spontaneous construction of S-Cu bonds is realized between S-CN and Cu NPs. The optimal hydrogen evolution rate of 1.64 mmol g h is obtained for S-CN-Cu, which is 5.5, 4.6 and 1.7 times that of pure CN, S-CN and S-CN-Cu, respectively. With further loading of a Pt co-catalyst to confirm the role of Cu NPs and improve the photocatalytic activity of the SCN-Cu, the photocatalytic rate can reach up to 14.34 mmol g h. Due to the NIR SPR effect of Cu NPs, the apparent quantum efficiency (AQE) of S-CN-Cu at 600 and 765 nm is 2.02% and 0.47%, respectively. The enhanced photocatalytic performance of S-CN-Cu compared with CN-Cu is mainly due to the introduced S-Cu bonds that improve the injection rate of hot electrons. This solution provides a simple and efficient interface optimization strategy for the construction of efficient NIR-driven photocatalysts.