Controlling size and distribution of Au nano-particles on C3N4 for high-efficiency photocatalytic hydrogen production

With advantages such as low cost, high stability, and ease of production, visible light photocatalytic C 3 N 4 with a unique microscopic layered structure holds significant potential for development. However, its hydrogen production efficiency remains low due to the pronounced recombination of photo-generated charge carriers and limited surface reaction sites. Normally, the photocatalytic performance of C 3 N 4 can be enhanced by loading noble metals with surface plasmon resonance. It is worth noting that the size of noble metal nanoparticles has a great influence on photocatalytic performance. In this study, accurate controlling of the size and distribution of Au nanoparticles was achieved on the surface of C 3 N 4 by introducing amino groups to improve photocatalytic performance. Results show that uniformly distributed Au nanoparticles in the range of 2–6 nm can be obtained on C 3 N 4 with a remarkable enhancement of hydrogen production efficiency, which is about 114 times the property of pure C 3 N 4 . The small-sized and uniformly distributed Au nanoparticles can provide more reaction sites and increase the separation of photo-generated charge carriers, in turn improving Au/NH 3 –C 3 N 4 photocatalytic hydrogen release rate to 6.85 mmol g −1  h −1 . This work offers a facile way to enhance photocatalytic performance by controlling the size of metal nanoparticles on C 3 N 4 precisely.