Plasmon Au/K-doped defective graphitic carbon nitride for enhanced hydrogen production

Knowledge of the photocatalytic H-2-evolution mechanism is of critical importance for water splitting, and for designing active catalysts for a sustainable energy supply. In this study, we prepared plasmon Au-modified K-doped defective graphitic carbon nitride (Au/KCNx) and then applied it in photocatalytic hydrogen-production tests. The hydrogen-production rate of the Au/KCNx photocatalyst (8.85 mmol g(-1) h(-1)) was found to be almost 104 times higher than that of Au/g-C3N4 (0.085 mmol g(-1) h(-1)), together with an apparent quantum efficiency of 12.8% at 420 nm. It could significantly improve the photocatalytic activities of the Au/KCNx sample, which was attributed to the synergistic effects of the plasmon effect, potassium doping, and nitrogen vacancy. In addition, the Au/KCNx photocatalyst had a large surface area, which was beneficial for photogenerated carrier separation and transfer. The novel strategy proposed here is a potential new method for the development of graphitic carbon nitride photocatalysts with obviously enhanced activities.

Automated summary

In this study, we prepared plasmon Au-modified K-doped defective graphitic carbon nitride and found that it significantly improved the photocatalytic activities. The hydrogen-production rate of the Au/KCNx photocatalyst was 104 times higher than that of Au/g-C3N4, with an apparent quantum efficiency of 12.8% at 420 nm. The synergistic effects of the plasmon effect, potassium doping, and nitrogen vacancy, along with the large surface area of Au/KCNx, contributed to its enhanced activities.