Ruthenium metal and crystalline carbon nitride exhibiting strong metal-carrier interactions for efficient photocatalytic hydrogen production

Graphitic carbon nitride (g-C 3 N 4 ) is widely recognized as the most promising photocatalysts for photocatalytic hydrogen evolution. However, the high charge recombination, low crystallinity, and low number of reactive sites limit its photocatalytic H 2 performance. To address above issues, we report that the modification of g-C 3 N 4 was realized through crystallinity-improving and element-doping, enhancing the photocatalytic performance of g-C 3 N 4 . Specifically, the ordered/disordered polymer crystalline carbon nitride was prepared by the molten salt method, which fragmentizes g-C 3 N 4 into order/disorder crystalline carbon nitride(CN-NH 4 -NaK). Then, crystalline carbon nitride was modified with Ru nanoclusters (Ru/CN-NH 4 -NaK). As a result, 0.38 %Ru/CN-NH 4 -NaK features extending visible light absorption and suppressing charge recombination, showing an excellent photocatalytic turnover frequency (14962.240 μmol . g −1 . h −1 ). This TOF value is approximately 7 times compared to the g-C 3 N 4 loaded with Ru (2147.075 μmol . g −1 . h −1 ). The phenomenon could be attributed to the metal-supported interaction between Ru nanoclusters and modified g-C 3 N 4 , which can control the local charge distribution, facilitating the effective charge transfer and enhancing the catalytic activity. This strategy provides a green and clean method to the preparation of ordered/disordered polymer crystalline carbon nitride with metal doping, aiming to improve charge separation efficiency and enhance photocatalytic performance.