Sulfidization of Platinum Nickel Bimetal-Decorated g-C₃N₄ for Photocatalytic Hydrogen Production: Photogenerated Charge Behavior Study

Abstract

Seeking a high-efficiency and low-cost cocatalyst above graphite-like carbon nitride (g-C3N4) photocatalytic hydrogen evolution has been regarded as one of the most effective tactics to alleviate energy crisis. Herein, a novel S-PtNix/g-C3N4 photocatalyst is obtained with sulfidization of PtNix/g-C3N4 through hydrothermal synthesis. Impressively, the optimal photocatalytic property of 0.5S-PtNix/g-C3N4 is far and away higher than g-C3N4 and also is almost twice as high as PtNix/g-C3N4, achieving 4966 μmol h–1 g–1. This outstanding activity could be attributed to two factors. On the one hand, the modification of PtNix on g-C3N4 not only improves the separation efficiency but also accelerates the transfer of photogenerated charges. On the other hand, NiSx could capture photogenerated electrons and work as a reactive site to participate in the photocatalytic reaction. In other words, the intensive activity of 0.5S-PtNix/g-C3N4 is ascribed to the synergistic effect of the charge transfer channel of PtNix and electron acceptor of NiSx. This work for the first time illuminates the photocatalytic mechanism through the systematic characterization of photogenerated charges, which provides a theoretical basis for designing the photocatalyst modified with the cocatalyst upon photocatalytic hydrogen production.