Enhanced charge transfer kinetics across the graphdiyne-metal sulfide ohmic interface for boosting photocatalytic hydrogen evolution

The design and construction of photocatalysts are the crucial step for solar-driven hydrogen evolution. Herein, a new type of graphdiyne (C n H 2n-2 )-based photocatalyst, which was prepared by one pot method, was used to promote hydrogen evolution reaction by constructing GDY/VS 2 ohmic junction with S sites anchoring on the surface. Actually, the unique two-dimensional conjugated carbon network of GDY can maintain the structural stability. The uneven surface facilitates the flow of electrons, which makes GDY a good electron donor. In addition, the expanded interlayer spacing of VS 2 exposes more hydrogen evolution active sites. The increase in surface electronegativity of composite catalysts enhances their redox ability and charge transfer kinetics. The band edge of the graphdiyne-metal sulfide Ohmic contact interface is bent, allowing electrons to flow into the co catalyst without resistance. These synergistic effects lead to the robust hydrogen production of GDY/VS 2 , which was increased by nearly 10.3 times compared with that of pure GDY. Finally, charge migration at the interface of graphdiyne-metal sulfide heterojunction was proposed and further verified combining in situ XPS and theory calculation. This research marks a significant stride for enhance the efficiency of photocatalytic hydrogen evolution by designing and constructing composite heterojunction materials.