Rational Design and Construction of Graphdiyne (CnH2n-2) Based NiMoO4/GDY/CuO in Situ XPS Proved Double S-Scheme Heterojunctions for Photocatalytic Hydrogen Production.

As a new two-dimensional (2D) carbon hybrid material, graphdiyne has attracted much attention due to its good conductivity, adjustable electronic structure, and special electron transfer enhancement properties. In this work, graphdiyne/CuO and NiMoO4/GDY/CuO composite catalysts were prepared by cross coupling method and high temperature annealing method. The CuI introduced by clever design not only acts as a catalytic coupling but also as a precursor of CuO. The CuO produced by the postprocessing improves the inefficient charge separation of graphdiyne and provides a good acceptor for the consumption of unwanted holes. The good conductivity and strong reduction ability of graphdiyne play key roles in the performance improvement of the composite catalyst. Under the dual evidence of XPS and in situ XPS, the charge transfer mode of double S-scheme heterojunction with graphdiyne as the active site of hydrogen evolution is constructed reasonably, which not only gives full play to the performance advantages of graphdiyne but also effectively improves the separation efficiency of photogenerated carriers. In this study, a clean and efficient multicomponent system was constructed by graphdiyne, which opened up a broad application prospect in the field of photocatalytic hydrogen production.