Graphdiyne-Based Co-Induced Schottky Heterojunction Boosting Photocatalytic Hydrogen Evolution

The effective strategy for enhancing the separation of photogenerated carriers is the construction of heterojunctions between photocatalysts. The metallic characteristics of CoCeOx, coupled with its extensive specific surface area, render it an ideal material for the photocatalytic production of hydrogen. Graphdiyne (GDY) has gained significant attention in the area of photocatalytic hydrogen production owing to its appropriate band gap and exceptional electrical conductivity. In this work, the Co element was introduced into CeO2 and a photocatalytic hydrogen evolution experiment was carried out with graphdiyne. It is found that the heterojunction between photocatalytic materials changes from type-I to a Schottky type after the introduction of the Co element by in situ X-ray photoelectron spectroscopy (XPS) and density functional theory. Simultaneously, the hydrogen evolution capacity of CoCeOx/graphdiyne has shown a significant enhancement while maintaining excellent stability. The Schottky junction formed at the interface of CoCeOx and graphdiyne further separates the photogenerated electrons from the holes and effectively reduces the photogenerated carrier recombination. This investigation establishes a theoretical foundation for the potential application of graphdiyne and cobalt–cerium-based catalysts in photocatalytic hydrogen generation.