Engineered graphitic carbon nitride-based photocatalysts for visible-light-driven water splitting: a review

Graphitic carbon nitride (g-C₃N₄), a polymeric semiconductor, has become a rising star for photocatalytic energy conversion because of its facile accessibility, metal-free nature, low cost, and environmentally benign properties. This work reviews the latest progress of g-C₃N₄-based materials in visible-light-driven water splitting to hydrogen. It begins with a brief history of g-C₃N₄, followed by various engineering strategies of g-C₃N₄, such as elemental doping, copolymerization, crystalline tailoring, surface engineering, and single-atom modification, for elevated photocatalytic water decomposition. In addition, the synthesis of g-C₃N₄ in different dimensions (0D, 1D, 2D, and 3D) and configurations of a series of g-C₃N₄-based heterojunctions (type II, Z-scheme, S-scheme, g-C₃N₄/metal, and g-C₃N₄/carbon heterojunctions) were also discussed for their improvement in photocatalytic hydrogen production. Lastly, the challenges and opportunities of g-C₃N₄-based nanomaterials are provided. It is anticipated that this review will promote the further development of the emerging g-C₃N₄-based materials for more efficiency in photocatalytic water splitting to hydrogen.Shuaijun Wang, Jinqiang Zhang, Bin Li, Hongqi Sun, and Shaobin Wan