Recent advances in the design and preparation of graphitic carbon nitride for photocatalysis

Graphitic carbon nitride (g-C₃N₄) has recently gained tremendous attention as a promising photocatalyst for environmental and energy-related applications owing to its high thermal and physicochemical stability as well as its suitable band structure. However, bulk g-C₃N₄, typically synthesized by directly heating N-rich small molecules, often suffers from severe aggregation, a low specific surface area for light harvesting and rapid recombination of photogenerated electron-hole pairs. These factors significantly hinder its photocatalytic efficiency. Consequently, considerable efforts have been devoted to the rational design and synthesis of g-C₃N₄ with tailored morphologies and controllable electronic and band structures, utilizing both top-down and bottom-up approaches. Thus far, in addition to the conventional and commonly used methods for carbon nitride preparation, new techniques and precursor families are continuously being developed. This review discusses the latest advancements in synthetic approaches for g-C₃N₄-based materials and provides valuable insights into utilizing these methods to enhance their photocatalytic performance. Finally, the review concludes by presenting an outlook on the future directions and challenges in the development of CN materials for photocatalysis.