Recent Advances of g-C3N4/LDHs Composite Photocatalysts in Water Pollution Treatment

Water pollution poses a pressing global environmental threat, driving an urgent need for efficient, stable, and eco-friendly water treatment techniques. Semiconductor photocatalysis has emerged as a highly promising solution, utilizing solar energy to thoroughly degrade pollutants under mild conditions without secondary pollution. Among numerous photocatalysts, the graphitic carbon nitride (g-C3N4)/layered double hydroxides (LDHs) heterostructures represent a kind of high-performance photocatalysts that combine the integrated advantages of both components. These composites exhibit enhanced visible-light absorption, a highly efficient charge separation and transfer, and a significantly increased specific surface area that promotes the enrichment and degradation of pollutants. The synergistic interaction between g-C3N4 and LDHs not only mitigates their individual limitations but also creates a superior photocatalytic system with improved adsorption capacity and reaction kinetics. This review systematically summarizes recent advances in g-C3N4/LDHs composite photocatalysts for aquatic pollutant removal. It elaborates on the structural synergies, synthesis routes, and optimization strategies, with a particular focus on applications and mechanistic insights into the degradation of various pollutants-including organic dyes, drugs, and phenolics. Finally, the review outlines current challenges and future research directions, such as deepening mechanistic understanding, designing multifunctional systems, and advancing toward scalable implementation, providing a valuable reference for developing next-generation photocatalytic water treatment technologies.