g‐C3N4 Based Composite Materials for Photo‐Fenton Reaction in Water Remediation: A Review of Synthesis Methods, Mechanism and Applications

Abstract Organic pollutants in water pose significant challenges for water treatment due to their harmful effects and resistance to conventional methods. The rapid increase in industrial wastewater discharge has heightened the need for effective pollutant degradation techniques. Photo‐Fenton technology, an advanced oxidation process, has gained attention for its ability to degrade a wide range of organic contaminants in water. Developing high‐performance photo‐Fenton catalysts is therefore crucial. Graphitic carbon nitride (g‐C 3 N 4 ) stands out in this field due to its suitable energy band structure, stable properties, and simple synthesis process. However, its application is limited by a low specific surface area, narrow light absorption, and high recombination rate of photogenerated carriers. This review provides a concise overview of current research on g‐C 3 N 4 in photo‐Fenton technology, covering synthesis methods, modifications, and the mechanisms enhancing its photo‐Fenton activity. It also highlights key factors affecting g‐C 3 N 4 ’s effectiveness in photo‐Fenton reactions and discusses recent advancements in its applications. The review concludes with an analysis of existing challenges and potential future directions for g‐C 3 N 4 ‐based photo‐Fenton catalysts, offering theoretical insights to advance their industrial use in wastewater treatment.