Synthesis, performance, mechanism, challenges and prospects of g-C3N4/perovskite composite photocatalysts for organic pollutant degradation: A review

Improper treatment and discharge of organic pollutants from industrial and agricultural sources are key factors in the worsening global water pollution. Photocatalytic degradation technology provides faster reaction rates and higher efficiency than traditional physical and biological methods. Under light irradiation, it decomposes organic pollutants into harmless inorganic molecules, such as water and carbon dioxide. Graphitic carbon nitride (g-C3N4) and perovskite-type oxides (ABO3) are emerging photocatalytic materials that have garnered significant attention. However, g-C3N4 suffers from high charge carrier recombination, while perovskite materials often exhibit poor stability, limiting their photocatalytic performance when used alone. Combining g-C3N4 with ABO3 effectively overcomes these limitations and enhances photocatalytic efficiency. In multiphase photocatalysis, selecting efficient and stable nanocatalysts is paramount. g-C3N4/ABO3 composites exhibit enhanced photocatalytic performance compared to single components, extending the light absorption range, promoting charge separation, and improving the degradation efficiency of organic pollutants. These composites also demonstrate superior structural stability and cycling performance. These benefits have sparked considerable research interest in g-C3N4/ABO3 composites in recent years. To understand the reasons behind this enhanced performance and to guide future development, a systematic review of recent progress is essential. This review summarizes recent advances in the synthesis methods, degradation performance of organic pollutants, and photocatalytic mechanisms of g-C3N4/ABO3 composites. It is also clarified that the synergistic effect of the composite material significantly enhances its photocatalytic performance. Finally, current challenges faced by g-C3N4/ABO3 composites are discussed, along with future research directions and critical issues for further investigation. This review aims to serve as a reference for innovative research and further development of g-C3N4/ABO3 composite materials.