Recent developments of doped g-C₃N₄ photocatalysts for the degradation of organic pollutants

Graphitic carbon nitride (g-C3N4), with a moderate band gap (∼2.7 eV), high chemical and thermal stability, has been the hotspot in environmental photocatalysis. However, its performance is still unsatisfactory because of insufficient absorption of visible light, poor surface area, low electronic conductivity and high recombination rate of photogenerated electron-hole pairs. The modification of g-C3N4 could overcome these problems to improve photocatalytic properties. Among various modification strategies, element doping is an efficient and simple strategy for adjusting electronic structure and accelerating photocatalytic performance. This review focused on the progress and trends of designing typical, cost-effective element-doped carbonized nitrogen and its degradation of environmental organic pollutants. The heterogeneous catalytic mechanisms of g-C3N4-based photocatalysts for organic pollutants degradation have been explicated in detail. The increased photocatalytic performance of g-C3N4 by doping various elements was discussed clearly. The surface properties, catalyst performance and pollution management of various elements-doped g-C3N4 were compared and subsequently analyzed some dilemmas and application strategies for g-C3N4 development in depth. This review can light up a new way and afforded valuable clues to design g-C3N4 doping elements to exploit more effective photocatalyts for real applications in environmental pollution management.