g-C3N4-based photocatalysts for organic pollutant removal: a critical review

With rapid global industrialization, environmental pollution has become one of the major problems of human society. Photocatalysis can be applied to solve environmental problem by using inexhaustible solar energy. As a novel two-dimensional material, graphite carbon nitride (g-C3N4) has been widely applied in many photocatalytic reactions. However, in terms of its practical applications, g-C3N4 still has limitations, including poor photoexcited charge separation, limited range of visible light absorption, and low surface areas. Hence, current research on g-C3N4 mainly focuses on improving its photocatalytic performance. In this review, we summarize various methods to improve g-C3N4’s light absorption and photo-induced charge transfer, including vacancy engineering, morphology control, heteroatom doping, and forming heterostructure. The applications of g-C3N4 and its derivatives in photodegradation of organic pollutants are also discussed in detail. Finally, the challenges and future research directions of g-C3N4 photocatalysts are summarized to promote their environmental applications. • Structural and optical properties of g-C3N4 are summarized in detail. • Methods for improving the photocatalytic activity of g-C3N4 are reviewed. • Applications of g-C3N4 in organic pollutant removal are discussed in detail. • Challenges and future direction of g-C3N4 for degrading organic pollutants are summarized.