“…As a type of organic semiconductor with an appropriate band gap, g-C 3 N 4 exhibits excellent photocatalytic performances. Simultaneously, as a typical polymer material, g-C 3 N 4 has a unique crystal structure and diffraction properties, and thus it has various photocatalytic applications, such as photocatalytic H 2 generation, 3,4 water splitting, 5,6 degradation of organic pollutants, 7,8 oxygen evolution reaction (OER), [9][10][11] CO 2 photoreduction 12,13 and NO oxidation. 14,15 Although g-C 3 N 4 possesses the potential advantages of a band gap, excellent crystal structure and outstanding light absorption, it still has many problems to be solved, such as its serious electron-hole recombination, narrow light absorption range, and low specific surface area utilization, which prevent the enhancement of the photocatalytic activity of g-C 3 N 4 .…”