Crystallinity-defect matching relationship of g-C3N4: Experimental and theoretical perspectives

Good crystallinity can reduce the charge recombination centers caused by defects, whilst structures with strong polycondensation have high charge mobility, leading to more charge transfer to the material surface for reaction. Much effort has been put into the preparation of a highly efficient g-C3N4 with defects to improve its application potential under the premise in high crystallinity. Hence, this review paper emphasizes the importance to balance the defect and crystallinity of g-C3N4. In addition, detailed discussion on the relationship between defects and activity of g-C3N4 was carried out based on its applications in environmental purification (e.g., VOCs oxidation, NOx oxidation, H2O2 evolution, sterilization, pesticide oxidation) and energy conversion (H2 evolution, N2 fixation and CO2 reduction). Lastly, the challenge in developing more efficient defective g-C3N4 photocatalytic materials is summarized.