C‐Doped g‐C3N4 for Enhanced Photocatalytic Degradation of Azo Dyes under Visible Light

Abstract A type of photocatalytic agent graphitic carbon nitride (g‐C 3 N 4 ) has been formed by the thermal polymerization of urea with citric acid, with various contents of C in its material (CN‐x). Through the characterization of its morphology, structure, chemical composition, and photoelectric properties, it is found that the introduction of C dopant enhances sunlight absorption and facilitates electron‐hole separation and charge transfer within the g‐C 3 N 4 structure. By further optimizing the doping amount of C, the photocatalytic degradation rates of CN‐10 on Rh B, methylene blue and amaranth reached 97.2 %, 94.2 %, and 91.2 % within 40 min, which were 1.1 times, 1.3 times, and 2 times of the unmodified g‐C 3 N 4 , respectively. Sacrifice experiments showed that ⋅O 2 − and ⋅OH were the main active substances in the photocatalytic degradation of Rh B and amaranth. In the degradation of methylene blue, ⋅O 2 − and h + were then the main active substances.