Preparation of Fe2O3/g-C3N4 Photocatalysts and the Degradation Mechanism of NOR in Water under Visible Light Irradiation

Fe2O3/g-C3N4 nano-heterostructures for photocatalytic degradation of NOR (norfloxacin) were successfully prepared by combining co-precipitation and calcination methods. The g-C3N4, Fe2O3, and different composite ratios of Fe2O3/g-C3N4 (FeCNs) were characterized by XRD, SEM, XPS, UV-vis DRS, PL, and electrochemical tests, and the mechanism of photocatalytic degradation of NOR was analyzed. The results indicated that the semiconductor was attached to the surface of g-C3N4 in the form of α-Fe2O3 crystal with good crystalline structure. The composite of Fe2O3 with g-C3N4 increased the specific surface area of the material, effectively reduced the band gap, strengthened the photogenerated e−/h+ pair separation, and improved the photocatalytic performance of the composite. The photocatalytic degradation of NOR was consistent with the quasi-primary reaction kinetic model. Among them, FeCN-25wt% showed the optimal photocatalytic degradation of NOR (72.3%) with the largest degradation rate (k = 0.00900 min−1). The Fe2O3/g-C3N4 composite structure is inferred to be a Z-type heterojunction.