High Photocatalytic Activity of g-C 3 N 4 /La-N-TiO 2 Composite with Nanoscale Heterojunctions for Degradation of Ciprofloxacin

Ciprofloxacin (CIP) in natural waters has been taken as a serious pollutant because of its hazardous biological and ecotoxicological effects. Here, a 3D nanocomposite photocatalyst g-C 3 N 4 /La-N-TiO 2 (CN/La-N-TiO 2 ) was successfully synthesized by a simple and reproducible in-situ synthetic method. The obtained composite was characterized by XRD, SEM, BET, TEM, mapping, IR, and UV-vis spectra. The photocatalytic degradation of ciprofloxacin was investigated by using CN/La-N-TiO 2 nanocomposite. The main influential factors such as pH of the solution, initial CIP concentration, catalyst dosage, and coexisting ions were investigated in detail. The fastest degradation of CIP occurred at a pH of about 6.5, and CIP (5 mg/L starting concentration) was completely degraded in about 60 min after exposure to the simulated solar light. The removal rates were rarely affected by Na + (10 mg·L −1 ), Ca 2+ (10 mg·L −1 ), Mg 2+ (10 mg·L −1 ), and urea (5 mg·L −1 ), but decreased in the presence of NO 3 − (10 mg·L −1 ). The findings indicate that CN/La-N-TiO 2 nanocomposite is a green and promising photocatalyst for large-scale applications and would be a candidate for the removal of the emerging antibiotics present in the water environment.