High Photocatalytic Activity of g-C3N4/La-N-TiO2 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-C3N4/La-N-TiO2 (CN/La-N-TiO2) 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-TiO2 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 center dot L-1), Ca2+ (10 mg center dot L-1), Mg2+ (10 mg center dot L-1), and urea (5 mg center dot L-1), but decreased in the presence of NO3- (10 mg center dot L-1). The findings indicate that CN/La-N-TiO2 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.