Enhanced visible-light photocatalytic activity of g-C3N4/LaFeO3 heterojunctions for the removal of tetracycline hydrochloride

LaFeO3 nanoparticles were synthesized with hydrothermal method and g-C3N4 nanosheets were prepared from bulk g-C3N4 in alkaline solution, and then g-C3N4/LaFeO3 nanocomposites were successfully synthesized via electrostatic self-assembly method. All samples were characterized by XRD, TEM, TGA, BET and UV–vis, which indicates that LaFeO3 nanoparticles are well-dispersed on g-C3N4 nanosheets to form g-C3N4/LaFeO3 nanocomposites. The photocatalytic activity of g-C3N4/LaFeO3 nanocomposites to tetracycline hydrochloride (TC-HCl) antibiotics under visible light irradiation is investigated and optimized in detail, indicating the excellent photocatalytic activity and chemical stability. The degradation efficiency of TC-HCl with 35%CNS/LF is 13.6-fold and 2.6-fold higher than those of pristine LaFeO3 nanoparticles and g-C3N4 nanosheets. The interface of g-C3N4/LaFeO3 p-n heterojunctions effectively separates the photogenerated electrons and holes, leading to the higher photocatalytic activity. Moreover, active species trapping experiments reveal that O2− is the dominant radical during photodegradation process.