P-g-C3N4/FeVO4 heterostructures with robust light responsiveness demonstrated remarkable efficiency in the removal of tetracycline

An eco-friendly, economical, and stable heterojunction composite phosphorus-doped graphite carbon nitride (P-g-C3N4)/FeVO4-X was synthesized by one-pot impregnation precipitation, and its physical and photoelectric properties were characterized, P-g-C3N4/FeVO4-400 demonstrated the best performance. The synergistic effect of P-g-C3N4 and FeVO4 promotes the prolongation of the photogenerated carrier lifetime while improving the electron-hole separation efficiency. The optimal reaction conditions were obtained by varying initial pH, hydrogen peroxide concentration, catalyst dosage, and tetracycline concentration. Meanwhile, tetracycline degradation was also investigated in complex systems with different anions and cations. The generation of hydrogen peroxide in the reaction process was determined by investigating the changes in hydrogen peroxide content, and its generation mechanism was explored. The results of 5 cycles show that the catalyst has good stability. The results of free radical trapping experiments and electron paramagnetic resonance spectroscopy indicate that the main reactive species in the reaction process are superoxide radicals. Therefore, the possible mechanism of tetracycline degradation by P-g-C3N4/FeVO4-400 was proposed alongside an analysis of the degradation pathway. The study provides a promising and effective way to develop high-performance type-II photocatalysts and paves the way for their practical application in wastewater treatment processes.