Efficient photocatalytic removal of ciprofloxacin antibiotic by dual Z-scheme Ag3PO4/g-C3N4/Bi2WO6 under solar irradiation

Abstract

This study reports the development of a novel Ag₃PO₄/g-C₃N₄/Bi₂WO₆ photocatalyst featuring a ternary heterostructure and a dual Z-scheme pathway mechanism. SEM and TEM analyzes confirmed the intimate contact between Ag₃PO₄, Bi₂WO₆, and g-C₃N₄, and hence the successful formation of the ternary heterojunction. Further, under natural solar light irradiation, the Ag₃PO₄/g-C₃N₄/Bi₂WO₆ photocatalyst, in comparison to single Ag₃PO₄, g-C₃N₄ and Bi₂WO₆ component_, achieved an improved and remarkable CIP antibiotic photodegradation efficiency of 94 % within 90 min. Reactive Oxygen Species (ROS) ^•OH and ^•O₂⁻ played the dominant roles in the photocatalytic reaction. The overall data suggest that the dual Z-scheme carrier transfer pathways are responsible for the superior photocatalytic activity as resulting from the efficient separation of photogenerated charge carriers while maintaining their strong redox capabilities. The Ag₃PO₄/g-C₃N₄/Bi₂WO₆ photocatalyst demonstrates promising potential for wastewater treatment applications due to its high efficiency, efficient charge separation, and generation of potent oxidizing species. Additionally, Monte Carlo simulation was used to calculate the interactions of Ag₃PO₄, Bi₂WO₆, and CIP, occurring on, respectively, g-C₃N₄, Ag₃PO₄/g-C₃N₄, and Ag₃PO₄/g-C₃N₄/Bi₂WO₆, in order to investigate their configurations and adsorption energies. The most stable geometries and pollutant remove were assessed from the negative adsorption energies (E_ad) values.