Assembling ZnMnFe2O4@Ag-AgVO3 nanostructure heterojunctions for photocatalytically degrading RhB and Pseudomonas aeruginosa bacteria under visible irradiation

Abstract

Improving the separation of photocarriers is a vital approach to create highly effective heterojunction photocatalysts for the photodegradation of environmental pollutants. In this work, coprecipitation and hydrothermal methods were employed to develop a new heterojunction of Zn0.5Mn0.5Fe2O4@Ag-AgVO3 magnetic nanocomposite as photocatalysts for the photodegradation of Rhodamine B (RhB) and bacterial inactivation of Pseudomonas aeruginosa (P. aeruginosa) when exposed to illumination of visible light. FESEM, EDX, UV–vis reflectance spectroscopy (DRS), N2 adsorption/desorption, TEM, PL, Brunauer-Emmett-Teller (BET) surface area, Vibrating Sample Magnetometer (VSM), and XRD techniques were used to investigate the structural and optical properties of synthesized materials. The Zn0.5Mn0.5Fe2O4@Ag-AgVO3 photocatalyst demonstrated noticeably higher photocatalytic activity for RhB degradation when compared to the pure constituents AgVO3, Ag-AgVO3, and Zn0.5Mn0.5Fe2O4 samples. The results revealed that when RhB was used at a concentration of 20 ppm, the Zn0.5Mn0.5Fe2O4@Ag-AgVO3 possessed a high degradation rate (93.43 % within 180 min), and this was sufficient to get the highest total organic carbons (TOC) removal (90 %). Besides, Zn0.5Mn0.5Fe2O4@Ag-AgVO3 possesses complete inactivation efficiency (log(CFU) decreased from 6.5 to 0.00001) toward P. aeruginosa in 120 min of visible illumination. The photodegradation mechanism was explained by the surface plasmonic resonance Z-type heterostructure, and tested by trapping experiments. It can beinferredthat the Zn0.5Mn0.5Fe2O4@Ag-AgVO3 photocatalyst was very stable and efficient in removing different organic pollutants and pathogenic bacteria from wastewater.