Visible light driven photocatalytic activity and efficient antibacterial activity of ZnFe2O4 decorated CdO nanohybrid heterostructures synthesized by ultrasonic-assisted method

Abstract CdO/ZnFe2O4 nanohybrid heterostructure was prepared by ultra-sonication assisted chemical precipitation technique in order to impose better separation of charge carriers, high photocatalytic and bactericidal activity. The formed CdO/ZnFe2O4 nanocomposites (NCs) was characterized by UV-Vis-DRS, XPS, SEM, EIS, EDAX, VSM, SAED, HRTEM, FTIR, XRD, photoluminescence (PL) and BET surface area analyzer. CdO/ZnFe2O4 poses narrow bandgap (2.04 eV) that enhanced the light harvesting in visible region. The high surface area of CdO/ZnFe2O4 (53.6 m2/g) relative to CdO (44.9 m2/g) and ZnFe2O4 (20.1 m2/g) provides more active sites that enhances the photocatalysis. The coupling of CdO and ZnFe2O4 improved the life time of charge carriers as confirmed by PL analysis. The photocatalytic performance of NCs was evaluated based on methylene blue dye degradation. The photocatalytic degradation rate by NCs was enhanced 1.2 and 1.4 folds than CdO and ZnFe2O4. VSM results showed super-paramagnetic nature of NCs with saturation of 42.4 emu/g which aids magnetic separation for its reusability. The reusability test of NCs showed almost same efficiency in all the 6 cycles. TOC analysis of degraded product supported high mineralization (71%) of MB. Scavengers’ studies indicated the major role of h+ and OH· radical in dye degradation. In addition, CdO/ZnFe2O4 NCs exhibited high antibacterial effect against S. aureus, B. subtils and E. coli. It is proposed that CdO/ZnFe2O4 NCs could be applied as a promising photocatalyst for environmental remediation and as an antimicrobial agent