Fabrication of intimately coupled CeO2/ZnFe2O4 nano-heterojunction for visible-light photocatalysis and bactericidal application

The present study highlighted the evaluation of visible-light-driven catalytic efficiency of ZnFe2O4 decorated CeO2 nanocomposite (CeO2/ZnFe2O4 NCs) fabricated by chemical co-precipitation method for degradation of methylene blue (MB) dye. HRTEM, SEM, and SAED confirmed it to be spherically shaped with polycrystalline nature and chemical states being analyzed using X-ray photoelectron spectroscopy. Kubelka-Munk plot showed the deviation in band gap energy of ZnFe2O4 (2.11 eV) and CeO2 (3.18 eV) to be 2.18, 2.38, and 2.49 eV for NCs-1:2, 2:1, and 1:1, respectively. The visible-light-driven catalytic activity of NCs-2:1 was determined to be 90.48% in comparison with NCs-1:2 (77.19%) and NCs-1:1 (76.84%). The apparent degradation constant of MB by NCs-2:1 was determined to be 0.011 min−1 that is 1.57 and 2.75 folds greater than their individual counterparts, ZnFe2O4 (0.007 min−1) and CeO2 (0.004 min−1) respectively. The degradation process professes the pseudo-first order kinetics wherein the generation of .OH prompted by NCs enhanced the degradation of MB under visible light irradiation with a reusable efficiency of 92.48%. The vital role of CeO2/ZnFe2O4 NCs-2:1 is affirmed with outcomes from this study and it elicited an effective potential to be a photocatalyst to eliminate water contaminants.