Fabrication of magnetically separable plasmonic composite photocatalyst of Ag/AgBr/ZnFe2O4 for visible light photocatalytic oxidation of carbamazepine

Abstract

Magnetically separable visible-light response Ag/AgBr/ZnFe2O4 plasmonic composite photocatalyst was synthesized and characterized by XRD, XPS, SEM, EDS, N2 Adsorption-Desorption (BET), VSM and, UV–Vis Diffuse Reflectance Spectra (DRS). Inductively Coupled Plasma (ICP) analysis was performed for measurement of leaching amount of Ag from catalyst to solution. The visible-light photocatalytic activity of the as-prepared Ag/AgBr/ZnFe2O4 was evaluated by the degradation of pharmaceutical drug, Carbamazepine (CBZ), and the Z-scheme mechanism of Ag/AgBr/ZnFe2O4 heterostructure photocatalyst was explained by the conduction and valance bands levels of semiconductors. The photocatalytic activity was also performed with the addition of oxidants of H2O2 and persulfate (PS). Addition of PS increased the photocatalytic activity of catalyst, however, H2O2 addition caused a decrease in photocatalytic activity. According to results of radical scavengers runs, the O2− and SO4− were confirmed to be the main active species in photocatalytic process both in the absence and in the presence of oxidants. Besides, Ag/AgBr/ZnFe2O4 is superparamagnetic and can be recycled by external magnet after photocatalytic reaction. Toxicity tests were also performed and the results showed that the intermediates formed in the photocatalytic oxidation of CBZ were less toxic compared to the parent CBZ molecule under the experimental conditions used.