Heterogeneous photocatalytic activation of persulfate ions with novel ZnO/AgFeO2 nanocomposite for contaminants degradation under visible light

Abstract

Novel ZnO/AgFeO2 nanocomposites are reported and utilized to activate persulfate (PS) ions to increase contaminant degradation under visible light. For this purpose, the ZnO/AgFeO2 photocatalysts were obtained by a facile hydrothermal procedure. The resultant materials were studied by various techniques and the ZnO/AgFeO2 (20%) photocatalyst showed premier degradation performance for methylene blue (MB), Congo red (CR), methyl orange (MO), and rhodamine B (RhB) in the presence of PS. Nearly 100% of RhB was degraded in 150 min using the ZnO/AgFeO2 (20%) nanocomposite in the presence of PS, while only 15.9%, 70.0%, and 46.9% of RhB were removed on the pure ZnO, ZnO/PS, and ZnO/AgFeO2 (20%) nanocomposite, respectively, which represents that there is synergistic effect of visible-light photocatalysis and PS activation within the ZnO/AgFeO2 (20%) nanocomposite. The improved photoactivity of the resultant photocatalyst was ascribed to the activation of PS ions by photoinduced electrons to generate sulfate radicals (·SO4−), more harvesting of visible light by AgFeO2, the improved separation of charges, and larger surface area. The results of this work accent that the novel ZnO/AgFeO2 nanocomposite can be utilized as an efficacious visible-light-induced photocatalyst for water treatment.