Dual reaction centers promote adsorption-photo Fenton synergistic efficient removal of tetracycline by reduced graphene oxide/CuFe2O4-oxygen vacancies

Abstract

To achieve absorption and advanced oxidation synergy for efficient removal of tetracycline (TC), a reduced graphene oxide modified oxygen vacancies-rich CuFe2O4 (rGO/CuFe2O4-OVs) with dual reactive centers was synthesized by a two-step method. H2O2 was added under visible light irradiation to construct an adsorption-photo Fenton synergistic degradation system. The synergistic degradation rate constants were 2.48 and 1.42 times higher than those of photocatalysis and Fenton reaction, respectively. Such efficient removal capacity ascribes the adsorption-photo Fenton synergy. On the one hand, the introduction of rGO not only increases the specific surface area of rGO/CuFe2O4-OVs, exposing more adsorption sites, but also accelerates the transfer of photogenerated electrons and promotes the generation of reactive species. On the other hand, the existence of dual reaction centers effectively improves the degradation efficiency of TC: (1) Fe and Cu in the reaction center (I) capture photogenerated electrons, promote the separation of photogenerated carriers, drive the valence cycle of Fe and Cu, and accelerate the Fenton reaction. (2) OVs in the reaction center (II) provide adsorption active sites for the activation of H2O2, promote the efficient decomposition of H2O2, and synergistically accelerate the degradation of TC.