Accelerated photodegradation of T-2 toxin over magnetic recyclable ZnO/CaFe2O4 nanocomposite with a p-n based Z-scheme heterojunction architecture

Abstract

T-2 toxin (T-2), one of the most toxic mycotoxins, has drawn extensive attention due to its universality and persistence in food and the environment. In this study, a novel magnetic ZnO/CaFe2O4 nanocomposite with a p-n based Z-scheme heterojunction was successfully constructed by a hydrothermal method for efficient photodegradation of T-2 toxin. The optimal cubic structure of ZnO/CaFe2O4 endows it with excellent photocatalytic efficiency in removing T-2 toxin, such that near-total degradation was achieved with an exceptionally high mineralization value (64 %) after 180 min of UV radiation. This efficacy was attributed not only to the abundant reaction sites on the binary composites, but also its Z-scheme heterojunction promoting the electron-hole (e−-h+) separation and hence favors redox processes. The OH played a major role in the photodegradation, and the decomposition pathway of T-2 was proposed based on the results of UHPLC-Q-TOF-MS/MS data and density functional theory (DFT) calculations. This work provided a green approach for removing the refractory natural pollutants.