Electrocatalytic oxidation of tetracycline by Bi-Sn-Sb/Γ-Al₂O₃ three-dimensional particle electrode

In this work, highly efficient Bi-Sn-Sb/γ-Al₂O₃ particle electrodes were prepared for effectively degrading tetracycline. The effects of a mass ratio (Sn: Sb), the mass ration of Bi:(Sn + Sb), impregnation times, calcination temperature, and calcination time on the electrocatalytic oxidation capacity of Bi-Sn-Sb/γ-Al₂O₃ particle electrode was investigated. Conditions in which mass ratio of (Sn: Sb) = 10:1, the mass ratio of Bi:(Sn/Sb) = 1:1, impregnation times 2 h, calcination temperature 500 °C., and calcination time 3 h were considered as optimal preparation conditions for Bi-Sn-Sb/γ-Al₂O₃ particle electrode. It was cherecterized by infrared spectroscopy (IR), scanning electron microscope (SEM), energy dispersive X-ray detector (EDX), X-Ray Diffraction (XRD), and X-ray fluorescence (XRF) techniques to conforming that the triclinic Bi₂O₃ formed in the preparation conditions has superior electrocatalytic activity. The electrocatalytic oxidation mechanism of tetracycline by Bi-Sn-Sb/γ-Al₂O₃ particle electrode is proposed by determining degradation intermediates through LC–MS detection. Electrocatalytic oxidation experiments by adding tert-butyl alcohol indicate that the formation of ^[rad]OH is the primary responsibility for degradating tetracycline. Electrocatalytic degradation of tetracycline at different initial concentration shows that the degradation of tetracycline meets the pseudo first-order kinetics. Results suggest that the three-dimensional electrochemical reactor with Bi-Sn-Sb/γ-Al₂O₃ particle electrodes could be an alternative for the pretreatment of antibiotic wastewater before biological treatment.