Degradation of bisphenol A by persulfate activation via oxygen vacancy-rich CoFe2O4–x

This research describes the function of oxygen vacancy on CoFe 2 O 4-x for persulfate (PS) activation. Novel CoFe 2 O 4-x with different vacancy degrees that were successfully developed via hydrogen calcination were characterized using X-ray diffraction analyzer (XRD), Fourier transform infrared (FTIR) spectra, Raman spectroscopy , scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), H 2 temperature-programmed reduction (H 2 -TPR), cyclic voltammetry (CV), electrochemical impedance spectra (EIS), nitrogen adsorption-desorption isotherms and dynamic light scattering. The activation of catalysts was analyzed using Bisphenol A (BPA) as pollutant, and the main active species generated during the reaction were identified by using N 2 bubbling and scavenger experiments. Possible oxidation degradation pathways of BPA were speculated using gas chromatography–mass spectrophotometry (GC-MS) and total organic carbon (TOC) analysis. Findings indicated that the oxygen vacancies promoted electronic transfer and participated in the redox cycle from Co 3+ /Fe 3+ to Co 2+ /Fe 2+ to generate 1 O 2 and O 2 - . O 2 - , OH and SO 4 - generated from oxygen vacancy; moreover, PS activation could further degrade BPA to small molecules, such as benzenes and quinones . Finally, the toxicity of the reaction mixtures was evaluated and found that the acute toxicity to Daphnia magna decreased after 120 min treatment.