Ultrasound-assisted synthesized BiFeO3 as FeOH+ promoted peroxymonosulfate activator for highly efficient degradation of tetracycline

A multiferroic BiFeO 3 (BFO) catalyst was fabricated through a mild one-pot hydrothermal process with a bath-ultrasound assisted dissolution of Fe(NO 3 ) 3 ·9H 2 O for 30 min. X-ray photoemission spectroscopy revealed that the BFO (BFO-u) catalyst with US assisted dissolution of Fe(NO 3 ) 3 ·9H 2 O in the synthetic process exhibited high Fe 2+ and OH − levels, which could be explained to be Fe 3+ + H 2 O → ) ) ) Fe 2+ + H + + • OH. As a result, BFO-u catalyst activated potassium peroxymonosulfate (PMS) efficiently for degrading tetracycline hydrochloride. In particular, visible-light assisted activation of PMS over BFO-u catalyst exhibited the highest degradation rate constant, at 0.352 min −1 . Species-trapping experiments revealed that the presence of PMS promoted the generation of • OH, • O 2 − and 1 O 2 that all participated in degrading TCH, in which 1 O 2 was primarily contributed to the degradation. Also, BFO-u catalyst was stable and recyclable and thus suitable for practical applications. • BFO was synthesized via a facile one-pot ultrasound-assisted hydrothermal process. • Higher FeOH + level in BFO-u catalyst promoted peroxymonosulfate activation. • BFO-u/PMS/VL system exhibited a highest degradation rate constant of 0.352 min −1 . • 1 O 2 was primarily contributed to the TCH degradation process. • BFO-u catalyst was efficient, stable and recyclable for degrading refractory TCH.