Comparing dark- and photo-Fenton-like degradation of emerging pollutant over photo-switchable Bi2WO6/CuFe2O4: Investigation on dominant reactive oxidation species.

• Magnetic p-n Bi 2 WO 6 /CuFe 2 O 4 for efficient photo-Fenton-like was fabricated. • Different ROS-dominated dark-and photo-Fenton-like reactions were explored. • Possible degradation pathways of TCH and products toxicity were analyzed. The extensive use of tetracycline hydrochloride (TCH) poses a threat to human health and the aquatic environment. Here, magnetic p-n Bi 2 WO 6 /CuFe 2 O 4 catalyst was fabricated to efficiently remove TCH. The obtained Bi 2 WO 6 /CuFe 2 O 4 exhibited 92.1% TCH degradation efficiency and 50.7% and 35.1% mineralization performance for TCH and raw secondary effluent from a wastewater treatment plant in a photo-Fenton-like system, respectively. The remarkable performance was attributed to the fact that photogenerated electrons accelerated the Fe(III)/Fe(II) and Cu(II)/Cu(I) conversion for the Fenton-like reaction between Fe(II)/Cu(I) and H 2 O 2 , thereby generating abundant •OH for pollutant oxidation. Various environmental factors including H 2 O 2 concentration, initial pH, catalyst dosage, TCH concentration and inorganic ions were explored. The reactive oxidation species (ROS) quenching results and electron spin resonance (ESR) spectra confirmed that •O 2 − and •OH were responsible for the dark and photo-Fenton-like systems, respectively. The degradation mechanisms and pathways of TCH were proposed, and the toxicity of products was evaluated. This work contributes a highly efficient and environmentally friendly catalyst and provides a clear mechanistic explanation for the removal of antibiotic pollutants in environmental remediation. [Display omitted] [ABSTRACT FROM AUTHOR]