Highly efficient activation of sulfite by oxygen vacancies-enriched ZnCe0.4Fe1.6O4 for methylparaben degradation

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 494; p. 152901
• Main Authors: Qin, Hangdao, Hao, Junnan, Cheng, Hao, Huang, Jiming, Wu, Sizhan, Chen, Jing, Shi, Wei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.08.2024
• Subjects: Degradation; Methylparaben; Oxygen vacancy; Sulfite; ZnCe0.4Fe1.6O4; Sulfite; Degradation; ZnCe0.4Fe1.6O4; Methylparaben; Oxygen vacancy
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2024.152901

•ZnCe0.4Fe1.6O4 exhibited a higher catalytic activity than that of ZnFe2O4.•About 85.2 % of MeP was removed in ZnCe0.4Fe1.6O4/PMS system within 60 min.•SO4− and OH was the main reactive oxygen species for MeP degradation.•Oxygen vacancies on ZnCe0.4Fe1.6O4 surface were crucial for sulfite activation.•The practical application prospect of ZnCe0.4Fe1.6O4/sulfite system was investigated. The exploitation of a novel catalyst was of great significance for sulfate radical-based advanced oxidation processes (AOPs) using sulfite as the precursor of sulfate radical. Herein, oxygen vacancies-enriched ZnCe0.4Fe1.6O4 was prepared and applied to activate sulfite for the degradation of methylparaben (MeP). ZnCe0.4Fe1.6O4 showed superior catalytic activity than that of ZnFe2O4, allowing an 85.2 % removal efficiency of MeP within 60 min. The initial pH showed a significant effect on the catalytic performance, and about 92.1 % of MeP could be removed at pH of 9.56 in ZnCe0.4Fe1.6O4/sulfite system. The quenching experiments and EPR tests verified SO4− and OH were the main reactive oxygen species (ROS) in ZnCe0.4Fe1.6O4/sulfite system. The catalytic mechanism was elucidated further by X-ray photoelectron spectroscopy (XPS) analysis of ZnCe0.4Fe1.6O4 before and after the reaction. The recycles of Zn2+/Zn3+, Fe2+/Fe3+ and Ce3+/Ce4+ were the key factor for the activation of sulfite, and oxygen vacancies on catalyst surface promoted the activation of sulfite. The degradation intermediates of MeP were determined by a liquid chromatography-mass spectrometer (LC-MS) and the degradation pathway was proposed. The reusability of ZnCe0.4Fe1.6O4 was evidenced by the recycling experiments. In addition, ZnCe0.4Fe1.6O4/sulfite system exhibited excellent applicability in treating other organic contaminants.