Oxygen vacancy induced peroxymonosulfate activation by Mg-doped Fe2O3 composites for advanced oxidation of organic pollutants. (September 2021)

• Record Type: Journal Article
• Authors: Guo, Sheng; Liu, Mengdie; You, Liming; Cheng, Gang; Li, Jun; Zhou, Kun
• Is Part Of: Chemosphere. Volume 279(2021)
• Publication Date: 2021-09
• Subjects: Mg doping -- Peroxymonosulfate -- Fe2O3 -- Oxygen vacancies -- Advanced oxidation process; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.130482
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Oxygen vacancy engineering has emerged as an effective approach to improve the performance of catalysts for peroxymonosulfate (PMS) activation. Herein, we report a facile precipitation method followed by calcination to synthesize cost-effective and environmentally friendly magnesium-doped hematite (Mg/Fe2 O3 ) composites. Multiple characterization results reveal that the incorporation of Mg can significantly increase the oxygen vacancies and specific surface area of 5%Mg/Fe2 O3, leading to a significantly enhanced performance in degrading Rhodamine B (RhB) through PMS activation. In a typical reaction, almost complete RhB (10 mg/L) removal can be achieved by the activation of PMS (0.2 g/L) using 5%Mg/Fe2 O3 (0.5 g/L). Moreover, the as-synthesized catalyst exhibits a broad pH working range (3.96–10.69), high stability, and recyclability. The effects of several parameters (e.g., catalyst amount, PMS dosage, solution pH and temperature, and coexisting inorganic anions) on the removal of RhB in the 5%Mg/Fe2 O3 /PMS system are investigated. A plausible PMS activation mechanism is proposed, and 1 O2 and O2 − are identified as the predominant reactive species in RhB degradation instead of SO4 − and OH. This study provides new insights into the development of highly efficient iron-based catalysts and highlights their potential applications in environmental purification. Graphical abstract: Image 1 Highlights: The degradation rate of RhB by 5%Mg/Fe2 O3 is 6.47 times higher than that of Fe2 O3 . Magnesium doping could significantly improve the stability of 5%Mg/Fe2 O3 . Rich oxygen vacancies and high surface area contribute to the degradation of RhB. 1 O2 and O2 − are the main reactive species, instead of conventional OH and SO4 − .