Manganese doped iron-carbon composite for synergistic persulfate activation: Reactivity, stability, and mechanism

Meiqiang Cai; Yu Zhang; Chunying Dong; Wentao Wu; Qian Wang; Zhijun Song; Yuejing Shi; Liguang Wu; Micong Jin; Dionysios D Dionysiou; Zongsu Wei

doi:10.1016/j.jhazmat.2020.124228

Manganese doped iron-carbon composite for synergistic persulfate activation: Reactivity, stability, and mechanism

J Hazard Mater. 2021 Mar 5:405:124228. doi: 10.1016/j.jhazmat.2020.124228. Epub 2020 Oct 14.

Authors

Meiqiang Cai¹, Yu Zhang², Chunying Dong², Wentao Wu³, Qian Wang², Zhijun Song², Yuejing Shi², Liguang Wu², Micong Jin⁴, Dionysios D Dionysiou⁵, Zongsu Wei⁶

Affiliations

¹ School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China. Electronic address: caimeiqiang@163.com.
² School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China.
³ School of Materials Science and Engineering, Taiyuan University of Science and Technology, 030024, China.
⁴ Key Laboratory of Health Risk Appraisal for Trace Toxic Chemicals of Zhejiang Province, Ningbo Municipal Center for Disease Control and Prevention, Ningbo 315010, China; Ningbo Key Laboratory of Poison Research and Control, Ningbo Municipal Center for Disease Control and Prevention, Ningbo 315010, China.
⁵ Environmental Engineering and Science Program, Department of Chemical and Environmental Engineering (ChEE), University of Cincinnati, Cincinnati, OH 45221, USA.
⁶ Centre for Water Technology (WATEC), Department of Engineering, Aarhus University, Hangøvej 2, DK-8200 Aarhus N, Denmark. Electronic address: zwei@eng.au.dk.

PMID: 33246821
DOI: 10.1016/j.jhazmat.2020.124228

Abstract

The heterogeneous catalytic process has been under development for aqueous pollutant degradation, yet electron transfer efficiency often limits the effectiveness of catalytic reactions. In this study, a novel composite material, manganese doped iron-carbon (Mn-Fe-C), was tailor designed to promote the catalytic electron transfer. The Mn-Fe-C composite, synthesized via a facile carbothermal reduction method, was characterized and evaluated for its performance to activate persulfate (PS) and degrade Rhodamine Blue (RhB) dye under different pH, catalyst dosages, PS dosages, and pollutant concentrations. Electron spin resonance, along with quenching results by ethanol, tert-butanol, phenol, nitrobenzene and benzoquinone, indicated that surface bounded SO₄^•- was the main contributor for RhB degradation, while the roles of aqueous SO₄^•- and ^•OH were very minor. Through characterization by XRD, XPS and FTIR analysis, it was determined that the electron transfer during activation of PS was accelerated by the oxygen functional groups on catalyst surface and the promoted redox cycle of Fe³⁺ and Fe²⁺ by Mn. Finally, the Mn-Fe-C composite catalyst exhibited an excellent reusability and stability with negligible leached Fe and Mn ions in solutions. Results of this study provide a promising design for heterogeneous catalysts that can effectively activate PS to remove organic pollutants from water at circumneutral pH conditions.

Keywords: Iron redox cycle; Mn doped Fe–C composite; Persulfate; Reusability; Surface bounded SO4(•−).

Publication types

Research Support, Non-U.S. Gov't