Tuning manganese (III) species in manganese oxide octahedral molecular sieve by interaction with carbon nanofibers for enhanced pollutant degradation in the presence of peroxymonosulfate

Manye Wang; Yi Wei; Qiancheng Zou; Wenyu Zhang; Aihua Xu; Xiaoxia Li

doi:10.1016/j.jcis.2018.10.055

Tuning manganese (III) species in manganese oxide octahedral molecular sieve by interaction with carbon nanofibers for enhanced pollutant degradation in the presence of peroxymonosulfate

J Colloid Interface Sci. 2019 Feb 15:536:271-280. doi: 10.1016/j.jcis.2018.10.055. Epub 2018 Oct 19.

Authors

Manye Wang¹, Yi Wei¹, Qiancheng Zou², Wenyu Zhang¹, Aihua Xu³, Xiaoxia Li⁴

Affiliations

¹ School of Environmental Engineering, Wuhan Textile University, Wuhan 430200, PR China.
² School of Chemistry and Chemical Engineering, Wuhan Textile University, Wuhan 430200, PR China.
³ School of Environmental Engineering, Wuhan Textile University, Wuhan 430200, PR China; Engineering Research Center for Clean Production of Textile Dyeing and Printing, Ministry of Education, Wuhan 430200, PR China.
⁴ School of Chemistry and Chemical Engineering, Wuhan Textile University, Wuhan 430200, PR China. Electronic address: lixxwh@163.com.

PMID: 30380427
DOI: 10.1016/j.jcis.2018.10.055

Abstract

The development of environmental-benign, efficient, and durable Mn based catalysts is of great importance for remediation of organic pollutants. In this study, a series of cryptomelane-type octahedral molecular sieve (OMS-2) and carbon nanofibers (CNFs) nanocomposites (OC) were synthesized by a facile refluxing approach under different conditions, and the catalytic activity was evaluated for Acid Orange 7 degradation under neutral conditions via peroxymonosulfate activation. It was revealed that the composites were more efficient than the pure OMS-2 and CNFs, due to the higher amounts of Mn(II) and Mn(III) species and the synergistic effects between OMS-2 and CNFs. The OC catalysts presented long-term stability without the leaching of Mn ions during seven consecutive cycles. Radical scavenger and EPR experiments indicated that the low valent Mn species in the composites were oxidized by PMS to produce sulfate radicals to degrade dyes. However, the structure and performance of OC were influenced significantly by CNFs dosage and refluxing time. Under a high CNFs ratio or a long refluxing time, OMS-2 was damaged and lost its catalytic activity completely. This study provides important implications for turning of the valence of Mn species in manganese oxides, and widens the practical applications of the manganese oxides/ carbon materials in wastewater treatment.

Keywords: Carbon nanofibers; Degradation; OMS-2; Peroxymonosulfate; Pollutants.