Activation of peroxymonosulfate by MnO2 with oxygen vacancies: Degradation of organic compounds by electron transfer nonradical mechanism

作者：Deng, Yuhui; Gao, Peng; Wang, Lu; Zhang, Yongqing^*; Fu, Juncong; Huang, Renfeng; Zhao, Shuaifei; Wang, Guangzhao; Wei, Yuancheng^*; Zhou, Shaoqi

来源：Journal of Environmental Chemical Engineering, 2022, 10(2): 107481.

DOI：10.1016/j.jece.2022.107481

• Advanced oxidation processes
• Manganese dioxide
• Oxygen vacancies
• Electron transfer
• Peroxymonosulfate

Recently, ecofriendly and low toxicity manganese-based materials are receiving increased attention for the activation of peroxymonosulfate (PMS). The surface property of manganese-based materials has strong effect on its activation performance. In this study, MnO2 with differing levels of oxygen vacancies (V-o-MnO2) were prepared and used for PMS activation. The effects of oxygen vacancies (V-o), activator dosage, PMS concentration, and the initial pH on para-chloroaniline (PCA) degradation were studied. In these studies, V-o-MnO2 showed good stability and reusability for PMS activation. In addition, a series of experiments revealed the PMS activation mechanism. Interestingly, center dot OH, SO4 center dot--and O-1(2) were not primarily responsible for PCA degradation. PCA was degraded by the reactive complex formed by PMS and V-o-MnO2. Based on the characterization results and DFT calculations, the introduction of V-o in MnO2 changed the charge distribution of Mn atoms and enhanced PMS adsorption. This is more favorable to form the reactive complex in electron transfer mechanism. Besides, V-o increases the Mn3+ content in MnO2, which enhances oxidation ability of reactive complex and the efficiency of electron transfer. The degradation efficiency of pollutants in the V-o-MnO2/PMS system has been improved significantly. This study highlights the pivotal roles of V-o in electron transfer mechanism and provides a new method for the practical application in wastewater treatment.

• 单位
  贵州大学