Oxygen Vacancies of Mn/CeOx-H induced non-radical activation of peroxymonosulfate through electron mediation for bisphenol A degradation
Junyong He, Ya Yang, Peidong Hong, Yulian Li, Chao Xie, Zijian Wu, Minqiang Li, Lingtao Kong
Abstract
The use of peroxymonosulfate (PMS) activation to eliminate organic contaminants is a promising technology to purify water owing to its strong reactivity. However, because of the existed rate limiting step, the performance of PMS activation was restrained and required external energy consumption. Therefore, a new strategy was proposed to solve this problem by preparing catalysts with abundant electron-rich sites and electron traps to accelerate PMS activation. In this research, a novel MnCeO x -H catalyst with rich surface oxygen vacancies was firstly synthesized to accelerate the transfer of electrons among the catalysts, oxidant and pollutants. The contaminants were rapidly eliminated in the MnCeO x -H/PMS system, while the reaction rate constant of MnCeO x -H/PMS system was 30 times higher than that of CeO 2 /PMS system. The surface oxygen vacancies were able to adsorb and trap PMS, then the free electrons of oxygen vacancies would reduce PMS and produced HO•, 1 O 2 and SO 4 •- , while 1 O 2 played a major role. The contaminants which acted as electron-donors in this system were adsorbed at Mn, Ce sites, achieving effective conversion recycling of Ce(IV)/Ce(III), Mn(III)/Mn(II) and Mn(IV)/Mn(III). This discovery is believed to inaugurate a novel way for designing powerful electron-rich sites and electron traps to accelerate PMS activation for contaminants degradation.