Oxygen Vacancies of Mn/CeOx-H induced non-radical activation of peroxymonosulfate through electron mediation for bisphenol A degradation

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 MnCeOx-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 MnCeOx-H/PMS system, while the reaction rate constant of MnCeOx-H/PMS system was 30 times higher than that of CeO2/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•, 1O2 and SO4•-, while 1O2 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.