Abundant oxygen vacancies constructed by deep reduction strategy to achieve ultra-high peroxomonosulfate activation efficiency for degrading organic pollutions in water

Abstract

Herein, peroxymonosulfate (PMS)-like Fenton oxidation catalyst (DR-Vo-Co3O4) with rich oxygen vacancies and carved flower-like structures were constructed using Co3O4 as precursor via deep reduction strategy. DR-Vo-Co3O4 could activate PMS to achieve almost 100% degradation of sulfadiazine (SD) within 1 min with ultra-high efficiency, possessing a degradation rate constant (k) value as high as 5.9 ± 0.2 min−1, which was 86 and 5 times higher than the unreduced and reported maximum, respectively. Furthermore, the catalytic system showed unparalleled reactivity towards 14 different types of contaminants, with the maximum k value even exceeding 20 min−1. The carved flower-like structure of DR-Vo-Co3O4 catalysts not only facilitated PMS adsorption, but also provided more reaction sites for PMS activation. Meanwhile, rich oxygen vacancies could effectively tune the DR-Vo-Co3O4 surface electronic state to further accelerate charge transfer, significantly enhancing PMS oxidation efficiency. Catalytic mechanism analysis revealed that 1O2 and O2•− played a dominant role in contaminant degradation.