Activation of peroxymonosulfate by cobalt-embedded carbon aerogels: Preparation and singlet oxygen-dominated catalytic degradation insight

Abstract

Carbonaceous catalytic composites mediated peroxymonosulfate-based advanced oxidation processes (PMS-AOPs) have received extensive attention for efficient organic pollutants remediation, due to the recognized advantages in contrast to the traditional Fenton-like process. In parallel, biomass was widely used in the environmental field as an important precursor of carbonaceous materials. Herein, cobalt-embedded carbon aerogels were prepared using lotus root starch as a precursor and employed as an efficient activator for PMS for carbamazepine degradation. Its excellent PMS activation performance could be attributed to the following synergistic factors: i) The hierarchical pore structure and large surface area of carbon aerogels could promote the fixed distribution of metal particles, reduce particle aggregation and metal leaching, increase active sites and facilitate the mass transfer process; ii) Carbon aerogels could efficiently activate PMS through active sites on the surface (such as defect structures, sp2-hybridized carbons, oxygen-containing functional groups, metal species, etc.); iii) The degradation of carbamazepine was promoted by π-π interaction and hydrogen bonding as the adsorption mechanism. Mechanistic studies showed that singlet oxygen (1O2) played a dominant role in the degradation of carbamazepine. In addition, the electrochemical analysis indicated that the electron transfer mechanism was also an efficient pathway in the Co-CA-900/PMS system. Overall, this study might provide new insights into the rational design and application of transition metal-embedded carbon aerogels for PMS activation in environmental remediation.