Density functional theory study the mechanism of oxygen-functionalized graphene to activate peroxymonosulfate for VOCs removal in aqueous solution

Utilization of carbon materials for persulfate activation has revolutionized advanced oxidation processes in effluent treatment. However, its potential volatile organic compounds (VOCs) removal in gas phase remains an intriguing research area. In this research, the peroxymonosulfate (PMS) activated by graphene functionalized with diverse oxygen groups was investigated, and the corresponding performances for VOCs treatment were examined. Furthermore, the feasibility of employing various functionalized graphene/PMS systems for VOCs treatment by simulating a wet scrubber system was explored. Density functional theory (DFT) calculations were served as a useful tool to comprehensively analyze the intricate chemical processes involved: the adsorption and the activation of PMS, as well as the adsorption and degradation of VOCs. The favorable activity of graphene materials incorporating ketone group was showcased in our findings, as evidenced by charge distribution trends, charge transfer during persulfate adsorption, and the lower energy barrier. The mechanism of employing functionalized graphene/PMS systems for effective VOCs treatment was shed light by this research, thereby contributing to the advancement of exhaust gas treatment methods.