Optimization of Co3O4 surface sites for photo-ozone catalytic mineralization of dichloromethane

Obtaining high removal rate of chlorinated volatile organic compounds (CVOCs) and CO 2 selectivity with a low ratio of O 3 /CVOC and energy consumption is challenging. Dodecylamine was used in this study to create active sites on Co 3 O 4 for photo-ozone catalytic mineralization of dichloromethane (DCM). Amine-Co 3 O 4 -450 is a dodecylamine-modified sample with high density of Co 3+ , Co 2+ , and hydroxyl due to its nanosheet structure and exposed (112) facets. The optimized surface significantly enhanced the cleavage of the C–Cl bond at low temperatures. Photocatalysis primarily participated in the oxidation of intermediates following DCM dichlorination and significantly improved CO 2 selectivity. The respective DCM removal rate and mineralization efficiency of Amine-Co 3 O 4 -450 with an O 3 /DCM molar ratio of 1.27 and one-sun irradiation were 14.9 and 15.0 times higher than the sum of those in the presence of light irradiation or O 3 alone. This finding indicated that a strong synergistic effect exists between O 3 and light.