Peroxymonosulfate activation by ultra-dispersed Co3O4 nanosheets for efficient 4-nitrophenol degradation

Abstract Traditional Co3O4 nanosheets tend to aggregate, leading to the concealment of active sites and causing a decrease in pollutant removal efficiency. In this study, waste fiber was employed as a sacrificial template to prepare highly ultra-dispersed Co3O4 (U-Co3O4) nanosheets with abundant exposed active sites. In a typical reaction, 4-NiP (40 mg/L) was almost completely degraded in 10 min by the activation of PMS (1.0 mmol) using U-Co3O4 (20 mg/L). It was found that U-Co3O4 nanosheets exhibited outstanding catalytic performance toward 4-nitrophenol (4-NiP) than conventional Co3O4. Moreover, the U-Co3O4 can degrade various pollutants within 10 minutes. Moreover, nine organic pollutants including 4-nitrophenol (4-NiP), 2-chloro-4-nitrophenol (2C4Nip), 2-chloro-6-nitrophenol (2C6Nip), tetracycline (TC), doxycycline (DOX), methyl orange (MO), oxytetracycline (OTC), methylene blue (MB), and methyl red (MR)were utilized to investigate the generality of catalyst. The possible interface mechanism of PMS activation by U-Co3O4 was proposed, the (111) facets of Co3O4 can activate PMS efficiently generating •OH, SO4• −, 1O2, and O2• −. This work provides a new strategy for preparing U-Co3O4 nanosheets catalysts via a sacrificial template method for efficient wastewater treatment.