Core–shell CoTiO3@MnO2 heterostructure for the photothermal degradation of tetracycline

The photothermal process exhibits the largest energy conversion efficiency among all solar energy utilization processes. In this study, a core–shell CoTiO 3 @MnO 2 (CTM) composite photothermal catalyst was synthesized by supporting MnO 2 on CoTiO 3 by hydrothermal synthesis. Binding to peroxymonosulfate (PMS) heterogeneous catalyst removed tetracycline in wastewater. The new catalyst was characterized by FT-IR, UV–Vis, XRD, BET, SEM, TEM, and so on. Kinetic analysis showed that CTM activated PMS at a rate of 3.2 and 3.5 times higher than that of pure light and heat conditions, with complete degradation of tetracycline (TC). Since the outer MnO 2 layer converted the absorbed solar energy into thermal energy, PMS was activated to generate active species while performing electron transfer, which resulted in a considerably improved catalytic efficiency. To prove the wide applicability of the catalyst, other pollutants were degraded, including bisphenol A (BPA), metronidazole (MNZ), and methyl orange (MO). The three pollutants were degraded within 40 min. Finally, our findings demonstrated the mechanism of the photothermal degradation process and provided a novel approach for environmental remediation using renewable solar energy. Graphical Abstract In this paper, the degradation efficiency of CoTiO 3 was improved by loading MnO 2 on CoTiO 3 . Binding to peroxymonosulfate (PMS) heterogeneous catalyst activation for the catalytic degradation of tetracycline. It was found by experiments that the core-shell structure of the composite material CoTiO 3 @MnO 2 had better photothermal catalysis efficiency than photocatalysis and thermal catalysis.