MnFe layered double hydroxides confined MnOx for peroxymonosulfate activation: A novel manner for the selective production of singlet oxygen

Abstract

Singlet oxygen (¹O₂) is a reactive species for the selective degradation of stubborn organic pollutants. Given its resistance to harsh water environment, the effective and exclusive generation of ¹O₂ is acknowledged as a key strategy to mitigate water production costs and ensure water supply safety. Herein, we synthesized MnO_x intercalated MnFe layered double hydroxides (MF-MnO_x) to selectively produce ¹O₂ through the activation of PMS. The distinctive confined structure endowed MF-MnO_x with a special pathway for the PMS activation. The direct oxidation of BPA on the intercalated MnO_x induced the charge imbalance in the MnFe-LDH layer, resulting in the selective generation of ¹O₂. Moreover, acceptable activity deterioration of MF-MnO_x was observed in a 10 h continuous degradation test in actual water, substantiating the application potential of MF-MnO_x. This work presents a novel catalyst for the selective production of ¹O₂, and evaluates its prospects in the remediation of micro-polluted water.

Keywords: Confined catalysis; Electron transfer process; Layered double hydroxides; Peroxymonosulfate; Singlet oxygen.