A bifunctional β-MnO2 mesh for expeditious and ambient degradation of dyes in activation of peroxymonosulfate (PMS) and simultaneous oil removal from water

Dual functional membranes that can simultaneously remove water-insoluble oil and degrade water-soluble dyes have received considerable attention. Nevertheless, there remain arduous challenges due to the critical restriction of slow degradation rate and the heavy dependence on external stimuli like light, electricity or heat. Herein, we report a superwetting and rapidly catalytic beta-MnO2 mesh prepared by one-step hydrothermal method. In activation of peroxymonosulfate (PMS), this beta-MnO2 mesh can expeditiously degrade dyes without any external stimuli and simultaneously remove oils. The removal efficiencies were all > 99% and the filtrates were proved eco-friendly through leaching test and toxic experiment. Furthermore, a mechanism on the excellent catalytic ability of beta-MnO2 mesh was proposed, i.e. H+ was immobilized in 1 x 1 tunnel of beta-MnO2, which made the mesh surface a positive zeta potential and attract more negative sulfate radicals, as a result inducing an improved degradation efficiency. Therefore, we anticipate this bifunctional and ingenious beta-MnO(2 )mesh can contribute a lot to prompt and mild sewage purifications. (C) 2020 Elsevier Inc. All rights reserved.