Ultrafast oxidation of refractory organics via PMS activation by Si-O doped biomimetic montmorillonite: Simultaneous enhanced radical/electron transfer pathways and efficient catalytic membrane system

Abstract

Carbon-based catalysts always rely on graphitized structure, heteroatomic doping, and defect sites as active sites, and still need to solve the problems of low catalytic activity and poor stability. In this work, a Si-O doped carbon-based catalyst with biomimetic montmorillonite (MT) structure (C/Si@MT) was prepared for oxidizing the refractory organic pollutants via peroxymonosulfate (PMS) activation. The C/Si@MT/PMS system exhibited ultrafast oxidation of versatile refractory organics and strong ability to resist interference from environmental matrixes via simultaneously enhancing both radicals and electron transfer process (ETP). The ETP oxidation of versatile pollutants in the C/Si@MT/PMS system were proceeded via the Si-O site as a bridge, with their kobs data positively correlated to the redox parameters (e.g., falling potential, energy gap between C/Si@MT+PMS* and pollutants). In addition, the inert aluminosilicate was removed in C/Si@MT while retaining the lamellar structure for promoting the continuous oxidation of pollutants with high stability in a catalytic membrane.