Carbon-coated MIL-101(Fe) core–shell tandem mediates the directional conversion of SO4·- to 1O2 to realize efficient removal of bisphenol A

Abstract

The effective oxidation of organic pollutants can realize the detoxification and safe treatment of wastewater. Here, a tandem interaction of core–shell structures is proposed to regulate the directional switching of reactive oxygen species (ROS) to achieve efficient oxidation removal of organic pollutants. Benefiting from the improvement of the electronic structure by the interfacial micro-electric field, the core–shell structure, the tandem effect and the promotion of electron transfer by the synergistic effect on the pollutant removal kinetics reached 150.4 times. The difference in electronic structure between MIL-101(Fe) and TC leads to the formation of an interfacial micro-electric field that promotes electron transfer to accelerate the Fe(III)/Fe(II) cycle. The unsaturated coordination Fe(II) of MIL-101(Fe) under the influence of TC increases, promoting the production of SO4·- and further conversion to 1O2. According to the result of electron paramagnetic resonance (EPR) and liquid chromatography mass spectrometry (LC-MS), we believe that there may be simultaneous degradation and polymerization of pollutants. This work highlights the tandem effect of core–shell structure on catalysis to provide new insights into ROS directed conversion.