Immobilizing Electron Shuttles into van der Waals Heterostructures for Boosted Fenton-like Reactions

The pervasive occurrence of antibiotic contaminants in aquatic environments poses significant threats to ecosystems and public health. The heterogeneous peroxymonosulfate (PMS)-based advanced oxidation process (AOP) has proven as an effective approach to remove such persistent contaminants but still suffers from sluggish catalytic kinetics owing to insufficient charge transfer and active metal circulation. Herein, a van der Waals (vdW) heterostructure was fabricated with two-dimensional (2D) cobalt oxides (CoOx) nanosheets and polyoxometalate (POM) by a molecular co-assembly and post-calcination process. As a benefit from the combined merits of superior interfacial charge transfer accelerated by the vdW heterostructure and rapid Co(III)/Co(II) cycling promoted by the immobilization of electron-shuttle-like POM, the as-synthesized CoOx–POM vdW heterostructure (vdW-CPNSs) achieved efficient activation of PMS and exhibited a 21.5-fold higher degradation rate than the conventional Co3O4 counterpart for the elimination of antibiotic pollutants. Mechanism studies demonstrated that both radical (SO4• –) and non-radical (1O2) contributed to the superior degradation performance. Additionally, vdW-CPNSs could be integrated into a flow-through wastewater treatment setup, achieving nearly 100% removal of environmentally realistic level antibiotic contaminants, which exhibited a great potential for practical wastewater purification. This work provides new insights for the rational design of high-performance catalysts to promote PMS-based AOPs for removing emerging contaminants.