Self-sustaining charge circulation in FeS₂/MoS₂ heterostructures for micropollutant removal

Advanced oxidation processes are widely utilized to eliminate persistent organic pollutants from water. However, their practical effectiveness is significantly constrained by irreversible catalyst deactivation and limited tunability of oxidant pathways. In peroxymonosulfate activation, a central challenge remains sustaining metal redox turnover while maintaining complementary reactive oxygen species under prolonged operation. Here we show that a FeS₂/MoS₂ heterointerface functions as an internal redox shuttle, driving a self-sustaining charge-circulation loop that autonomously regenerates dual active sites. A built-in electric field enforces directional electron transfer from Mo to Fe, thereby stabilizing continuous iron redox cycling for the production of radicals (•OH and SO₄^•−). Simultaneously, this architecture enables Mo-mediated generation of nonradical singlet oxygen, which mitigates catalyst deactivation and sustains oxidant output. As a result, the system achieves rapid removal of acetaminophen and retains 91.5% of its catalytic activity after 3000 min of continuous operation in various water matrices. These findings establish self-sustaining interfacial charge circulation as a broadly applicable and highly effective strategy for designing robust catalysts for sustainable water treatment.