Ti3C2/FeS-Mediated Electron Cycling System Enables Highly Efficient Purification of Refractory Organic Pollutants in Aqueous Environment

Abstract

Establishing an efficient electronic transfer channel has been a consistent underlying bottleneck in the metal-doped Fenton like system. Herein, we designed a novel two-dimensional (2D) catalytic system in which FeS was integrated into Ti₃C₂ MXene layers (Ti₃C₂/FeS) for H₂O₂ activation for the first time. This innovative design establishes a self-sustaining electron cycle, where the formation of electron-rich and -poor regions boosts the decomposition of H₂O₂ and O₂ to produce •OH and •O₂^–, respectively, and meanwhile continuously extracts electrons from pollutant molecules. It enables efficient atrazine (ATZ) decomposition, efficaciously addressing the limitations of conventional heterogeneous Fenton processes, particularly their dependence on iron consumption and suboptimal •OH generation. The system enabled 100% removal of ATZ (initial concentration of 20 mg/L) within 30 min, demonstrating a rate constant over 24 times higher than the Fenton system (0.4096 min^–1 vs 0.0165 min^–1). It also exhibited strong resilience to coexisting substances (anions and humic acids) as well as various actual water media and low acute toxicity. This new strategy provides significant reference for similar Fenton like materials and contributes to highly efficient purification of refractory organic pollutants and the assurance of water quality safety and sustainability.