Boosting PMS Activation Through Fe3S4/WO3: The Essential Impact of WX and SX on Catalyst Activity and Regeneration Fe Active Sites for Efficient Pollutant Removal

Fe-based heterogeneous catalytic advanced oxidation processes show great potential for treating wastewater. However, catalyst instability often hinders their practical use, mainly due to the slow regeneration of Fe2+sites. Herein, we developed a Fe3S4/WO3catalyst, where the electron-rich Wx and Sx sites promoted efficient electron transfer, enabling continuous regeneration of Fe2+active sites on the catalyst surface. The Fe3S4/WO3catalyst exhibited outstanding degradation efficiency for tetracycline (TC) in the peroxymonosulfate (PMS) system, achieving a 92.5% removal efficiency, significantly higher than its individual components of Fe3S4(52.8%), WO3(43.1%), and WS2(53.2%). Moreover, the Fe3S4/WO3/PMS system demonstrated a broad operational pH range (3.0–9.0), excellent degradation efficiency for various emerging pollutants, minimal interference from background electrolytes and organic matter, and strong stability in real water treatment. Chemical scavenger tests and electron paramagnetic resonance (EPR) analysis confirmed that the oxidative degradation of TC was driven by multiple reactive species, including SO4•−,•OH,•O2−, and1O2. This study provides a novel strategy for regulating active sites in Fe-based catalysts to ensure sustained performance, offering a pathway for the rational design of next-generation Fenton-like catalysts for efficient and sustainable micropollutant removal from wastewater.