Non-Radical Dominated PMS Activation by High-Entropy Alloy for Water Decontamination

Abstract

Toxic and carcinogenic organic pollutants in wastewater severely threaten public health and environmental sustainability. Advanced oxidation processes (AOPs) can degrade such pollutants by generating highly reactive species, but their efficiency and durability depend heavily on the reaction pathways and mechanisms. Non-radical pathways offer notable advantages for complex wastewater due to their strong resistance to interference from impurities and coexisting ions. Herein, we demonstrate that the entropy can drive a transition in the peroxymonosulfate (PMS) activation mechanism from free-radical- to non-radical-dominated pathway. This is exemplified by the Co55Fe15Cu10Mn10Ni10 high-entropy alloy (HEA), which achieves over 98% degradation of Rhodamine B within 15 minutes using a low PMS dosage of 0.15 g/L, significantly outperforming monometallic and binary alloy catalysts. The non-radical mechanism combined with high structural stability of HEA catalysts also grants exceptional resistance to coexisting ions and reliable performance in real water samples with multiple impurities. These findings highlight the promise of HEA catalysts in addressing key challenges in wastewater treatment, including pollutant diversity, impurity resilience, and system durability.