Nickel–manganese sulfide on nickel foam toward highly efficient and stable potassium periodate activation for organic pollutant degradation

Nickel–manganese bimetallic sulfide microparticles in situ grown on Ni foam (NiMnS@NF) with controllable morphology and composition were developed via a hydrothermal method to boost potassium periodate activation for oxidation of multiple micropollutants. Benefiting from the unique morphology and structure, along with a synergistic effect of different components, the optimized NiMnS@NF exhibits outstanding performance and durability in potassium periodate activation, surpassing other oxidant systems (e.g., H₂O₂, peroxydisulfate, and peroxymonosulfate). Electron spin resonance analysis, scavenging tests, electrochemical analysis, and galvanic oxidation tests unveiled that NiMnS@NF can initiate the activation of potassium periodate, resulting in the formation of high-potential metastable intermediates (NiMnS@NF–potassium periodate*). Additionally, superoxide radical anions play a cooperative role in organic elimination. The experimental results further indicate that the synergy among Mn/Ni and S induces a local charge redistribution, improving electron transfer capability and Mn(II)/Mn(III)/Mn(IV) and Ni(II)/Ni(III) redox reactions. This work proposes a feasible and efficient monolithic catalyst for environmental remediation.