Multi-Cation Doped MnO₂ Induced Dual Nonradical Peroxymonosulfate Activation Pathways for Efficient Degradation of...

Regulating electron transfer between peroxymonosulfate (PMS) and catalysts is a promising strategy to enhance the activity of the catalytic system. This work demonstrates a multi-cation co-doping strategy (Fe,Ni,Cu) to engineer the electronic configuration of δ-MnO₂, creating a novel nanocatalyst that synergistically couples electron transfer (PMS-ETP) with singlet oxygen (¹O₂) generation for efficient pollutant degradation. The optimized catalyst exhibits excellent PMS activation efficiency, achieving a removal rate of >90.6% for diverse refractory contaminants within 10 min while maintaining satisfactory durability and structural stability during catalytic tests. Advanced synchrotron-based X-ray diffraction (SXRD) and density functional theory (DFT) verify that Fe,Ni,Cu co-doping optimized the d-band center of Mn and provides the electron-absorbing sites. The in situ Raman spectroscopy, electrochemical analysis, and quenching tests confirm that the modified electronic structure facilitates bidirectional electron transfer between PMS and the catalyst, enabling broad-spectrum purification capabilities across complex water matrices. This work provides atomic-level insights into the multi-metallic modulation of redox-active catalysts and new ideas for designing energy-efficient oxidation systems toward sustainable water remediation.