MXene-enabled interfacial electronic modulation steers high-valent metal-oxo generation toward boosting water purification

A CoMn 2 O 4 /MXene hybrid catalyst was rationally constructed to overcome the sluggish redox kinetics and inefficient interfacial electron transfer. • MXene functions not only as a conductive scaffold but also as an interfacial electronic modulator. • MXene-mediated electronic coupling promotes high-valent metal-oxo species as the dominant reactive intermediates. • Toxicity evaluation confirmed substantially reduced ecotoxicity of the treated BPA-containing water. Selective nonradical oxidation via high-valent metal-oxo (HVMO) species represents a promising yet mechanistically underexplored pathway for eliminating emerging contaminants. Here, a CoMn 2 O 4 /MXene (CMM) hybrid catalyst was rationally constructed to overcome the sluggish redox kinetics and inefficient interfacial electron transfer, which constrain HVMO species generation in spinel oxide/peroxymonosulfate (PMS) systems. MXene acts as both a conductive scaffold and interfacial electronic modulator, accelerating CoMn 2 O 4 -PMS charge transfer and steering PMS activation toward selective nonradical oxidation. The optimized CMM catalyst achieves complete bisphenol A removal within 5 min ( k  = 0.98 min −1 ), nearly double the rate of pristine CoMn 2 O 4 . In addition, this system exhibited broad pollutant degradation, high PMS utilization efficiency, wide pH adaptability, and robust tolerance to complex water matrices. Combined experimental and theoretical analyses reveal that MXene-mediated electronic coupling promotes HVMO species as the dominant reactive intermediates. Toxicity evaluation using three-dimensional excitation-emission matrix (3D-EEM) fluorescence spectroscopy and mung bean germination assays confirmed substantially reduced ecotoxicity of the treated BPA-containing water. Continuous flow operation further demonstrated near-complete BPA removal over 6 h, underscoring practical scalability. This work highlights interfacial electronic regulation as an effective strategy for engineering HVMO-mediated routes in advanced water purification. Download: Download high-res image (372KB) Download: Download full-size image