Dual non-radical pathways triggered by Mn3O4@g-C3N4 with synergistic interfacial effect toward PMS activation for bisphenol A degradation

Efficient and durable activation of peroxymonosulfate (PMS) for the degradation of persistent organic pollutants remains challenging owing to the instability of active catalytic sites. Here, a Mn 3 O 4 @g-C 3 N 4 heterostructured catalyst (MCN-2) is constructed to enable efficient PMS activation and enhance the generation of non-radicals for rapid bisphenol A (BPA) degradation. MCN-2 preferentially adsorbs the peroxy oxygen atom of PMS, facilitating O-O and O-H bond cleavage to form the high-valent Mn-oxo species (Mn(IV)=O), which further reacts with PMS to yield singlet oxygen ( 1 O 2 ). The resulting 1 O 2 (60.5%) and Mn(IV)=O species (39.5%) synergistically drive rapid non-radical oxidation. Here, Mn 3 O 4 provides catalytic active sites, whereas g-C 3 N 4 enhances adsorption, shortens the mass-transfer distance between BPA and reactive oxygen species (ROS), and functions as an electron reservoir to sustain Mn redox cycling. Consequently, the synergistic 1 O 2 and Mn(IV)=O species system delivers a k-value of 0.258 min −1 for BPA degradation, which is 258 times and 6.45 times higher than that of the g-C 3 N 4 /PMS and Mn 3 O 4 /PMS systems, respectively. Moreover, MCN-2-based catalytic membranes enable stable BPA removal under continuous-flow conditions, and toxicity assessments demonstrate significantly reduced acute toxicity and mutagenicity of the transformation products, highlighting the potential for scalable and environmentally benign water treatment.