Unveiling the Direct Electron Transfer Regime of Peracetic Acid Activation: Quantitative Structure-Activity Relationship Analysis of Carbon Nanotube Catalysis

The demands for high-efficient and green activation ofperaceticacid (PAA) have triggered research in exploring carbon catalysis.Nevertheless, the efforts in designing reaction-oriented and high-performancecarbon catalysts are largely impeded by an ambiguous understandingof the fundamental carbon structure-PAA activation performancerelationship. Herein, we investigated the quantitative structure-activityrelationship (QSAR) of carbon nanotubes (CNTs) for PAA activationand micropollutant (MP) removal, by tuning the physiochemical propertiesof CNT via thermal annealing. The CNT/PAA system was dominated bythe nonradical direct electron transfer (DET) oxidation pathway, showinghigh MP removal rates under complex water matrices. By conductingQSAR analysis, improved catalytic efficacy of the surface-regulatedCNTs was attributed to the reinforced DET via the elevated oxidativepotential of the CNT-PAA complex and the enhanced electricalconductivity of CNT. Furthermore, the larger specific surface areaand lower oxygen content of CNT gave rise to the elevated oxidativepotential of the CNT-PAA complex, while the electrical conductivityof CNT was positively correlated with the graphitization degree ofCNT. Overall, this work sheds light on the influence cascade of thephysicochemical properties of CNT for MP removal and PAA activation,providing guidelines for the fit-for-purpose design of the DET-mediatedcarbon catalysts for PAA oxidation.