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

Abstract

The demands for high-efficient and green activation of peracetic acid (PAA) have triggered research in exploring carbon catalysis. Nevertheless, the efforts in designing reaction-oriented and high-performance carbon catalysts are largely impeded by an ambiguous understanding of the fundamental carbon structure–PAA activation performance relationship. Herein, we investigated the quantitative structure–activity relationship (QSAR) of carbon nanotubes (CNTs) for PAA activation and micropollutant (MP) removal, by tuning the physiochemical properties of CNT via thermal annealing. The CNT/PAA system was dominated by the nonradical direct electron transfer (DET) oxidation pathway, showing high MP removal rates under complex water matrices. By conducting QSAR analysis, improved catalytic efficacy of the surface-regulated CNTs was attributed to the reinforced DET via the elevated oxidative potential of the CNT–PAA complex and the enhanced electrical conductivity of CNT. Furthermore, the larger specific surface area and lower oxygen content of CNT gave rise to the elevated oxidative potential of the CNT–PAA complex, while the electrical conductivity of CNT was positively correlated with the graphitization degree of CNT. Overall, this work sheds light on the influence cascade of the physicochemical properties of CNT for MP removal and PAA activation, providing guidelines for the fit-for-purpose design of the DET-mediated carbon catalysts for PAA oxidation.