posted on 2024-02-27, 10:04authored byPeng Zhang, Minglu Sun, Chenying Zhou, Chuan-Shu He, Yang Liu, Heng Zhang, Zhaokun Xiong, Wen Liu, Peng Zhou, Bo Lai
Metal-free carbon material-mediated nonradical oxidation
processes
(C-NOPs) have emerged as a research hotspot due to their excellent
performance in selectively eliminating organic pollutants in aqueous
environments. However, the selective oxidation mechanisms of C-NOPs
remain obscure due to the diversity of organic pollutants and nonradical
active species. Herein, quantitative structure–activity relationship
(QSAR) models were employed to unveil the origins of C-NOP selectivity
toward organic pollutants in different oxidant systems. QSAR analysis
based on adsorption and oxidation descriptors revealed that C-NOP
selectivity depends on the oxidation potentials of organic pollutants
rather than on adsorption interactions. However, the dominance of
electronic effects in selective oxidation decreases with increasing
structural complexity of organic pollutants. Moreover, the oxidation
threshold solely depends on the inherent electronic nature of organic
pollutants and not on the reactivity of nonradical active species.
Notably, the accuracy of substituent descriptors (Hammett constants)
and theoretical descriptors (e.g., highest occupied molecular orbital
energy, ionization potential, and single-electron oxidation potential)
is significantly influenced by the complexity and molecular state
of organic pollutants. Overall, the study findings reveal the origins
of organic pollutant-oriented selective oxidation and provide insight
into the application of descriptors in QSAR analysis.