Exploring the synergism of sunlight and electrooxidation on persulfate activation for efficient degradation of bisphenol S: Performance, Pathway, and mechanism

DFT Calculation of Nonperiodic Small Molecular Systems to Predict the Reaction Mechanism of Advanced Oxidation Processes: Challenges and Perspectives

“…However, since corresponding products cannot be detected experimentally, several studies selectively ignored these O atoms on the basis that they cannot undergo further oxidation. 11,17,39,40,54,62,91,116,117 In fact, the electrophilic attack of free radicals on the oxygen atom may result in the destruction of adjacent sites. Therefore, it is unreasonable to disregard the high reactivity of the oxygen atoms.…”

“…In the field of AOPs, the Fukui function is widely utilized for predicting reaction sites. It has been established that high f – values are indicative of electrophilic reactions, ,,− while high f + values suggest nucleophilic reactions. , High f 0 values are susceptible to attack by free radicals. Among the AOPs, free radicals are considered to be the most important active substances; therefore, f 0 is widely utilized. ,,,,,,− ,,,,,,− It is noteworthy that f 0 considers both the electrophilic and nucleophilic properties of the radical.…”

“…It has been established that high f – values are indicative of electrophilic reactions, ,,− while high f + values suggest nucleophilic reactions. , High f 0 values are susceptible to attack by free radicals. Among the AOPs, free radicals are considered to be the most important active substances; therefore, f 0 is widely utilized. ,,,,,,− ,,,,,,− It is noteworthy that f 0 considers both the electrophilic and nucleophilic properties of the radical. However, when the radical exhibits predominantly electrophilic properties in a reaction, f – may be more appropriate for predicting the reaction site.…”

“…In particular, when using ESP, FED, and Fukui functions to identify reactive sites, there are often cases where the function value of certain O atoms is high due to their lone pair electrons. However, since corresponding products cannot be detected experimentally, several studies selectively ignored these O atoms on the basis that they cannot undergo further oxidation. ,,,,,,,, In fact, the electrophilic attack of free radicals on the oxygen atom may result in the destruction of adjacent sites. Therefore, it is unreasonable to disregard the high reactivity of the oxygen atoms.…”

“…Gao et al62 investigated the degradation of bisphenol S (BPS) by SO 4 • − and •OH using transition state theory. By comparing the energy barriers of SO 4 • − and •OH attacking the eight sites of BPS, it was found that regardless of the mechanism (HAT or RAF or SET) the reaction energy barrier for SO 4 • − is lower.…”