Solar-light-activated periodate for degradation and detoxification of highly toxic 6PPD-quinone at environmental levels

Degradation and detoxication of highly toxic 6PPD-quinone remain great challenges due to its stable structure. Here we establish a solar-light-driven IO4- activation system for efficient degradation of 6PPD-quinone at environmental concentration levels (10-100 mu g l-1), with residual concentration below 5.7 ng l-1 (detection limit) within 30 min. IO3 center dot was determined as the primary reactive species after IO4- activation for cleavage of the highly toxic quinone structure. Single electron transfer is the most favourable route for IO3 center dot attacking, in which single electrons achieve self-driven transfer from 6PPD-quinone to IO3 center dot due to the maintenance of spatial inversion symmetry generated by dipole moments. Femtosecond transient absorption spectra confirmed the formation of 6PPD-quinone cationic radical (6PPD-quinone center dot+), which was the key reaction intermediate. This study proposes a promising technology for degradation and detoxification of highly toxic 6PPD-quinone in water and brings deep insight into the reaction mechanism within IO4- activation systems.