Peroxydisulfate activation by photo-generated charges on mesoporous carbon nitride for removal of chlorophenols

Abstract Lewis basic sites of MCN induced the interface hydrolysis of PDS to produce hydroperoxyl anions (HOO−) and peroxide ions (O22−). Photogenerated hole (h+), superoxide radical (O2·−) and singlet oxygen (1O2) were verified as the most important active species for 2,4,6-trichlorophenol (TCP) removal. The efficiently separated electron (e−) was responsible for the nucleophilic attack toward the C-Cl bond of TCP. Moreover, the electrical energy per order (EEO) of vis/MCN/PDS (3.75 × 106 kW h m−3 order−1) was an order of magnitude lower than that of UV/PDS (3.14 × 107 kW h m−3 order−1). This work highlighted the metal-free MCN with Lewis basic sites as a photocatalyst to activate PDS and elucidated a new strategy of PDS activation for chlorophenol pollutants removal.