Efficient photo-Fenton like activity in modified MIL-53(Fe) for removal of pesticides: Regulation of photogenerated electron migration

Abstract In this study, we regulated the electronegativity of Fe-O clusters and BET surface area in MIL-53 (Fe) by D-sorbitol(D-M-Fe) and xylitol(XY-M-Fe), guiding the transfer of photogenerated electrons. Compared with MIL-53(Fe), D-M-Fe and XY-M-Fe exhibit excellent activation ability of persulfate irradiated by the visible light (λ ≥ 420 nm) to achieve efficient degradation of Thiamethoxam(TMX), after 45 minutes of degradation experiments, the removal rate of TMX reached separately to 50% and 96%. The particle sizes of D-M-Fe and XY-M-Fe become smaller and the specific surface area is greatly increased. These processes make MIL-53(Fe) have more active reaction centers. After adding Xylitol, the reduction of the ratio of FeII/FeIII causes the lower electron density around Fe atoms. The FeIII with higher electronegative has a greater ability to attract negative electrons, which can reduce positron annihilation rate and increase positron lifetime.