Sunlight-driven degradation of diethyl phthalate via magnetically modified biochar catalysts in water: Internal electron transfer mechanism.

This study presents a one-step synthetic approach for magnetic biochar (MBC) photo-degradation of diethyl phthalate (DEP). The results showed that MBC exhibited better catalytic property for DEP degradation than BC, and its catalytic performance was influenced by the amount of Fe doping. Electron paramagnetic resonance (EPR), quenching experiments, and chemical probe studies confirmed the presence of persistent free radicals (PFRs), hydroxyl radicals (·OH), and superoxide anion radical (·O ₂ ^- ) in both of BC and MBC. Solar light promoted the formation of PFRs in BC system, which transferred electrons to oxygen to form ·O ₂ ^- , thus yielding ·OH. On the other hand, electron transfer occurred between PFRs and Fe ³⁺ for MBC, Fe ²⁺ played an important role in activation of O ₂ and ·O ₂ ^- production. Subsequently, photo-Fenton reaction was primarily responsible for ·OH formation. This work compared the different generation pathways for ROS between BC and MBC and provides new insight into the possible mediatory roles of BC in O ₂ activation under solar light by transition metals.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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