Direct oxygen transfer mediated controllable oxidation in electrochemical membranes facilitate eco-friendly removing...

Dimethyl sulfoxide (DMSO), a prevalent organic solvent in industrial wastewater, poses challenges in conventional treatments such as Fenton oxidation or ozonation due to excessive chemical-energy consumption and uncontrolled carbon emissions. Herein, we introduce an electrocatalytic chlorine-mediated direct oxygen transfer pathway, enabling controllable oxidation of DMSO into the more biodegradable and less toxic dimethyl sulfone (DMSO₂). We found that the electrocatalytic membrane modified with multi-Sn/Sb sites possess a desirable activity for chlorine evolution reaction, which could generate a high steady-state concentration (1.73 × 10^-13 M) of ClO• radicals. DFT calculations reveal that ClO• radicals more readily engage with DMSO via sulfur-oxygen bridging, rapidly forming DMSO₂ through chlorine-oxygen bond cleavage. Under these circumstances, the electrocatalytic membrane achieves near-complete DMSO (100 mg L^-1) removal at 10 min, with an energy consumption of only 0.20 kWh m^-3. Moreover, the system implements controllable oxidation of DMSO, reaching up to 88.6 % conversion to DMSO₂ at a flux of 800 L m⁻² h⁻¹, while generating only 0.26 kg-CO₂ m^⁻3 of greenhouse gas emissions - significantly lower than those from Fenton and PMS activation processes. These findings highlight the promise of direct oxygen transfer mediated controllable oxidation as a sustainable and eco-friendly strategy for organic wastewater purification.