Selective O<sub>2</sub>‑to‑H<sub>2</sub>O<sub>2</sub> Electrosynthesis\nby a High-Performance, Single-Pass\nElectrofiltration System Using Ibuprofen-Laden CNT Membranes

Producing H<sub>2</sub>O<sub>2</sub> through a selective,\ntwo-electron\n(2e) oxygen reduction reaction (ORR) is challenging, especially when\nit serves as an advanced oxidation process (AOP) for cost-effective\nwater decontamination. Herein, we attain a 2e-selectivity H<sub>2</sub>O<sub>2</sub> production using a carbon nanotube electrified membrane\nwith ibuprofen (IBU) molecules laden (IBU@CNT-EM) in an ultrafast,\nsingle-pass electrofiltration process. The IBU@CNT-EM can generate\nH<sub>2</sub>O<sub>2</sub> at a rate of 25.62 mol g<sub>CNT</sub><sup>–1</sup> h<sup>–1</sup> L<sup>–1</sup> in the\npermeate with a residence time of 1.81 s. We demonstrated that an\ninterwoven, hydrophilic–hydrophobic membrane nanostructure\noffers an excellent air-to-water transport platform for ORR acceleration.\nThe electron transfer number of the ORR for IBU@CNT at neutral pH\nwas confirmed as 2.71, elucidating a near-2e selectivity to H<sub>2</sub>O<sub>2</sub>. Density functional theory (DFT) studies validated\nan exceptional charge distribution of the IBU@CNT for the O<sub>2</sub> adsorption. The adsorption energies of the O<sub>2</sub> and *OOH\nintermediates are proportional to the H<sub>2</sub>O<sub>2</sub> selectivity\n(64.39%), higher than that of the CNT (37.81%). With the simple and\ndurable production of H<sub>2</sub>O<sub>2</sub> by IBU@CNT-EM electrofiltration,\nthe permeate can actuate Fenton oxidation to efficiently decompose\nemerging pollutants and inactivate bacteria. Our study introduces\na new paradigm for developing high-performance H<sub>2</sub>O<sub>2</sub>-production membranes for water treatment by reusing environmental\nfunctional materials.