Selective O2-to-H2O2 Electrosynthesis by a High-Performance, Single-Pass Electrofiltration System Using Ibuprofen-Laden CNT Membranes

Producing H₂O₂ through a selective, two-electron (2e) oxygen reduction reaction (ORR) is challenging, especially when it serves as an advanced oxidation process (AOP) for cost-effective water decontamination. Herein, we attain a 2e-selectivity H₂O₂ production using a carbon nanotube electrified membrane with ibuprofen (IBU) molecules laden (IBU@CNT-EM) in an ultrafast, single-pass electrofiltration process. The IBU@CNT-EM can generate H₂O₂ at a rate of 25.62 mol g_CNT^-1 h^-1 L^-1 in the permeate with a residence time of 1.81 s. We demonstrated that an interwoven, hydrophilic-hydrophobic membrane nanostructure offers an excellent air-to-water transport platform for ORR acceleration. The electron transfer number of the ORR for IBU@CNT at neutral pH was confirmed as 2.71, elucidating a near-2e selectivity to H₂O₂. Density functional theory (DFT) studies validated an exceptional charge distribution of the IBU@CNT for the O₂ adsorption. The adsorption energies of the O₂ and *OOH intermediates are proportional to the H₂O₂ selectivity (64.39%), higher than that of the CNT (37.81%). With the simple and durable production of H₂O₂ by IBU@CNT-EM electrofiltration, the permeate can actuate Fenton oxidation to efficiently decompose emerging pollutants and inactivate bacteria. Our study introduces a new paradigm for developing high-performance H₂O₂-production membranes for water treatment by reusing environmental functional materials.