Intramolecular Charge Polarization Drives Bifunctional Electrocatalytic Oxidation in a Nonmetallic Electrified Confinement Membrane

Abstract

Electrocatalytic water purification suffers from metal leaching, sluggish mass transfer, and inefficient electrode utilization. Here we present a free-standing oxygen and defect co-tuned carbon nanofiber (O–CN) membrane as a bifunctional electrocatalyst for concurrent anodic and cathodic pollutant degradation. Fabricated via electrospinning and gradient annealing, O–CN features dense submicron channels enabling ultrafast transport. Oxygen doping with defect passivation induces charge polarization, intensifying the density of states near the Fermi level and creating electron-rich and electron-deficient regions. This promotes anodic direct oxidation via a downshifted HOMO and cathodic singlet oxygen production via a decreased work function. Complete removal of emerging contaminants occurs within 0.4 s, flux of ∼936.5 L m–2 h–1 bar–1, energy consumption of ∼0.096 kWh m–3, and >99% efficiency over 300 h. Costs and environmental impact are reduced by >65% versus conventional systems. This work establishes a sustainable electrified water treatment paradigm by converging atomic-level electronic modulation with nanoscale transport optimization.