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

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.