Defect-Tailored Titanate Nanowire Filters for Highly Efficient Electrooxidation in Water Treatment

Abstract

Electrooxidation (EO) offers a sustainable approach for decentralized water treatment, degrading micropollutants using only electric current. However, its practical implementation is still limited by the lack of low-cost, durable anode materials. Here, we report a palladium-doped titanate nanowire filter that functions as a highly efficient EO anode for flow-through water treatment. The nanowires self-assemble into an ultrathin, porous network on graphite felt, which provides extensive electrocatalytic surface area with nanoscale open channels for efficient solute transport. When integrated into a flow electrolyzer, the nanowire filter achieved an order-of-magnitude higher removal efficiency for the model micropollutant benzoic acid compared with a commercial mixed metal oxide mesh anode under identical conditions and effectively degraded a broad spectrum of persistent organic micropollutants. Mechanistic studies revealed that micropollutant oxidation proceeds predominantly through direct electron transfer at defect-tailored titanate sites, largely bypassing inhibition by radical scavengers commonly present in natural waters. The filter also exhibited long-term stability and robust performance in simulated real-water matrices. By overcoming mass-transfer limitations and directing reaction pathways through rational nanowire filter design, this work establishes a versatile electrode innovation strategy that advances EO technologies toward affordable and scalable water treatment.