Pulse-driven electrocatalysis with engineered wooden electrode for high-efficiency, energy-saving and sustainable water treatment

Electro-Fenton technology holds great promise for wastewater treatment but is constrained by the high cost of electrodes, high-purity oxygen input, rapid catalyst loss and sludge generation. Here we present a low-cost and self-supporting wooden electrode with pulsed excitation of ambient air and Fe3+ reduction, overcoming all the above issues in electro-Fenton processes. The electrode was fabricated via controlled wood delignification and carbonization, transforming into a self-supporting porous and functionalized architecture for efficient oxygen capture from air and two-electron reduction to H2O2. Periodic positive voltage pulses restored iron species from the electrode for in situ generation of radicals, minimizing surface iron accumulation and securing periodical electrode refreshing. A scaled-up system maintains a long-term operation in 30 days for bisphenol A removal without a performance loss at a low energy consumption of 0.013 kWh per gram of bisphenol A. This wooden-pulsed electro-Fenton system provides a low-cost and sustainable solution to practical wastewater treatment. The pulsed electrochemical method, combined with a wood-based electrode, enables the simultaneous reduction of oxygen to generate hydrogen peroxide and the regeneration of Fe3+ to active Fe2+ for radical production. This approach offers a cost-effective and sustainable electro-Fenton process for wastewater treatment.