Sustainable and feasible reagent-free electro-Fenton via sequential dual-cathode electrocatalysis

Electro-Fenton processes aim at producing oxidizing radicals with fewer added chemicals and residues but are still unable to completely eliminate both. This study demonstrates that a reagentfree electro-Fenton process that runs solely on oxygen and electricity can be achieved by sequential dual-cathode electrocatalysis. H2O2 is produced on an electrodeposited PEDOT on carbon cloth (PEDOT/CC) cathode and subsequently converted to hydroxyl radicals on a stainless-steel-mesh cathode. The dual-cathode system demonstrates efficient decolorization and total organic carbon (TOC) removal toward organic dyes at optimized cathodic potentials of -0.9 V for PEDOT/CC and -0.8 V for the stainless-steel mesh. The sequential dual-cathode process also displays high reusability, no iron leaching, high removal efficiency using air instead of oxygen, and low installation and operation costs. This work demonstrates a preeminent and commercially viable example of pollution control rendered by the catalysis instead of chemical reagent philosophy of green chemistry.

Automated summary

This study presents a novel reagent-free electro-Fenton process achieved solely with oxygen and electricity through sequential dual-cathode electrocatalysis. The process demonstrates efficient decolorization and TOC removal towards organic dyes with high reusability and low operation costs, showcasing a commercially viable example of pollution control through green chemistry principles.