Dual-Function Nanostructured Anodes for Simultaneous Electrochemical Degradation of Organic Pollutants and In-Situ Corrosion Protection of Metallic Substrates

Document Type : Original Article

Author

Department of Research and Development, UOP, Santiago, Chile

Abstract
Electrochemical advanced oxidation processes (EAOPs) have emerged as promising technologies for the degradation of persistent organic pollutants (POPs) through the in-situ generation of reactive oxygen species, particularly hydroxyl radicals (•OH) . However, the practical application of EAOPs faces two critical challenges: the competitive chloride oxidation reaction (COR) caused by chloride ions in real wastewater, which leads to low Faradaic efficiency and severe corrosion of anode active sites, and the limited service life of electrodes due to dissolution of catalytic layers under harsh operating conditions . This comprehensive review systematically examines nanostructured anodes designed for dual-function applications—simultaneously achieving efficient electrochemical degradation of organic pollutants while providing in-situ corrosion protection of metallic substrates. Nanostructuring approaches, including TiO₂ nanotube arrays and hydrophobic surface modification, have demonstrated remarkable performance enhancement: TiO₂-NTs/SnO₂-Sb-PTFE composite electrodes achieve high oxygen evolution potential (2.4 V vs Ag/AgCl), significantly enhanced TOC removal efficiency for phenolic pollutants, and substantial reduction in Sn ion leaching compared to conventional electrodes . Surface hydrophobicity promotes effective release of free hydroxyl radicals from the anode surface into solution, facilitating pollutant mineralization while the hydrophobic PTFE layer acts as a barrier inhibiting anodic dissolution . Anti-corrosion design principles for seawater electrolysis—including selective oxygen evolution reaction active sites, anion exclusion layers, and electronic structure redistribution—offer valuable strategies for enhancing anode stability in chloride-rich environments . Recent advances in iridium-coated titanium anodes demonstrate service lives of 2-5 years with iridium loss below 0.1 mg/cm²/year, while PANI-modified iron anodes achieve corrosion inhibition efficiency of approximately 35% after repeated electrocoagulation treatment cycles . This review concludes that dual-function anodes represent a transformative approach for sustainable wastewater treatment, combining catalytic activity with corrosion resistance.

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Articles in Press, Accepted Manuscript
Available Online from 04 July 2026