High-efficiency electro-Fenton mineralization of triclosan using a novel octahedral iron(iii) complex: structure, mechanism, and performance

Abstract

This study reports the synthesis and structural elucidation of a novel iron(III) coordination complex, [Fe(CO₃)(en)₂]Cl (1), and its integration as an efficient cathodic modifier in an advanced electro-Fenton (EF) system for the degradation of the emerging pollutant triclosan. Unlike conventional EF systems, the rationally designed iron complex enhances iron redox cycling and hydroxyl radical generation, leading to significantly improved mineralization efficiency. Under optimized conditions, the modified system achieved over 97% TOC removal within 210 min, following pseudo-first-order kinetics (k = 0.0195 min⁻¹). Mechanistic investigations revealed progressive dechlorination and oxidation into short-chain carboxylic acids prior to complete mineralization. This work demonstrates how coordination chemistry can be strategically integrated into electrochemical advanced oxidation processes to improve efficiency, stability, and sustainability in wastewater treatment applications.