Electrochemical Degradation of 2,4,6‐Trinitrotoluene (TNT) Using Ti/SnO 2 ‐Sb/Nd@β‐PbO 2 ‐PEDOT Electrode Combined With Persulfate Activation

This study developed a persulfate‐assisted electrochemical system for the degradation of 2,4,6‐trinitrotoluene in aqueous solution using a multilayer Ti/SnO 2– Sb/Nd@β‐PbO 2 –PEDOT electrode. XRD, SEM–EDS, FTIR, TGA, XPS, CV, and EIS analyses supported the successful formation of the designed multilayer electrode with good surface integrity and favorable charge‐transfer characteristics. Under the selected conditions of 5 mM persulfate, pH 5, and a current density of 15 mA cm −2 , approximately 95.9% TNT removal was achieved within 60 min. Control experiments demonstrated a clear synergistic effect between electrode modification and persulfate activation, with the final Ti/SnO 2 –Sb/Nd@β‐PbO 2 –PEDOT/PS system exhibiting an apparent pseudo‐first‐order rate constant of 0.0564 min −1 . EPR spin‐trapping combined with radical‐scavenging experiments provided convergent evidence for the participation of both •OH and SO 4 • − in TNT oxidation. Divided‐cell experiments showed greater persulfate consumption and stronger accumulation of 2‐ADNT and 4‐ADNT in the cathodic compartment, indicating preferential cathodic nitro‐group reduction and electron‐assisted persulfate activation, whereas TOC removal was substantially higher in the anodic compartment. LC–HRMS analysis showed the sequential formation of 2‐ADNT/4‐ADNT, oxygenated aromatic products including nitrophenol and hydroquinone, and low‐molecular‐weight products including acetate and formate, supporting a coupled reduction–oxidation and ring‐opening pathway. The approximately 42% TOC removal obtained in the anodic compartment after 60 min indicates substantial transformation but only partial carbon mineralization. The electrode retained high treatment performance over five consecutive cycles, with TNT removal decreasing only from approximately 94% to 91%, while the specific energy consumption remained approximately 0.19–0.20 kWh g −1 TNT removed.