Ti2O3 film electrode for water treatment via electrochemical chlorine evolution

Abstract

This work introduces a low-cost and earth-abundant Ti₂O₃ thin film electrode as the anode for chlorine-driven electrochemical water treatment. A simple method of immobilizing Ti₂O₃ powder onto a conductive glass substrate has been developed and studied. Electrochemical characterization showed that the chlorine evolution reaction (CER) was more favorable than the oxygen evolution reaction (OER) for the Ti₂O₃ film electrode. The Ti₂O₃ film electrode showed high efficiency of free chlorine production, which leads to a good performance in degrading methyl orange (97.9% in 1.5 h) and tetracycline (78.0% in 1.5 h) via chlorine evolution. Pollutant degradation reaction by chlorine is observed to be the major reaction (75%) in this electrochemical water treatment system, while direct electron transfer (DET) reaction also contributed to pollutant degradation. Ti₂O₃ film electrodes can work efficiently for several cycles with the help of an easy regeneration step between cycles.