Multilayer stable Sn1Ru3Ox/TiNTs anode with high chlorine evolution reaction selectivity for efficient simultaneous removal of ammonia nitrogen and phenol

Chlorine-mediated electrochemical advanced oxidation technology has significant potential for pollutant removal. However, the oxygen evolution reaction (OER), which has a similar onset potential to the chlorine evolution reaction (CER), often interferes with chlorine production, limiting the development of high performance CER electrodes. This study presents a novel, highly stable multilayer SnRuO x /TiNTs anode. Using a four-quadrant model-based evaluation system for chlorination and oxygen evolution activities, the Ru and Sn ratio was optimised to enhance the performance of the SnRuO x /TiNTs anode. Electrochemical tests showed that the Sn 1 Ru 3 O x /TiNTs electrode exhibited excellent CER activity with weak OER activity, achieving a CER selectivity of up to 90.07 %. This effectively addressed the issue of OER interference with CER. Experiments showed that under low-chloride (500 mg/L) conditions, Sn 1 Ru 3 O x /TiNTs achieved 100 % ammonium nitrogen removal within 3 h and almost complete phenol degradation within 5 h. Accelerated life tests showed that the Sn 1 Ru 3 O x /TiNTs anode exhibited excellent stability, with an estimated life of up to 2.119 years. Furthermore, DFT calculations demonstrated that the optimized synergistic interaction between Ru and Sn atoms in the Sn 1 Ru 3 O x /TiNTs electrode significantly increases the density of active electronic states, making it an ideal material for the CER. This research provides new insights and strategies for the preparation of high-performance chlorine evolution electrodes.