Efficient chlorine evolution of CuO modified RuO2 electrode and its application in preparation of electrochemical disinfectant.

• The CuO/RuO 2 electrode was prepared by the two-step thermal decomposition method for the first time. • Compared with the ordinary RuO 2 electrode, the selectivity of CER of CuO/RuO 2 electrode is remarkably improved. • During the preparation of AEW, the HClO content of AEW2 (prepared by CuO/RuO 2) is 2.5 times that of AEW1 (prepared by RuO 2). • In the sterilization experiments on E. coli and B. subtilis , the germicidal efficacy of AEW2 is obviously superior to that of AEW1. Electrochemical chlorine evolution reaction (CER) is one of the most important practical applications of electrochemical reaction, which can be used for electrochemical disinfection. The electrochemical disinfectant of acidic electrolyzed water (AEW) is obtained by electrolyzing extremely dilute chlorine-containing solution in ion-exchange membrane electrolyzer. In the anode area, HClO is produced by CER, which has a strong bactericidal effect. Due to the low concentration of chloride ion, it is necessary to improve the CER selectivity of the electrode in order to improve the efficiency of chlorine electrolysis. In this paper, CuO/RuO 2 electrode was prepared by the two-step thermal decomposition method, and the surface morphology and electronic structure of RuO 2 electrode were modified. Compared with the ordinary RuO 2 electrode, the CER activity of CuO/RuO 2 electrode is improved. For the oxygen evolution reaction (OER), the activity of CuO/RuO 2 electrode is significantly lower than that of RuO 2 electrode. The CER mechanism of CuO/RuO 2 electrode is the second electron transfer, and the OER mechanism is the formation and transformation of OH ads. The potential difference between CER and OER of CuO/RuO 2 -3 electrode is 105 mV, which is 52 mV higher than that of RuO 2 electrode, so the selectivity of CER of CuO/RuO 2 electrode is remarkably improved. During the preparation of AEW, the HClO of AEW2 (prepared by CuO/RuO 2 -3 electrode) is 0.72 mmol/L, which is 2.5 times that of AEW1 (prepared by RuO 2 electrode). In the sterilization experiments on E. coli and B. subtilis , the germicidal efficacy of AEW2 (3.71 and 2.99 log 10 CFU/mL) is obviously superior to that of AEW1 (0.76 and 0.61 log 10 CFU/mL). [ABSTRACT FROM AUTHOR]