Effect of Elemental Composition on the Structure, Electrochemical Properties, and Ozone Production Activity of Ti/Sn O 2 -Sb-Ni Electrodes Prepared by Thermal Pyrolysis Method

Abstract

Ti/SnO 2 -Sb-Ni electrodes with various Ni- and Sb-doping levels have been prepared by dip-coating thermal pyrolysis procedure, and their simultaneous electrochemical ozone production (EOP) and oxygen evolution reaction (OER) were investigated. The effects of electrode composition on the nanostructure, morphology, electrochemical behavior, kinetic parameters, and lifetime of the electrodes were systematically studied using X-ray diffraction, scanning electron microscopy, cyclic voltammetry, linear sweep voltammetry, and chronopotentiometry. Dissolved ozone was produced in a quartz cell and its concentration was monitored by in situ UV spectrophotometry. The presence of small amounts of Ni (Ni : Sn atomic ratio of 0.2 : 100) gives valuable characteristics to the electrodes such as increasing EOP activity and service life. Higher Ni concentrations increase the electrode film resistance and decrease its capacitance, roughness factor, and service life, while increasing Sb level up to 12 atom% improves the electrode performance with respect to these parameters. Nevertheless, the Sb/Sn atomic ratio of more than 2% reduces the EOP current efficiency in favor of OER. The optimum composition of the electrode for EOP was determined to be Sb/Sn and Ni/Sn atomic ratios of 2% and 0.2%, respectively. The highest current efficiency was 48.3% in 0.1 M H 2 SO 4 solution at room temperature.