Characterization and electrochemical behavior of Ti/TiO2–RuO2–IrO2–SnO2 anodes prepared by sol–gel process

Abstract

The present study focused on the morphology and electrochemical properties of Ti/TiO2–RuO2–IrO2–SnO2 anodes prepared by sol–gel process, using field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), potentiostatic polarization, cyclic voltammetry, electrochemical impedance spectroscopy (EIS), and accelerated corrosion test (ACT). The findings showed that the morphology of all the coatings is a cracked-mud morphology after heat treatment, including cracks with different widths between 100 nm and 1 μm. The results of phase analysis of the anode surfaces indicated a better coverage of substrate by Ti/TiO2–RuO2–IrO2–SnO2 anode with a molar ratio of 60:25:5:10 as compared to two other anodes with molar ratios of 60:25:10:5 and 60:20:5:15. It was also found that Ti/TiO2–RuO2–IrO2–SnO2 anode with a molar ratio of 60:25:5:10 exhibits a longer lifetime (543 min) and better electrocatalytic property, as it tends to enhance the chlorine gas evolution so that the reaction occurs at a lower potential with a lower slope. EDX analysis of this anode surface showed a less reduction in the content of active elements (Ru, Ir, and Sn) after ACT than anodes 1 and 3, to about 59%, 82%, and 75% of the original, respectively.