Electrodeposition of nanostructured Ti/(Ru + Ti + Ce)O2 coatings

Abstract

A nanostructured ternary coating of Ti/(Ru + Ti + Ce)O2 was prepared by the conventional electrodeposition on the titanium substrate as the cathode with different numbers of coating layers. The main objective of this work was to study nanostructured coatings of ceramic materials. For this purpose, the amount of precursor materials in the electrolyte was a variable parameter. Furthermore, the salt of TiCl4/RuCl3·xH2O/Ce(NO3)3·6H2O with different amounts, hydrogen peroxide, methanol, and distilled water were used as an aqueous–unaqueous bath. In addition, the coated samples were put to heat at 300, 450, 650, and 850 °C in an electric furnace for 1 h. The crystalline phase of the coating was characterized by X-ray diffraction (XRD). The chemical composition and microstructure of the coating were studied using energy-dispersive spectroscopy (EDS) and scanning electron microscopy analysis (SEM). Moreover, the electrochemical measurement of Ti/(Ru + Ti + Ce)O2 coatings was carried out. Results show that with the increase in the number of coating layers, the quality of morphology is improved. Then, the best quality of coatings is obtained at six layers on the titanium substrate with electrolyte including TiO2/RuO2/CeO2 with the molar ratio of 70:5:25 after heat treatment at 450 °C for 1 h. Besides, with the increase in CeO2 content from 5 wt% to 25 wt% and the number of coating layers, higher thickness of about (20.0 ± 0.1) µm and minimum over potential for chlorine evolution were obtained.