Despite the well-known favorable chemical and mechanical properties of titanium-based materials for orthopedic and dental applications, poor osseointegration of the implants, bacteria adhesion, and excessive inflammatory response from the host remain major problems to be solved. Here, the antioxidant and anti-inflammatory enzyme-like abilities of ceria (CeO_x) were coupled to the advantageous features of titanium nanotubes (TiNTs). Cost-effective and fast methods, such as electrochemical anodization and drop casting, were used to build active surfaces with enhanced bioactivity. Surface composition, electrochemical response, and in vitro ability to induce hydroxyapatite (HA) precipitation were evaluated. The amount of cerium in the coating did not significantly affect wettability, yet a growing ability to induce early HA precipitation from simulated body fluid (SBF) was observed as the oxide content at the surface increased. The presence of 4%wt CeO_x was also able to stimulate rapid HA maturation in a (poorly) crystalline form, indicating an interesting potential to induce rapid in vivo osseointegration process.

Ruthenium oxide (RuOx) thin films were spin coated by thermal decomposition of alcoholic solutions of RuCl₃ on titanium foils and subsequently annealed at 400 °C. The effect of spin coating parameters, such as spinning speed, volume, and molar concentration of the precursor as well as the number of deposits, on the morphology and electrochemical performance of the electrodes was investigated. The films were characterized by scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDX), cyclic voltammetry (CV) with and without chloride, and linear sweep voltammetry (LSV). The prepared materials were also compared to drop cast films and spin-coated films obtained by adopting low-temperature intermediate treatments. The results indicate that even dispersion of the oxide layer was always achieved. By tuning the spin coating parameters, it was possible to obtain different electrochemical responses. The most influential parameter is the number of deposits, while the concentration of the precursor salt and the rotation speed were less relevant, under the adopted conditions.

The development of mixed oxide electrodes is being intensively investigated to reduce the high cost associated with the use of noble metals and to obtain versatile and long-lasting devices. To evaluate their use for charge storage or anodic oxidation, in this paper, thin-film electrodes coated with ruthenium (RuO_x) and copper oxide (CuO_x) are fabricated by thermal decomposition of organic solutions containing the precursors by drop-casting on titanium (Ti) foils. The coating consisted of four layers of metal oxide. To investigate the effect of copper (Cu) on electrochemical performances, different approaches are adopted by varying the ratios of precursors’ concentration and including a RuO_x interlayer. A comparison with samples obtained by only RuO_x has been also performed. The electrodes are characterized using scanning electron microscopy (SEM), cyclic (CV) and linear sweep (LSV) voltammetry, electrochemical impedance spectroscopy (EIS), and corrosion tests. The addition of Cu enhances the capacitive response of the materials and promotes electron transfer reversibility. The coatings obtained by the highest Ru:Cu ratio (95:5) exhibit a more uniform surface distribution and increased corrosion resistance. The interlayer is beneficial to further reduce the corrosion susceptibility and to promote the oxygen evolution but detrimental in the charge storage power. The results suggest the possibility to enhance the electrochemical performance of expensive RuO_x through a combination with a low amount of cheaper and more abundant CuO_x.

Growing thin layers of mixed-metal oxides on titanium supports allows for the preparation of versatile electrodes that can be used in many applications. In this work, electrodes coated with thin films of ruthenium (RuOx) and manganese oxide (MnOx) were fabricated via thermal decomposition of a precursor solution deposited on a titanium substrate by spin coating. In particular, we combined different Ru and Mn precursors, either organic or inorganic, and investigated their influence on the morphology and electrochemical properties of the materials. The tested salts were: Ruthenium(III) acetylacetonate (Ru(acac)₃), Ruthenium(III) chloride (RuCl₃·xH₂O), Manganese(II) nitrate (Mn(NO₃)₂·4H₂O), and Manganese(III) acetylacetonate (Mn(acac)₃). After fabrication, the films were subjected to different characterization techniques, including scanning electron microscopy (SEM), polarization analysis, open-circuit potential (OCP) measurements, electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV), cyclic voltammetry (CV), and galvanostatic charge–discharge (GCD) experiments. The results indicate that compared to the others, the combination of RuCl₃ and Mn(acac) produces fewer compact films, which are more susceptible to corrosion, but have outstanding capacitive properties. In particular, this sample exhibits a capacitance of 8.3 mF cm⁻² and a coulombic efficiency of higher than 90% in the entire range of investigated current densities.