Surface modification of titanium oxides by platinum nanoparticles: Implications for corrosion and wear resistance in biomedical devices

In this work, we decorated biocompatible titanium dioxide (TiO2) nanoscale films with platinum (Pt) using anodization and photoreduction, a simple and efficient route to synthesize functional nanotubular coatings. The anodization was performed at 60 V and 27 °C for 120 minutes. Morphological characterizations using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed a highly ordered TiO2 nanotubular structure with an inner diameter of 72.99 nm and an outer diameter of 33.10 nm. Our study focused on the physicochemical, electrochemical, and tribological characterization of the coatings using scratch tests. The results showed a dense and uniform morphology coupled with enhanced interfacial properties. The adhesion of the TiO2 coatings was evaluated using scratch tests, and the Pt/TiO2 layers demonstrated a critical adhesion load (LC3) of 7.06 after 3 hours of photoreduction. The tribological properties were studied using a multi-pass scratch test at constant loads of 1, 2, and 3 N, which enabled the determination of the friction coefficient and the energy rate. The friction coefficients decreased as the load increased. It was observed that the wear energy increases with increasing load, but the number of hours of Pt nanoparticle decoration by the photoreduction method reduced the energy dissipated during wear. The specific wear energies were 1.354, 3.984, and 8.082 J for 1, 2, and 3 N, respectively. TiO2 thin films, known for their biocompatibility and biological performance, have shown tribological properties that make them suitable for use in hip and knee implants. In addition to their mechanical and biological advantages, The study highlights the critical role of deposition time in optimizing the anti-corrosion performance of Pt/TiO2 coatings. The samples prepared with 2 hours of photoreduction demonstrate superior barrier properties, characterized by an exceptionally low Qdl = 0.006 F/cm2 and near-ideal capacitive behavior (n = 0.73), while maintaining Rct = 3.2 Ω⋅cm2. These findings establish Pt/TiO2 as a promising protective coating for demanding biomedical and industrial applications.