Corrosion Study of TiO₂ Nanotubes Decorated with Ag Silver Nanoparticles Prepared by Photoreduction Process

The electrochemical anodization has become increasingly common as a surface modification technique for biomaterials. One specific application involves the modification of TiO2 nanotube (TiO2-NTs) coatings by loading Ag silver nanoparticles (Ag-NPs) onto the TiO2-NTs. The Ag nanoparticles were carried out using the photoreduction process by varying the anodization potential starting from 20 V to 70 V. The samples were characterized using several physical methods such as x-ray diffraction (XRD), scanning electron microscopy (SEM) combined with energy-dispersive x-ray spectroscopy (EDXS) as well as the transmission electron microscope (TEM). The x-ray diffraction (XRD) analysis revealed that the samples crystallized in anatase at 400 °C regardless of the anodization potential during annealing. The scanning electron microscopy (SEM) revealed that the vertically aligned TiO₂-NTs were characterized by a homogeneous morphology and had uniform distribution on the substrate. The diameter of the TiO₂-NTs reached a dimension of the order of 100 nm. Lastly, the decoration of the TiO₂-NTs surface with silver nanoparticles was examined using the transmission electron microscopy (TEM). The incorporation of AgNPs on TiO₂ nanotubes enhanced the passive layer resistance considerably and reduced corrosion current density (I_corr), compared to the substrate. High corrosion resistance was obtained especially for TiO₂ + 10 min Ag coating sample (E_corr = − 0.119 V and I_corr = 5.18 mA.cm⁻²).