Electrochemical and Mechanical Properties of Hexagonal Titanium Dioxide Nanotubes Formed by Sonoelectrochemical Anodization

Katarzyna Arkusz; Aleksandra Jędrzejewska; Piotr Siwak; Mieczysław Jurczyk

doi:10.3390/ma17092138

Electrochemical and Mechanical Properties of Hexagonal Titanium Dioxide Nanotubes Formed by Sonoelectrochemical Anodization

Materials (Basel). 2024 May 2;17(9):2138. doi: 10.3390/ma17092138.

Authors

Katarzyna Arkusz¹, Aleksandra Jędrzejewska¹, Piotr Siwak², Mieczysław Jurczyk¹

Affiliations

¹ Department of Biomedical Engineering, Faculty of Mechanical Engineering, University of Zielona Gora, 9 Licealna Street, 65-417 Zielona Gora, Poland.
² Institute of Mechanical Technology, Faculty of Mechanical Engineering, Poznan University of Technology, 3 Piotrowo Street, 60-965 Poznan, Poland.

Abstract

This study aimed to investigate the fabrication and characterization of hexagonal titanium dioxide nanotubes (hTNTs) compared to compact TiO₂ layers, focusing on their structural, electrochemical, corrosion, and mechanical properties. The fabrication process involved the sonoelectrochemical anodization of titanium foil in various electrolytes to obtain titanium oxide layers with different morphologies. Scanning electron microscopy revealed the formation of well-ordered hexagonal TNTs with diagonals in the range of 30-95 nm and heights in the range of 3500-4000 nm (35,000-40,000 Å). The electrochemical measurements performed in 3.5% NaCl and Ringer's solution confirmed a more positive open-circuit potential, a lower impedance, a higher electrical conductivity, and a higher corrosion rate of hTNTs compared to the compact TiO₂. The data revealed a major drop in the impedance modulus of hTNTs, with a diagonal of 46 ± 8 nm by 97% in 3.5% NaCl and 96% in Ringer's solution compared to the compact TiO₂. Nanoindentation tests revealed that the mechanical properties of the hTNTs were influenced by their diagonal size, with decreasing hardness and Young's modulus observed with an increasing diagonal size of the hTNTs, accompanied by increased plastic deformation. Overall, these findings suggest that hTNTs exhibit promising structural and electrochemical properties, making them potential candidates for various applications, including biosensor platforms.

Keywords: corrosion resistance; hexagonal titanium dioxide nanotubes (hTNTs); mechanical properties; morphology and composition; sonoelectrochemical anodization.

Grants and funding

This research was funded by the program of the Polish Minister of Science and Higher Education under the name ‘Regional Initiative of Excellence’ in 2019–2023, project no. 003/RID/2018/19, funding amount 11 936 596.10 PLN, and under the program SPUB, project no. 40/530410/SPUB/SP/2022.