Fabrication of patterned TiO2 nanotube layers utilizing a 3D printer platform and their electrochromic properties

[Display omitted] •A modified 3D printer is used to easily create patterned TiO2 nanotube layers.•The TiO2 nanotube layer is formed at a high speed of 1 mm/s on titanium substrates.•The viologen-anchored TiO2 (V-TiO2) showed significantly improved electrochromic performance. Anodization enables nano-structure fabrication through electrochemical parameter control. While various approaches exist for creating localized or patterned oxide layers, many are complex and time-consuming. This study adopted a commercial 3D printer for high-speed (1 mm/s) anodization, forming TiO2 nanotube layers on Ti substrates in G-code-designed patterns. Comprehensive characterization using XRD, SEM, XPS, and simulated electric field distribution analysis revealed well-defined nanostructures and provided insights into the formation mechanism. Furthermore, viologen-anchored TiO2 showed significantly improved electrochromic performance compared to pristine TiO2, with a higher reflectance difference (46.2% vs. 6.85%). This 3D printing-anodization hybrid method offers a rapid approach to fabricating patterned TiO2 nanostructures, showing promise for electrochromic devices with enhanced optical modulation capabilities.