High aspect ratio TiO2 nanotube layers obtained in a very short anodization time

Over the past years, growth of high aspect ratio (HAR) anodic TiO2 nanotubes in a very short time (minute scale) has remained challenging. In present report, nanotube (TNT) layers with HAR ≈ 450 were obtained during only 15 min optimized anodization. The key feature is use NH4F/H2O/ethylene glycol (EG) electrolytes addition lactic acid (LA) that prevents dielectric breakdown and enables anodization at higher potentials compared to classical NH4F/H2O/EG electrolyte without LA. thickness average diameter TNT for minutes’ 160 V approximately 80 µm 170 nm, respectively. Furthermore, we show first temperature anodizing, previously introduced as driving force time, can be avoided by an accurate optimization conditions room temperature. results clearly containing LA serve promising candidate ergonomic economic production on Ti substrates times, i.e. LA, significantly reduced from several hours or days 15–30 min.