Various sized nanotubes on TiZr for antibacterial surfaces

► Nanotubes on TiZr alloy with various sized nanotubes produced by two step anodization. ► The TiO2 nanotubes on TiZr have diameters between 20 and 70 nm. ► Inhibition of the growth of E. coli bacteria was evaluated. ► Highest antibacterial behavior is observed for nanotubes with diameters of 20-30 nm. ► The highest bacteria growth inhibition is for nanotubes with largest active surface.