Electrochemical stability of TiO2 nanotubes with different diameters in artificial saliva

► We measured the effect of the diameter of TiO2 nanotube on the corrosion behavior. ► With increasing the diameter led to the variation of the electrochemical stability. ► The existence of TiO2 nanotube improved the stability below 60 nm in diameter. ► Changes depend on the diameter and thickness of the barrier layer.