In situ investigation of initial stage growth of anodic ZrO2 nanotubes by spectroscopic ellipsometry

• SE is first used for in situ probing of the initial stage growth of anodic ZrO2.
• Four successive phases are clearly distinguished during the first 80s anodization.
• The growth dynamics of anodic ZrO2 film is mainly dependent on that of porous layer.
• The anodic ZrO2 growth dynamics obeys the linear kinetics with a rate of 25.6 nm/s.
• This method can be applicable for screening of BmTβH inhibitors.

The highly sensitive spectroscopic ellipsometry (SE) was first employed to in situ monitor the growth of anodic ZrO2 nanotubes in F−-containing inorganic electrolyte within the first 80 s anodization. The evolution of the characteristic parameters of anodic ZrO2 film upon anodization was obtained by deconvoluting the ellipsometric spectra with appropriate models. Four successive phases, namely, formation of compact barrier layer, formation of pores, pore evolution to nanotubes and the nanotube steady-growth, were clearly distinguished during the initial stage of anodization; even the third phase was indiscernible from the i–t curve and likely to be ignored. The growth dynamics of the anodic ZrO2 film was mainly dependent on that of the porous layer, obeying the linear growth kinetics with a rate of 25.6 nm/s.