Barrier-oxide layer engineering of TiO2 nanotube arrays to get single- and multi-stage Y-branched nanotubes: Effect of voltage ramping and electrolyte conductivity

摘要: Abstract Single and multi-stage Y-branched TiO 2 nanotube arrays (TNAs) have been fabricated by a voltage ramping down process using potentiostatic two-step anodization in 0.5 wt% hydrofluoric acid (HF)/glycerol (1:2 volume ratio) electrolyte. Initially, the is kept at 40 V for 3 h then it ramped to different voltages (e.g. 30 V, 34 V, 36 V, 38 V 39 V) rate of either −1.0 V s −1 or −0.5 V s one time two-time aged electrolytes. The growth mechanism Y-branching TNAs modeled explained terms unequal interfacial movements two interfaces across barrier oxide layer (BOL) under non-steady-state regime. ‘pinched off’ area BOL propagation front can be controlled effectively with relative levels electrolyte's conductivity obtain TNAs.