2. Factor affecting geometry and composition of TNA

The anodic growth of self-organized tubular structure is well known as the equilibrium reaction between electrochemical oxidation at the metal/electrolyte interface and chemical dissolution at the oxide/electrolyte interface [12, 13]. The structural characteristics of the nanotube arrays can be controlled through various synthesis parameters, including applied potential [14–16], anodization time [14, 17, 18], electrolyte type and chemical composition [12, 13, 19]. Therefore, this section provides a comprehensive review on the influence of aforementioned parameters on the formation of TNA.
