Synthesis and Formation Mechanism of ZnO Nanotubes via an Electrochemical Method

摘要

ZnO nanotube arrays were synthesized by a two-step process: electrodeposition and selective dissolution. In the first step, ZnO nanorod arrays were grown on an Au/Si substrate by using a homemade electrodeposition system. ZnO nanorod arrays were then selectively dissolved in an etching solution composed of 0.125 M NaOH, resulting in hollow ZnO nanotube arrays. It is suggested that the formation mechanism of the ZnO nanotube arrays might be attributed to the preferred surface adsorption of hydroxide ion (OH1) on a positive polar surface followed by selective dissolution of the metastable Zn-terminated ZnO (0001) polar surface caused by the difference in the surface energy per unit area between the ZnO nanorod and nanotube.