Conversion of large-scale oriented ZnO rod array into nanotube array under hydrothermal etching condition via one-step synthesis approach

In order to obtain oriented nano/micro-structured materials via a simple method for potential nanoelectronic/microelectronic applications, a study on preparation of oriented ZnO structures under hydrothermal reaction condition was carried out. The deposition film was characterized with scanning electron micrographs (SEM), X-ray diffraction (XRD) and photoluminescence (PL) spectra. The experimental results under the optimized reaction condition indicated that a ZnO nanotube array on a glass substrate can be directly formed via a one-step approach in ammonia aqueous solution. The XRD results showed the highly preferential growth of the ZnO nanotubes along the c-axis orientiation. The PL results showed the strong photoluminescence property of the ZnO nanotube array in a wide light range (387–416 nm). The possible mechanism to form the ZnO nanotube array via such a simple in-situ deposition approach was discussed. This template-less, surfactant-free and seed-free aqueous synthesis method makes it possible to synthesize large-scale, low-cost and well-oriented ZnO nano/microtube film at moderate temperature.