Hydrothermal oxidization preparation of ZnO nanorods on zinc substrate

ZnO nanorods were prepared via a simple hydrothermal oxidization process on zinc substrate. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrum (EDS), transmission electron microscopy (TEM) and photoluminescence (PL) spectrum were used to characterize the nanorods. The nanorods are single crystalline wurtzite structure with a length longer than 10 μm. The effects of the hydrothermal temperature, pressure and time on the morphology, diameter and length of the ZnO nanorods have been also analyzed. It is considered that time keeping the temperature and pressure is the main factor that influences the length of the ZnO nanorods. The PL spectrum shows a strong blue light emission at 439 nm, which is considered to be caused by radiative recombination of photo-generated holes with singularly ionized oxygen vacancies. The growth process of the ZnO nanorods is proposed based on the solid–liquid–solid (SLS) mechanism.