Synthesis and characterization of ZnO nanowires by solvothermal method and fabrication of nanowire-based ZnO nanofilms

In our work, we prepared zinc oxide (ZnO) nanowires (NWs) by a simple solvothermal method. Zinc acetate and NaOH were used as the precursors and ethanol as the solvent. The process flow is a simply one step process that can synthesize a mass of ZnO NWs with high aspect ratios. The solvothermal process typically results in the synthesis of ZnO NWs, having characteristic lengths and dimensions of 1 um ~ 10 um and 10 nm ~ 50 nm, respectively. Additionally, we have developed a novel method for the fabrication of ZnO nanofilms (NFs) based on the ZnO NWs process. Following uniform dispersion in ethanol, the ZnO NWs were filtered out using micro porous filtration. Consequently, ZnO NWs were stacked on the microfiltration membrane with uniform thickness about 160 um ~ 170 um. After drying at room temperature, a thin ZnO NFs resulted, which could be wholly stripped off from the membrane. The ZnO NWs and NFs were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM). The XRD and SEM figures show that the ZnO NWs are good single crystals growing along the [0001] direction with wurtzite crystal structure.