Abstract:

By using the seeded growth method and solution treatment, a layer of torch-like ZnO nano-array thin film was obtained on the surface of gas sensor devices. Proceeding at low temperature, this method was both environment-friendly and energy-conserving. The thin film’s X-ray diffraction (XRD) pattern indicated that the components of the film were mainly derived from Wurtzite type ZnO. The structural information obtained with field-emission scanning electron microscopy (FESEM) showed the morphology of hollow ZnO nanotorches with a height of 5 μm, an outside diameter of 2 μm and thickness of 200 nm,  were generally even-sized as well as regularly arrayed. These ZnO nanotorches were mainly assembled by even finer ZnO particles with a diameter of around 20 nm. Also , a possible growth mechanism of the ZnO nanotorches was discussed. Finally, the gas sensitivity to ethanol of these  hollow ZnO nanotorches material was measured, and the result demonstrated that the ZnO nanotorches had better gas sensitivity  than those already known ZnO materials with morphologies such as nanorods and nanowalls.

Key words: ZnO nanotorches, morphology control, seeded growth, solution treatment, gas sensitivity