Synthesis and humidity sensing properties of feather-like ZnO nanostructures with macroscale in shape

Feather-like ZnO nanostructures with macroscale in shape have been synthesized via the vapor-phase transport method with Cu catalyst at 900 degrees C. Two basic parts build this novel feather-like structure: a long central trunk with length several millimeters and lots of secondary branches composed of well-oriented nanorods. The humidity sensor based on as-synthesized product shows high sensitivity and fast response time due to unique structure of the ZnO feathers with large surface-to-volume ratio. It can be found that the resistance of the ZnO materials decreases obviously with increasing relative humidity (RH) at room temperature (26 degrees C). The results demonstrate that these ZnO nanostructures are potential to be used as effective and high performance humidity sensors. (c) 2007 Elsevier B.V. All rights reserved.