ZnO nanorods decorated with Au nanoparticles applied as gas sensors

G. Gasparotto, T. Mazon, G. Gasparotto, R.A. Silva, M.A. Zaghete, L.A. Perazolli, J.A. Varela

Keywords: ZnO, Au nanoparticles, gas sensor


Zinc oxide (ZnO) is a n-type semiconductor with energy band gap of 3:37 eV and a large binding energy of 60 meV at room temperature. ZnO nanostructures can be easily obtained with different morphologies by different methods. Recently, researchers have demonstrated that the incorporation of Au nanoparticles into ZnO nanorods exhibit interesting chemistry and physical properties. However, in order to achieve better electrical, optoelectronic, and biological behaviors of ZnO/Au nanocomposites for industrial applications, alternative treatments and processes are required. In this paper, vertically aligned ZnO NRs were grown by using a simple wet method. Au NPs were deposited on ZnO NRs by sputtering. Chemical bath deposition was used to grow ZnO nanorods at 90 ° C for 1 h. The Au nanoparticles are deposited by sputtering. The samples were characterized by FE-SEM and gas sensing measurements. The Au NP decorated ZnO nanorods showed a uniform distribution of the nanoparticles throughout the surface. The gas sensor measurements showed that ZnO nanostructures showing a typical behavior of a n-type semiconductor and a good sensitivity. The results indicate that the ZnO nanostructures have good sensor response for reducing gases and the samples decorated with Au NPs showed better response.