Growth and selective acetone detection based on ZnO nanorod arrays

High preferential c-axis oriented ZnO nanorods aligned on SiO2/Si substrates with interdigital electrodes have been successfully fabricated through aqueous solution methods. The transparent ZnO buffer layer covered on both the conducting electrodes and the insulating SiO2 spacer regions acts as lattice-matched template for the assembly of c-axis oriented ZnO nanorod arrays, and the subsequent growth of ZnO nanorods has been completed via a low temperature hydrothermal process. Detailed structural characterizations reveal that the as-synthesized nanorods are single crystalline, with a hexagonal phase, and with growth along the [0 0 1] direction. The gas-sensing properties of ZnO nanorod thin films are studied. It is found that the ZnO nanorod thin film sensor exhibits excellent sensing properties towards acetone at 300 °C with the response time shorter than 5 s.