Growth and properties of ZnO nanorods by RF-sputtering for detection of toxic gases

There is a strong demand for nanostructured materials prepared by an industrially-scalable technique. The current work is devoted to the preparation of ZnO polycrystalline nanorods using RF sputtering at 400 °C and Sn droplets as a catalyzer layer, for highly sensitive gas sensors. Nanorods with diameters ranging from 100 to 200 nm can be tailored by changing the RF power and the deposition time. Raman and PL spectroscopy indicate that the material obtained is ZnO, with a characteristic emission spectrum in the UV region and in the visible. The functional properties of the ZnO nanorods were investigated by studying the response to CBRN (acetonitrile and DMMP), explosive (H), and pollutant gases (HS, acetone, and NO) in the temperature range 200-500 °C. The sensors showed good response to reducing gases at higher temperatures (500 °C) and to NO at lower temperature (200 °C).