Pulse-like highly selective gas sensors based on ZnO nanostructures synthesized by a chemical route: Effect of in doping and Pd loading

A low-temperature chemical route was used for the synthesis of hexagonal ZnO nanorods having an aspect ratio of ∼10. The sensing properties of the thick films made from these nanorods were investigated. It was observed that the surface irregularities, calcination temperature and operating temperature altered the structure and thus the gas sensing properties. An effort was made to create surface misfits by doping indium into the zinc oxide and study the changes in the sensor performance. Effect of palladium loading on the selectivity was also investigated. It was observed that indium doping favors the ethanol sensing and palladium loading enhances the sensor response toward LPG. The quick response, high sensor response and selectivity are the main features of this work.