Investigation on flower like ZnO and effect of processing parameters on 'Green' ZnO gas sensors

Abstract

In the present study, we proposed synthesis of ZnO powder with flower like microstructure and its characterization by XRD, FESEM, and UV. Lead free thick film pastes were formulated using the synthesized ZnO powder, lead free glass frit and organic vehicle. The formulated pastes were then screen printed on alumina substrates for potential use as gas sensor. Further we have investigated the effects of different peak firing temperatures on the microstructure of thick films and their acetone vapour sensing properties. We further reports the preparation of thick films with varying weight percentages of lead free glass binder and its effect on microstructural and gas sensing properties. It was also found that loading an appropriate amount of Ag on ZnO enhances the gas sensing properties. The possible reason of the improved sensing property is that the metallic Ag distributed on the ZnO films enhances chemical adsorption and promote catalytic reaction at the surface.