Fabrication of Au decorated porous ZnO microspheres with enhanced gas sensing properties

Abstract

Porous ZnO and Au decorated ZnO porous microspheres have been successfully synthesized for gas sensors. Specifically, the ZnO porous microspheres were fabricated through a low temperature hydrothermal (60°C) route followed by a thermal treatment process. The surface area of the ZnO porous microsphere was 33.9m2/g. Gas sensing test results show that the Au decorated ZnO porous microspheres exhibited excellent gas sensing performance to ethanol and acetone gases including high response, low optimum operating temperature and fast response and recover speed. In particular, Au decorated ZnO exhibited high response to ethanol under low operating temperature (100°C). The enhancement of the sensing properties can be mainly attributed to the fact that the porous structure provides a high reaction surface area and abundant channels for the probe gas and oxygen, and Au nanoparticles act as the catalyst to promote the reaction of the probe gas molecules with oxygen ions.