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 degrees C) route followed by a thermal treatment process. The surface area of the ZnO porous microsphere was 33.9 m(2)/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 degrees 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. (C) 2017 Elsevier B.V. All rights reserved.