Facile synthesis and superior ethyl acetate sensing performance of Au decorated ZnO flower-like architectures

Au decorated ZnO flower-like architectures assembled from single crystal nanowires have been successfully synthesized. A facile thermal treatment route was employed, utilizing the composite gel of zinc acetate and polyvinyl pyrrolidone (PVP) as raw materials and was followed by a subsequent Au reduction process. PVP served as a surfactant and played a critical role in the generation of crystalline nanowires as well as for the formation of ZnO flower-like structure. Based on control experiments, the growth mechanism of ZnO flower-like structures was proposed. The diameter of ZnO crystalline nanowires was approximately 50-80 nm and the size of Au particles deposited on the surface of ZnO nanowires was approximately 5 nm. When tested as gas sensing material, the as-prepared Au decorated ZnO flower-like architecture exhibited superior gas sensing performance compared to ethyl acetate in terms of high response (approximately 102 at 100 ppm), short response and recovery times (10 s and 13 s, respectively), and low operating temperature (240 °C). The superior gas sensing performances are mainly attributed to the synergistic effects of ZnO crystalline nanowires and Au nanoparticles, as well as to the flower-like structure.