Highly stabilized and rapid sensing acetone sensor based on Au nanoparticle-decorated flower-like ZnO microstructures

Abstract

Hierarchical flower-like ZnO microstructures were synthesized by a two-step hydrothermal method. Flower-like ZnO microstructures were made up of ZnO nanorods (NBs) with the diameters of about 100 nm. Then Au nanoparticles (NPs) with the diameter of 10–20 nm were decorated on the surface of flower-like ZnO microstructures by the wet decorating process. The properties of the sensing material were analyzed with X-Ray diffraction (XRD), Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX), Transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). Gas sensing device was prepared by thick film technology and tested primarily for acetone gas at different testing temperatures as well as concentrations. At the optimum operating temperature of 280 °C the sensor showed a good response and rapid response-recovery time. Furthermore, because of the stable microstructure the sensor had an excellent stability for six months.