One-pot synthesis of Au-supported ZnO nanoplates with enhanced gas sensor performance

A novel sensor material of Au nanoparticles-functionalized ZnO nanoplates was fabricated via a facile one-pot hydrothermal method. The obtained Au-functionalized ZnO nanoplates were characterized by means of X-ray diffraction (XRD), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). Comparative gas sensing studies were carried out on both pristine ZnO and Au/ZnO nanoplates in order to investigate the effect of Au nanoparticles on the sensor performances. Obtained results demonstrated that the Au/ZnO nanoplate sensor exhibited faster response and recovery as well as higher response compared with the pristine ZnO sensor. At 300 °C, the response time of Au/ZnO to 5 ppm ethanol is 13 s, while that of ZnO is up to 135 s. The enhanced sensor performances were attributed to the unique chemical properties of Au nanoparticles and the electronic metal–support interaction. A possible sensing mechanism was proposed for the Au/ZnO nanoplates.