Fast and low concentration detection of liquefied petroleum gas by Au-activated ZnO sensor

Highlights: • As-synthesized and Au-activated ZnO samples are studied as an LPG sensor. • The operating temperature of ZnO sensor decreases after activation by Au layer. • LPG sensitivity of ZnO sensor shows a significant enhancement after activation. • The Au-activated ZnO sensor is able to quick response to LPG. - Abstract: The development of a reliable and fast liquefied petroleum gas (LPG) sensor due to its highly inflammable and explosive nature is crucial to ensure a safe and healthy environment. In this research, as-synthesized and Au-activated nanostructured ZnO were prepared and investigated as an LPG sensor. The samples were structurally and morphologically characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). LPG sensitivity of the sample shows a significant enhancement after activation with the Au layer. The results also show that the Au-activated sample is able to detect the LPG in the range of 100–1000 ppm (and more concentrations) with the response time of 33-18 S that can be remarkable compared to the previous reports attributed to different materials and technologies.