Special nanostructure control of ethanol sensing characteristics based on Au@In2O3 sensor with good selectivity and rapid response
Abstract
A unique Au@In2O3 core–shell nanostructure was firstly prepared through a simple sol–gel method, the structure and morphology were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX). The results showed that unique architectures were core–shell nanostructure assembled from an Au core and an In2O3 shell. The gas sensing properties of the as-prepared pure In2O3 and Au@In2O3 core–shell samples were tested toward various gases. The sensor based on a Au@In2O3 core–shell nanostructure showed excellent selectivity toward ethanol at the operating temperature of 160 °C, giving a response of about 36.14 to 100 ppm, which was about 1.5 times higher than that of the sensor based on pure In2O3. The τres and the τrec values of the Au@In2O3 sensor to 100 ppm ethanol were 4 s and 2 s respectively, while those of the pure In2O3 sensor were relatively long. The enhancement might be attributed to the unique core–shell structure and existence of a Schottky junction between Au/In2O3.