Highly sensitive and low operating temperature SnO2 gas sensor doped by Cu and Zn two elements

Abstract

In order to improve the sensitivity and reduce working temperature of tin oxide sensor, two elements of copper, zinc doped tin oxide gas sensor has been successfully synthesized using one-step hydrothermal method. During the preparation process, the common zinc acetate and cupric chloride were adopted as copper, zinc source, respectively. The morphology and structure of the as-prepared sample were further characterized using X-ray diffraction (XRD), energy dispersive spectrometry (EDS), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HR-TEM), selected area electron diffraction (SAED), and ASAP 2460 (used for mesoporous distribution analysis). It’s found that octahedral nanoparticle enclosed by (221) high energy crystal facet had been prepared. The results also demonstrated that the as-prepared tin oxide doped by copper, zinc elements was single crystal structure of tetragonal system and the size of the crystalline grain was about 50nm. During the gas sensing performance experiments, the sample’s gas-sensing properties have been proved to be greatly enhanced in sensitivity and working temperature. The response value to 50ppm ethanol at 110°C of the sample was increased to 210 that was almost 10 times higher than reported values. Besides, the optimal working temperature was decreased to be 110°C from reported 350°C.