Ppb-Level N-propanol Gas Sensor Based on Ce Doped Flower-Like In2O3 Compounded on rGO Nanosheets

N-propanol gas inhaled by human body can cause vomiting, headache, and other symptoms, causing serious harm to health. Therefore, it is indispensable to research a highly sensitive and efficient $\boldsymbol {n}$ -propanol gas sensor. However, conventional gas sensors cannot detect ppb-level $\boldsymbol {n}$ -propanol gas. In this article, combining the excellent properties of rare earth element Ce and reduced graphene oxide (rGO), 4%rGO-In2O3-4%Ce ternary composite was prepared by one-step hydrothermal method. The micromorphology and elemental composition of 4%rGO-In2O3-4%Ce were characterized by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS), respectively. The microstructure of rare earth element Ce-doped flower-like In2O3 composited on rGO had been successfully prepared. Then the gas sensitivity of 4%rGO-In2O3-4%Ce nanocomposite material was tested. The experiment indicated that, compared with pure In2O3, 4%Ce-In2O3, and 4%rGO-In2O3, the 4%rGO-In2O3-4%Ce has the better gas sensitivity to $\boldsymbol {n}$ -propanol, and the optimal operating temperature of 4%rGO-In2O3-4%Ce was 200 °C. Furthermore, the 4%rGO-In2O3-4%Ce gas sensor could detect 1 ppb $\boldsymbol {n}$ -propanol gas. Moreover, the gas-sensitive mechanism of 4%rGO-In2O3-4%Ce to $\boldsymbol {n}$ -propanol gas was explained.