High response and selective ag-SmFeO3 methanol gas sensors

Due to the special structure and properties, the metal oxides have potential applications. The molecular imprinting technique has been promisingly applied in the preparation of gas-sensitive materials. In this paper, Ag-SmFeO₃ methanol gas sensor with different ratio of monomer was prepared by molecular imprinting technique. Based on the observation of X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and transmission electron microscope (TEM), the structure and morphology of the products were characterized. The methanol gas-sensing characteristics for the sample were examined between 175°C and 295°C. The experimental results indicate that the sensor based on the molecular imprinted Ag-SmFeO₃ shows excellent gas-sensing properties to methanol gas. At the optimal operating temperature of 295°C, the response of the sensor based on molecular imprinted Ag-SmFeO₃ to 5 ppm methanol is 24.4, while to other test gases, the response is all lower than 6. With increasing concentration of methanol, the response of the sensor based on the sample Ag-SmFeO₃ increases. The response and recovery times for the sample to methanol gas are 41 s and 53 s, respectively.