Constructing a Resistive Gas Sensor Based on the Highly Stable Mil-53(Fe)/Ag/CNT Ternary Nanocomposite for Sensing Polar Volatile Organic Compounds Such as Methanol

In this study, MIL-53(Fe) nano-sized crystals were synthesized under microwave irradiation with various powers (80, 100 W) and ‎times (5, 10 min). Then, the crystals that had the best porous ‎structure were selected to prepare the MIL-53(Fe)/Ag/CNT ternary nanocomposite. Nano-sized crystals were characterized by scanning electron microscopy, Fourier transform infrared ‎spectroscopy, X-ray diffraction, and specific surface area analysis. Prepared nanocomposite was used to fabricate a resistive gas sensor device for detecting volatile organic compounds in environmental conditions (10% relative humidity and 25°C). The resistive gas sensor showed higher response to volatile organic compounds with higher polarity such as methanol. The lowest detectable concentration of methanol was 1.2 ppm. Linearity of the calibration curve was obtained in a wide range from 0 to 30 mg/L.