Nanoporous MIL-101(Cr) as a sensing layer coated on a quartz crystal microbalance (QCM) nanosensor to detect volatile organic compounds (VOCs). Issue 42 (7th August 2019)

• Record Type: Journal Article
• Authors: Haghighi, Elahe; Zeinali, Sedigheh
• Is Part Of: RSC advances. Volume 9:Issue 42(2019)
• Page Start: 24460
• Page End: 24470
• Publication Date: 2019-08-07
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c9ra04152d
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Metal–organic frameworks can be used as sensing layer in QCM fabrication because of their huge surface area. Abstract : The application of metal–organic frameworks (MOFs) as a sensing layer has been attracting great interest over the last decade, due to their high porosity and tunability, which provides a large surface area and active sites for trapping or binding target molecules. MIL-101(Cr) is selected as a good candidate from the MOFs family to fabricate a quartz crystal microbalance (QCM) nanosensor for the detection of volatile organic compound (VOC) vapors. The structural and chemical properties of synthesized MIL-101(Cr) are investigated by X-ray diffraction (XRD), Fourier-transfer infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) and so on. A stable and uniform layer of MOF is coated onto the surface of a QCM sensor by the drop casting method. The frequency of the QCM crystal is changed during exposure to different concentrations of target gas molecules. Here, the sensor response to some VOCs with different functional groups and polarities, such as methanol, ethanol, isopropanol, n -hexane, acetone, dichloromethane, chloroform, tetrahydrofuran (THF), and pyridine under N2 atmosphere at ambient conditions is studied. Sensing properties such as sensitivity, reversibility, stability, response time, recovery time, and limit of detection (LOD) of the sensor are investigated. The best sensor response is observed for pyridine detection with sensitivity of 2.793 Hz ppm −1 . The sensor shows short response/recovery time (less than two minutes), complete reversibility and repeatability which are attributed to the physisorption of the gases into the MOF pores and high stability of the device.