« Previous AbstractAmphiphilic Oxygenated Amorphous Carbon-Graphite Buckypapers with Gas Sensitivity to Polar and Non-Polar VOCs    Next AbstractMicronutrient Fertilization of Greenhouse Cucumbers Mitigates Pirimicarb Resistance in Aphis gossypii (Hemiptera: Aphididae) »

ACS Sens

Title:		MOF/MWCNT-Nanocomposite Manipulates High Selectivity to Gas via Different Adsorption Sites with Varying Electron Affinity: A Study in Methane Detection in Parts-per-Billion
Author(s):		Homayoonnia S; Phani A; Kim S;
Address:		"Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta T2N 1N4, Canada"
Journal Title:		ACS Sens
Year:		2022
Volume:		20221212
Issue:		12
Page Number:		3846 - 3856
DOI:		10.1021/acssensors.2c01796
ISSN/ISBN:		2379-3694 (Electronic) 2379-3694 (Linking)
Abstract:		"Metal-organic frameworks (MOFs) present specific adsorption sites with varying electron affinity which are uniquely conducive to selective gas sensing but are typically large-band-gap insulators. On the contrary, multiwall carbon nanotubes (MWCNTs) exhibit superior mesoscopic transport exploiting strong electron correlations among sub-bands below and above the Fermi level at room temperature. We synergize them in a new class of nanocomposites based on zeolitic imidazolate framework-8 (ZIF-8) and report selective sensing of CH(4) in approximately 10 parts-per-billion (ppb) with a determined limit of detection of approximately 0.22 ppb, hitherto unprecedented. The observed selectivity to CH(4) over non-polar CO(2), polar volatile organic compounds, and moisture has roots in competing electron-sharing mechanisms at its different adsorption sites. This important result provides a significant reference to guide future MOF-related composite research to achieve the best sensing performance. On molecular adsorption, MWCNTs facilitate electrical transport via manipulating the ZIF-8 band gap to show a p-type semiconductor behavior with lower activation energy to induce a measurable resistance change. Excellent repeatability and reversibility are shown. A carbon-engineered MOF composite has the potential to actuate similar selective response to low reactive gases via carrier manipulation in the energy band gap"
Keywords:		Zif-8 band gap chemiresistive sensor metal-organic frameworks methane sensing multiwall carbon nanotubes;
Notes:		"PubMed-not-MEDLINEHomayoonnia, Setareh Phani, Arindam Kim, Seonghwan eng 2022/12/13 ACS Sens. 2022 Dec 23; 7(12):3846-3856. doi: 10.1021/acssensors.2c01796. Epub 2022 Dec 12"