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DOE OSTI · 2278642

Enhanced ZIF-8-enabled colorimetric CO 2 sensing through dye-precursor synthesis

Davey, Adrian K.·Li, Zhou·Lefton, Natalie·Leonhardt, Branden E.·Pourghaderi, Alireza·McElhany, Stuart·Popple, Derek·Dai, Chunhui·Kahn, Salman·Dods, Matthew N.·Zettl, Alex·Carraro, Carlo·Maboudian, Roya
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Abstract

The accumulation of carbon dioxide (CO 2 ) within enclosed spaces, along with volatile organic compounds, under certain humidity, temperature, and ventilation conditions is associated with detrimental human health symptoms such as fatigue. Color-based chemical sensing is a promising approach to detect CO 2 levels relevant to indoor air quality through producing fast, quantifiable output visible to the naked eye. In a prior work, a colorimetric gas sensor was fabricated through synthesizing the metal-organic framework, ZIF-8, as the adsorbent, followed by post-synthetic mixing with a dye, phenol red (PSP), and primary amine, ethylenediamine (ED). While this sensor (termed PSP-ED/ZIF-8) maintained its structural integrity in atmospheric conditions and exhibited an increasing fuchsia-to-yellow color change with increasing CO 2 levels in dry environment, the colorimetric response greatly suffered in the presence of humid CO 2 . Here in this work, a significantly improved colorimetric CO 2 sensor (referred to as ED/PSP:ZIF-8) is accomplished through directly incorporating phenol red in the ZIF-8 metal and linker precursor solutions and then blending with ethylenediamine. MATLAB-generated color distributions and in-situ ultraviolet-visible (UV-Vis) spectroscopic studies quantitatively demonstrate an enhanced colorimetric gas response of ED/PSP:ZIF-8 compared to that of PSP-ED/ZIF-8 across an important range of CO 2 for indoor air quality monitoring (500 – 3500 ppm) and across a range of humidity. The new sensor also exhibits high selectivity to CO 2 compared to select volatile organic compounds, such as acetone and ethanol, which contribute to human health symptoms experienced indoors. The enhanced performance is attributed to the proposed incorporation of phenol red within ZIF-8, while maintaining the chemical stability of the MOF.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRYIndoor air qualityUV-VisVolatile organic compounddye-precursor synthesisin-situ ultraviolet-visiblespectroscopy

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Davey, Adrian K., Li, Zhou, Lefton, Natalie, Leonhardt, Branden E., Pourghaderi, Alireza, McElhany, Stuart, Popple, Derek, Dai, Chunhui, Kahn, Salman, Dods, Matthew N., Zettl, Alex, Carraro, Carlo, Maboudian, Roya. 2022-10-04. Enhanced ZIF-8-enabled colorimetric CO 2 sensing through dye-precursor synthesis. https://doi.org/10.1016/j.snb.2022.132783

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