Capturing Harmful Air Pollutants Using an Electrospun Mesh Embedded with Zinc-based Nanocrystals

Metal-organic frameworks (MOFs) are compounds consisting of metal ions supported by organic ligands and may have the potential to combat the growing issue of air pollution. Zeolithic midazolateframework-8 (ZIF-8) is a specific MOF that has favorable qualities for use in an air filter including high porosity, high surface area, and a high positive surface charge. ZIF-8 is known to be capable of adsorbing particulate matter. Therefore, the objective of this experiment was to determine the effectiveness of ZIF-8 in adsorbing polar, gaseous air pollutants, specifically nitrogen dioxide and hydrogen sulfide. In order to determine effectiveness, the percent change in concentration for each gas after the application of ZIF-8 crystals was measured via Fourier-transform infrared spectroscopy (FTIR). This is a technique used to obtain high resolution infrared absorption or emission spectra of solids, liquids or gases over a wide spectral range. Both experimental gases, nitrogen dioxide and hydrogen sulfide, were adsorbed by an average of ~32% over just 5 minutes, and the leakage within the capsule was an average of ~3.5%. These results were confirmed with the Kruskal-Wallis tests (p-value = 0.05). In the future, ZIF-8 could be embedded into existing air filters or electrospun on its own and tested for its effectiveness in adsorbing other polar pollutants such as carbon monoxide and ammonia. Our work highlights crystals as a potentially promising alternative or addition to current filter materials to reduce atmospheric pollution.