Fluorescent Zn(II)-Based Metal-Organic Framework: Interaction with Organic Solvents and CO2 and Methane Capture

Abstract

Adsorption of carbon dioxide (CO2), as well as many other kinds of small molecules, is of importance for industrial and sensing applications. Metal-organic framework (MOF)-based adsorbents are spotlighted for such applications. An essential for MOF adsorbent application is a simple and easy fabrication process, preferably from a cheap, sustainable, and environmentally friendly ligand. Herein, we fabricated a novel structural, thermally stable MOF with fluorescence properties, namely Zn [5-oxo-2,3-dihydro-5H-[1,3]-thiazolo [3,2-a]pyridine-3,7-dicarboxylic acid (TPDCA)] • dimethylformamide (DMF) •0.25 H2O (coded as QUF-001 MOF), in solvothermal conditions by using zinc nitrate as a source of metal ion and TPDCA as a ligand easy accessible from citric acid and cysteine. Single crystal X-ray diffraction analysis and microscopic examination revealed the two-dimensional character of the formed MOF. Upon treatment of QUF-001 with organic solvents (such as methanol, isopropanol, chloroform, dimethylformamide, tetrahydrofuran, hexane), interactions were observed and changes in fluorescence maxima as well as in the powder diffraction patterns were noticed, indicating the inclusion and intercalation of the solvents into the interlamellar space of the crystal structure of QUF-001. Furthermore, CO2 and CH4 molecule sorption properties for QUF-001 reached up to 1.6 mmol/g and 8.1 mmol/g, respectively, at 298 K and a pressure of 50 bars.

Emerging trends in direct air capture of CO2: a review of technology options targeting net-zero emissions

“…These materials compose of organic molecules that surrounds positive metal ions. MOFs have large surface area, low density, and porosities up to 6000 m 3 g −1 , which make MOFs a potential adsorbent, 105 however, MOFs have poor adsorption capacity for low CO 2 partial pressure compared to zeolite and activated carbon (0.1–0.2 bar). 106 MOFs adsorption from the ambient air requires very high CO 2 partial pressure, moreover, adsorption selectivity is negatively affected by the presence of moisture in air.…”

Dry Water as a Promoter for Gas Hydrate Formation: A Review

“…where the R is the radius of the nanoparticle, γ aw is water-air interfacial tension, and θ is the contact angle of water on the nanoparticle. Equation (1) shows that the size of nanoparticles has a direct impact on the energy required to remove them from a water-air interface into either the bulk water phase or to the bulk air phase. The negative sign in the bracket applies when removing the nanoparticle to the water phase, whereas the positive sign applies when removing it to the air phase.…”

“…Compared to aqueous solutions, the amount of gas that can be accommodated in the form of clathrate is much greater, making it a promising option for gas storage applications. For example, CO 2 hydrate can be used to capture and sequester CO 2 , which is a main greenhouse gas whose emission target was set to its reduction by about 45% by 2030 [1]. Transporting flammable or potentially explosive gases like H 2 and natural gas is also safer with clathrate hydrate than with other methods like liquefaction.…”