Metal Centers and Organic Ligands Determine Electrochemistry of Metal –Organic Frameworks

2D Cu-2MI, bulk Cu-BTC, and dodecahedron Zn-2MI, synthesized by changing metal centers and organic ligands exhibit different structural and electrochemical properties. 2D and ultra-thin Cu-2MI has a porous structure, a big surface area, and strong interaction with xanthine, hypoxanthine, and malachite green in solutions, leading to its sensitive and selective monitoring of these organic analytes. AbstractThe properties and applications of metal-organic frameworks (MOFs) can be tuned by their metal centers and organic ligands. To reveal experimentally and theoretically the influence of metal centers and ligands on electrochemical performance of MOFs, three MOFs with copper or zinc centers and organic ligands of 2-methylimidazole (2MI) or 1,3,5-benzenetricarboxylic acid (H3BTC) are synthesized and characterized in this study. 2D and porous Cu-2MI exhibits a larger active area, faster electron transfer capability, and stronger adsorption capacity than bulk Cu-BTC and dodecahedron Zn-2MI. Density functional theory calculations of adsorption ability of three MOFs toward xanthine (XA), hypoxanthine (HXA), and malachite green (MG) prove that 2D Cu-2MI has the strongest adsorption energies to three targets. Rotating disk electrode measurements reveal that 2D Cu-2MI features the biggest intrinsic heterogeneous rate constant toward three analytes. On 2D Cu-2MI sensitive and selective monitoring of XA, HXA, and MG is then achieved using differential pulse voltammetry. Their monitoring i...
Source: Small - Category: Nanotechnology Authors: Tags: Research Article Source Type: research