Solvothermal synthesis and characterization of novel [Ni(II)(Tpy)(Pydc)].2H2O metal-organic framework as an adsorbent for the uptake of caffeine drug from aqueous solution
The discharge of pharmaceuticals and personal care products effluent after industrial processes with little or without treatment is increasing at an alarming rate. Health risk associated with this discharge cannot be over emphasized. Therefore, there is urgent needs to develop supramolecular solid materials that can be used to adsorb pharmaceuticals and personal care products before the discharge of waste water into the environment. [Ni(II)(Tpy)(Pydc)].2H2O supramolecular solid was synthesized from the reaction of nickel nitrate, terpyridine (Tpy) and pyridine dicarboxylate (Pydc) via solvothermal method of synthesis. The synthesized supramolecular solid was characterized with melting point determination, elemental analysis, hot stage microscope, thermogravimetric analysis, SEM and x-ray crystallography analysis. All result clearly show the coordination of the nickel II to the two ligands. In application, [Ni(II)(Tpy)(Pydc)].2H2O supramolecular solid was used in adsorption of caffeine. The result clearly show that 98.4 mg of caffeine was adsorbed by 1 g of [Ni(II)(Tpy)(Pydc)].2H2O supramolecular solid at 30 0C, pH of 4 for 1 hour via multiple binding site (Freundlich isotherm). Characterization of the aqueous caffeine solution after adsorption show a negligible amount of nickel metal. [Ni(II)(Tpy)(Pydc)].2H2O supramolecular solid is a potential adsorbent that could be used for removal of caffeine from aqueous solution.