Efficient Removal of Anionic Organic Dyes from Aqueous Solution with Cu-Organic Frameworks

Cu-metal-organic frameworks (Cu-MOFs) were synthesized in one step using copper acetate, glutamic acid, and small-molecular organic amines at room temperature. Organic amines served as modulators to modify the structure of Cu-MOFs. Characterization results proved that the addition of modulators changes the surface morphology. Batch adsorption data indicated high adsorption capacities for anionic organic dyes with glutamic-Cu-triethylamine (Glu-Cu-TA), higher than that of most MOFs reported. An acid pH was the optimum adsorption parameter. The easy regeneration of recycled Cu-MOFs suggested there were weak intermolecular interactions between Cu-MOFs and dyes. The main adsorption forces included electrostatic interaction, ion exchange, pi-pi complexation, and hydrogen bonds.