Design of 3D-supramolecular metal organic framework of zinc as photocatalyst for the degradation of methylene blue through advanced oxidation process

Abstract

A 3D- supramolecular zinc incorporated metal organic framework has been synthesized using 2,6-naphthalene disulphonic acid as the ligand and 4,4’-bipyridine as the co-ligand by adopting a hydrothermal strategy. The MOF was characterized for its composition, functional groups, morphology as well as crystal structure, by resorting to various analytical techniques. The visible light driven photocatalytic activity of the MOF was analyzed with respect to the degradation of methylene blue. The addition of hydrogen peroxide as the electron acceptor to an analyte system of Zn-MOF and the dye remarkably enhanced the photocatalytic activity. The degradation of the dye proceeds through ligand-to-metal charge transfer (L-MCT). The enhanced photocatalytic activity in the presence of the electron acceptor is attributed to advanced oxidation process. The trapping experiments using scavengers indicate that hydroxyl radicals and holes are the species responsible for photocatalytic degradation of MB using Zn-MOF. Leaching experiments prove the stability of the MOF. Recycling experiments proves the long term stability of the MOF photocatalyst in the degradation of methylene blue.