Synthesis, Characterization And Application Of Novel Metal-Organic Frameworks For Photo-Transformation Of Organic Pollutants In Water

Abstract

The release of coloured organic pollutants from the production and application industries into water bodies is extremely worrying. Recently, metal-organic frameworks (MOFs) have attracted exceptional attention as heterogeneous catalysts in the removal of organic and inorganic pollutants through photocatalysis. As a result of this emerging technique, research to synthesize MOFs with photocatalytic functionalities to efficiently transform coloured organic pollutants found in water was studied. Six MOFs namely Zr-BTC, Zr- 5abdc, Ce-BTC, Ce-5abdc, Cu-BTC and Cu-5abdc were synthesized using the solvothermal synthetic technique. The synthesized MOFs were characterized by Fourier transform infrared (FTIR) to investigate the bond formation between metals and organic ligands, by X-ray diffraction (XRD) to assess their crystallinity, by Scanning Electron Microscope-Energy Dispersive X-ray (SEM-EDX) to investigate their morphology, by Single crystallography to evaluate their topology and by Thermogravimetric analysis to assess their thermal stability. The photocatalytic activity of MOFs to transform Lissamine green SF (LGSF), Tetraethylrhodamine (TeRh), and Remezol Brilliant Violet 5R (RBV5R) into less toxic compounds was investigated. The photoactivity was subjected to three parameters which included the pH, dye concentration and catalyst loading. Various intermediates were detected from the breakdown of LGSF, TeRh, and RBV5R during their transformation using the GC/MS. The kinetics and isotherms of LGSF, TeRh, and RBV5R adsorption by the MOFs were studied. The removal activity, kinetics and isotherm study of mixed textile dye by Zr-BTC MOFs was also investigated. Conclusively, the MOFs were proven to be effective catalysts in transforming the pollutants into less toxic compounds.