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.
