Chloride-Less Approach Using Waste Linker Source in Zirconium-based Metal-Organic Framework (UiO-66)

Abstract

UiO-66 was synthesized using a chloride-less approach with waste plastic bottles as a possible organic linker at room temperature. UiO-66 features an arrangement of structure from the coordination of zirconium-based metal clusters interconnected by benzene dicarboxylate (BDC) linkers. BDC can be extracted from waste plastic bottles by depolymerization. The structural comparison of UiO-66 using a pristine linker and PET-derived BDC linker was investigated with and without the presence of chloride ions. The (011), (111), (002), and (022) reflection planes from X-ray diffraction peaks for all samples show successful UiO-66 crystal formation. Thermal analysis on as-synthesized samples exhibited the decomposition in three stages of weight loss which are attributable to the solvent’s evaporation at ca. [Formula: see text]C, loss of water molecules physisorbed in the structure at ca. [Formula: see text]C, and mass reduction at ca. [Formula: see text]C due to decomposition of organic linkers, respectively. FT-IR spectra exhibited absorption peaks corresponding to the stretching vibration ([Formula: see text]-H) in asymmetric and symmetric C–H bonds in aromatic compounds originating from BDC. By using the Scherrer equation, the primary crystallite size was calculated at a range of ca. 15–32[Formula: see text]nm. The crystallite size calculated showed a similar value to the grain observed using a Williamson–Hall (WH) plot in the range of ca. 14–29[Formula: see text]nm. However, the WH plot for samples without chloride ions showed small crystallite sizes as well as low relative crystallinity suggesting loose agglomerations of the particles.