Facile solvothermal synthesis of MIL-53 (Al) using waste consumer PET: structural considerations

Abstract

A facile solvothermal method was applied to synthesize MIL-53 (Al) at room temperature with an organic linker from waste consumer PET. MIL-53 (Al) was built from Al(NO₃)₃.9H₂O connected by 1,4-benzenedicarboxylate (BDC) linkers. The waste plastic bottle was depolymerized to produce monomer BDC. The structural considerations of MIL-53 (Al) were done by using three different linkers, which are a pure linker, a BDC-PET linker, and a BDC-comm-PET linker. The investigation was obtained at two different aging durations of 24 hours and 48 hours. The X-ray diffraction peaks indicated the crystallization formed at diffraction planes of (110), (011), and (211), and the 48-hour samples observed higher crystallinity. Thermal analysis of samples exhibited weight loss at three stages attributed to the removal of solvent and molecules, trapping BDC, and the departure of BDC to the framework, respectively. Raman shift was obtained to show the MIL-53 (Al) structure while the FTIR spectra exhibited the absorption peaks and stretching vibrations of each group. The primary crystallite size was calculated from the Scherrer equation, and the range was between ca. 10 nm and 32 nm. Furthermore, the value observed using a William-Hall (WH) plot showed the crystallite size was almost similar in the range of ca. 8 nm to 21 nm. The FESEM morphology observed the rod-like structure of MIL-53 (Al), and the 48-hour samples observed the larger particle.