Abstract
In this study, we synthesized Metal Organic Frameworks (MOFs) using five transition metals from the 3d series: iron, cobalt, nickel, copper, and zinc. The ligands employed were Terephthalic Acid, also known as H₂TPA (benzene 1,4-dicarboxylate acid), recovered from PET bottles. The process of obtaining H₂TPA involved alkaline hydrolysis of PET bottle fragments in a 10 mol·L⁻¹ NaOH solution (40% m/w) placed under reflux. Once H₂TPA was obtained, it could be mixed with transition metal acetates. When these mixtures were combined in N,N’-dimethylformamide (DMF) solutions, the formation of metallic MOFs was observed. Some characteristics of the MOFs, particularly their adsorption capacity, were demonstrated through UV-Vis absorption spectroscopy using solutions of common laboratory acid-base indicator dyes such as Methylene Blue (NB), Methyl Orange (MO), Nile Blue (NB), and Malachite Green (MG). This type of simple experiment can be applied in undergraduate Chemistry classes, involving synthesis, characterization, and applications of MOFs compounds extensively documented in scientific literature. Furthermore, the use of the H₂TPA ligand through chemical recycling adds an environmentally friendly aspect to the experiments, resulting in low-cost, easily executable procedures that align with green chemistry principles.