Metal Organic Framework (MOF) Materials: Synthesis and Characterization Study

Metal Organic Frameworks (MOFs) are microporous materials with crystalline structure composed of organic and inorganic species. MOF materials have gained popularity among researchers due to their potential for gas capture, separation, catalysis and other applications. Zn(BDC)(TED)0.5 is one of the MOFs with characteristic such as high hydrophobicity and large channels properties. The current project emphasizes on synthesis and characterization of Zn(BDC)(TED)0.5. Thus, the effect of synthesis conditions on the formation of the MOFs was studied. The MOFs were synthesized at different temperature (ranged from 120°C to 150°C) and synthesis time (ranged from 24 hr to 48 hr). The synthesized MOFs were characterized using Scanning Electron Microscope (SEM), X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy, Thermogravimetric Analysis (TGA) and tested for its gas adsorption capacity using Brunaur-Emmett-Teller (BET). All SEM images show polydispersity in size and shape of the MOF synthesized. X-ray Diffraction (XRD) pattern obtained shows similarity to the XRD pattern of MOF-2 as reported by Chen et al. (2009). Thus, the synthesized MOF is indeed MOF-2 with some unknown phase. The change of the crystalline structure of Zn(BDC)(TED)0.5 to MOF-2 was due to the exposure to the air longer than 36 hours. The FTIR spectrum of the synthesized MOF shows the presence of aromatics C-H bond, alkoxy C-O bond, aromatic ring C=C bond, carboxylic acids O-H bond, amine N-H bond and alcohols or phenols O-H bond. The TGA plots diagrams shows three steps of weight losses where the first step was the loss of water molecules, second step was the loss of N,N-Dimethylformamide (DMF) molecules and the last step was the decomposition of the MOF-2. The total weight loss for all synthesized MOF at 120°C and 150°C samples were in the range of 73 wt% to 84 wt%. The BET surface area and total pore volume for CO2 and N2 adsorption are 2.19 m2/g and 14.8 m2/g and 1.1633 cm3/g and 0.0199 cm3/g respectively.