Microwave-assisted Synthesis Of UIO-66 And Application

Metal-organic frameworks (MOFs) materials are a class of functional porous materials as coordination polymers by self-assembly of organic ligands and metal ions MOFs are still materials of interest to scientists and have broad application prospects in terms of gas separation and storage, catalysis, host-guest chemistry, and so on because of its high surface area and high porosity. Some of MOFs are less stable in water and organic solvents, thus limiting its space applications. The UIO-66 due to the high thermal stability (up to 500 ℃) and chemical stability, has become a hot research.However the current synthesis of UIO-66 with solvothermal method is time-consuming, high temperature, their good nature is difficult for industrial applications. Trying to use acetic acid as a stabilizer, we obtain method of rapid synthesis of a high-quality UIO-66 by microwave-assisted. Reaction time the method need is 90min, and the reaction temperature was 100 ℃. Four different UIO-66 synthesized are referred to as MW-BA-UIO-66, MW-HAC-UIO-66, Heating-HAC-UIO-66, and MW-UIO-66.By powder X-ray diffraction analysis, the position and relative intensities for the diffraction peaks of preparation of UIO-66 by four methods is consistent with the simulated XRD. So we can confirm the four materials are UIO-66.By thermal gravimetric analysis, TG curve of UIO-66 synthesized by four methods did not occur significantly differ.Thermal stability is still high, about 500 ℃, and consistent with the literature values.TEM shows that MWUIO-66 is a cross-linked aggregates of irregular small crystals, but by using stabilizers MWBA-UIO-66, MWHAC-UIO-66 and HHAC-UIO-66 are complete octahedral morphology of single dispersed nanoparticles.The particle size was about 100 nm,250 run,400 nm. HHAC-UIO-66 particle size is the largest, due to the traditional method of heating the reaction time is longer, resulting in a large high crystallinity,and particle size.Seen by N2 adsorption, MW-BA-UIO-66> MW-HAC-UIO-66> Heating-HAC UIO-66> MW-UIO-66, it illustrates the use of additives and microwave radiation helps to improve its specific surface area.Regarding Dye solution as simulate industrial waste water, MW-HAC-UIO-66 as adsorbent, and acid chrome blue K as probe,adsorption experiment results show that adsorption of MW-HAC-UIO-66 to Acid Chrome Blue K reaches saturation in about 180 min,and its adsorption capacity reached 150 mg/g. MW-HAC-UIO-66 can be used repeatedly.