Preparation Of Zeolitic Imidazolate Framework-8/Graphene Oxide Composites With Enhanced Dichloromethane Adsorption Capacity

Metal Organic Frameworks material (MOFs) is a coordination polymer having a three-dimensional mesh spatially periodic structure with the advantages of high surface area, highlighting large porosity, low cost and adjustable structure, etc., so that such ma-terials have broad application prospects in catalysis, gas storage, gas selective adsorp-tion and separation and other fields.(?)Zeolitic Imidazolate Frameworks (ZIFs) is a new class of porous materials, which belong to the family of metal organic frameworks. Because ZIFs material has the simi-lar topology with zeolite, result in better chemical stability and thermal stability. ZIFs have become a hot spot in recent years.Graphene oxide (GO) is a derivative of graphene. GO is hydrophilic, which is so-luble in water and some organic solvents. Graphene oxide having a scalable and adjust-able layered structure, and provide a good design platform for chemical modification and a wide range of reaction sites. Typically, oxidation and reduction process will pro-duce some defect sites in graphene, these defect sites help it has a very distinct advan-tage.on the gas adsorption, storage, separation and other applicationsMethylene chloride (dichloromethane, DCM) has a very wide range of applications and is highly volatile and abundant in the atmosphere. Methylene chloride is the one of the priority control 12 persistent organic pollutants in "Stockholm Convention", and al-so be included as environmental hazards by EC. Currently the most commonly used treatment methods to dealing with dichloromethane is adsorption. Adsorption of methy-lene chloride to remove the effect of the gas is very good and relatively inexpensive compared to other methods. Common dichloromethane gas adsorbent is activated car-bon and molecular sieves.Methanol was used as solvent to synthesize pure ZIF-8 crystals, and successfully prepared ZIF-8@GO composites. Series of characterization techniques confirmed the formation of strong interactions between ZIF-8 and GO in the synthesized composites. Such as X-ray diffraction (XRD), N2 adsorption specific surface area (BET), Fourier transform infrared spectroscopy (FTIR) characterization of scanning electron microsco-py (SEM) The results showed that the as-synthesized ZIF-8 and ZG-X nano-composites have both advantages of pure ZIF-8 and graphene oxide. There exists a synergistic ef- fect between the ZIF-8 and GO. The surface area of the pure Nano-ZIF-8 is slightly higher than material ZG-X composite.In this paper ZIF-8 and ZG-X sample material are used as an adsorbent to methylene chloride, aiming to explore the adsorption properties of the sample through a gas chro-matograph. Finally, the breakthrough curves of seven samples are obtained. Analysis of the data showed that the surface areas and pore volumes of the ZG-X composites are smaller than those of the nanosized ZIF-8 and micro-sized ZIF-8, while the ZG-X com-posites exhibited excellent performance with high methylene chloride uptake compared to the pure ZIF-8. With the increase of the content of GO, the methylene chloride ad-sorption capacity enhanced, and the maximum adsorption capacity was up to 240 mg/g.