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        검색결과 7

        1.
        2023.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Core–shell ZIFs wrapped CuO hybrid materials (CuO@ZIF-67(Co)) were designed, synthesized, characterized, and employed as peroxymonosulfate (PMS) activators to degrade methylene blue (MB). It demonstrated outstanding catalytic activity on account of the unique structure and the synergistic effect between CuO cores and ZIF-67(Co) shells, resulting in complete degradation of MB (10 mg/L) in 1 min. Reactive oxygen species (ROSs) research showed that both SO4 − and OH were responsible for the removal of MB. The synergistic activation mechanisms in the CuO@ZIF-67(Co)/PMS system were investigated, which mainly involved the effective electron transfer of CuO and ZIF-67(Co) for accelerating the cycle of CuII/ CuI and CoIII/ CoII. This study broadens the application of MOF-derived materials for wastewater treatment.
        4,500원
        2.
        2022.05 구독 인증기관·개인회원 무료
        Efficient capture and storage of radioactive iodine (consisting of two isotopes: 129I and 131I), produced or released from nuclear activities, are of paramount importance for sustainable development of nuclear energy due to their volatility and long half-life. Therefore, it is very important to develop new adsorbents for efficient utilization of radioactive iodine from nuclear waste. Various methods and materials are used for I2 capturing and removing, including MOFs due to their high porosity and fast adsorption kinetics, which are rightfully considered effective sorbents for removing I2. Metal–organic frameworks (MOFs) are porous crystalline materials which have diverse pore geometry and unique physicochemical properties, have attracted enormous attention for use in gas storage, separation and catalysis. The ability of MOFs to adsorb volatile products at room temperature can significantly improve the cost-effectiveness of the utilization process. This work describes the synthesis and characterization of three new metal-organic frameworks based on pyrazine (pyz), 44’bipyridine (bpy), 1,2 -bis(4 - pyridyl) – ethane (bpe) and copper (II) hexafluorozironate, as potential adsorbents for I2 capture. All of these three MOFs exhibit a two - dimensional (2D) crystal structure consisting from infinity non-crossing linear chains. The crystal structure of [Cu(pyz)2(ZrF6)2(H2O)2], [Cu(bpy)4(H2O)2ZrF6] and [Cu(bpe)4(H2O)2ZrF6] were characterized using powder X-ray diffraction (PXRD), single crystal X-ray diffraction (SC-XRD). Comparative characteristics of synthesized MOFs, including Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were also performed. The I2 sorption experiments were examined by UV-vis spectroscopy.
        3.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Metal–organic frameworks (MOFs) are network-like frameworks composed of transition metals and organic ligands containing oxygen or nitrogen. Because of its highly controllable composition and ordered porous structure, it has broad application prospects in the field of material synthesis. In this work, Zn4( PYDC)4(DMF)2∙3DMF (ZPD) was synthesized via a hydrothermal method. Self-doped nitrogen porous carbon ZPDC-T was then prepared by one-step carbonization. The results show that the self-doped nitrogen porous carbon ZPDC-850 has a micro/mesoporous structure with a specific surface area of 1520 m2 g− 1 and a nitrogen content of 6.47%. When a current density is 1.0 A g− 1, its specific capacitance is 265.1 F g− 1. After 5000 times of constant current charging and discharging, the capacitance retention rate was 79.2%. Thus, self-doped nitrogen porous carbon ZPDC-850 exhibits excellent electrochemical properties and good cyclic stability. Therefore, the self-doped nitrogen porous carbon derived from MOFs can be a promising electrode material for supercapacitors.
        4,000원
        5.
        2018.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Nitrogen is a serious contaminant in natural gas because it decreases the energy density. The natural gas specification in South Korea requires a N2 content of less than 1 mol%. Thus, cost-effective N2 removal technology from natural gas is necessary, but until now the only option has been energy-intensive processes, e.g., cryogenic distillation. Using porous materials for the removal process would be beneficial for an efficient separation of CH4/N2 mixtures, but this still remains one of the challenges in modern separation technology due to the very similar size of the components. Among various porous materials, metal-organic frameworks (MOFs) present a promising candidate for the potential CH4/N2 separation material due to their unique structural flexibility. A MIL-53(Al), the most well-known flexible metal-organic framework, creates dynamic changes with closed pore (cp) transitions to open pores (ops), also called the ‘breathing’ phenomenon. We demonstrate the separation performance of CH4/N2 mixtures of MIL-53(Al) and its derivative MIL-53-NH2. The CH4/N2 selectivity of MIL- 53-NH2 is higher than pristine MIL-53(Al), suggesting a stronger CH4 interaction with NH2.
        4,000원
        6.
        2018.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The stereotype of flexible MOFs(Amino-MIL-53) and carbonized porous carbon prepared from renewable resources is successfully synthesized for CO2 reduction application. The textural properties of these microporous materials are investigated, and their CO2 storage capacity and separation performance are evaluated. Owing to the combined effects of CO2-Amino interaction and its flexibility, a CO2 uptake of 2.5 mmol g−1 is observed in Amino-MIL-53 at 20 bar 298 K. In contrast, CH4 uptake in Amino-MIL-53 is very low up to 20 bar, implying potential sorbent for CO2/CH4 separation. Carbonized samples contain a small quantity of metal residues(K, Ca, Mg, S), resulting in naturally doped porous carbon. Due to the trace metal, even higher CO2 uptake of 4.7 mmol g−1 is also observed at 20 bar 298 K. Furthermore, the CH4 storage capacity is 2.9 mmol g−1 at 298 K and 20 bar. To evaluate the CO2 separation performance, the selectivity based on ideal adsorption solution theory for CO2/CH4 binary mixtures on the presented porous materials is investigated.
        4,000원
        7.
        2018.05 구독 인증기관·개인회원 무료
        MOF는 높은 표면적, 균일한 공극, 크기를 가지는 새로운 클래스의 porous material 이다. MOF는 금속과 organic linker가 coordination 결합에 의해 연결되어 있고, 온도에 대한 강한 안정성을 나타내고, 높은 표면적 때문에 촉매, 분리, 개스저장 등 다양한 분야에 적용될 수 있는 잠재력이 풍부하다. MOF는 zeolite보다 높은 표면적을 가지고 작용기를 organic linker에 따라 쉽게 바꿀 수 있는 장점 때문에 최근에 많은 관심을 받게 되었다. 다양한 MOF가 합성되었고 CO2/N2 선택도, 흡착량, 수분과 산성가스에 대한 안정성이 분석되었다. 최종적으로 선택된 MOF는 폴리머와 결합하여 하이브리드 멤브레인을 만드는 데에 사용되었다.