Zeolitic imidazolate frameworks (ZIFs) along with carbon nanofibers and polyaniline composite have been explored as an electrochemical sensing platform in nitrite measurement at trace level. Owing to their topology, high surface area and porous structure, these metal–organic frameworks (MOFs) find widespread utility in different application domains. Nitrites are widely used as preservatives in dairy, meat products, and packaged food stuffs. They form N-nitrosamines, which are potential carcinogens and cause detrimental health effects. These ZIF-based MOFs along with carbon nanofibers and polyaniline have emerged as an efficient electrochemical sensing material. The composite has been characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and BET surface area studies. The electrochemical performance of the composite has been evaluated by forming as a thin film of composite on the surface of glassy carbon electrode and studying its impedance as well as electrochemical sensing behavior. The sensor exhibited good analytical response in nitrite measurement with a limit of detection of 8.1 μM. The developed sensing platform has been successfully applied to quantify the nitrite levels from water samples. The results obtained are in good agreement with the results of standard protocol.

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.

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.