Jha Ravindra Kumar, Murali Meenu, Bhat Navakanta
Department of Electronics and Electrical Engineering, Indian Institute of Technology, Guwahati-781039, India.
Centre for Nanoscience and Engineering, Indian Institute of Science, Bangalore-560012, India.
Nanotechnology. 2022 May 3;33(29). doi: 10.1088/1361-6528/ac6815.
We report on the usability aspect of triphenylene ligand-based metal-organic frameworks (MOF) as the potential gas sensing element in chemiresistive devices. Among various possibilities, we explored mono-metallic (Nickel-based) and bi-metallic (Nickel and copper-based) in room temperature gas sensing. Our investigations suggest that the chemiresistive device based on nickel catecholate MOFs were highly sensitive to ethyl alcohol gas in the concentration range of 5-100 ppm with decent sensing parameters such as response time, recovery time, repeatability, stability, etc. We also investigated bimetallic (Nickel and copper) catecholate based MOFs in gas sensing with different metallic content ratios (Cu: Ni:: 60:40 and 40:60). We found that the 1D CuNi-CAT nanostructures-based gas sensor to be selective towards Hgas (0.2-7 ppm) at room temperature. We further explored the gas sensing abilities of CuNi-CAT based devices, and we found them to be selective towards NOgas. However, it was not possible to obtain the current versus concentration curve due to the gas molecules' aggressive chemisorption. However, the device could perform well (with a hysteresis error of ∼10%) for detecting NO gas (which has the 2nd best absolute response after NO). These results indicate that the ratio of metal ions in the MOF directly influences the sensing capabilities. Hence, rational synthetic variations in the metal content in MOF can lead to the design and develop highly selective and sensitive chemiresistive sensors.
我们报道了基于三亚苯配体的金属有机框架（MOF）作为化学电阻器件中潜在气体传感元件的可用性方面。在各种可能性中，我们探索了室温气体传感中的单金属（镍基）和双金属（镍和铜基）材料。我们的研究表明，基于儿茶酚镍MOF的化学电阻器件在5 - 100 ppm浓度范围内对乙醇气体高度敏感，具有响应时间、恢复时间、重复性、稳定性等良好的传感参数。我们还研究了不同金属含量比（Cu:Ni::60:40和40:60）的双金属（镍和铜）儿茶酚基MOF的气体传感性能。我们发现基于一维CuNi - CAT纳米结构的气体传感器在室温下对氢气（0.2 - 7 ppm）具有选择性。我们进一步探索了基于CuNi - CAT器件的气体传感能力，发现它们对一氧化氮气体具有选择性。然而，由于气体分子的强烈化学吸附，无法获得电流与浓度曲线。不过，该器件在检测一氧化氮气体时表现良好（滞后误差约为10%）（一氧化氮气体的绝对响应在所有气体中排第二）。这些结果表明，MOF中金属离子的比例直接影响传感能力。因此，MOF中金属含量的合理合成变化可以导致设计和开发出高选择性和高灵敏度的化学电阻传感器。
