Wang Mingjing, Shen Zhurui, Zhao Xiaodong, Duanmu Fanpeng, Yu Huijun, Ji Huiming
Key Laboratory of Advanced Ceramics and Machining Technology (Ministry of Education), School of Materials Science and Engineering, Tianjin University, Tianjin, PR China.
Key Laboratory of Advanced Ceramics and Machining Technology (Ministry of Education), School of Materials Science and Engineering, Tianjin University, Tianjin, PR China.
J Hazard Mater. 2019 Jun 5;371:352-361. doi: 10.1016/j.jhazmat.2019.02.098. Epub 2019 Feb 26.
Porous metal oxides are promising materials for VOCs (volatile organic compounds) chemical sensors, because they have large specific surface areas and enough internal space for the fast gas diffusion. Recently, metal-organic framework (MOF) materials with varied shapes and sizes have been regarded as good templates for preparing porous metal oxides. Herein, four kinds of Co-MOFs were prepared by altering the ratios of Co ions and 2-methylimidazole at room temperature, which exhibited well-controlled shapes. Then, corresponding porous CoO assembled from nanoparticles was acquired by heating Co-MOFs, and showed a good sensing performance for n-butanol, with a response up to 21.0 toward 100 ppm n-butanol. Moreover, it is found that the shape and the size of CoO assemblies can significantly influence their sensing performances. For porous CoO assemblies, when the nanoparticles are small enough (˜10 nm), a porous structure with a larger proportion of the nanoparticles close to its surface tends to show a better gas-sensing performance. The findings can be used in the design of gas-sensing materials in the future.
多孔金属氧化物是用于挥发性有机化合物（VOCs）化学传感器的有前景的材料，因为它们具有大的比表面积和足够的内部空间用于快速气体扩散。最近，具有各种形状和尺寸的金属有机框架（MOF）材料被视为制备多孔金属氧化物的良好模板。在此，通过在室温下改变钴离子和2-甲基咪唑的比例制备了四种Co-MOFs，它们呈现出形状可控的特点。然后，通过加热Co-MOFs获得了由纳米颗粒组装而成的相应多孔CoO，并且对正丁醇表现出良好的传感性能，对100 ppm正丁醇的响应高达21.0。此外，发现CoO组装体的形状和尺寸会显著影响其传感性能。对于多孔CoO组装体，当纳米颗粒足够小（约10 nm）时，纳米颗粒靠近其表面比例更大的多孔结构往往表现出更好的气敏性能。这些发现未来可用于气敏材料的设计。
