Detecting formaldehyde at low operating temperature and maintaining long-term stability are of great significance. In this work, a hierarchical Co₃O₄ nanostructure has been fabricated by calcining Co₅-based metal–organic framework (MOF) microcrystals. Co₃O₄-350 particles were used for efficient gas-sensing for the detecting of formaldehyde vapor at lower working temperature (170 °C), low detection limit of 10 ppm, and long-term stability (30 days), which not only is the optimal value among all reported pure Co₃O₄ sensing materials for the detection of formaldehyde but also is superior to that of majority of Co₃O₄-based composites. Such extraordinarily efficient properties might be resulted from hierarchically structures, larger surface area and unique pore structure. This strategy is further confirmed that MOFs, especially Co-clusters MOFs, could be used as precursor to synthesize 3D nanostructure metal oxide materials with high-performance, which possess high porosity and more active sites and shorter ionic diffusion lengths.

中文翻译：

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基于Co ₅的MOF微晶衍生的3D分层Co ₃ O _4的甲醛高效气体传感

在低工作温度下检测甲醛并保持长期稳定性具有重要意义。在这项工作中，通过煅烧基于Co ₅的金属-有机骨架（MOF）微晶，制造出了分层的Co ₃ O ₄纳米结构。Co ₃ O ₄ -350颗粒用于在较低的工作温度（170°C），低的检测极限（10 ppm）和长期的稳定性（30天）下对甲醛蒸气进行有效的气敏检测。是所有报告的纯Co ₃ O ₄感测材料中用于检测甲醛的最佳值，但也优于大多数Co ₃ O ₄基复合材料。这种特别有效的特性可能是由于层次结构，较大的表面积和独特的孔结构而引起的。该策略进一步证实了MOF，尤其是共簇MOF，可以用作合成3D纳米结构金属氧化物材料的前驱物，该材料具有高孔隙率，更多的活性位点和更短的离子扩散长度。