Metal-Organic Framework-Derived Hollow Hierarchical Co3O4 Nanocages with Tunable Size and Morphology: Ultrasensitive and Highly Selective Detection of Methylbenzenes

Young Moo Jo, Tae Hyung Kim, Chul Soon Lee, Kyeorei Lim, Chan Woong Na, Faissal Abdel-Hady, Abdulaziz A. Wazzan, Jong Heun Lee

Research output: Contribution to journalArticlepeer-review

76 Citations (Scopus)


Nearly monodisperse hollow hierarchical Co3O4 nanocages of four different sizes (∼0.3, 1.0, 2.0, and 4.0 μm) consisting of nanosheets were prepared by controlled precipitation of zeolitic imidazolate framework-67 (ZIF-67) rhombic dodecahedra, followed by solvothermal synthesis of Co3O4 nanocages using ZIF-67 self-sacrificial templates, and subsequent heat treatment for the development of high-performance methylbenzene sensors. The sensor based on hollow hierarchical Co3O4 nanocages with the size of ∼1.0 μm exhibited not only ultrahigh responses (resistance ratios) to 5 ppm p-xylene (78.6) and toluene (43.8) but also a remarkably high selectivity to methylbenzene over the interference of ubiquitous ethanol at 225 °C. The unprecedented and high response and selectivity to methylbenzenes are attributed to the highly gas-accessible hollow hierarchical morphology with thin shells, abundant mesopores, and high surface area per unit volume as well as the high catalytic activity of Co3O4. Moreover, the size, shell thickness, mesopores, and hollow/hierarchical morphology of the nanocages, the key parameters determining the gas response and selectivity, could be well-controlled by tuning the precipitation of ZIF-67 rhombic dodecahedra and solvothermal reaction. This method can pave a new pathway for the design of high-performance methylbenzene sensors for monitoring the quality of indoor air.

Original languageEnglish
Pages (from-to)8860-8868
Number of pages9
JournalACS Applied Materials and Interfaces
Issue number10
Publication statusPublished - 2018 Mar 14


  • CoO
  • gas sensor
  • hollow hierarchical nanocages
  • methylbenzene
  • zeolitic imidazolate framework

ASJC Scopus subject areas

  • Materials Science(all)


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