Sulfur dioxide gas-sensitive materials based on zeolitic imidazolate framework-derived carbon nanotubes

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 6; no. 25; pp. 12115 - 12124
• Main Authors: Li, Qun, Wu, Jiabin, Huang, Liang, Gao, Junfeng, Zhou, Haowen, Shi, Yijie, Pan, Qinhe, Zhang, Gang, Du, Yu, Liang, Wenxi
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 2018
• Subjects: adsorption; ambient temperature; Bimetals; Carbon; Carbon nanotubes; Carrier density; Cobalt; coordination polymers; Detection; durability; Electrical conductivity; Electrical resistivity; Embedding; First principles; Gas sensors; High temperature; Metal-organic frameworks; Morphology; Nanotechnology; Nanotubes; Operating temperature; Pyrolysis; Selectivity; Sensitivity; Sulfur; Sulfur dioxide; Temperature effects; Zinc
• ISSN: 2050-7488; 2050-7496; 2050-7496
• DOI: 10.1039/C8TA02036A

Novel sensing materials that combine high sensitivity and selectivity as well as proper working temperature are essential for advanced gas detection applications. Metal organic framework (MOF)-based materials are promising candidates for many applications including gas sensing, but they exhibit some limitations such as a low electrical conductivity and high operating temperature, which have to be overcome. Herein, we demonstrate the synthesis of gas-sensing materials for sulfur dioxide, namely, carbon nanotube networks based on zinc-doped zeolitic imidazolate frameworks (ZIF-67) (bimetallic MOFs). The particles synthesized via bimetal co-doping of cobalt and zinc and the pyrolysis process possess a porous polyhedral morphology with abundant interconnecting carbon nanotubes (CNTs) on the surface, which results in significant sensitivity, cross-selectivity and durability towards SO 2 at room temperature. This approach combines the advantages of both MOFs and CNTs. First-principles calculations further elucidate that the doped zinc embedding on the nanotube changes the SO 2 adsorption level to a narrow p accepting level, which increases the hole carrier concentration remarkably and subsequently improves the conductivity to a large extent, thus providing excellent sensing performance with respect to the target gas.