Metal–Organic-Framework-Decorated Carbon Nanofibers with Enhanced Gas Sensitivity When Incorporated into an Organic Semiconductor-Based Gas Sensor
Eun Hye Kwon, Mi‐Yeon Kim, Mi‐Yeon Kim, Chang Yeon Lee, Min Gyu Kim, Min Gyu Kim, Yeong Don Park
Abstract
Because of their high porosity, metal–organic framework (MOF) materials have attracted much attention for use in gas-sensing applications. However, problems with the processability of MOFs for use in reliable gas-sensing electronics remain unsolved. Herein, combination of the strong gas-adsorbing properties of MOF nanomaterials and organic thin-film transistor-type chemical sensors is proposed and experimentally demonstrated. The hybrid blend system with inorganic MOF nanomaterials and organic semiconductors likely exhibits thermodynamic instability because of each phase’s self-aggregation, which is difficult to settle without surface functionalization. We propose a novel method to produce an inorganic–organic hybrid sensor by introducing carbon nanofibers as a scaffold. We demonstrate that the carbon nanofibers perform dual functions: enabling the attachment of MOF nanoparticles at the fiber surface, which stabilizes the nanoparticle-embedded polymer layer, and maintaining reliable conductivity for improved gas-sensing performance. On the basis of our characterization of their nanomorphology and nanocrystal structure, the MOF nanoparticles and carbon nanofibers are shown to render a hybrid core–shell structure in the conjugated polymer matrix. This organic–inorganic hybrid system was incorporated into a field-effect transistor device to detect hazardous NO2 gas analytes, operating in real-time with high responsivity. The prototype chemical sensor holds enormous promise for other chemical sensors.