Synthesis of hierarchical ZIF-8/carbon nanotube structure via zinc hydroxide nanostrands as a butanol QCM nanosensor.

A composite of ZIF-8 metal organic framework/multi-walled carbon nanotube (MWCNT) was synthesized at room temperature using zinc hydroxide nanostrands (ZHNSs) as the metal source. ZHNS not only served as a metal source but also acted as a template, confining the nucleation and growth of ZIF-8 on the MWCNT. This led to the low linker/metal ion molar ratio necessary for ZIF-8 synthesis. The resulting composite was used in the fabrication of a quartz crystal microbalance (QCM) nanosensor for detecting volatile organic compounds (VOCs). The nanosensor was assessed in a N2 atmosphere with various VOCs, including n-hexane, n-pentane, acetone, ethanol, methanol, methyl butanol, and butanol at different concentrations. Among these VOCs, the sensor displayed the most significant response to butanol, showing a sensitivity of 2.20 Hz ppm-1.