2D ZIF-derived ZnO nanosheets—an example for improving semiconductor metal oxide detector performance in gas chromatography through material design strategy

Semiconductor metal oxide (SMO)-based GC detector was investigated by rational design of 2D materials used as detector sensing film, which was verified to be a feasible way to overcome tailing and peak spreading phenomena usually existed in SMOs-based GC detector. Specifically, 2D flake-like ZnO chosen as an example was successfully synthesized by employing 2D ZIF-8 as template, and then acted as detector in portable gas chromatograph. The properties of detector were evaluated via detection of alcohols and other oxygen-containing VOCs. The results exhibited good linear dependence between peak heights and concentrations of target gases with a short response and recovery time (several seconds) and a high sensitivity, low detection limit (ppb level), together with prominent selectivity for oxygen-containing VOCs than hydrocarbons. Moreover, tailing and peak spreading phenomena mentioned above were hardly observed due to a smaller diffusion barrier for 2D material as compared to 3D counter parts. It is concluded that 2D materials-based portable GC detectors indeed possess great potential in practical application in the future.