Investigation of the room temperature gas sensing properties of metal–organic charge transfer complex CuTCNQF4†
The ability to detect and monitor toxic and greenhouse gases is highly important, however to achieve this at room temperature and allow for remote sensing applications is a significant challenge. Here, we tackle this issue and investigate conductometric gas sensors that operate at room temperature using a microstructured CuTCNQF4 (TCNQF4 = 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane) sensing layer formed via simply immersing an e-beam evaporated Cu film in an acetonitrile solution of TCNQF4. These films were characterised by scanning electron microscopy, Fourier transform infra-red, Raman and X-ray photoelectron spectroscopy. The sensors show a significant response to NO2 and NH3 gases and a negligible response to ethanol at 25 °C. Significantly a low detection limit of 100 ppb is achieved for NO2 gas.