Characterization of a carbon xerogel-based sensor for detection of acetone, ethanol, and methanol vapors

We report on the sensing properties of carbon xerogel (CX) for detection of acetone, ethanol, and methanol vapors. The sensor was prepared by deposition of a dispersion of CX dispersion onto an FR4 epoxy resin/fiber glass printed circuit board with interdigitated electrodes. The gas sensing performance was monitored by AC impedance spectroscopy. It was found that exposure to acetone, ethanol, and methanol vapors resulted in a change of sensor impedance that was proportional to the gas concentration. The CX sensor showed greater sensitivity to ethanol and acetone vapor, compared to methanol vapor, indicative of selectivity to larger molecules. However, faster response and recovery times were obtained for methanol vapor, indicative of lower binding energy.