Fuel-Cell Type Ceramic-Carbon Oxygen Sensors

Several classes of sol-gel derived, fuel-cell-type gas sensors are described. The electrochemical sensors are comprised of a hydrophobically modified silicate network and a dispersion of carbon powder and inert metal (palladium or platinum in the zero valent state) or organometallic (e.g., cobalt porphyrin) catalyst modifier. The carbon powder provides conductivity, the Ormosil network assures high porosity, which is pertinent for gas permeation through the back of the electrodes, and the hydrophobic functional group assures that only a thin layer at the outermost section of the electrode is wetted by the electrolyte, thus providing fast dynamic response.