A simplified way of sensing gases based on electrochemical cells

A simple approach for sensing gases is reported by employing an electrochemical cell which is fabricated in the general configuration of sodium as anode and a mixture of MnO2 + graphite powder (1:1) as cathode and a polymer electrolyte. The interaction of the mobile sodium ions with the gases at the cathode surface is observed. Fluorine and chlorine gases have been detected which were prepared from mixtures of manganese dioxide with hydrofluoric and hydrochloric acid, respectively. The sensing of gases is based on the observation of voltage and current changes of the electrochemical cell. The working conditions of sensor and the limitations are discussed as well as the basic performance, such as sensitivity, response speed and reproducibility.