Electrochemical nitrogen dioxide gas sensor based on solid polymeric electrolyte

Gold has been prepared on a solid polymeric electrolyte (SPE) by the chemical plating method. The characteristics of Au/SPE and the electrochemical behaviour of the cathodic reduction of nitrogen dioxide on the prepared electrode have been studied in this paper. The loading of Au on SPE increases when the concentration of reductants and the pH increase. The maximum roughness factors of Au/Nafion(R) are 340 and 460 when hydrazine dihydrochloride and sodium borohydride are used as reductants, respectively, for the chemical plating. A linear relationship between the limiting current and the concentration of NO2 is obtained and the sensitivity is 0.33 mu A ppm(-1) when the NO2 concentration is in the range 20.8 to 104.0 ppm.