SO2 gas sensor based on Ag-Ag2SO4-BaSO4 sensing electrode

A sulfur dioxide (SO2) gas sensor based on a novel structural sensing electrode was fabricated. The sensor consists of yttria-stabilized zirconia as the oxygen ion conductor, silver sulfate-based salts as the auxiliary phase, a silver/platinum mixed paste as the sensing electrode/catalyst, and a platinum paste as the reference electrode. Ball milling was employed to decrease the particle size of the silver sulfate-barium sulfate (Ag2SO4-BaSO4) auxiliary phase. After the Ag2SO4-BaSO4 mixture ball-milling for 20 h, the as-obtained sensor showed the highest sensitivity to SO2 gas. Furthermore, in order to optimize the sensing electrode, particles of metallic silver were mixed with silver sulfate-based salts, and the as-designed sensing electrode displayed an improved sensitivity to SO2 gas at a low temperature (400 A degrees C).