Two-electrode PAni/Pt/Nafion®/Pt electrochemical sensor for deterimination of chlorine concentration

An electrochemical sensor for determination of chlorine concentration was developed by impregnation-reduction of Pt and then electro-polymerization of aniline on solid polymer electrolyte (SPE) to prepare PAni/Pt/Nafion(R)Pt electrode. The current response of the electrode was examined by step change of chlorine in a flowing gas system. The preparing conditions of the PAni/Pt/Nafion(R)/Pt electrode including impregnation concentration of Pt-solution, concentration of reducing agent HBO4, and its pH were optimized. Meanwhile, the conducting polymer- poly-aniline was coated on the electrode by electropolymerization, which was taken place by cyclic voltammograms (CV) in a monomer solution including the aniline and sulfuric acid. The cycle times and scanning rates weres testified to obtain the maximum response current. The potential windows of chlorine gas on the electrode were determined. The interference of the gases, NO2, SO2, CO2 and Cl-2, on the chlorine sensing were estimated, also the interference of humidity was investigated.