Cavity microelectrode for studying manganese dioxide powder as pH sensor.
The potential-pH response of an electrolytic manganese dioxide is investigated by means of a cavity microelectrode (CME). The potential-pH curves show a complex evolution that could be explained by the disporportionation of MnOOH species, leading to the formation of Mn(2+) ions on the MnO(2) surface. Such a behaviour is not suited for pH sensor application. However when the tip of the electrode is coated by a Nafion membrane, the potential-pH evolution shows a unique slope close to -60 mV pH(-1). In addition, the sensor exhibits short time responses to pH variations, a good selectivity, and it can be easily renewed compared to classical sensors.
Cachet-Vivier
Christine
C
Electrochimie et Synthèse Organique, Institut de Chimie et Matériaux Paris Est, CNRS, Université Paris Est Créteil, Thiais, France. cachet@icmpe.cnrs.fr
Tribollet
Bernard
B
Vivier
Vincent
V
D006863:Hydrogen-Ion Concentration; D017895:Manganese Compounds / Q000737:chemistry*; D008839:Microelectrodes; D010087:Oxides / Q000737:chemistry*; D011208:Powders / Q000737:chemistry*; D013997:Time Factors
D017895:Manganese Compounds; D010087:Oxides; D011208:Powders; C016552:manganese dioxide