Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10268562 | Electrochimica Acta | 2011 | 10 Pages |
Abstract
An electrolysis technique at a constant potential was used to develop a highly reproducible and fast elaboration method of adherent manganese dioxide thin films on a glassy carbon electrode from aqueous solutions containing sulfuric acid and manganese sulfate. The resulting films were found to have a nanostructured character presumably due rather to birnessite (δ-MnO2) than to γ-MnO2, as suggested by their Raman and XRD signatures. They lead to modified electrodes that present an obvious although complex pH dependent potentiometric response. This sensor indeed showed a single slope non-Nernstian linear behaviour over the 1.5-12 pH range for increasing pH direction (“trace”), whereas a Nernstian two slopes linear behaviour was observed for decreasing pH direction (“re-trace”). Preliminary EIS experiments carried out at a pH value of 1.8 seem to reveal a sensitivity mechanism based on proton insertion process at least at highly acidic pH values.
Keywords
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
N. Cherchour, C. Deslouis, B. Messaoudi, A. Pailleret,