"Para-Ni-Tetraaminophenylporphyrin/Co-Cobaltite/SnO2:F Modified Electrodes: Electrocatalytic Behavior Toward the Oxidation of Hidrazine"

The aim of this work was the study of three different modified electrodes where the substrate and the porphyrin used to modify the electrodic surface was the same. The surface electrode was a glass covered by a layer of SnO2 doped with fluor. On this layer was formed a cubic spinel of Co-cobaltite. On this modified electrode was deposited or polymerized para-tetraaminophenylporphyrin of Ni (II). In each case, the treatment of the deposition of the porphyrin was different and the electrocatalytic behavior of the modified electrodes toward the oxidation of hydrazine drastically changes. In the case of a simple physically adsorbed layer of porphyrin, practically no electrocatalytic activity was found. In the case of a porphyrin deposited by reflux and cycled in basic solution, there is an important electrocatalytic activity giving N2 as product. This electrode was proved as an amperometric sensor of hydrazine and a very good linear relationship between current and concentration was determinate. Also, the polymeric electrode showed an important catalytic behavior toward the oxidation of hydrazine.Authors acknowledge financial support of Fondecyt, project 1010695, Dicyt-Usach project 05-0342TO. G.R. acknowledges a Conicyt Doctoral Fellowship and AT-403139 Conicyt Doctoral Research Fellowship