The platinized platinum interface under cathodic polarisation. Morphology changes under the influence of tetralkylammonium salts in super-dry solution.
Résumé
Under the use of super-dry DMF contg. tetraalkylammonium salts (TAAX with X = Cl, Br, I, ClO4, BF4, etc.) platinized Pt layers may exhibit a reversible charging process that occurs at quite neg. potentials (more neg. than -2.2 V vs. SCE). The mode of reactivity of the electrolyte and the reversibility of the Pt charging of platinized layers (whatever the type of conducting substrate - Au and glassy C can also be used successfully) are discussed in terms of the nature of the salt. After cathodic charge and oxidn. by air of samples removed from the cell, a huge change of morphol. of the original platinized layer was obsd. During repeated redn./oxidn. stages, the original amorphous platinized layer was progressively transformed, with a noticeable swelling of the original layer. This transformation, based essentially on cathodic swelling due to the peculiar reactivity of Pt in the presence of bulky tetraalkylammonium salts, is the precondition for a new kind of Pt interface.