Combined radiometric and electrochemical study of the behaviour of Tc (vii) ions at gold and platinized surfaces in acidic media

The sorption and deposition of technetium species formed from TcO₄^– at gold and platinized surfaces was followed by a coupledin situ radiometric and electrochemical technique. It was found: (i) that a layer of TcO₂ species is formed preceding the massive deposition of technetium species, and (ii) that the deposition process is not connected with hydrogen evolution or reaction with adsorbed hydrogen as has been assumed in the literature. An important new finding, the electrocatalytic reduction of ClO₄ ions at surfaces covered by technetium species, was demonstrated on the basis of a comparative study of the phenomena observed in H₂SO₄ and HClO₄ supporting electrolytes.This paper is dedicated to Professor Brian E. Conway on the occasion of his 65th birthday, and in recognition of his outstanding contribution to electrochemisty.