Activation of a gold electrode by electrochemical oxidation-reduction pretreatment in hydrochloric acid

Abstract Gold electrodes were activated for the oxidation of ascorbic acid by applying electrochemical oxidation-reduction cycles in hydrochloric acid. The electrode surfaces were examined by XPS, SEM, PXD and electrochemical techniques. The results indicate that the gold atoms on the electrode surface are rearranged to form a single-crystal-like surface by the electrochemical pretreatment. The active site must be either a (111) facet of gold, or the edges or peaks of the pyramid structure constructed from (111) facets. Heat treatment also activates the gold electrode.