Adsorption isotherm of iodide ions on copper single crystal planes in sulfuric acid

The surface coverage of I- on different crystal planes of Cu in H2SO4 at pH 1 and 30° was detd. by dissoln. measurements. Surface coverage increased to 0.9 at 10-​4M I- on the (110) plane which adsorbed more I- than either the (100) or (111) planes. The data support the dissoln. of Cu → Cu+ → Cu2+ in 2 single-​electron transfer steps. The corrosion potential indicates a pos. charge on the crystal planes and inhibition of acid corrosion by the adsorbed I-​