摘要：

The oxidation of sulphide species in solution has been investigated on a gold electrode in borate solutions of pH 6.8 and 9.2 and in 1 mol dm #x2013;3 NaOH. Sub-monolayer coverage by sulphur occurs at underpotentials. At more positive potentials, multilayers of sulphur can be deposited. The reaction producing sulphur, and the reverse process, involve the formation of poly sulphides as intermediates. The predominant polysulphide intermediate is S 2 2 #x2013; . Oxidation of sulphide to sulphate occurs to some extent in parallel with sulphur deposition. Both reactions are inhibited by the presence of a surface layer of sulphur. At high potentials, sulphur is oxidized to sulphate.

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