Change in Surface Chemistry of Magnesium by Alkylbromide Immersion Pretreatment

Tetrahydrofuran solutions containing alkylmagnesium halides (Grignard reagent) provide effective halo-magnesium species on magnesium surface, and deliver reversible magnesium deposition-dissolution without overpotential by a passivation layer on magnesium surface. For this study, the reaction between passivation layer and halogen-containing species has been reproduced by the immersion of magnesium plate in alkylbromides. The immersion in various alkylbromides, especially 1,6-dibromohexane, reduced the passivation overpotential significantly. The treated surface is unstable and replaced by soaking in tetrahydrofuran. XPS reveals that a thick oxide layer remains, while multiple bromine species distribute in the surface layer after immersion in 1,6-dibromohexane. (c) The Electrochemical Society of Japan, All rights reserved.