On the identification of favourable factors for corrosion inhibition of aluminium by 8-hydroxyquinoline and its derivatives: DFT and electrochemical studies

Computational and electrochemical experimental approaches were combined to identify factors which would be favourable or detrimental to corrosion inhibition of aluminium by 8-hydroxyquinoline (8Hq) and its sulfonic derivative (8HqSH). 8HqSH exhibited a strong adsorption on Al(111) but a greater solubility in water than 8Hq, including Al complexes, which might increase Al corrosion. This was confirmed by the electrochemical measurements. In the presence of 8HqSH, an acceleration of the aluminium dissolution was observed, whereas, in the presence of 8Hq, a protective film was formed on the Al surface.