Unusual electrochemical behaviour of AuBr4- in ionic liquids. Towards a simple recovery of gold(III) after extraction into an ionic liquid

摘要

The electrochemistry of AuBr4- complexes extracted into ionic liquids [C8PYR][NTf2]or [C8MIM][NTf2] saturated with water and gas has been studied by cyclic voltammetry on a glassy carbon macro electrode and by linear voltammetry on a platinum microelectrode. Unlike AuCl4-, the reduction of AuBr4- to Au(0) is achieved following a one reduction step involving three electrons. The deposition of Au(0) from AuBr4- is carried out at a potential above that of water, leading to the simple and easy deposition of gold and subsequently to the extraction of AuBr4- into an ionic liquid.