Mechanism of the Transfer of AuCl4- and TOA+ Ions Across the Liquid/Liquid Interface

The Brust-Schiffrin (BS) two-phase method to synthesize nanoparticles has been widely used. In this method, the transfer of tetrachloroaurate (AuCl4-) from aqueous phase into organic phase is the first step. However, the mechanism of the transfer of AuCl4- is still not clear. In this paper, we studied the mechanism of the transfer of AuCl4- across a micrometer-sized interface between two immiscible electrolyte solutions (ITIES). Our results revealed that the presence of TOA(+) can enhance the transfer of AuCl4- from aqueous phase into organic phase. The enhanced transfer of AuCl4- is explained by the shuttling mechanism which has been developed by Laforge et al.