The electroreduction of “C60” films in aqueous electrolyte does not lead to alkali metal ion insertion—Evidence for the involvement of adventitious poly-epoxidated C60 (C60On)

In this letter, we present experimental data which challenges the model proposed since the mid-1990s that the reduction of C60 films in aqueous electrolytes involves the formation of [M+nC60n−] where M+ represents a metal cation or proton. Instead we provide voltammetric, XPS and UV–vis evidence that the reduction of “C60” films in aqueous media is instead the reduction of adventitious poly-epoxidated C60On with subsequent chemically irreversible loss of “O2−” as water, and that C60 is not reduced within the potential windows of aqueous electrolytes.