Electrochemical and thermodynamic study of the electroreduction of Bi(III) ions in the presence of cysteine in solutions of different water activity

► The cysteine and activity water influence the rate of Bi(III) electroreduction. ► The multistage process is confirmed by the not rectilinear ln kf = f(E) dependences. ► This fact is connected with the active complex formation on electrode surface. ► Cysteine is a mediator in the formation of these complexes.