Molecular approach about the effect of water on the electrochemical behaviour of Ag ions in urea-choline chloride-water mixture.

The water influence on electrochemical behaviour of Ag ions in urea and choline chloride mixture was investigated by cyclic voltammetry technique, while the molecular insights about the investigated systems were obtained from molecular dynamic (MD) simulation. The water content was variated from 0 up to 10% (v/v). Cyclic voltammetry technique showed that the peak potential for Ag/Ag redox couples shifted in direction to more positive potentials with the gradual increase of water content in solution, indicating that the addition of water electrocatalyses the kinetics of the reduction of Ag ions. The MD simulations demonstrated that water molecules do not interact strongly with Ag ions but induce a small reduction in the number of urea molecules around of the ion and that the water molecules adjust to free spaces in the mixture.