Liquid-solid contact electrification and its effect on the formation of electric double layer: An atomic-level investigation

Abstract

Contact electrification at liquid-solid interface has aroused many research interests. Some recent researches suggest that the formation of electric double layer may be dominated by the charge transfer from liquid-solid contact electrification, which challenges the traditional electric double layer models. However, how the liquid-solid contact electrification affects the electrical double layer is still lacking of atomic-level mechanism details. In this work, an atomic-level investigation on the effect of contact electrification on the liquid-solid electric double layer are performed via first-principles and molecular dynamics simulations. The results suggest that the liquid-solid contact electrification can influence the ions distribution in the solution, thus influencing the formation of electric double layer and can even reversing its polarity under specific surface charge density. The mechanism is that the contact charges on the solid surface can affect the adsorption energy of anion/cation at the liquid-solid interface. The conclusion of this work can provide a more comprehensive understanding of the effect of contact electrification to the electric double layer.