Solvent effects determine the sign of the charges of maximum entropy and capacitance at silver electrodes

Fully harnessing electrochemical interfaces for reactions requires a detailed understanding of solvent effects in the electrochemical double layer. Predicting the significant impact of solvents on entropic and electronic properties of electrochemical interfaces has remained an open challenge of computational electrochemistry. Using molecular dynamics simulations of silver-water and silver-acetonitrile interfaces, we show that switching the solvent changes the signs for both the charge of maximum capacitance (CMC) and charge of maximum entropy (CME). Contrasting the capacitance and CME behavior of these two interfaces, we demonstrate that the preferred orientation of the solvent molecule and the corresponding charge density determine the sign of the CMC and CME and, hence, the qualitatively different charge asymmetry of the electrochemical interface.

Automated summary

Fully harnessing electrochemical interfaces for reactions requires understanding the impact of solvents on properties of the electrochemical double layer. Using molecular dynamics simulations, we show that changing the solvent can switch the signs of the charge of maximum capacitance and charge of maximum entropy at the interfaces. We demonstrate that the preferred orientation of solvent molecules and corresponding charge density determine the charge asymmetry of the electrochemical interface.