Understanding the interaction of the water-metal system at an atomic level is extremely important in in electrocatalysis for fuel cells applications and electrodes for hydrogen evolution in photocatalysis among other systems. Understanding liquid ordering at the interface involves a detailed study of the nature of the interactions between water-water and water-substrate. In that sense, a first principles description of all components of the system is the most appropriate methodology to be used. In this work we analyze in detail the structural, dynamic and energetic properties of liquid-water interacting with (111) Au and Pd surfaces at ambient temperature, using first principles molecular dynamics.
We also present a methodology to study an electrochemical cell in the presence of an external bias applied to the electrodes. We combine density functional theory (DFT) and non-equilibrium Green's functions methods (NEGF) to provide a more quantitative connection between the macroscopic voltage and the microscopic interfacial charge distribution, thus simulating a realistic out-of-equilibrium open system.