  The electrified solid-liquid interface plays an essential role in many
renewable energy-related applications, including hydrogen production and
utilization. Limitations in computational modelling of the electrified
solid-liquid interface have held back the understanding of its properties at
the atomic-scale level. In this study, we applied the grand canonical density
functional theory (GC-DFT) combined with a hybrid implicit/explicit solvation
model to reinvestigate the widely studied electrified platinum-water interface
affordably. The calculated double layer capacitances of the Pt(111)-water
interface over the applied bias potential closely match the experimental and
previous theoretical data from expensive ab-initio molecular dynamics
simulations. The structural analysis of the interface models reveals that the
applied bias potential can significantly affect the Pt(111)-water atomic
interface configurations. The orientation of the water molecules next to the
Pt(111) surface is vital for correctly describing the potential of zero charge
(PZC) and capacitance. Additionally, the GC-DFT results confirm that the
absorption of the hydrogen atom under applied bias potential can significantly
affect the electrified interfacial properties. The presented affordable GC-DFT
approach, therefore, offers an efficient and accurate means to enhance the
understanding of electrified solid-liquid interfaces.
