Atomic Scale Ordering of Liquid Water at a Dynamic Pt(111) Interface Under Electrochemical Conditions Imaged by Electron Holography

ABSTRACT Imaging atomic structure and electric fields of the electric double layer at electrode‐water interfaces is essential for understanding electrochemical reactions. The wave properties of electrons in an environmental transmission electron microscope were used to reconstruct the atomic scale electric potentials of a platinum (111) interface in water by phase shifting electron holography. This progress allowed the observation of ordered water layers at the dynamic state of the platinum (111) surface and the water reorganization under applied electric potentials. The obtained projected electric potential of the Pt‐water interface is quantitatively compared to ab‐initio molecular dynamics simulations, revealing an extended ordered water region. We conclude that the potential drop at the Pt ‐H 2 O interface is mainly carried by the polarization field of the ordered water structure. The impact of different surface Pt configurations and the presence of adsorbates on the ordered structure are discussed.