Dynamics of Au (001) Surface in Electrolytes: In-Situ Coherent X-ray Scattering and Scanning Tunneling Microscopy

TL;DR

This study combines in-situ coherent x-ray scattering and STM to investigate the real-time surface dynamics of Au (001) in electrolytes, revealing how surface reconstruction responds to potential changes.

Contribution

First application of coherent x-ray scattering to in-situ electrochemical interface studies, linking surface dynamics with morphological evolution during potential sweeps.

Findings

Surface reconstruction lifts at anodic potentials.

Surface dynamics are consistent with STM morphological changes.

Coherent x-ray scattering effectively measures equilibrium surface dynamics.

Abstract

We studied dynamics of Au (001) surface in situ in 0.1 M HClO4 electrolyte solution using both coherent x-ray scattering and scanning tunneling microscopy (STM). The surface of Au (001) is known to reconstruct at cathodic potentials; the reconstruction lifts at anodic potentials. In our in-situ STM experiments, the measurements focus on time-dependent progressions of surface morphology during slow potential sweep. In our in-situ coherent x-ray scattering measurements, we demonstrate that the equilibrium surface dynamics are directly measurable and the measured dynamics are consistent with morphological evolution of the STM images. These experiments represent the first successful application of coherent x-ray scattering to the study of electrochemical interfaces in situ.