Atomic-level characterization of liquid/solid interface

The detailed understanding of various underlying processes at liquid/solid interfaces requires the development of interface-sensitive and high-resolution experimental techniques with atomic precision. In this perspective, we review the recent advances in studying the liquid/solid interfaces at atomic level by electrochemical scanning tunneling microscope (EC-STM), non-contact atomic force microscopy (NC-AFM), and surface-sensitive vibrational spectroscopies. Different from the ultrahigh vacuum and cryogenic experiments, these techniques are all operated in situ under ambient condition, making the measurements close to the native state of the liquid/solid interface. In the end, we present some perspectives on emerging techniques, which can defeat the limitation of existing imaging and spectroscopic methods in the characterization of liquid/solid interfaces. (topical review)