STM imaging of noble metal electrodes in solution under potentiostatic control

Abstract

SUMMARY We have combined a three‐electrode cell arrangement with a scanning tunnelling microscope (STM) to image the surfaces of polycrystalline noble metal electrodes under potentiostatic conditions. STM imaging was made in the potential range where a tip and the electrodes are ideally polarized. We have observed on a submicron scale that the electrochemically roughened Ag electrode surface relaxed over times of 40 min at −0·16 V versus SCE in 0·1 m KCl. We have also imaged a dynamic process (formation and dissociation) of the submicron‐scale reconstruction of the Au electrode subjected to electrochemical oxidation‐reduction cycles. The results can be explained by the absorption of Cl− ions and the surface diffusion of adatoms or clusters. STM imaging under potentiostatic control leads to the discovery of phenomena occurring at solid metal/electrolyte interfaces.

Scanning tunneling microscopy of silicon and carbon

“…It is becoming common to use the technique to study surfaces (electrodes) while the potentials of the surfaces are controlled (11)(12)(13)(14)(15). The method has been used to observe electrochemical depositions and stripping (16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34). It also has been used to perform microscale fabrications (35).…”