A simple approach for effectively improving the resolution of scanning electrochemical cell microscopy

Abstract

The high-resolution scanning electrochemical cell microscopy (SECCM) is a powerful tool that can directly explore the structure-property correlation of materials at nanometer scale. However, so far, the attainable maximum resolution is still restricted by the diameter of the droplet probe. Here, we report a simple and effective approach that can highly reduce the effective size of a nanopipette probe in SECCM. The effective working size was reduced to tens of nanometers by using the conventional droplet probe with an opening size of ∼129 nm through one-step oil coating. Furthermore, both the topographical and electrochemical activity of the Au nanoplate were simultaneously recorded successfully at the pixel size of sub-10 nm in the x-axis direction, meaning the potential to achieve a sub-10 nm resolution. Finally, the modified probe displays excellent applicability with acidic, neutral and alkaline electrolytes. The method retains the advantages of the droplet probe and breaks the limitation of its opening size on the SECCM imaging resolution, opening a broad avenue for both further rapid commercialization and broad applications of SECCM.