A practical introduction to electrochemical atomic force microscopy and scanning tunneling microscopy

Journal of Physics Energy, vol. 8, pp. 033003

Abstract

Abstract Directly monitoring the structure and evolution of an electrode surface during reaction provides uniquely powerful insight into interfacial processes. Electrochemical atomic force microscopy (EC-AFM) and Scanning Tunneling Microscopy (EC-STM) have therefore become essential tools for linking potential-controlled surface transformations to macroscopic current and product outcomes. In EC-AFM, surface features are measured from the deflection of a typically laser-tracked cantilever, enabling imaging of metals, semiconductors, and insulators in liquid electrolytes. By selecting appropriate probes and operating modes, EC-AFM maps topography together with complementary channels such as mechanical response, friction, and local electrical contrast, offering a multi-parametric view of the electrified interface during processes such as film formation, corrosion, gas evolution, and electrodeposition. By contrast, EC-STM measures the tunneling current between a conductive tip and a conductive substrate, providing access to atomic-scale surface order, reconstruction, and adsorbate structures under EC control. In liquid environments, STM performance is limited by parasitic faradaic currents and capacitive coupling, making careful EC configuration and robust tip insulation (coated everywhere except the apex) critical for stable imaging. This tutorial summarizes practical EC cell considerations, probe preparation, alignment and calibration steps, and data-handling best practices for acquiring reproducible in-operando SPM datasets. This tutorial seeks to make EC-AFM/EC-STM measurements more approachable for beginners by clearly explaining the fundamental principles as well as practical considerations, allowing practitioners to gain highly informative EC insights on their systems of interest. Throughout, we emphasize common EC artifacts and decision rules that help newcomers distinguish true potential-dependent surface dynamics from drift, bubble interference, leakage currents, and feedback-induced contrast, enabling reliable interpretation of AFM/STM observations in EC environments.

Authors 5

1. Inhee Park corresponding

   Forschungszentrum Jülich

   Affiliation as printed

   Institute of Energy Technologies, Fundamental Electrochemistry (IET-1), Forschungszentrum Jülich

2. Austin D. Ready corresponding

   Lawrence Berkeley National Laboratory

   Affiliation as printed

   Lawrence Berkeley National Laboratory

3. Rayan Alaufey corresponding

   Lawrence Berkeley National Laboratory

   Affiliation as printed

   Lawrence Berkeley National Laboratory

4. Robert M. Kostecki corresponding

   Lawrence Berkeley National Laboratory

   Affiliation as printed

   Lawrence Berkeley National Laboratory

5. Florian Hausen corresponding Aachen Institute of Physical Chemistry

   Forschungszentrum Jülich · RWTH Aachen University

   Affiliation as printed

   Institute of Energy Technologies, Fundamental Electrochemistry (IET-1), Forschungszentrum Jülich

   Institute of Physical Chemistry, RWTH Aachen University