In Operando Visualization and Dynamic Manipulation of Electrochemical Processes at the Electrode-Solution Interface.

Revealing the dynamic processes at the electrode-solution interface is imperative for understanding electrochemical phenomena. Most techniques have been developed to sense the electrode surface changes at the nanoscale, but provide limited information on potential-induced interfacial ion redistribution at the mesoscale. Herein, we present an in operando visualization method utilizing a microfabricated electrochemical cell combined with a laser scanning confocal microscope to observe high-resolution and fast-response interfacial processes. We report potential-induced formation and transformation of the Nernst diffusion layer, demonstrating that pulsed voltage dynamically perturbs the interface and promotes ion diffusion. This provides an additional insight into developing a dynamic manipulation method to control the electrochemical process. Our novel visualization method can easily be applied to monitor different ionic behaviors in electrochemical reactions at the mesoscale.