Concurrent study of the electrochemical response and the surface alterations of silver nanowire modified electrodes by means of EC-AFM. The role of electrode/nanomaterial interaction

The use of nanomaterials as electrode modifiers permits the enhancement of electrode performance using a great variety of approaches, from electrocatalytic enhancement to the improvement of charge transfer processes. The control and understanding of the interaction between the modifiers and the electrode itself are of key importance for the final performance of the modified electrode. This becomes especially relevant in the case of nano -structured materials since their physical response is rarely trivial.In this work, we combined electrochemistry and atomic force microscopy (EC-AFM) to in-situ investigate the surface condition of electrodes modified with silver nanowires (AgNWs) during EC measurements for the first time. EC-AFM allows us to perform cyclic voltammetry and electrochemical impedance spectroscopy together with the assessment of the electrode surface directly in the electrolytic solution. On the other hand, the use of the Langmuir-Blodgett technique provides homogeneity and reproducibility to the electrode modification process.The electrochemical response of the modified electrodes has been found to strongly depend on the selected substrate, but also on the deposition procedure. This opens the path for a better understanding of electrode modification process, and also supports the viability of EC-AFM on open problems involving electrochemistry and surface science.