A Linear Sweep Voltammetric Procedure Applied to Scanning Electrochemical Microscopy for the Characterization of Carbon Materials towards the Vanadium(IV)/(V) Redox System

Abstract

Abstract A linear sweep voltammetric procedure applied to scanning electrochemical microscopy is presented to investigate carbon materials towards their activity for vanadium redox reactions of relevance for redox flow batteries. A linear sweep voltammetric experiment is performed at an ultramicroelectrode (UME) in close distance to an electrocatalytically active material, triggering a competition situation where both the UME and the material compete for the same molecule (VO 2+ ). Depending on the redox activity of the catalytic material at the applied potential and thus the consumption of VO 2+ , a decreased current in the detection sweep at the UME is observed. After evaluating relevant experimental parameters using a glassy carbon electrode as substrate, the mode is applied to a commercial carbon material where its redox behavior was examined and compared with results from cyclic voltammetry. Finally, it is shown that the presented linear sweep voltammetry–scanning electrochemical microscopy (LSV‐SECM) method can be used to visualize catalytic activity.