Redox-Dependent Spatially Resolved Electrochemistry at Graphene and Graphite Step Edges

Abstract

The electrochemical (EC) behavior of mechanically exfoliated graphene and highly oriented pyrolytic graphite (HOPG) is studied at high spatial resolution in aqueous solutions using Ru(NH 3 ) 6 3+/2+ as a redox probe whose standard potential sits close to the intrinsic Fermi level of graphene and graphite. By coupling scanning electrochemical cell microscopy (SECCM)

Impact of Adsorption on Scanning Electrochemical Microscopy Voltammetry and Implications for Nanogap Measurements

“…Fresh HOPG basal surfaces were prepared by gently pressing down Scotch tape on to the sample and pullingoff the top layers, as reported extensively in the literature. 33,[60][61][62][63] Cyclic Voltammetry and SECM Instrumentation cm 2 ) with the counter and reference electrode placed into the droplet. 63 An advantage of this electrochemical cell is that it can be assembled and used within seconds of sample cleavage, 63 minimizing surface contamination.…”

Versatile Polymer-Free Graphene Transfer Method and Applications

“…The ion conductance current or iDC can be indicative of the size of the meniscus between pipet and substrate, 41,[52][53][54] and was used here to diagnose landing of the meniscus on the surface and control of the pipet (as described previously 58 ). These approaches are representative of more than 16 measurements carried out for each of these two scenarios.…”

Nanoscale Electrocatalysis of Hydrazine Electro-Oxidation at Blistered Graphite Electrodes

“…[37][38][39][40] In this paper, we use a hopping voltammetric mode SECCM regime, in which a linear sweep voltammetry (LSV) measurement is performed at each location (pixel) of the defined scan area. These data can be processed to provide electrochemical activity maps, comprising hundreds of spatially-resolved current measurements as a function of potential, that can be played back as a movie, from which potential-resolved snapshots can be extracted, and from which current-voltage curves, Tafel analysis, etc.…”