Experimental and Computational Study of Dopamine as an Electrochemical Probe of the Surface Nanostructure of Graphitized N-Doped Carbon

N-doped carbon nanomaterials have received increased attention from electrochemists because of their applications in the metal-free electrocatalysis of important redox processes. In this work, a series of graphitized undoped and nitrogen-doped carbon electrodes prepared by thermal annealing of sputtered amorphous carbon films were prepared and characterized using a combination of X-ray photoelectron spectroscopy and Raman spectroscopy. Adsorption of the surface-sensitive redox probe dopamine at each electrode surface was then studied using cyclic voltammetry and the results correlated to the physicochemical characterization. Results indicate that dopamine adsorption is influenced by both the nitrogen surface chemistry and the degree of graphitization of the carbon scaffold. N-doping, with predominantly graphitic N-sites, was found to increase adsorption of dopamine more than 6-fold on carbon surfaces when the introduction of N atoms did not result in substantial alterations to the sp2 network. However, wh...