Tuning the morphological and electrical properties of graphite surface by self-assembled viologen nanostructures

Abstract

In this contribution, a combination of cyclic voltammetry (CV), atomic force microscopy (AFM), electrochemical scanning tunneling microscopy (EC-STM) and Kelvin probe force microscopy (KPFM) is used to characterize the electrochemical, structural and electronic properties of the dibenzyl viologen (DBV) molecules based adlayers electrochemically deposited on highly oriented pyrolytic graphite (HOPG) surface. The adlayer formations on HOPG are dependent on its redox states in-situ modulated by the electrode potential and the used concentration. Relying on the intrinsic solubility of individual reduced molecules one enables permanent modulation the modification degree of HOPG surface. In addition, at the potentials where HOPG surface is merely modified by DBV0 molecules, the electrical properties of HOPG surface can also be modulated by various DBV2+ concentrations as the variable.