The Use of Electrochemical Scanning Tunneling Microscopy to Study the Initial Stages of Electrodeposition in situ; Overpotential Deposition of Pb and Pt on HOPG

SUMMARYThe advent of the Electrochemical Scanning Tunneling Microscope has opened up the possibility of studying the structural development of electrodeposits in situ on a near atomic scale. The principles of Scanning Tunneling Microscopy, the incorporation of electrochemical cells and the application of such instruments to electrocrystallization studies are reviewed briefly. The overpotential depositions of Pb and Pt on graphite are used as examples to illustrate the wealth of information which can be extracted. The Pb exhibits a deposit topology consistent with conventional diffusion controlled mechanisms whilst Pt shows much more complex behaviour. The potential and limitations of the instrument are discussed.