Design of a scanning tunneling microscope for electrochemical applications

Abstract

A design for a scanning tunneling microscope that is well suited for electrochemical investigations is presented. The construction of the microscope ensures that only the tunneling tip and the sample participate in electrochemical reactions. The design also allows rapid replacement of the tip or sample, and enables facile introduction of auxiliary electrodes for use in electrochemical experiments. The microscope utilizes stepper motor driven approach mechanics in order to achieve fully remote operation and to allow reproducible coarse control of tip/sample spacings for electrochemical experiments. Highly ordered pyrolytic graphite images at atomic resolution in air and aqueous solutions can be obtained with this microscope.

In Situ Scanning Tunneling Microscopy of Polycrystalline Platinum Electrodes under Potential Control: Copper Electrodeposition and Pyrrole Electropolymerization

“…The scanning tunneling microscope (STM) allows very high resolution (atomic or near-atomic) examination of the surfaces of conductive or semiconductive substrates (1,2). Although originally mainly applied to samples in a vacuum or a gaseous environment, this technique has been used to investigate various substrates immersed in aqueous and nonaqueous solutions (3)(4)(5)(6)(7)(8)(9). We have further demonstrated the in situ study of anodic dissolution of nickel electrodes in sulfuric acid solution under external polarization conditions and open-circuit corrosion of stainless steel in aqueous chloride media (10).…”