Spatially resolved electrochemical measurements

By its nature, electrochemistry deals with reactions occurring at interfaces. It provides a tool for measuring the energy of a process (via the potential at which it occurs) and its kinetics (via the current measured at an electrode). Bulk electrochemical measurements where a reaction at a large (on the order of square millimetres or more) section of surface is measured is important for many fields including corrosion, biosensing, electrocatalysis and battery materials. While these bulk measurements are very powerful and useful techniques, information about heterogeneity of a reaction's energetics over the surface is lost. Two techniques for performing electrochemistry with spatial resolution, scanning electrochemical cell microscopy (SECCM) and direct-current scanning electrochemical microscopy (SECM) are introduced and strategies for their use in quantifying kinetics and thermodynamics are discussed.