A primer to in-situ opto- and spectro-electrochemistry

Electrochemistry is promising to study interfacial electron transfers and redox reactions, but its lack of access to molecular structural information limits understanding on complicated systems. Complementary optical and spectroscopic measurements in situ become necessary to visualize the electrochemical processes, providing the electronic and structural identification of the reactants and products. Recent advancement in instrumentations and nanostructures has enabled spatiotemporal resolution of molecules during complex reactions, opening opportunities to optically reveal intermediates, mechanisms, and rates, as the keys to fundamental and theoretical electrochemistry. This short review introduces the latest optical and spectroscopic techniques that are feasible for electrochemists to start with, including dark-field, Raman, infrared, and ultraviolet-visible-near infrared opto- and spectro-electrochemistry.