spectroelectrochemical

Spectroelectrochemistry, or spectroelectrochemical analysis, is an analytical approach that combines electrochemical control with spectroscopic detection to monitor chemical species and processes in real time. It provides complementary information: electrochemical data such as redox potentials, currents, and electron transfer steps, together with spectroscopic data such as absorbance, Raman, or infrared signatures of species present during electrochemical reactions.

In a typical spectroelectrochemical setup, a cell integrates an electrochemical arrangement with a light path to the sample. A working electrode applies potential while spectra are recorded either simultaneously or sequentially. Configurations include in situ or operando arrangements, often using transparent electrodes or optical windows. Common modalities include UV–Visible spectroelectrochemistry, infrared spectroelectrochemistry, and Raman or surface-enhanced Raman spectroelectrochemistry.

UV–Vis SEC is widely used to track changes in electronic states and to identify colored intermediates; IR SEC can probe vibrational modes of functional groups; Raman SEC, including SERS, can enhance signals from low-concentration species. Time-resolved and flow-through configurations enable kinetic studies and rapid-scan experiments, respectively.

Applications span redox chemistry and mechanism studies, identification of short-lived intermediates, catalytic cycles, battery and supercapacitor materials, corrosion processes, sensors, and environmental analyses. Data interpretation typically involves correlating spectral changes with applied potential or time, allowing species identification by spectral fingerprints and monitoring of concentration changes during electrochemical steps. Limitations include spectral overlap, the need for suitable optical windows and transparent electrodes, potential scattering or fluorescence effects, and the requirement for careful calibration and baseline correction.