Time domain spectroscopy: an application to electrochemistry

Electrochemistry uses current and impedance data to derive chemical rate constants and to obtain information about reaction mechanisms, usually with techniques operating below 100 kHz. By the application of time-domain spectroscopy this region can be extended to nano- or picoseconds and information about the electronic structure of cell components, e.g. electrodes, can be obtained. Fast transient faradic and nonfaradic currents of electrochemical cells can be measured conveniently by a new apparatus which combines the conventional time domain spectroscopy configuration with a potentiostat. The system is applied to semiconductor electrodes in contact with an aqueous electrolyte and multiexponential relaxation spectra are observed.