Аннотация:The kinetics of charge transfer was studied at an illuminated copper electrode in alkaline solutions at potentials where a Cu2O/CuO two-phase structure is present on the electrode surface. The main processes occurring at these potentials are the photoreduction of CuO by electrons excited in the Cu2O film and the formation of intermediates, presumably O-, which escape by diffusion into the CuO phase and are at the same time oxidized at the Cu2O/CuO interface. Depending on the electrode's potential, the intermediates can be oxidized by reacting, either with photoexcited or with equilibrium holes from the Cu2O. The flat-band potential of Cu2O in this system (-0.1 V vs. nhe), the diffusion coefficient of the photogenerated intermediates in the CuO phase (10(-11) cm2/s), and the order of magnitude of the rate constant of their oxidation at the Cu2O/CuO interface (10(-5) to 10(-4) cm/s) were estimated.