HydrodynamicVoltammetry

Voltammetry with forced flow of the solution towards the electrode surface. A linear potential scan, at sufficiently slow scan rates so as to ensure a steady state response, is usually applied. Mass transport of a redox species enhanced by convection in this way results in a greater electric current. Convective mass transfer occurs up to the diffusion-limiting layer, within which the mass transfer is controlled by diffusion. Electroactive substance depletion outside the diffusion layer is annulled by convective mass transfer, which results in steady- state sigmoidal wave-shaped current-potential curves. The forced flow can be accomplished by movement either of the solution (solution stirring, or channel flow), or of the electrode (electrode rotation or vibration).