diffusion current (diffusion-controlled current)

A @[email protected] whose magnitude is controlled by the rate at which a reactant in an electrochemical process diffuses toward an electrode-solution @[email protected] (and, sometimes, by the rate at which a product diffuses away from that @[email protected]). For the @[email protected]
there are two common situations in which a @[email protected] current can be observed. In one, the rate of formation of B from electroinactive C is small and the current is governed by the rate of @[email protected] of B toward the electrode surface. In the other, C predominates at equilibrium in the bulk of the solution, but its @[email protected] into B is fast; C diffuses to the vicinity of the electrode surface and is there rapidly converted into B, which is reduced.
PAC, 1985, 57, 1491. (Recommended terms, symbols, and definitions for electroanalytical chemistry (Recommendations 1985)) on page 1495 [Terms] [Paper]