Title: diffusion current
Long Title: IUPAC Gold Book - diffusion current
DOI: 10.1351/goldbook.D01722
Status: current

Definition
A faradaic current whose magnitude is controlled by the rate at which a reactant in an electrochemical process diffuses toward an electrode-solution interface (and, sometimes, by the rate at which a product diffuses away from that interface). For the reaction mechanism  there are two common situations in which a diffusion 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 diffusion of B toward the electrode surface. In the other, C predominates at equilibrium in the bulk of the solution, but its transformation into B is fast; C diffuses to the vicinity of the electrode surface and is there rapidly converted into B, which is reduced.

Related Terms
- diffusion: https://goldbook.iupac.org//terms/view/D01716
- faradaic current: https://goldbook.iupac.org//terms/view/F02321
- interface: https://goldbook.iupac.org//terms/view/I03082
- reaction mechanism: https://goldbook.iupac.org//terms/view/M03804
- transformation: https://goldbook.iupac.org//terms/view/T06446

Source
- PAC, 1985, 57, 1491. 'Recommended terms, symbols, and definitions for electroanalytical chemistry (Recommendations 1985)' on page 1495 (https://doi.org/10.1351/pac198557101491)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/D01722/html
- json: https://goldbook.iupac.org/terms/view/D01722/json
- xml: https://goldbook.iupac.org/terms/view/D01722/xml

Citation: Citation: 'diffusion current' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.D01722
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Accessed: 2025-11-19T01:12:37+00:00