Title: area-related parameters
Long Title: IUPAC Gold Book - area-related parameters
DOI: 10.1351/goldbook.13992
Status: current

Definition
Quantities expressed in terms of "per area" are denoted as area-related parameters.

Notes
1) In photocatalysis, the area-related parameters do not characterise the catalyst as they do in heterogeneous dark catalysis. In general, the properties of a photocatalyst are not directly proportional to its area, especially in view of the fact that light may not equally reach every part of the surface of a particle. The light may not enter the pores of a porous surface and in this case only the outer area behaves as catalyst. A similar situation may occur when particles are aggregated.
2) When the surface area that is accessed by the light cannot be established, it is recommended to use the total surface area in terms of the \(\rm{BET}(\ce{N2})\) area. This implies that most probably a lower limit of the quantity is obtained, because the surface determined by \(\ce{N2}\) adsorption will be larger than that reached by the radiation.

Related Term
- BET(N<sub>2</sub>) area: https://goldbook.iupac.org//terms/view/13997

Source
- PAC, 2011, 83, 931. 'Glossary of terms used in photocatalysis and radiation catalysis (IUPAC Recommendations 2011)' on page 940 (https://doi.org/10.1351/PAC-REC-09-09-36)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/13992/html
- json: https://goldbook.iupac.org/terms/view/13992/json
- xml: https://goldbook.iupac.org/terms/view/13992/xml

Citation: Citation: 'area-related parameters' 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.13992
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Accessed: 2026-05-07T00:07:40+00:00