14036 IUPAC Gold Book - photoadsorption efficiency 10.1351/goldbook.14036 14036 current 1 Ratio of the maximal (typically the initial) rate of photoadsorption of entities \(\ce{B}\) (molecules, atoms, or ions) to the integrated incident (superscript 0, zero) photon flux, \(\int_{\lambda_{1}}^{\lambda_{2}} q_{\rm{p},\lambda}^{0}{\rm{d}}\lambda = q_{\rm{p}}^{0} = {\rm{d}}N_{\rm{p}}^{0}/{\rm{d}}t\), in the wavelength range \(\lambda_{1}{-}\lambda_{2}\). Both rates should be measured under otherwise identical conditions (preferably as initial rates) in order to avoid concentration and/or surface area effects. Mathematical expression: \[P_{\rm{AE}} = \frac{{\rm{d}}N_{\ce{B}}/{\rm{d}}t}{\int_{\lambda_{1}}^{\lambda_{2}} q_{\rm{p},\lambda}^{0}{\rm{d}}\lambda} \ {\rm{for}}\ t \to 0\] where \({\rm{d}}N_{\ce{B}}/{\rm{d}}t\) is the rate of adsorption of entities (the initial quasi-stationary rate of photoadsorption). The initial rate of photoadsorption in SI units is \({\rm{d}}p/{\rm{d}}t\) (\(\pu{Pa s-1}\)) for gas/solid systems, with \(p\) the pressure and in SI-coherent units \({\rm{d}}c/{\rm{d}}t\) (\(\pu{mol L-3 s-1}\)) for liquid/solid systems, with \(c\) the amount concentration of the adsorbate in solution. For \(P_{\rm{AE}}\) determined under first-order conditions on photon flux and zero-order on concentration (or pressure), it corresponds to the efficiency of formation of the active photoadsorption centre. photoadsorption centre https://goldbook.iupac.org//terms/view/14035 PAC, 2011, 83, 931. 'Glossary of terms used in photocatalysis and radiation catalysis (IUPAC Recommendations 2011)' on page 965 (https://doi.org/10.1351/PAC-REC-09-09-36) https://goldbook.iupac.org/terms/view/14036/html https://goldbook.iupac.org/terms/view/14036/json https://goldbook.iupac.org/terms/view/14036/plain Citation: 'photoadsorption efficiency' 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.14036 The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using. 2026-05-07T00:06:24+00:00