Practical Chemical Actinometry—A Review

Abstract

Actinometers are physical or chemical systems that can be employed to determine photon fluxes. Chemical actinometers are photochemical systems with known quantum yields that can be employed to determine accurate photon fluxes for specific photochemical reactions. This review explores in detail several practical chemical actinometers (ferrioxalate, iodide-iodate, uranyl oxalate, nitrate, uridine, hydrogen peroxide and several actinometers for the vacuum ultraviolet). Each actinometer is described with recommended conditions for its use.

Photokinetics of Dacarbazine and Nifedipine under polychromatic light irradiation and their application as new reliable actinometers for the ultraviolet range

“…It is, however, interesting to notice that the above integrand was variably formulated, for instance, by replacing the term by the product ( ) where represented the energy of the light beam 25 , or by ( ) 26 , or by ( ) 27 , with, in this case, the spectral irradiance being expressed in W cm −2 nm −1 , or by ( ) 28 , where t is the integration time for the measurement of the lamp’s emission spectrum. Recently, a rate equation, claimed to be a general chemical rate expression, for any photoreaction irradiated by a polychromatic light source, omitted the ratio from the integral given above, and considered the exponential factor to be equal to 29 . Another form of the rate equation was based on only initial and final absorbances of the medium 30 .…”

“…Despite their differences, these differential rate equations are, unfortunately, not analytically solvable. Usually, the kinetic trace is calculated by numerical integration 21 – 29 . As a consequence, there are no analytically established simple algebraic equations, of the form , to map out the kinetic traces and the behaviour of reactions under polychromatic light.…”

Impact of Reaction Parameters and Water Matrices on the Removal of Organic Pollutants by TiO2/LED and ZnO/LED Heterogeneous Photocatalysis Using 365 and 398 nm Radiation

“…The photon flux of the light sources was measured by potassium-ferrioxalate actinometry, a standard one recommended by IUPAC [ 62 ] that is widely investigated and applied in the literature [ 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 ]. The 1.0 × 10 −2 M Fe 3+ -oxalate solutions were irradiated, the released Fe 2+ was measured after complexation with 1,10-phenanthroline.…”

Device for automated screening of irradiation wavelength and intensity – investigation of the wavelength dependence of photoreactions with an arylazo sulfone in continuous flow

“…Chemical actinometers are commonly used to measure the photon flux density. 40 It is, however, practically impossible to find an actinometer that can be used over the entire wavelength range represented by the LED array library. 21 Several actinometers, with different quantum yields, would have to be used to measure the photon flux density of the 16 LED arrays, with different emission bandwidths, making a sufficiently accurate irradiance matching of the LED arrays unlikely.…”