Abstract
Experimental dependency of the photosystem's response on the wavelength of exciting radiation, also known as action spectrum, may be substantially affected by the spectrum shape of this radiation. This is especially important in the case, when different radiation sources are used for the investigation of action spectrum. For instance, too wide emission peaks of radiation sources can blur the scopes of actual action spectrum and distort information about the properties of photosystem at certain wavelength regions. Here, we propose a method for the correction of experimental action spectrum by the recalculation of experimental data of photoresponse according to actual spectra of exciting radiation. In the case of overlapping radiation spectra from different radiation sources, this method results in much better correlation of experimental action spectrum to actual action spectrum or absorption spectrum of photosystem. The data on photoactivity of several photocatalysts are presented to illustrate and validate the proposed method.•Activity of photosystem depends on the actual spectrum of the radiation source•Single-peak optical radiation sources with the same basic wavelength may cause a different photoactivity•Effect of actual spectrum of the light source on the photoactivity is to be considered.