2.4.7. Photochemical Analysis

The photostability of the samples was spectrophotometrically investigated. Absorption spectra of the powder samples were recorded by a Varian Cary 4000 spectrophotometer (Varian, East Lyme, CT, USA), equipped with a 150-mm integration sphere, and a barium sulfate tablet was used as a reference. The recorded spectra were analyzed by the Kubelka-Munk equation.

Steady-state irradiation experiments were performed using a Xenon lamp 150 W(Agilent, Santa Clara, CA, USA) as light source, the irradiation wavelength was selected by a monochromator, and a band-pass slit of 35 nm was used. The spectra analysis was carried out at different irradiation times.
