2.3.2. Photodegradation Effect

To establish the photodegradation capacity of the synthesized solids, methylene blue powder (C16H18N3Cl S) was taken as the reference organic molecule to be degraded. This powder was dissolved in distilled water at a concentration of 55 ppm and 200 mL were taken from the resulting solution and poured into a 250-mL precipitation glass. Then, 10 mg of the synthesized powders were weighed and added to the methylene blue solution. The mixture was agitated for the time determined from the adsorption kinetics to eliminate or reduce as much as possible the adsorption effect, and then transferred to a "solar simulator" constructed in the laboratory. The suspension was placed in the simulator and the UV lamps (Phillips TUV 15 W lamps, maximum intensity at 254 nm, Phillips, Lausanne, Switzerland) turned on to begin the photodegradation process. During this process, the system was maintained at a continuous agitation of 500 rpm/min, taking samples periodically every 5 min. The samples were placed in a small quartz container and placed in the UV-Vis spectrophotometer to obtain the system's absorbance value at a wavelength of 665-nm; identical steps were followed for the photolysis test, but using only the methylene blue solution. Upon determining the absorbance, the suspension was again poured into the precipitation glass. This process was repeated every 5 min, until minute 20, and then every 10 min until minute 60. Finally, the methylene blue percentage degradation over time curve was obtained with respect to the calibration curve. The photodegradation effect was determined by employing a laboratory designed photo-reactor. Monitoring of the disappearance of methylene blue in the solution was carried out using UV-Vis spectroscopy.
