PHOTOCATALYSTS BASED ON TITANIUM DIOXIDE AND ZINC PHTHALOCYANINE COMPOSITES FOR PHOTODEGRADATION OF METHYLENE BLUE

The aim of this work is to analyze the photocatalytic degradation of a model methylene blue solution using titanium dioxide composites with zinc phthalocyanine as the sensitizing photocatalyst under sunlight. The objects of the study are TiO2-based photocatalysts derived from the spent catalyst of the Shurtan GCC after heat treatment at 650°C (T-650), as well as a composite containing zinc phthalocyanine (T-650/PcZn). It has been established that the photodegradation reaction follows a pseudo-first-order model, while the rate constant for the TiO2/PcZn composite is significantly higher than that of pure TiO2, indicating greater efficiency. The composite is stable and effectively decolorizes the dye, but the decay products accumulate in solution and begin to absorb light across the entire wavelength range, increasing the spectral background.