Photocatalytic Degradation of Methylene Blue under Visible Light Using TiO2 Thin Films Impregnated with Porphyrin and Anderson-Type Polyoxometalates (Cu and Zn)

In this work, tetra(4-carboxyphenyl)porphyrin (TCPP) and two Anderson-type polyoxomolybdates (containing Cu Zn, respectively; CuPOM, ZnPOM) were synthesized deposited on TiO2 thin films. The properties of the obtained materials characterized through UV–vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR), diffuse reflection scanning electron microscopy (SEM) energy-dispersive X-ray (EDX). adsorption photodegradation under visible light irradiation methylene blue (MB) studied for TiO2, TCPP/TiO2, TCPP/CuPOM/TiO2 TCPP/ZnPOM/TiO2 films in aqueous solution. results reflectance showed bands spectrum TCPP/POM/TiO2 systems compared to unmodified that does not show any same region spectrum. a higher removal MB, with an rate near 31% film 9% film. kinetic pseudo-second order model was best fitting MB process onto fabricated materials. studies better performance films, efficiency 49% 44% solution TCPP/ZnPOM/TiO2, respectively. reusability test indicated porphyrin are moderately stable after performed cycles.