Characterization and Evaluation of the Efficiency of TiO2/Zinc Phthalocyanine Nanocomposites as Photocatalysts forWastewater Treatment Using Solar Irradiation

Abstract

This work reports the characterization of composites prepared by the association between zinc phthalocyanine (ZnPc) and titanium dioxide. These composites are better photocatalysts for wastewater decontamination ediated by solar radiation than pure TiO2, performance that remains even when reused. The UV-Vis diffuse reflectance absorption spectra show for these composites two intense absorption bands. The first covers the ultraviolet and part of the visible spectrum region until 460nm (2.7 eV), whereas the second, nonstructured, goes from 475nm until the near infrared with an absorption peak at 683nm attributed to the Q band of ZnPc. The production of additional e−/h+ pairs by these aggregates when photoexcited, their capability to act as charge carrier, the thickness and regularity of their distribution on the TiO2 surface seem to be important parameters for the performance observed for these composites.