Characterization and Evaluation of the Efficiency of TiO_2/Zinc Phthalocyanine Nanocomposites as Photocatalysts for Wastewater Treatment Using Solar Irradiation

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 mediated by solar radiation than pure TiO 2 , 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 460 nm (2.7 eV), whereas the second, nonstructured, goes from 475 nm until the near infrared with an absorption peak at 683 nm 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 TiO 2 surface seem to be important parameters for the performance observed for these composites.