Preparation and Characterization of Phthalocyanine Photocatalysts Supported on Mixed Metal Oxides

This research explores the development of hybrid photocatalysts by combining GeO₂ doping of metal oxides with phthalocyanine functionalization to enhance the degradation of Methyl Orange (MO) dye under visible light. Four metal oxide supports, TiO₂, Al₂O₃, SiO₂, and ZrO₂, were tested in their pristine form, then modified with GeO₂ and further functionalized by solution adsorption using two types of zinc phthalocyanines: F₁₆PcZn and F₆₄PcZn. The degradation of MO was monitored using UV-Vis spectroscopy, and kinetic models were applied to evaluate the reaction rates. The results showed that the bare oxides exhibited little to no photocatalytic performance. GeO₂ doping improved activity modestly. The greatest enhancement was observed after they were functionalized with phthalocyanines, particularly F₆₄PcZn. Among all tested systems, TiO₂/GeO₂/F₆₄PcZn and Al₂O₃/GeO₂/F₆₄PcZn demonstrated the fastest degradation, with half-life values of 20 and 18 minutes, respectively, marking a dramatic improvement compared to over 2000 minutes for bare TiO₂. These findings highlight the synergistic effects of oxide doping and molecular sensitization in designing efficient photocatalysts for potential environmental applications.