Visible Light-Induced Photocatalytic Degradation of Acid Orange 7 in Aqueous TiO sub(2) Suspensions

Tests implemented under visible light irradiation sought to evaluate the photocatalytic degradation of a model azo dye (e.g., Acid Orange) in aerated aqueous titanium dioxide suspension. Scientists adopted a set of appropriate quenchers of these species for experiments investigating the presence and role of oxidative species, including singlet oxygen, superoxide, and hydroperoxy radicals. Researchers also evaluated the reaction pathway to dye degradation via monitoring of the temporal evolution of intermediates and final products on both the surface of the photocatalyst and in solution. Evidence underscored the potential for complete decolorization of the solution along with a simultaneous reduction in the chemical oxygen demand of the solution.