Synthesis of Cunb2o6 by Self-Combustion Method, Immobilization on Chitosan Membrane and Optimized Photocatalytic Activity with Visible Light in the Degradation of Azo Dye

The food dye Tartrazine yellow, is an example of Azo dye, widely used by industry, consequently new remediation technologies are studied to minimize their environmental impact. This work presents the synthesis of the photocatalyst CuNb2O6 by the self-combustion method, its immobilization on polymeric chitosan membrane, and optimization of photocatalytic activity with visible light in the degradation of Azo dye Tartrazine, as a promising alternative in the development of degradative methodologies for this substance. The synthesized and immobilized CuNb2O6 was characterized, presenting high purity, high crystallinity, good homogeneity, a bandgap of 1.30 eV, with excellent morphology of immobilization on membrane by casting method. A statistical analysis was performed with the support of the Doehlert matrix, to study the influence of pH and concentration of CuNb2O6 immobilized on a chitosan membrane, during the photocatalytic reaction; with better performance in optimized conditions of pH equal to 7.34 and 2.27 g L-1 of CuNb2O6 in the membrane. The immobilized photocatalyst was efficient and promising in the degradation of Azo dye, in an associative process adsorption/photodegradation, with a reduction of 94% of chromophore compounds (430 nm), and reduction of 86% of aromatic compounds (260 nm), and similar percentage after six cycles of reuse.