摘要： This project studied the preparation of new Nb2O5/tannin-formaldehyde xerogel composites (XTF-wNb) for photocatalytical applications. The choice of tannin biomass and niobium recycled scraps as precursors is aimed at reducing costs and environmental impacts. The composites were characterized by diffuse re?ectance spectroscopy (DR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), infrared spectroscopy (IR), and X-ray diffraction (XRD). The photocatalytic properties of the composites were evaluated by methylene blue decomposition. The in?uence of the catalyst dosage and the initial concentration of dye in the adsorption and photocatalysis processes were studied. The X-ray pro?les of the XTF-wNb show the presence of niobic acid in the structure of the materials, proving the presence of the inorganic oxide in the matrix of these composites. The tannin/Nb ratio had a signi?cant in?uence on the morphology of the formed composites, causing changes in the shape and size of the particles composing each material. All materials have pHPZC < 5. The XTF-24Nb was the most effective photocatalyst, its photocatalytic ef?ciency superior to the one of titanium dioxide, evidencing the bene?cial effect of the xerogel coupling on the photocatalytic properties of the material.