Photo and Chemical Reduction of Copper onto Anatase‐Type TiO 2 Nanoparticles with Enhanced Surface Hydroxyl Groups as Efficient Visible Light Photocatalysts

In this study, the photocatalytic efficiency of anatase‐type TiO 2 nanoparticles synthesized using the sol–gel low‐temperature method, were enhanced by a combined process of copper reduction and surface hydroxyl groups enhancement. UV –light‐assisted photo and Na BH 4 ‐assisted chemical reduction methods were used for deposition of copper onto TiO 2 . The surface hydroxyl groups of TiO 2 were enhanced with the assistance of Na OH modification. The prepared catalysts were immobilized on glass plates and used as the fixed‐bed systems for the removal of phenazopyridine as a model drug contaminant under visible light irradiation. Na OH ‐modified Cu/TiO 2 nanoparticles demonstrated higher photocatalytic efficiency than that of pure TiO 2 due to the extending of the charge carriers lifetime and enhancement of the adsorption capacity of TiO 2 toward phenazopyridine. The relationship of structure and performance of prepared nanoparticles has been established by using various techniques, such as XRD , XPS , TEM , EDX , XRF , TGA , DRS and PL . The effects of preparation variables, including copper content, reducing agents rate (Na BH 4 concentration and UV light intensity) and Na OH concentration were investigated on the photocatalytic efficiency of Na OH ‐modified Cu/TiO 2 nanoparticles.