Synthesis, characterization and photocatalytic activity of PdO/TiO₂ and Pd/TiO₂ nanocomposites

Sol–gel, sol–gel–hydrothermal and photodeposition methods were used to synthesize pure TiO₂, PdO/TiO₂ and Pd/TiO₂ nanostructures. Citric acid was used as a stabilizer, reducing and capping agent, since it is green, available, clean and nontoxic. During the one of the steps, stearic acid was used as an organic solvent to obtaining homogenized sol. In the following, Pd/TiO₂ nanostructures were synthesized by photodeposition in 0.1, 0.5 and 1 wt% Pd on the surface of P25 nanoparticles under ultraviolet (UV) irradiation. Product characterization was performed by X-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy and diffuse reflectance spectroscopy. The photocatalytic behaviors of pure TiO₂, PdO/TiO₂ and Pd/TiO₂ nanocomposites were evaluated using the degradation of a Rhodamine B aqueous solution under UV light irradiation. Among them, excellent performance for Pd/TiO₂ nanocomposite containing just 1 % palladium in photocatalytic dye degradation was observed and only after 20 min, 88 % of dye was degraded.