A hydrothermal synthesis of Pr³⁺ doped mesoporous TiO ₂ for UV light photocatalysis

Pr³⁺ doped mesoporous TiO₂ photocatalysts with a different molar ratio of Pr to Ti were prepared by a hydrothermal method using triblock copolymer as the template. The as-prepared samples were systematically characterized by X-ray diffraction, N₂ adsorption-desorption, X-ray photoelectron spectra, transmission electron microscopy and UV-visible diffuse reflectance spectroscopy. The characterizations indicated all the samples had mesoporous structure and narrow pore size distribution. Pr³⁺ doping enlarged the surface area and decreased the crystallite size. The surface area of the samples varied from 136 to 170 m²/g, and the average crystallite size ranged between 5.04 and 7.60 nm. The effect of Pr³⁺ doping amount on the photocatalytic activity of mesoporous TiO₂ was evaluated by the degradation of methyl orange under UV light irradiation. The results showed that the suitable amount of Pr³⁺ doped samples exhibited the higher photocatalytic activity than mesoporous TiO₂. Among the samples, 1 at.% Pr³⁺ doped mesoporous TiO₂ showed the highest photocatalytic activity.