A Hydrothermal Synthesis of Pr<SUP>3+</SUP> Doped Mesoporous TiO<SUB>2</SUB> for UV Light Photocatalysis

Abstract

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.

Fabrication of Pr-PVP-Co-Doped NanoTiO2Film on Titanium Matrix with Outstanding Electrocatalytic Reduction Activity for Oxalic Acid

“…22 Furthermore, the diffraction peaks of the Pr-PVP-doped TiO 2 films were nearly same as those of the pure TiO 2 films, indicating that Pr 3+ may be integrated into TiO 2 in an intergranular fashion rather than via lattice substitution. 24,25 The average size was determined from Scherrer's equation using the diffraction peaks at 25.3 • C and the average sizes were found to be about 11 nm, 20 nm, and 21 nm for Pr-PVP-doped, PVP-doped, and undoped Ti/TiO 2 films, respectively. The decrease in crystal size could be attributed to the formation of Pr 2 O 3 on the surface, with Ti 4+ entering into the Pr 2 O 3 , inhibiting the agglomeration of TiO 2 nanoparticles, thereby restrain TiO 2 crystal growth.…”

Rare Earth‐Doped Anatase TiO2 Nanoparticles

“…The absorption of praseodymium ion in TiO 2 hosts is reported in Refs. [28,55,80,81]. From reflectance spectrum of TiO 2 :Pr presented in Figure 10(a), absorptions of Pr 3+ ions in TiO 2 absorption edge are observed at approximately 445, 480 and 595 nm that could be attributed to the transition from 3 H 4 ground state to the 3 P 2-0 and 1 D 2 excited states of the Pr 3+ ions.…”

“…The contents of RE ions used in sol-gel synthesis are usually in the 0.1-3% range, while further addition of RE ions (≥5%) effectively obstructs TiO 2 crystallinity owing to a lattice distortion, and remarkably reduces the crystallite size [22,25]. The increase of doping concentration leads to a higher content of RE-O-Ti bonds that inhibit the growth of TiO 2 crystal grains restricting the direct contact of anatase particles, shifts diffractions to lower 2 theta angles, and as a consequence of smaller crystallites, broadening of X-ray diffraction (XRD) maxima [18,55,72,73]. Even in undoped TiO 2 , the anatase phase is reported to be thermodynamically stable at very low particle size.…”

Preparation of C/Ho co-doped TiO2 for enhancing the photocatalytic degradation efficiency of tetracycline hydrochloride

“…The photocatalytic degradation rates of TCH by CHT-0.08 and CHT-0.1 were a little lower than that of CHT-0.05, possibly because excessive doping with Ho could result in photogenerated electron-hole recombination and, thus, lowered photocatalytic activity. 60 For example, Yu et al 7 prepared a heteropolyacid-chitosan/TiO 2 (PMA-CS/TiO 2 ) composite photocatalyst for the degradation of TCH, obtaining a degradation rate of 78.28%. Chen et al 8 prepared an N-doped TiO 2 /diatomite composite photocatalyst, and the optimum degradation rate of TCH was 91%.…”