On structure and phase transformation of uranium doped La₂Hf₂O₇ nanoparticles as an efficient nuclear waste host

Abstract

Doping induced phase transformation and speciation of the uranium ions in La2Hf2O7 nanoparticles as nuclear waste host were investigated.

Luminescent PVDF nanocomposite films and fibers encapsulated with La2Hf2O7:Eu3+ nanoparticles

“…The seven O 2− ions being randomly distributed across the eight anionic sites cause a high degree of disorder in the crystal lattice allowing for only one vibrational mode of the DFP structure [46]. On the other hand, the pyrochlore structure shows a total of six vibrational modes located at 302 cm −1 , 320 cm −1 , 400 cm −1 , 506 cm −1 , 520 cm −1 , and 610 cm −1 correspondings to the F 2g , E g , F 2g , A 1g , F 2g , and F 2g vibrational mode respectively [47]. The Raman spectrum of the our LHOE NPs (Fig.…”

Graphene Oxide-based Nanomaterials for Uranium Adsorptive Uptake

“…[11,12] Uranium, as a critical radioactive element, has been widely used to produce nuclear power, which is increasing the necessity for uranium as an energy resource. [13][14][15][16] However, uranium and its radioactive isotopes contribute to a high-level of nuclear waste, which needs to be properly disposed. Therefore, we carried out speciation (e.g.…”

“…oxidation state and coordination geometry) study of uranium ion doped in RE2Hf2O7 serves as a prerequisite for their capability for nuclear waste immobilization and eventually safe nuclear energy and sustainable environment. [15,16] Moreover, the terrestrial deposits of uranium are predicted to become a shortage owning to the booming energy demand. Seawater also contains uranium at low concentrations (~3.3 ppb).…”

Bright aspects of defects and dark traits of dopants in the photoluminescence of Er2X2O7:Eu3+ (X = Ti and Zr) pyrochlore: an insight using EXAFS, positron annihilation and DFT

“…In this context, A 2 B 2 O 7 materials with various favourable properties, such as high radiation stability, negligible leaching, and the ability to accommodate large concentrations of lanthanides and actinides at both the A-and B-sites can be used as nuclear waste hosts. 14 A 2 B 2 O 7 compounds exist in two different structures, viz., the ideal pyrochlore (IP) and disordered fluorite (DF) structures, which have the space groups Fd% 3m and Fm% 3m, respectively. The phase transition from the pyrochlore to the defect-fluorite structure is an order-disorder transition that is very sensitive to chemical composition and electronic configuration and can be induced by heating or irradiation.…”