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Although it plays a critical role in the photophysics and catalysis of lanthanides, spin–orbit coupling of electrons on individual lanthanide atoms in small clusters is not well understood. The major objective of this work is to probe such coupling of the praseodymium (Pr) 4f and 6s electrons in Pr2O2 and Pr2O2+. The approach combines mass-analyzed threshold ionization spectroscopy and spin–orbit multiconfiguration second-order quasi-degenerate perturbation theory. The energies of six ionization transitions are precisely measured; the adiabatic ionization energy of the neutral cluster is 38 045 (5) cm−1. Most of the electronic states involved in these transitions are identified as spin–orbit coupled states consisting of two or more electron spins. The electron configurations of these states are 4f46s2 for the neutral cluster and 4f46s for the singly charged cation, both in planar rhombus-type structures. The spin–orbit splitting due to the coupling of the electrons on the separate Pr atoms is on the order of hundreds of wavenumbers. [ABSTRACT FROM AUTHOR]

Ultraviolet C (UVC) light has a great promising application in the field of sterilization. However, how to obtain efficient UVC emission with peak maximum at 265 nm that is called 'golden sterilization wavelength' remains a great challenge. Herein, we propose a defect-engineering strategy to obtain enhanced UVC emission at the golden sterilization wavelength of 265 nm through introducing oxygen vacancies into Pr3+ doped Ba 2 MgSi 2 O 7 melilite phosphors. Combined with X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR) and thermoluminescence (TL) characterizations, it is confirmed that the calcination of Ba 2 MgSi 2 O 7 :Pr3+ in an inert atmosphere could efficiently increase oxygen vacancy concentration, promoting the efficient energy transfer from the melilite host to Pr3+ ions. It could lead to a significant enhancement of the luminescence intensity to 2.43 times of the initial one with less oxygen vacancies. The optimized Ba 2 MgSi 2 O 7 :0.4%Pr3+ phosphor could effectively inactivate 100 % of Staphylococcus aureus within 8 min, showing higher efficiency than commercially available mercury lamp. This work provides an effective solution for the design and preparation of UVC phosphors using defect engineering to achieve golden UVC emission. [Display omitted] [ABSTRACT FROM AUTHOR]

In this paper, we use hydrothermal technique to synthesise the nanoparticle of praseodymium, cerium telluride (Pr0.2Ce0.5Te0.2) using 0.2 mol of praseodymium (III) oxide (Pr2O3), and 0.5 mol of cerium (III) nitrate hexahydrate (Ce(NO3)3.6 H2O) and 0.2 mol of Te(NO3)4and evaluate how varying annealing temperature influences the material's optical, structure, morphology, and electrical characteristics. The XRD pattern reveals a polycrystalline structure with 2theta angle of 8.418°, 9.644°, 11.037°, 13.824°, 16.442°, 19.151°, 22.262°, 40.938°. Corresponding to the diffraction peaks (011), (012), (111), (121), (114), (200), (211), (311) it was observed that the praseodymium cerium telluride nanoparticles display a significant nanoflake structure. It was observed that the size of the large nanoflakes decreased. When subjected to annealing, the surface energy of the material increased due to the presence of nanoparticle clusters. The nanoparticle that underwent annealing at 400°C was found to be more susceptible to agglomeration due to the strains that resulted from the high-temperature treatment. Praseodymium cerium telluride is highly absorbent, especially in the ultraviolet and blue light ranges. The unannealed praseodymium cerium telluride nanoparticles have a bandgap energy of 2.75 eV, which is observed to narrow down to a range of 2.61–2.37 eV as the temperature for annealing is increased. Research Highlight: The XRD pattern reveals a polycrystalline structure. The praseodymium cerium telluride nanoparticles display a significant nanoflake structure. The unannealed praseodymium cerium telluride nanoparticles have a bandgap energy of 2.75 eV. The bandgap energy for the annealed nanoparticles is 2.61–2.37 eV. [ABSTRACT FROM AUTHOR]

By examining the diffraction data, the microstructure of the ball-milled synthesized powder sample ( Ba 0. 9 9 9 8 Pr 0. 0 0 2 TiO3) was characterized. Through the application of Rietveld's powder structure refinement approach to analyze X-ray powder diffraction data of ball-milled powder mixes, structural and microstructural alterations in terms of lattice defects have been assessed in the formation of single-phase praseodymium-modified BaTiO3. Bond lengths, bond angles, and generated locations of the Ba 0. 9 9 8 Pr0 . 0 0 2 TiO3 ceramic have been discussed about its generated structure. X-ray diffraction with respect to the first sharp diffraction peak (FSDP) is used to study the nanostructure of void species. General equations were utilized to determine various FSDP characteristics such as interlayer separation, correlation length, nanovoid diameter and scattering vector magnitude. Although the literature reports on many properties of Pr-modified barium titanate ceramic, this sample's quantitative analysis and nanovoid determination are presented for the first time. [ABSTRACT FROM AUTHOR]

Visible‐to‐ultraviolet (UV) upconversion provides a fascinating strategy to achieve deep UV emission through readily accessible visible light. However, the intensity of deep UV emission obtained through visible‐to‐UV upconversion progress is still far from satisfactory, severely constraining its practical applications. Herein, a novel class of praseodymium ion (Pr3+)‐doped rare‐earth oxyhalides (YOCl, YOBr, and LuOBr) to achieve efficient upconverted deep UV emission in the spectral range of 250–350 nm is developed. The upconverted UV emission intensity of LuOBr:Pr3+ is determined to be 56.7 times stronger than that of the well‐established Lu7O6F9:Pr3+. When employed as a photon‐converter to activate photocatalytic water splitting reactions, upconverted deep UV emission enables H2 generation under visible light (λ > 420 nm) excitation from a xenon lamp. The efficient deep UV upconversion stems from tuning 4f15d1 state of Pr3+ by oxyhalide constituent which both facilitates the absorption of excitation photons in long‐lived intermediate 4f2 states and suppress the probability of nonradiative relaxation from 4f15d1 state. These findings not only provide new insights into a mechanistic understanding of the host effect on upconversion process but also make a breakthrough in developing efficient deep upconversion materials that will expand their further applications. [ABSTRACT FROM AUTHOR]

The incorporation of large‐sized rare earth (RE) elements with high coordination characteristics into transition metal dichalcogenide (TMD) absorbers while preserving a high 1T phase content during post‐processing poses a significant challenge. To address this, a novel strategy involving the confinement of RE elements within the 1T‐MoS2 lattice via liquid plasma assistance, is proposed. This approach effectively mitigates the environmental impact on the 1T phase of MoS2, yielding a remarkable 1T phase content of 82.69% for Ce20‐D7 (20 wt.% Cerium trinitrate and 7 kV applied voltage). Combining experimental and theoretical investigations reveals that the multi‐orbital characteristics of RE elements facilitate hybridization between the RE‐4f and Mo‐4d orbitals on the MoS2 surface, leading to the occupation of weakly bound electrons in bonding orbitals with short‐distance motion, enhanced inter‐orbital electron‐electron interactions, and induced polarization loss. Notably, the results demonstrate that the Pr15‐D7 sample (15 wt.% praseodymium nitrate and 7 kV applied voltage) exhibits an effective absorption bandwidth (EAB) of 7.12 GHz at 2.6 mm, with a minimum reflection loss of ‐52.02 dB while the Ce20‐D7 sample achieves an EAB of 6.96 GHz at 2.7 mm. These findings provide valuable insights for the rational design and development of high‐performance TMD absorbers leveraging RE‐modified materials. [ABSTRACT FROM AUTHOR]

Lanthanide ion doped garnet is one of the representative persistent luminescence (PersL) phosphors that have been widely investigated. However, the role of the trap centers, either intentionally added co‐dopants or intrinsic defects arising during the sintering process, and their effect on the performance of PersL has not been completely elucidated, especially when they coexist. In pursuit of clarifying the relationship among different trap centers and their impact on the afterglow, herein, low‐concentration Pr3+ and Cr3+/Yb3+ (electron trap) co‐doped Y3Al2Ga3O12 ceramic phosphors are synthesized using a solid‐state reaction method under a vacuum atmosphere and some of them are further subjected to annealing condition. The observed thermoluminescence glow curves are composed of two strong peaks related to oxygen vacancies and a weak peak formed by each Cr and Yb trap based on the relative concentration ratio. On the other hand, it is found that the Cr3+ and Yb3+ions act as prominent near‐infrared (NIR) PersL centers in the NIR‐I and NIR‐II region, respectively, matching with the first and the second biological window. This work allowed for an exploration of the properties of distinct trap centers and how they influence the PersL and are likely to hasten the development of new PersL materials. [ABSTRACT FROM AUTHOR]

Praseodymium doped lanthanum arsenate, denoted as La 1-x Pr x AsO 4 , has been synthesized with different concentrations of the dopant (x = 0.5 %; 1 %; 2 %; 3 % and 5 %) via the combustion method and their optoelectronic properties have been investigated. A study of the crystalline structure and size of the compound by XRD confirms that both the pristine LaAsO 4 and Pr-doped LaAsO 4 are pure and maintain a monoclinic crystal structure, with the crystalline size ranging from 60 to 76 nm. The morphological study of the nanoparticles by SEM analysis reveals that all samples, regardless of the concentration of Pr3+, consist of homogeneously packed and irregularly shaped small particles. The optical studies by absorption and fluorescence spectroscopies highlight the unique optoelectronic characteristics of La 1-x Pr x AsO 4 , with absorption predominantly in the UV and blue regions and prominent emission peaks in the visible spectrum, most notably at 610 nm. The optimal luminescence is observed at a 0.5 % Pr3+ doping level, deviating from typical trends as higher concentrations lead to diminished emission intensity and lifetime due to concentration quenching effects. The application of Density Functional Theory (DFT) with GGA + PBE and GGA + PBE + U approximations has effectively elucidated the electronic structure and optical properties of the Pr-doped LaAsO 4. The incorporation of Pr's 4f states within the LaAsO 4 forbidden band significantly alters the material's electronic landscape, notably reducing the optical band gap from 4.45 eV to 2.299 eV. This modification in the band structure aligns favourably with the dielectric function curves and density of states analyses, corroborating the observed visible light emission in the doped samples. [ABSTRACT FROM AUTHOR]

The behavior of praseodymium in a forest soil with different quantities of organic matter was investigated. The forest soil (FS) was treated with acid and alkali solutions to separate the soluble organic matter (fulvic and humic acids) (IM-FS), and then IM-FS was treated with hydrogen peroxide (IM-FS(b)). The materials (FS, IM-FS, and IM-FS(b)) were characterized by X-ray diffraction (XRD), scanning electron microscopy(SEM)-EDS, and Fourier-transformed infrared spectroscopy (FT-IR). The points of the zero charge (PZC) and the organic carbon percentages were also determined. The effect of the organic matter, contact time, praseodymium concentration, temperature, and praseodymium desorption were evaluated. The minerals found in the materials were quartz, albite, and kaolinite; the PZC were 6.12, 7.28, and 6.11 for FS, IM-FS, and IM-FS(b), respectively, and their organic carbon percentages were 9.1 ± 0.1, 7.2 ± 0.6, and < 0.1, respectively. The adsorption kinetic data for FS and IM-FS were best adjusted to the pseudo second-order model, and the isotherms data to the Langmuir–Freundlich model indicating a chemical adsorption mechanism on heterogeneous materials, the maximum adsorption capacities were 18.53, 12.98 mg/g and virtually negligible for FS, IM-FS, and IM-FS(b) respectively. The adsorption processes were exothermic; the desorption processes showed that praseodymium is more stable in FS than IM-FS, and Na2H2EDTA was the best desorbent agent. The adsorption capacities and praseodymium stability depend on the organic matter content. The adsorption capacities followed the order: FS > IM-FS > IM-FS(b). [ABSTRACT FROM AUTHOR]

Medium-fluence fast electron irradiation (1019 e/cm2 to 1020 e/cm2) or the changes in the praseodymium concentration in the range of 0.0 ≤ z ≤ 0.5 on the excess conductivity of YBa2Cu3O7–δ single crystals ware investigated. These can lead to a wider range of the temperature interval of excess conductivity which narrows the interval of linearity in the ab plane. At fluences 0 ≤ Φ ≤ 6.5 × 1019 e/cm2, there was a threefold increase in the transverse coherence length ξc(0) with an increase in Φ of more than four times as the praseodymium concentration increased to z ≈ 0.42. The two-dimensional–three-dimensional (2D–3D) crossover point shifted upward in temperature. Conversely, to irradiation with low fluences (Φ ≤ 1019 e/cm2) or low praseodymium doping (z ≤ 0.39), irradiation with medium fluences or high praseodymium doping led to a non-monotonic dependence of ξc(0) on the irradiation fluence, with characteristic maxima at Φ~(7–8) × 1019 e/cm2 and z ≈ 0.42, likely due to the suppression of the superconducting characteristics. [ABSTRACT FROM AUTHOR]

AbstractAll the data recently reported for the purported air/water stable PrIV complex, [(L)PrIV(L)4(OH0.94Cl0.06)2PrIV(L)]n (L = N-acetylanthranilate) [1], have been reinterpreted to show that it is, in fact, the PrIII complex [Pr2L6(H2O)2]n. Importantly, it is isomorphous with its reported EuIII analogue [Eu2L6(H2O)2]n [2], providing further evidence of the incorrect assignment in the literature. [ABSTRACT FROM AUTHOR]

The development of economical catalysts that exhibit both high activity and durability for chlorinated volatile organic compounds (CVOCs) elimination remains a challenge. The oxidizing and acidic sites play a crucial role in the oxidation process of CVOCs; herein, praseodymium (Pr) was introduced into CrOx catalysts via in situ pyrolysis of MIL-101(Cr). With the decomposition of the ligand, a mixed micro-mesoporous structure was formed within the M-Cr catalyst, thereby reducing the contact resistance between catalyst active sites and the 1,2-dichloroethane molecule. Moreover, the synergistic interaction between chromium and praseodymium facilitates Oβ species and acidic sites, significantly enhancing the low-temperature catalytic performance and durability of the M-PrCr catalyst for 1,2-dichloroethane (1,2-DCE) oxidation. The M-30PrCr catalyst possess enhanced active oxygen sites and acid sites, thereby exhibiting the highest catalytic activity and stability. This study may provide a novel and promising strategy for practical applications in the elimination of 1,2-DCE. [ABSTRACT FROM AUTHOR]

The booming demand for electric vehicles, driven by the pursuit of enhanced efficiency, faces significant hurdles attributed to the costly integration of rare earth magnets like NdFeB. M-type strontium ferrite emerges as a promising alternative owing to its economic viability and exceptional magnetic characteristics, rendering it suitable for electric vehicle motor applications. This research focuses on the synthesis and characterization of SrFe 12 O 19 and Sr 1-x Pr x Fe 10 Al 2 O 19 (where x = 0.00 to 0.20) hexaferrites, with praseodymium (Pr) substitution. Magnetic particles were synthesized utilizing the sol-gel auto-combustion technique, employing a calcination temperature of 1100 °C for a duration of 4 h. Structural and magnetic studies of aluminium-praseodymium (Al–Pr) doped samples are performed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and vibrating-sample magnetometry (VSM). The structural analysis reveals a decrease in both particle size from 42 nm to 31.76 nm and lattice parameter with increasing doping concentration. Magnetic analysis yields crucial insights: Al3+ doping induces a substantial rise in coercivity from 5500 Oe to 10,500 Oe which is quite comparable to NdFeB, while Pr doping shows a subtle impact, enhancing remanence from 17 emu/g to 23.05 emu/g. These findings underscore the potential for optimizing magnetic properties through meticulous control of dopant concentrations in M-type hexaferrites, thereby positioning them as promising substitutes for rare earth magnets. [ABSTRACT FROM AUTHOR]

Herein, a scheme of Sr2+/Ca2+ ion substitution was employed to simultaneously regulate the defect and intervalence charge transfer (IVCT) state of Sr2−xCaxNb2O7:Pr3+ phosphors, resulting in a dual-modulation strategy for enhancing phosphor thermal stability. [ABSTRACT FROM AUTHOR]

The present work reports on the structural and spectroscopic properties of Pr3+ doped ZnS nanoparticles in silicate glasses prepared by sol–gel technique. Structural characterization was performed by X-ray diffraction, Fourier-transform infrared, scanning electron microscopy and transmission electron microscopy. The structural studies reveal the presence of nanosized in the amorphous silica glass. Spectroscopic studies were performed through absorption and photoluminescence (PL) techniques. The radiative parameters such as transition probability (Aed), radiative lifetimes (τR), and branching ratios (βR), the Judd–Ofelt intensity parameters Ωλ were determined from the absorption spectra of the prepared samples. The increase absorption as well as PL intensity was observed. This enhanced intensity is observed due to the effective increased in oscillator strength of Pr3+ doped ZnS. We observed strong stimulated emission cross-sections for the transition 3P0 → 3H6, at 614 nm. It may be useful for good lasing material in reddish-orange region. CIE chromaticity coordinates were also evaluated from the emission spectra of each glass. The development of visible reddish-orange lasers may be effectively facilitated by SiZPr1.5 glass, as indicated by the observed emission cross-sections and CIE chromaticity coordinates. [ABSTRACT FROM AUTHOR]

Pr doped La 2 Zr 2 O 7 (LPZ) TBCs have been deposited by electron beam physical vapor deposition. This work concentrates on the thermophysical properties and microstructure evolution of LPZ/YSZ duplex TBCs before and after thermal cyclic so as to probe into the merit and the application feasibility. The thermal expansion, thermal conductivity and phase structure have been measured and analyzed in comparison to other classical TBCs materials. Typical feathery microstructure and intra-columnar gaps did not provide desired thermal cyclic counts for LPZ/YSZ TBCs. Two principal categories of degradation mechanism limited the cyclic lifetime. The first principal degradation mode is the pulverization of LPZ after thermal cyclic due to the Pr rare earth elements modification in lanthanum Zirconates. Pr instability created the pulverization degradation mode instead of spalling. The second degradation mode is the cracks extension paralleled to interface inside TGO due to the brittle spinel generated by excessive oxidation. This study of thermal properties and degradation mechanism might offer thought and inspiration for other advanced TBCs. [ABSTRACT FROM AUTHOR]

Praseodymium (Pr) is a critical mineral for the global clean energy industry. The global demand for Pr continues to increase. China possesses the largest proven reserves and highest production of Pr worldwide. However, a future Pr supply-demand gap still could occur in China. Developing a circular economy and promoting material recycling are considered solutions to the potential supply constraints. This study adopts a material flow analysis method and combines it with the recycling input rate (RIR) indicator to estimate the potential quantities of the Pr recycling supply in China from 2011 to 2020. The key findings are as follows: (1) From 2011 to 2020, 7.902 × 104 t Pr entered the anthropogenic cycle system in China from the supply side, of which 1.639 × 104 t Pr originated from recycling; (2) 1.369 × 104 t Pr was recycled from NdFeB magnet production scraps, with the RIR remaining stable at approximately 17%; (3) theoretically, 2.7 × 103 t Pr could be recycled from end-of-life (EoL) products, and the RIR of EoL products could increase from 0.04% to 5.17%. In view of the major challenges in realizing Pr recycling from EoL products, this study proposes improvement strategies to promote Pr recycling in China. They include improving the extended producer responsibility of China, progressively establishing consumer responsibility for relevant products, and guiding the industry to formulate recycling-related technical specifications and industry standards.

This work explores the synthesis and energy applications of the novel hetero-system based on (cerium/praseodymium/neodymium)-oxides doped titanium dioxide (Ce/Pr/Nd)3+-doped TiO 2). With the narrow band gap energy spanning over the range of 3.62–3.89 eV, this semiconductor acquired anatase phase and average crystallite size of 77.41 nm. Rare earths triply doped TiO 2 exhibited bi-functionality towards production of O 2 an H 2 via oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively. Lowest overpotential (OER: 140 mV and HER: 135 mV) and Tafel slopes (OER: 69.1 mV dec−1 and HER: 57.2 mV dec−1) reflected the efficiency of this material for energy generation. Furthermore, Ce/Pr/Nd)3+-doped TiO 2 is an excellent electrode material exhibiting electrical double layer capacitance (EDLC) with specific capacity of 749 F g−1 and a lower equivalent series resistance (Rs) of 0.12 Ω. In terms of photovoltaic applications, 16.71% efficient perovskite solar cell device containing Ce/Pr/Nd)3+-doped TiO 2 as an electron transport layer was fabricated that was fully functional at the ambient conditions. The developed material possessed commendable band gap alignment with the perovskite material resulting in higher efficiency. Lanthanide doped TiO 2 is an efficient, easy to prepare, sustainable, and cost effective option having potential to substitute costly energy materials. [Display omitted] • Semiconductor (Ce/Pr/Nd)3+-doped TiO 2 hetero-system synthesis. • Energy generative bifunctional catalyst for OER/HER. • Electrical double layer capacitance with excellent storage potential. • Electron transport layer in perovskite solar cells. • Highly durable and electrochemically stable material. [ABSTRACT FROM AUTHOR]

Samarium praseodymium (Sm–Pr) co-doped ceria was synthesized by the co-precipitation technique as an electrolyte for low-temperature solid oxide fuel cell (LT-SOFC) applications. The structural, morphological, compositional, and electrical characterization of the synthesized samples were evaluated via x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX) and impedance spectroscopy. The generation of a single-phase fluorite structure of co-doped ceria without any secondary phases has been verified by XRD analysis, exhibiting the successful incorporation of Sm and Pr ions into the ceria lattice. Vegard's law is utilized for Pr redox behavior explaining the variation in lattice constant values. SEM pictures show that the co-doped ceria powder has a homogeneous and well-dispersed microstructure, and has enhanced particle size. The impedance spectroscopy results indicate that Sm–Pr co-doped ceria has much higher ionic conductivity than single-doped ceria. The highest amount of ionic conductivity (σ i o n i c ) for the composition Ce 0.80 Sm 0.10 Pr 0.10 O 2 − δ recorded as 2.12 × 10 − 2 S / c m at 500 ° C , and 6.19 × 10 − 2 S / c m at 750 ° C with the lowest activation energy E a = 0.48 e V , which has been not reported earlier. Sm and Pr are chosen as dopants because of their capacity to generate oxygen vacancies and improve ceria's ionic conductivity. This study contributes to the enhancement in the ionic conductivity of co-doped ceria by co-precipitation technique and the temperature-dependent frequency exponent factor "s" is also explored to comprehend the conduction mechanism of the prepared samples. [ABSTRACT FROM AUTHOR]

A comprehensive study of the thermoelectric properties of CuCr0.99Ln0.01S2 (Ln = La...Lu) disulfides was carried out in a temperature range of 300 to 740 K. The temperature dependencies of the Seebeck coefficient, electrical resistivity, and thermal conductivity were analyzed. It was found that the cationic substitution of chromium with lanthanides in the crystal structure of layered copper–chromium disulfide, CuCrS2 resulted in notable changes in the thermoelectric performance of CuCr0.99Ln0.01S2. The cationic substitution led to an increase in the Seebeck coefficient and electrical resistivity and a thermal conductivity decrease. The highest values of the thermoelectric figure of merit and power factor corresponded to the praseodymium-doped sample and an initial CuCrS2-matrix at 700–740 K. The cationic substitution with lanthanum, cerium, praseodymium, samarium, and terbium allowed for an enhancement of the thermoelectric performance of the initial matrix at a temperature range below 600 K. The cationic substitution of CuCrS2 with lanthanum and praseodymium ions appeared to be the most promising approach for increasing the thermoelectric performance of the initial matrix. [ABSTRACT FROM AUTHOR]

Laser spectroscopy is a very precise tool in determining atomic structure data. However, in the case of complex spectra, when the individual components of the spectra cannot be separated, precise analysis is hindered by the appearing saturation effect. Sometimes this effect is so large that the spectrum simulation does not provide precise results. In the present work, we present the analysis of the Zeeman spectra of seven praseodymium lines in the range of 566–652 nm, which were recorded using the LIF technique in the presence of the saturation effect. To analyze these spectra, we used a specially dedicated computer program, which allowed for very accurate matching of the simulated spectrum to the recorded experimental shape. As a result of the conducted research, we determined 14 Lande factor values, 3 of which are new. [ABSTRACT FROM AUTHOR]

In this brief report, omitting the step of dissolving sodium alginate with water, directly mixing sodium alginate powder with calcium chloride powder sufficiently, and gelatinizing sodium alginate by the impregnation method improve the characteristics of sodium alginate gel which is in the form of jelly and has poor mechanical properties. In this paper, micron-sized gel particles were prepared by slow impregnation method using mixed powder of sodium alginate and calcium chloride. The preparation method is simple and low-cost, and can be used for the recovery of rare earth ions from aqueous solutions. The SAG-2 gel prepared at a mass ratio of sodium alginate to calcium chloride of 1:1 showed the best adsorption performance; the particle size varies from 50 to 200 µm. The adsorption capacities of SAG-2 for La(III), Ce(III), Pr(III), and Nd(III) were 334.1, 349.8, 360.1, and 364.5 mg g−1 at pH = 5. The adsorption equilibrium was reached in 35 min. The kinetic study showed that the adsorption process was chemisorption and the adsorption isotherm was well fitted with the Freundlich model. The adsorption mechanism was explored using FTIR and XPS characterization, indicating that both -OH and -COOH functional groups were involved in adsorption. The desorption of rare earths by different eluents was explored and the recyclability of the adsorbent was examined. [ABSTRACT FROM AUTHOR]

Pr3+ doped bismuth borate glass samples were prepared by melt quenching method with the chemical composition (45- x) Bi2O3: 10ZnO: 10Li2O: 10WO3: 10Na2O: 10CaO: 15B2O3 :xPr2O3 (where x = 1,1.5.2 mol%).The glassy nature of the prepared glass samples was confirmed by X-ray diffraction patterns. The FTIR spectra shows that the existence of different functional and structural groups of glasses, such as BO3 and BO4. The values of Urbach energy and optical energy band gap were determined by Mott-Davis relation. The absorption, transmittance and reflectance spectra of glasses were recorded in the wavelength range 450–900 nm. The optical energy band gap for direct and indirect were found to be range 2.54–2.52 eV and 2.48–2.38 eV respectively. The values of Urbach's energy lies between 0.1860 and 0.3590 eV. The physical properties like density, average molecular weight, molar volume filed strength, ion concentration, polaron radius, oxygen packing density, interionic distance, optical basicity were calculated using appropriate formulae. The resulted indicated that Pr3+ doped bismuth borate glasses has potential applications for optical and photonic applications. [ABSTRACT FROM AUTHOR]

Interaction of Pr/Dy with oxygen in nickel melts at PAr = 0.1 MPa and constant temperature was studied using the EMF instantaneous fixing method using a Mo[Cr/Cr2O3//ZrO2(MgO)//O(Nil)]Mo cell and certified sensors. Dependences a[O] = f[Pr/Dy, %] expressed in the form of logarithmic equations made it possible to compare them with each other in the concentration range of 0.001–0.2 wt % of each deoxidizer and determine that the deoxidizing ability of Pr is 1.7 times higher compared to Dy. The activity of oxygen a[O] in Ni–O–Al–(Pr/Dy) melts was calculated in comparison with Al at a concentration of 0.05 wt % of elements and its sevenfold decrease was shown for the first deoxidizer and elevenfold for the second. The morphology of nonmetallic inclusions in metallographic sections of Ni–O–Pr/Dy alloys has been studied, indicating that the inclusions are located along grain boundaries and have different configurations and a complex heterophase composition. Analysis of nonmetallic inclusions with the maximum content of deoxidizing element proved the existence of Pr/Dy oxygen compounds, which confirmed the data of thermodynamic and mass spectrometric studies. The average content of Zr in nonmetallic inclusions during the deoxidation of Pr is two times higher than in experiments during the deoxidation of Dy, which indicates the interaction of Pr/Dy with the EMF ZrO2 sensor and the preferential interaction of Pr compared to Dy and correlates with the data on the determination of a[O]. [ABSTRACT FROM AUTHOR]

Ruddlesden–Popper manganites are strongly correlated, quasi two-dimensional systems with highly tunable functional properties, which can, for example, be controlled by composition, strain, and defects. Praseodymium calcium manganite is a particularly interesting Ruddlesden–Popper system due to its remarkably high temperature at which ordering phenomena set in, enabling correlation physics above room temperature. However, in order to utilize the correlation phenomena and the quasi-two-dimensionality of the Ruddlesden–Popper systems for applications, one needs to grow thin film junctions, making it necessary to control the structure–property relation of Ruddlesden–Popper thin films. Here, we present a cryogenic transmission electron microscopy study of praseodymium calcium manganite thin films, deposited on niobium doped strontium titanate substrates, where we analyze the structure of the manganite thin film, as well as the effect of the epitaxial strain and defects on the charge/orbital order of the system. We identify a structural phase transition above the onset of charge/orbital order, frequently occurring extended defects and the temperature dependence and spatial distribution of charge/orbital ordering in the film. Our results show in detail the relationships between strain/defects and properties of the ordered phases and thus give important insights into how to tailor the functional properties of thin film junctions of strongly correlated materials. [ABSTRACT FROM AUTHOR]

The Pr3+ -doped BaZrGe3O9 gallogermanate phosphors are reported to have a well-defined successive deep defect structure that effectively mitigates thermal carrier fading. This phosphor also presents a red emission with a peak at 615 nm, originating from the Pr3+ transtition from ¹D2 to ³H4. We investigated the impact of Pr3+ -activated BaZrGe3O9 (referred to as BZG:Pr) on the lighting characteristics of light emitting diodes (LED) packages in this paper. By combining BZG:Pr with TiO2 particles and silicone, we produced a phosphor layer (designated as BZG:Pr@TiO2). The optical performance of the resulting LED was systematically examined by varying the TiO2 doping percentage. Our findings reveal that the incorporation of the BZG:Pr phosphor enhances the red spectral component, thereby contributing to improved homogeneity in color distribution. However, a progressive increase in TiO2 content within the phosphor layer corresponds to diminishing luminous output and decreased chromatic rendering efficiency of the LED. Employing a lower concentration of TiO2 proves advantageous, as it capitalizes on the scattering-enhancing attributes while leveraging the red emission of the BZG:Pr phosphor. This synergistic approach yields a favorable balance between luminosity and color quality, enhancing the LED’s overall performance. [ABSTRACT FROM AUTHOR]

A simple, efficient, direct and economical method for the mutual separation of Nd and Pr was developed by the selective dissolution of Nd2O3 from their oxide mixtures in an ionic liquid containing 2‐thenoyltrifluoroacetone (HTTA) resulting in an unprecedented separation factor (βNd/Pr)>500, which is 277 times more than the thus far reported βNd/Pr values. The proposed mechanism was supported by DFT computations. [ABSTRACT FROM AUTHOR]

The reaction of triphenylcyclopentadienyl potassium and bipyridine with lanthanum, praseodymium, erbium, lutetium, and scandium chloride tetrahydrofuranates results in the formation of binuclear [CpPh3Ln(Bipy)Cl(μ2-Cl)]2 (Ln = La (I), Pr (II)) and mononuclear [CpPh3Ln(Bipy)Cl2(THF)] (Ln = Er (III), Lu (IV), [CpPh3Sc(Bipy)Cl2] (V) complexes (CpPh3 = 1,2,4-triphenylcyclopentadienyl, Bipy = bipyridine). The decrease in the REE radius in the series La...Sc results in the formation of mononuclear instead of binuclear complexes and in a decrease in the coordination number of the central ion. The coplanar arrangement of two different π-systems gives rise to stacking interactions between the triphenylcyclopentadienyl ligand and bipyridine. The molecular structure of complexes I–V was established by X-ray diffraction analysis (CCDC nos. 2308609 (I), 2308608 (II), 2308610 (III), 2308611 (IV), 2308607 (V)). [ABSTRACT FROM AUTHOR]

The recent COVID-19 pandemic has made everyone aware of the threat of viruses and the growing number of antibiotic-resistant bacteria. It has become necessary to find new methods to combat these hazards. One tool that could be used is UVC radiation, i.e., 100–280 nm. Currently, the available sources of this light are mercury vapor lamps. However, the modern world requires more compact, mercury-free, and less energy-consuming light sources. This work presents the results of our research on a new material in which efficient UVC radiation was obtained. Here, we present the results of research on Ca9Y(PO4)7 polycrystals doped with Pr3+ ions prepared using the solid-state method. The absorption, excitation, emission, and emission decay profiles of praseodymium(III) ions were measured and analyzed. The upconversion emission in the UVC region excited by blue light was observed. Parameters such as energy bandgap, refractive index, and thermal stability of luminescence were determined. The studied phosphate-based phosphor possesses promising characteristics that show its potential in luminescent applications in future use in medicine or for surface disinfection. [ABSTRACT FROM AUTHOR]

The various structural and conductive attributes of barium cerate, BaCeO3 position it as a highly promising matrix for energy storage purposes. The current study illustrates that barium cerate can be effectively tailored by introducing trivalent praseodymium ions, thereby enhancing its optical properties as well. In this work, single-phased orthorhombic crystalline powders of barium cerate incorporated with Pr3+ (BaCeO3: Pr3+) were synthesized using the gel combustion procedure, followed by calcination. We conducted a comprehensive investigation into their crystal structure, vibrational characteristics, optical properties, and potential applications in wLEDs. The structure refinement indicates that Pr3+ occupies Ce4+ site, which results in the expansion of the cell and facilitates the generation of defects such as Pr Ce ′ and oxygen vacancies V O ⋅ ⋅ . By correlating information gathered from diffuse reflectance spectra with that obtained from photoluminescence spectra, we gained a deeper understanding of the electronic level structure and the mechanism of energy transfer. We successfully achieved a finely tuned cool white light emission with very low color purity (CP), a high color rendering index (CRI), and a high correlated color temperature (CCT) with a quantum efficiency of 36.3 % by exciting the material with a 321 nm wavelength. Because of the transfer of energy within activators through dipole–dipole interaction, luminescence quenching occurs when Pr3+ concentration reaches 1 wt%. To the best of our knowledge, this is the initial investigation of luminescence properties of Pr-incorporated barium cerate perovskites. [ABSTRACT FROM AUTHOR]

In recent years, Pd/CeO2 materials have proven to be effective catalysts for the total oxidation of methane. In this work, three different synthesis routes were used to prepare high specific surface area supports, consisting of pure CeO2 and 10 at% Pr‐doped ceria (Ce90Pr10). Nano‐structured spheres were obtained with a microwave‐assisted synthesis, dumbbell‐like particles were produced through a urea‐based hydrothermal method, and ordered mesoporous oxides were prepared by using SBA‐15 as hard‐template. The six materials were then impregnated with 2 wt% Pd, calcined at 500 °C, and comprehensively characterized. All the samples retained their high surface area after impregnation (75–110 m2 g−1), allowing a good dispersion of palladium. No significant structural or morphological differences were observed upon Pr doping, but a higher Pd oxidation state was induced by Pr‐doped supports. However, all Pd/CeO2 and Pd/Ce90Pr10 catalysts exhibited similar activity for dry methane oxidation below 500 °C, regardless of the synthesis technique and of the Pr presence: they all achieved almost complete CH4 oxidation at 400 °C, showing a really remarkable improvement with respect to analogous low surface area supports. A promoting role of Pr was instead noticed in wet conditions, thanks to its ability to counteract water‐induced deactivation phenomena. [ABSTRACT FROM AUTHOR]

Herein the synthesis, structural characterization, and magnetic properties of a Pr(IV) complex [Pr(OSiPh3)4(L)] (1, L = 4,4′-dimethoxy-2,2′-bipyridine) are reported. The stability of the Pr(IV) complex significantly enhanced with the use of the bidentate ligand L. Slow magnetic relaxation was observed at low temperatures, indicating that the complex may be the first single-ion magnet with a tetravalent lanthanide ion being the magnetic center. [ABSTRACT FROM AUTHOR]

The magnetic, electronic, and structural properties of the cubic phase of lead-doped alloys of praseodymium bismuth compounds with the generic formula PrPbxBi1-x (x = 0, 0.25, 0.50, 0.75, and 1.0) have been reported in this paper by employing the formalism of density functional theory (DFT). For the analysis of physical properties, we have executed the full-potential linearized augmented plane wave plus local orbit (FPLAPW+lo) technique, while the exchange-correlation potentials in the Kohn-Sham equation (KSE) are implemented within the generalized gradient approximation (GGA) extended by the Perdew-Burke-Ernzerhof (PBE) correction. The structural parameters, lattice constants, volume, bulk modulus, pressure derivatives, and energy have been computed with the Wein2k code by fitting total energy through Murnaghan's equation of state. The structural stability of the compounds has been reported from the spin-polarized calculations. The electronic energy bands and total and partial densities of states of the compounds have been calculated in both majority and minority spins, depicting them as metallic. The similar spectrum intensities of the Pr(5d+4f) and (Pb +Bi)2p states account for the majority of the contribution to the density of states near the Fermi energy level. The spin magnetic moments computed for the supercell of the doped compounds have indicated that they are magnetic materials. From the comparison of spin magnetic moments in the PrBi compound, we noticed an improvement in the magnetic moments after doping lead into the PrBi compound. [ABSTRACT FROM AUTHOR]

Spectroscopic analysis of trivalent praseodymium (Pr+3) and neodymium (Nd+3) ions have received very much interest and reveals good fluorescence efficiency in visible and near IR (NIR) region. Cadmium sulfide (CdS) nanomaterial sample doped with Pr+3 and Nd+3 ions are synthesized at room temperature by simple chemical precipitation method. The synthesized sample has been characterized by powder X‐ray diffraction studies, scanning electron microscopy, transmission electron microscopy, and energy dispersive X‐ray spectra. Absorption spectra of CdS:Nd3+ and CdS:Pr3+ nanoparticles have been recorded at room temperature. Various parameters such as interplanar spacing, micro strain, dislocation density, distortion parameter, and particle size of nanomaterial are computed. TEM and XRD analysis reveal the spherical structure of the CdS:Nd3+ and CdS:Pr3+ nanoparticles in the prepared samples. Energy interaction parameters of the CdS:Nd3+ and CdS:Pr3+ nanoparticles are computed using UV‐visible absorption spectrum. Actually, CdS nanoparticle amplifies the luminescence intensity of Pr+3, Nd+3 ions by up conversion processes. So energy transfer can be observed from CdS nanoparticles doped with Pr+3, Nd+3 ions. Therefore, the use of pump sources and diode lasers in the UV range can be used to excite these samples to work as lasers. CdS:Nd3+ and CdS:Pr3+ nanoparticles find potential application as a window material for hetero‐junction solar cell, light emitting diodes (LED), biological sensors, address decoders, gas detectors, opto‐electronic devices, etc. CdS nanomaterials are also used as pigment in paints and in engineered plastic due to their good thermal stability. [ABSTRACT FROM AUTHOR]

In this research, a comprehensive series of Pr3+-doped lithium niobate and sodium niobate materials were obtained at different temperatures via solid-state sintering, and their structures and properties were compared. NaNbO3: 0.75% Pr3+ phosphors were synthesized by sintering at 1150 °C for 2 h and emitted red persistent luminescence for more than 1200 s, peaking at 612 nm under UV excitation, which was a typical long persistent luminescence phenomenon. Furthermore, the sample glowed when pressurized, and a red bright luminescence which lasted for several seconds was visible to the naked eye. This was a typical mechanical luminescence phenomenon of samples under mechanical stress, directly converting mechanical energy into light energy. It was determined that NaNbO3:Pr3+ and LiNbO3:Pr3+ both possess multimode luminescence. Owing to their red long persistent luminescence (LPL) and mechano-luminescence (ML) properties, Pr3+ phosphors can be employed in fields, such as display technologies, stress sensing, structural damage detection, and other complex applications. [ABSTRACT FROM AUTHOR]

A comparative analysis of praseodymium (Pr3+)-doped fluoride glasses, APLF [20Al(PO3)3–80LiF–PrF3], BCAYF (19BaF2–33.25CaF2–42.75AlF3–5YF3–PrF3), and BCAPLF (19BaF2–33.25CaF2–42.75AlF3–15P2O5–20LiF–PrF3), reveals the effect of the host matrix on the optical properties, particularly the luminescence behavior of Pr3+ ions. X-ray absorption near edge structure (XANES) spectroscopy verifies the presence of Pr ions in the glasses with a +3 oxidation state. Absorption spectra results suggest that the lowest energy level of the Pr3+ 4f5d configuration is influenced by the oxide/fluoride ratio of the glasses. As both interconfigurational 4f5d and intraconfigurational 4f2 transitions are observed, the energy gap between the lowest level of the 4f5d configuration and the overlapping 1S0 level of the 4f2 configuration is found to influence the predominance of UV emissions from the 4f5d and 1S0 levels as well as their decay times. Consequently, a larger 4f5d-1S0 energy gap of ∼5000 cm−1 leads to a more intense UV emission from the 4f5d level with a faster decay time. These results underscore the significance of minimizing the energy of the 4f5d level and increasing the gap between 4f5d-1S0 levels to be able to obtain fast UV emissions from Pr3+-doped fluoride glasses.

A correlation of the ferroelectric and photoluminescence response to the structural ordering of praseodymium doped (Na0.41K0.09Bi0.5)TiO3 has been investigated. It has been observed that the ferroelectric and photoluminescence response lacks one-to-one correlation. The ferroelectric response is generally driven by long-range polar ordering. On the contrary, photoluminescence response is concomitant to the local site symmetry around the praseodymium ion. The optimum ferroelectric response has been observed for 1.0 at. % praseodymium doped (Na0.41K0.09Bi0.5)TiO3, whereas for the sample with higher doping concentration, it diminishes gradually due to disruption of the long-range ordering. On the other hand, with the establishment of long-range ordering, no noticeable shift in the position and shape of the photoluminescence lines has been observed. However, a quenching in the photoluminescence intensity of the hypersensitive transitions (1D2 → 3H4) takes place, which has been associated with the modification in the local site symmetry. It has been argued that structural modification has an influence on the photoluminescence intensity but does not affect the energy levels of these transitions. The observed dielectric, piezoelectric, and photoluminescence response has been explained on the basis of the amphoteric nature of praseodymium in (Na0.41K0.09Bi0.5)TiO3. [ABSTRACT FROM AUTHOR]

Praseodymium (Pr3+) ion and the transition metal vanadium (V5+) ion with d0 electronic configuration can form an intervalence charge transfer (IVCT) band, which can function both as a compensatory channel for its red emission and as a quenching channel, thus affecting the luminescence thermal stability of the phosphors. Research studies reveal that the emission of Pr3+ in the YVO4 matrix can be quenched by the IVCT mechanism, thereby limiting the application of phosphors. As such, the present contribution is based on the solid solution replacement strategy to inhibit the constitutent of the IVCT quenching channel and thus improve thermal stability. Therefore, phosphonium (P5+) with a valence state matching V5+ and a similar ion radius was selected for the V/P substitution. It lacks a d0 electron configuration, preventing the formation of an IVCT band with Pr3+ and thereby inhibiting the construction of the quenching channels to enhance thermal stability. While the empirical formula of IVCT indicates a decrease in the IVCT energy level from 3.32438 to 3.06251 eV upon the introduction of P5+, the PLE spectra demonstrate a sharp reduction in IVCT intensity, i.e., weakening of the quenching channel. The thermal stability of the phosphors at different excitation locations was enhanced with the rise of P5+ concentration. When excited at the 3P2 level, the Y0.995PO4:0.5%Pr3+ phosphor demonstrated highly stable red emission from 303 to 523 K, with a luminescence integrated intensity ranging from 95.5% to 105.3% compared to that at 303 K. This research provides a novel approach for inhibiting the IVCT quenching channel and broadens the commercial value of YVO4:Pr3+ phosphor for various applications. [ABSTRACT FROM AUTHOR]

This study presents a comprehensive exploration of the electronic properties of hydroxyapatite (HA) doped with zinc (Zn), silver (Ag), and praseodymium (Pr). Five distinct compositions—0.4Pr-HA, 0.4Zn-0.4Pr-HA, 0.8Zn-0.4Pr-HA, 0.4Ag-0.4Pr-HA, and 0.8Zn-0.4Pr-HA were systematically investigated through Density of States (DOS) and band structure calculations. The computed band gap values, ranging from 4.4037 to 4.1554 eV, revealed a progressive decrease in band gap energy from 0.4Pr-HA to 0.8Ag-0.4Pr-HA, emphasizing the substantial impact of dopant composition on electronic properties. Additionally, the incorporation of Pr induced distinct bands and peaks in the density of states, signifying the emergence of specific energy levels associated with Pr and suggesting a clear effect on the electronic structure. Furthermore, the study explores the influences of dopant type and quantity on the electronic structure, microstructure, spectral, thermal, and in vitro cell viability properties of Pr-based HA samples. Theoretical results demonstrated a continuous decrease in the bandgap with Ag or Zn dopants, and the study observed controllable changes in LAC values based on co-dopant type and quantity. Experimental outcomes revealed significant effects on crystallinity, crystallite size, lattice parameters, and unit cell volume, confirmed through XRD, SEM, EDX, FTIR, and Raman analyses. These findings provide valuable visions into the tunability of the electronic properties of HA through controlled doping with Zn, Pr, and Ag. This knowledge is crucial for modifying materials with desirable electronic properties, and thus holds promise for various applications in electronic devices and biocompatible coatings. [ABSTRACT FROM AUTHOR]

When investigating complex atomic spectra, it may happen accidentally that two or even several transitions between different pairs of combining energy levels have nearly the same wavenumber, and the observed spectral lines are overlapping (blend situations). In such cases, investigations of hyperfine structures can be very helpful in the identification of the involved transitions. In this paper, two complicated blend situations within the spectra of lanthanide atoms (Praseodymium and Lanthanum) are discussed as examples. The experimental methods applied are optogalvanic and laser-induced fluorescence spectroscopy, combined with emission spectra gained via Fourier transform spectroscopy. It is shown that, in such cases, a combination of optogalvanic and laser-induced fluorescence detection is necessary to find all transitions contributing to the observed spectral signatures. [ABSTRACT FROM AUTHOR]

We report a comprehensive investigation on customization process of Oxide Dispersion-Strengthened alloys through Sm 2 O 3 , Pr 2 O 3 , and Er 2 O 3 incorporation into 316L stainless steel matrix in terms of a desired enhancement in structural, physical, and nuclear radiation shielding properties. Oxide powders are incorporated into 316L stainless steel powder all with the same purity of 99.5%. These were Erbium oxide (Er 2 O 3), Praseodymium oxide (Pr 2 O 3), and Samarium oxide (Sm 2 O 3). First, X-Ray diffraction and Scanning Electron Microscope/Energy-dispersive X-ray spectroscopy analyses are conducted in order to investigate their physical and structural properties. Next, two different experimental setups are employed using a133Ba and 241Am/Be sources for the measurements of gamma-ray and neutron transmission properties of Oxide Dispersion-Strengthened alloys. The maximum density increment is achieved through Er 2 O 3 compared to other reinforced oxides. The detector counting value reached its minimum level when a 5% Er 2 O 3 oxide dispersion was introduced into the 316L SS matrix. Similarly, the most significant degree of photon absorption, the highest values of mass attenuation coefficient, lowest half value layer, and most effective atomic number, were all attained by the same sample. Based on the findings derived from the investigation, it can be concluded that incorporating Er 2 O 3 oxide into 316L steel can be considered as a viable option in terms of enhancing the critical properties of Oxide Dispersion-Strengthened alloys for extreme conditions such as nuclear reactors and other similar fields, where the behavioral attributes of the utilized materials are at utmost importance. [ABSTRACT FROM AUTHOR]

Metal sulfide nanoparticles are synthesized for their biomedical applications, including cancer drug targeting. This paper reports a novel nanocomposite made of praseodymium sulfide nanoparticles and poly-cyclodextrin. The praseodymium sulfide nanoparticles were synthesized hydrothermal, autoclaving the nitrate precursors at 150 °C for 18 hours. The material is characterized using XRD and shows an orthorhombic crystal system with high crystallinity. The size and morphology of the nanomaterial were optimized. The material shows a rod-shaped morphology, as seen in the TEM image, with 150 ± 3 nm length and 25 ± 5 nm width. Particle size analysis supports this size range. The colloidal particles were stable in the aqueous medium without precipitation at neutral pH. The elements in the material in the polymer-coated form and their electronic states are studied by X-ray photoelectron spectroscopy. Thermogravimetry confirms that the material contains about 18.5% of the weight of the polymer. The material has an observable magnetic property at room temperature due to the praseodymium element. The UV–vis–NIR absorption spectrum of the material shows a long absorption range that extends to 1200 nm. The drug 5-fluorouracil is encapsulated in the nanoparticles through host: guest association, and its release profile is analyzed. The release is modulated at a slightly acidic pH, indicating the pH-tunability. The nanoparticles and 5-fluorouracil were taken in the w/w ratio of 2:1 (2/1 mg in 1 mL of deionized water). Further, the in vitro anticancer activity of the drug-encapsulated material is screened on breast cancer and non-cancerous cell lines. The IC 50 values are reported, and the advantageous properties of the material as drug carriers are discussed. • Drug carrier nanorods are designed using praseodymium sulfide and poly-cyclodextrin. • The nanoparticles are weakly magnetic with low saturation. • It shows a long tail absorption band that extends up to the NIR-II wavelength range. • The encapsulated 5-fluorouracil is released continually for more than 10 days. • Drug-containing Pr2S3 nanoparticles are selectively active on MCF-7 cell lines. [ABSTRACT FROM AUTHOR]

Pr3+-ion doped YF3, LaF3, and GdF3 nanoparticles (NPs) were chemically prepared at a lower temperature (80 °C) to investigate the comparative physiochemical characteristics. X-ray diffraction profile of the nanoproducts exhibited the orthorhombic phase in YF3:Pr and GdF3:Pr NPs, whereas hexagonal structure was found in LaF3:Pr NPs with an estimated crystalline size 12, 23, and 15 nm, respectively. The unit cell constants for YF3:Pr (a = 6.340 Å, b = 7.269 Å, c = 4.317 Å, and unit cell volume = 198.97 (Å)3), LaF3:Pr (a = b = 7.171 Å, and c = 7.388 Å, and unit cell volume = 329.092 (Å)3) and GdF3:Pr (a = 6.465 Å, b = 7.008 Å, and c = 4.528 Å, and unit cell volume = 205.225 (Å)3) were considered to examine the influence of the dopant ions and the host ion's ionic radius on the crystal phase, and crystallinity. An orthorhombic phase GdF3:Pr NP sample revealed better thermal stability in comparison to the hexagonal phase LaF3:Pr NPs as received in the thermogravimetric outcomes. FTIR spectra exhibited the surface-fastened water molecules which promote the development of colloidal solution in aqueous solvents under the environmental conditions as achieved in absorption spectral analysis. Band gap energy was calculated from the UV/visible spectra to examine the optical behavior of the optically active NPs. The excitation and emission spectrums demonstrated the sharp excitation and emission transitions of the doped Pr3+ ion under excitation from the blue region. Comparatively, the emission and excitation transitions of the YF3:Pr NPs were dominant with respect to the orthorhombic GdF3:Pr and hexagonal LaF3:Pr NPs. YF3:Pr NPs are a useful host matrix for the loading of the activator Pr3+-ion for their use in luminescent phosphor material development. [ABSTRACT FROM AUTHOR]