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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]

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 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]

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]

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]

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]

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]

So far, overcoming thermal quenching remains a huge challenge in the application of phosphor materials. The intervalence charge transfer (IVCT) state has an inestimable role in the compensation of antithermal-quenching effects and is widely used in the research of applications in optical temperature sensing, yet little study has been reported on its modulation of thermal quenching properties. In this contribution, the thermal quenching properties of praseodymium-activated solid-solution substituted GdNb 1-x Ta x O 4 phosphors were investigated systematically for the inaugural time from the perspective of IVCT energy level positions. According to the empirical formula, the IVCT level positions in the phosphor increase sequentially from 32960.71 cm−1 to 33442.15 cm−1, the DFT calculates the extension of the substrate band gap from 3.6408 eV to 4.3066 eV, and the contributing energy level of the conduction band is determined. The variation in the position of the IVCT energy level explains the alteration of the luminescence intensity at room temperature for different composition phosphor 3P 0 and 1D 2 energy levels. More particularly, it was analyzed that in the variable temperature spectra, x = 0–0.75 exhibited different degrees of efficient antithermal-quenching properties at 303–523 K, while no antithermal-quenching was presented at x = 1. By analyzing the IVCT energy level position and other influencing factors such as band gap, the feasibility of the IVCT energy level position as a competing model for the compensation and quenching channels is established, and the internal mechanism of regulating thermal quenching property is revealed. Effective control of the phosphor resistance to thermal quenching performance was achieved, which directly determines whether enhanced or diminished thermal quenching can be obtained. This finding provides a new effective strategy for the tuning of thermal quenching luminescence of Pr3+-doped Nb/Ta system phosphors. [Display omitted] [ABSTRACT FROM AUTHOR]

Multifunctional ceramics with the 0.93(Na 0.5 Bi 0.5) 1- x Pr3+ x TiO 3 -0.07BaTiO 3 (abbreviated as BNBT- x Pr, x = 0.00, 0.002, 0.004, 0.006, 0.008) were synthesized using the solid-phase reaction method. This study systematically investigated the phase structure, microstructure, dielectric, ferroelectric, piezoelectric, and photoluminescence properties. As the value of x increased, the ceramics underwent a transition from a co-existing rhombohedral (R) and tetragonal (T) phases to a T phase with a slight R distortion. In addition, the grain size decreased, and the relative density increased. The Pr3+ doping led to a decrease in the coercive field and an improved reversible phase transition, accompanied by a reduction in the depolarization temperature (T d) from 91 °C to 41 °C. The ceramic with x = 0.006 showed excellent piezoelectric properties, with a d 33 = 201 pC/N and k p = 30.6%. Such properties were ascribed to the appropriate R/T phase ratio, increased relative density, decreased coercive field, and improved reversible phase transition. Moreover, under excitation at 451 nm, the ceramics exhibited bright red emission bands at 611 nm and 655 nm, corresponding to the transitions of 1D 2 →3H 5 and 3P 0 →3F 2 , respectively. After polarization, the relative intensity of the emission peak at 655 nm significantly increased due to the changed lattice environment caused by the electric field. These Pr-doped BNBT ceramics demonstrated great potential in applications requiring electro-optic integration and coupling devices as multifunctional materials. [ABSTRACT FROM AUTHOR]

In this work, MgGeO 3 :Pr3+ system is prepared by high-temperature solid phase method under the condition of different temperature and Pr content. MgGeO 3 :Pr3+ could emit 622 nm (red), 716 nm (red), 903 nm (NIR) and 1081 nm (NIR) lights under the external excitation of 251 nm and 425–500 nm. Due to the different excitation wavelengths, MgGeO 3 :Pr3+ has completely different electronic transition paths, resulting in a much larger emission intensity under 251 nm excitation than that excited by 425∼500 nm. When the incident light wavelength is 251 nm, the excitation process is VB→1D 2 level of Pr3+, and the emission is due to transition of 1D 2 →3H 4 , 1D 2 →3H 5 , 1D 2 →3H 6 (3F 2) and 1D 2 →3F 3,4. When the wavelength of incident light is 425∼500 nm, the excitation process is 3H 4 →CB, the emission is CB→1D 2 , and then 1D 2 →3H 4 , 1D 2 →3H 5 , 1D 2 →3H 6 (3F 2) and 1D 2 →3F 3,4. At the same time, the emission spectrum and X-ray diffraction measurements show that the most fundamental factor determining the emission intensity of the sample is the concentration of the luminescent center (Pr3+ that can emit light) in the MgGeO 3 grain. Increasing the sintering temperature and Pr element content in raw materials can increase the of Pr3+ concentration in the grain (increase the concentration of the luminescent center). However, if the concentration of Pr3+ in the grain is too high, Pr3+ would lose the function of the luminescence center, resulting in a decrease in the concentration of the luminescence center, thereby reducing the luminescence intensity. [ABSTRACT FROM AUTHOR]

The separation of praseodymium (Pr) and neodymium (Nd) is particularly challenging within the lanthanide series. A new strategy was developed for enhanced separation of Pr and Nd, using interfacial "push and pull" complexation induced by a kinetic effect. We found that the specific addition order of diethylenetriaminepentaacetic acid (DTPA) had an obvious influence on the separation behaviors of Pr/Nd. Notably, the separation coefficient was up to 3.25 with the addition of DTPA when the extraction process just started. This suggested that different complexation rates decided differences of extraction kinetics between Pr and Nd. It revealed differences in complexation rates of adjacent RE(III) with DTPA and dissociation rates of RE-DTPA complexes by stopped-flow spectrophotometry. The results indicated that the complexation rate constant of Nd3+ was higher than Pr3+. On contrary, the dissociation rate constant of Nd-DTPA was smaller than Pr-DTPA. Molecular dynamics (MD) simulations showed that the interfacial "push and pull" complexation effect led to differences in interfacial molecule arrangements and diffusion mass transfer rates near the interface. And thus, the separation of Pr/Nd can be enhanced. This research provides an efficient strategy for the purification of metals that are difficult to separate. [Display omitted] • Kinetic enhanced separation of Pr and Nd under "push and pull" complexation effect. • Competitive complexation of RE ions with [A336][NO 3 ] and DTPA. • Separation coefficients were affected significantly by the added order of DTPA. • Complexation kinetics were studied by stopped-flow spectrophotometry. • Study extraction kinetics via analysis of mean square distance based on MD. [ABSTRACT FROM AUTHOR]

CaMoO 4 :Pr3+ thermochromic phosphors with diverse thermal responses for temperature sensing were prepared by the traditional solid-phase reaction method. The typical CaMoO 4 :Pr3+ had scheelite structure belonging to tetragonal crystal system and space group of I 4 1 / a (88). Pr3+ ions can be easily substituted for Ca2+ ions of host CaMoO 4 because of similar ionic radius. CaMoO 4 : 1.5% Pr3+ have the block structure with mean size of 6.84 μm. The E g (∼3.93 eV) value of pure CaMoO 4 is bigger than that (∼3.65 eV) of CaMoO 4 : 1.5%Pr3+, attributing to the existence of intermediate defect energy levels. Appropriate Pr3+ doping concentration is 1.5%, and the concentration quenching phenomenon can be explained by the concrete electric multipole type of d-d interaction. The emission peak at ∼605 nm from 1D 2 →3H 4 transition have a good thermal stability of 99.452%@423 K, while the wide band centered at ∼490 nm from 3T 1,2 → 1A 1 transition in the MoO 4 2− complex and 3P 0 →3H 4 transition in Pr3+ have a poor thermal stability of 27.572%@423 K. Calculated activation energy is 0.239 eV. Temperature-dependent FIR for optical thermometry was constructed due to their diverse thermal responses. CaMoO 4 : Pr3+ phosphor had good relative sensitivities of 2.216%, 0.969% and 0.932% based on FIR of I 605 nm /I 490 nm with Boltzmann distribution, modified Boltzmann distribution and exponential equation fitting. Thermochromic behavior and thermal quenching mechanism are investigated. The obtained relative sensitivity is better than that of most phosphors, implying that CaMoO 4 : Pr3+ has a potential for application in optical thermometry. [ABSTRACT FROM AUTHOR]

The sediment deposited behind a dam (DS) and its inorganic materials (IM-DS) were characterized and used for the removal of praseodymium (Pr) from aqueous solutions. Quartz, albite, and kaolinite were found in the sediment by X-ray diffraction. Kinetic data fit well to a pseudo second-order model, the equilibrium time for DS and IM-DS was 2 h and 3 min, respectively, and the adsorption capacity was higher for Pr/DS (q e = 4.91 mg/g) than for Pr/IM-DS (q e = 3.01 mg/g) in these conditions. Pr/DS and Pr/IM-DS data isotherms were in agreement with the Langmuir–Freundlich model and the maximum adsorption capacities were 4.95 and 4.01 mg/g, respectively. Both processes are exothermic (enthalpy change, Δ H 0 = −22.8 and −21.8 kJ/mol for DS and IM-DS, respectively), the increase of the randomness is small, and the feasibility and spontaneity are low. Praseodymium was desorbed by ethylenediaminetetraacetic acid disodium (EDTA-Na 2), sodium chloride, nitric, citric, and humic acids solutions, and one hundred percent of praseodymium was desorbed by the EDTA-Na 2 solution. The Pr 2 (EDTA) 3 (praseodymium ethylenediaminetetraacetate) complex was completely desorbed from both materials (DS and IM-DS). Distribution coefficients (K D) depend upon praseodymium concentration, temperature, pH, and the kind of adsorbent. Chemical reactions of praseodymium with kaolinite and iron minerals could explain the adsorption. [ABSTRACT FROM AUTHOR]

Little information is published on the hardness and corrosion resistance properties of WC-Mn-Cu-Ni alloys infiltrated by an NdPrFeB alloy. Is iron-neodymium-praseodymium inter-metallic compound a desirable choice for a binder for liquid sintering or spontaneous infiltration at high temperatures? Also, is it an opportunity to study the effect of the particle size (d < 30 μm) and the percentage of addition (<5%) of neodymium and praseodymium on the mechanical and electrochemical properties of the composite WC-Cu-Ni-Mn/binder? These inter-metallic composites associating elements of different sizes and electronegativities make it possible to have metallic bonds, but also localized interactions, of the covalent type, between metals and semi-metallic element. The influence of the mechanisms of dissolution and progressive precipitation intervening in the process of densification in the liquid phase allows for obtaining micro-hardness with a value of 1580 HV0.3 and a relative density of 0.798. The micrographs reveal additional information concerning the strong chemical activity of Nd and Pr. The advantage of using the NdPrFe alloy is to take advantage of both the qualities of each element via the coupling of the conduction electrons of the two elements. The behavior of the composite sample in an aggressive (1 M NaOH) medium was examined. Electrochemical parameters determined from Tafel lines show a significant diminution of I corr when a grain size decreases. For the sample elaborated by spontaneous infiltration the polarization resistance increases to 3686 Ωcm2 and the addition of 4–5 wt% of rare earth (RE) is recommended. In relations to their composition and hardness, we can consider these materials as candidates for magnetic drilling tools. [ABSTRACT FROM AUTHOR]

The study investigates the ability of synthetic ZrSiO 4 to host the combined occupancy of Pr3+/PO 4 3− in its tetragonal crystal lattice. Sol-gel method has been utilized to synthesize a series of Pr3+/PO 4 3− additions in SiO 2 –ZrO 2 binary oxides and the feasibility of the resultant to transform into a ZrSiO 4 by the influence of thermal treatment were investigated through series of analytical techniques. The overall results indicated the feasibility of ZrSiO 4 lattice to host a maximum of 10 mol.% Pr3+/PO 4 3− to retain a unique solid solution beyond which the crystallization of PrPO 4 as a secondary phase is noticed. The temperature effect has played a pivotal role in the phase behaviour of SiO 2 –ZrO 2 binary oxides due the invariable range maintained in the Pr3+/PO 4 3− additions. The data obtained from the absorption spectra, luminescence, lifetime decay measurements, morphological, magnetic and mechanical analysis of the investigated systems ensured the significance of phase composition to yield the desired properties. Formation of ZrSiO 4 solid solution until 10 mol.% saturation occupancy limit of Pr3+/PO 4 3− beyond which the crystallization of PrPO 4 is witnessed. [Display omitted] [ABSTRACT FROM AUTHOR]

The fabrication of electrode material with unique physiochemical properties is significant to enhance electrochemical performance. In this work, we synthesized praseodymium vanadate (PrVO 4) through green deep eutectic solvents (DES) by the solvothermal approach and explored it as an electrochemical sensor for furaltadone (FLD) detection. The as-prepared PrVO 4 was characterized by using appropriate microscopic and spectrophotometric techniques. The modification of the electrode on PrVO 4 showed excellent electrochemical performance due to its high conductivity, active sites, and fast electron transfer ability. The PrVO 4 -modified electrode displayed a dynamic linear range (0.008–91 μM), trace-level detection limit (0.002 μM), high sensitivity (4.276 μA µM–1 cm–2), and strong selectivity for FLD detection under optimum experimental conditions. The practical applicability of PrVO 4 modified electrode was successfully investigated for the effective determination of FLD in pond water, human urine, and fish samples, revealing its potential application for real samples analysis. This work provide applicable guidelines for the design and development of DES-based electrode materials for the electrochemical sensor application. [ABSTRACT FROM AUTHOR]

A new glass series with nominal molar composition of 60B 2 O 3 + 30NaF + 10Al 2 O 3 co-doped with Dy3+ and Pr3+, synthesized by melt quench was reported. The influence of Rare Earth (RE) ratio variation on prepared glasses was investigated by using Fourier Transform Infra-Red spectroscopy, UV–Vis–NIR absorption spectroscopy, Photoluminescence, Decay curves and Density measurements. Their X-Ray Diffraction and FTIR spectra revealed the glassy nature and confirmed that AlO 6 , AlO 4 , BO 3 and BO 4 units are the main structural units of that matrix. A non-linear variation following the same trend for tetragonal borate units (N 4), Band gap, non-linear optical properties, Density, Molar Volume etc. was observed. Different optical parameters were obtained by UV–Vis–NIR spectroscopy. The Bonding parameter obtained from Nephelauxetic study indicated ionic nature of Dy3+ and covalent nature of Pr3+ ions. Photoluminescence excitation and emission spectra were recorded under variety of excitation wavelengths and corresponding color parameters were calculated using 1931 CIE standards. A detailed yellow to blue ratio analysis was reported as a function of RE ion concentration and excitation wavelengths. Composition DPNAB(x = 0.7) displayed the best performance with CIE coordinates (0.33, 0.37). Existence of Energy transfer from Dy3+ and Pr3+ was evidenced by the spectral overlap diagram and lifetime values obtained from fitting of Decay curves. From the obtained results, prepared glasses can be suggested for solid-state lighting devices like WLEDs and display devices. • Dysprosium (Dy3+) and Praseodymium (Pr3+) co-doped alumino-borate glasses were prepared. • FTIR exploration confirmed the existence of AlO 6 , AlO 4 , BO 3 and BO 4 units in the structure. • Optical transitions of Dy3+ and Pr3+ were observed. • Photoluminescence investigations predict the applicability of prepared glasses in tunable visible lighting applications. • Yellow to Blue (Y/B) ratio was discussed as a function of Dy3+concentration and excitation wavelengths. [ABSTRACT FROM AUTHOR]

Transparent Pr3+ doped Ca 1-x Gd x F 2+x (x = 0, 0.01, 0.03, 0.06, 0.10, 0.15) polycrystalline ceramics with fine-grained microstructures were prepared by the hot-pressing method. The dependence of microstructure, optical transmittance, luminescence performances and mechanical properties on the Gd3+ concentrations for Pr3+:Ca 1-x Gd x F 2+x transparent ceramics were investigated. The Gd3+ ions show positive effects on the microhardness of Pr3+:Ca 1-x Gd x F 2+x transparent ceramics as a result of the decrease in the grain sizes. Excited by the Xenon lamp of 444 nm, typical visible emissions located at 484 nm, 598 nm and 642 nm were observed. Furthermore, the incorporation of Gd3+ ions can greatly enhance the photoluminescence performance owing to the improvement in the concentration quenching effect. The quenching concentration of Pr3+ ions in CaF 2 transparent ceramics increased to 1 at.% as a result of the positive effect of Gd3+ codoping. The energy transfer mechanism of Pr3+ in the Pr3+:Ca 1-x Gd x F 2+x transparent ceramics has been investigated and discussed. [ABSTRACT FROM AUTHOR]

Cobalt-free layered perovskite as a promising mixed ionic electronic conductor cathode has shown outstanding performance in conventional oxygen-ion conducting solid oxide fuel cells (O–SOFCs), but not in next-generation proton-conducting solid oxide fuel cells (H–SOFCs) due to insufficient oxygen vacancy so far. We propose a facile A-site doping strategy to enable higher-oxygen-vacancy cobalt-free layered perovskite cathode for higher-performing protonic ceramic fuel cells at reduced temperatures. As proof of concept, two different typical A-site doping of mixed-rare-earth Nd and alkali-metal K in PrBaFe 1.9 Zn 0.1 O 5+δ are chosen as potential H–SOFC cathode materials. Pr 0.8 Nd 0.2 BaFe 1.9 Zn 0.1 O 5+δ (PNBFZ) and PrBa 0.9 K 0.1 Fe 1.9 Zn 0.1 O 5+δ (PBKFZ) layered perovskite cathodes were synthesized using a nitrate-gel combustion method. Both PNBFZ and PBKFZ have a layered perovskite structure and are chemically compatible with protonic BaZr 0.1 Ce 0.7 Y 0.2 O 3−δ (BZCY) electrolyte. Both Nd and K doping dramatically improve the electrical conductivities under operation temperatures. Compared with PBKFZ, PNBFZ shows a lower average thermal expansion coefficient (TEC) of 13.9✕10−6 K−1, being thermally compatible with the BZCY electrolyte without cracks. A-site doping in Fe-based layered perovskite cathodes promotes the single-cell output performance by around 100-26% at 550–700 °C, especially for the mixed-rare-earth doped PNBFZ with high peak power densities of 401–650 mW cm−2. [ABSTRACT FROM AUTHOR]

The study of the piezoelectric response in praseodymium-doped (Na 0.41 K 0.09 Bi 0.5)TiO 3 (NKBT) revealed an unusual behaviour at doping level near 0.5 and 1.0 at%. Although there is a marginal increment in the piezoelectric charge coefficients for samples with praseodymium doping of 0.5–1.0 at% compared to undoped NKBT, importantly, the response drastically diminishes for doping concentrations exceeding 1.0 at%. To comprehend the observed anomaly, X-ray photoelectron spectroscopy (XPS) and temperature dependent conductivity measurement was carried out. These investigations provided critical insights into the role of oxygen vacancy and the behaviour of praseodymium ions in the NKBT matrix. The XPS analysis revealed the presence of core level peak corresponding to O-1s with asymmetric broadening at higher energy side implying the presence of oxygen bound to the perovskite lattice (binding energy: 529.2±0.3 eV) along with oxygen vacancy (binding energy: 531.5±0.4 eV). The XPS study further revealed that the concentration of the oxygen vacancy is lowest around 0.5 at% of praseodymium doping and beyond this the oxygen vacancy increases. The high temperature conductivity measurement supported these findings by showing similar trends in the electrical conductivity. Both the XPS and conductivity measurements further corroborate the conjecture that praseodymium behaves as amphoteric ion. The praseodymium occupies the A-site of perovskite (Na 0.41 K 0.09 Bi 0.5)TiO 3 for lower praseodymium concentration (<1.0 at%), whereas for higher doping concentration (>1.0 at%) it occupies the B-site exhibiting acceptor like behavior that deteriorates the piezoelectric response. • In present work the anomaly in Pr+3 doped lead-free ferroelectric i.e. (Na 0.41 K 0.09 Bi 0.5)TiO 3 ceramic was investigated. • Piezoelectric coefficients increase for lower doping i.e. ≤ 1.0 at%, and it decreases monotonically for higher doping. • High resolution XPS spectra reveals the presence of Na-1s, Bi-4f, Bi-4d, Ti-2p, and Pr-3d core level peaks. • XPS data reveals that oxygen defect concentration decreases initially (<1.0 at%) with Pr+3 content & then increases. • The conductivity measurement shows that fall of oxygen defect concentration for ≤1.0 at% and it increases for higher doping. • The XPS and ac-conductivity measurements support the idea that praseodymium behaves as amphoteric ion. • Pr+3 occupies the A-site for lower concentration (≤1.0 at.%) and increases the piezoelectric response. • For >1.0 at%, Pr+3 occupies the B-site and lowered the piezoelectric response due to increased oxygen vacancy. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesis of un-doped and CeO 2 :Pr3+ (1–11 mol %) phosphor by utilizing a solution combustion route with Tulsi extract as a bio-fuel. • Under 444 nm excitation, the NPs exhibit intense orange-red emission at 613 nm, corresponding to the 3P 0 →3H 6 transition. • Transparent anticounterfeiting film, fabricated using highly efficient phosphors exhibits bright red emission, ensuring anticounterfeiting performance. • Lip prints are developed on various substrates using optimized CeO 2 :5Pr3+ phosphor, demonstrated effective detection of lip prints. • Thermostability of the sample is excellent, therefore CeO 2 :5Pr3+ phosphor can be used as an effective candidate for w-LEDs. Synthesis of CeO 2 phosphor, both un-doped and Pr3+ (1–11 mol %) doped, utilizing a solution combustion route with Tulsi extract as a bio-fuel, has been investigated. Characterization through X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), and photoluminescence (PL) analysis reveals successful inclusion of Pr3+ at the Ce3+ /Ce4+ site, inducing defects and oxygen vacancies, while maintaining the crystal structure and expanding the CeO 2 lattice. Energy Dispersive X-ray spectra confirm the composition with desired stoichiometry. Under 444 nm excitation, the phosphor exhibits intense orange-red emission at 613 nm, corresponding to the 3P 0 →3H 6 transition. With a relative sensitivity of 2.65 % K−1 and an absolute sensitivity of 0.023 K−1, CeO 2 :5Pr3+ phosphor exhibits remarkable temperature sensor capabilities. Moreover, a transparent nanocomposite (NCs), fabricated using highly efficient phosphors and soluble poly vinyl alcohol (PVA), exhibits bright red emission upon UV 365 nm light, ensuring anti-counterfeiting (AC) performance. The sustainability, excellent flexibility, and foldability of these materials open up possibilities for diverse anticounterfeiting applications. Overall, the results highlight the potential of CeO 2 :Pr3+ phosphors as versatile luminescent platforms for optical thermometers, flexible films, lip prints (LPs) detection, and AC applications. [ABSTRACT FROM AUTHOR]

The commercial viability of solid oxide electrolysis cells (SOECs) for the electrochemical reduction of CO 2 to CO is hampered by the sluggish electrocatalytic activity of the electrode materials. In this study, a series of perovskites, Pr 0.5 Sr 0.5 Cr 0.1 Fe 0.9-x Ni x O 3-δ (x = 0.1, 0.2, PSCFN x) with different Ni doping levels were synthesized. The results showed that increasing Ni doping led to the creation of more oxygen vacancies. Furthermore, treatment of PSCFN x in a reducing atmosphere resulted in a structural transformation into a composite with a heterogeneous interface between the Ruddlesden-Popper perovskite (RP-PSCFN x) and an exsolved Ni-Fe metal alloy. The re-PSCFN 0.2 -based cell showed a current density of 2.40 A cm−2 and a Faraday efficiency (FE%) of almost 100 % at 850 °C and 1.6 V, an improvement of 18 % in comparison to the re-PSCFN 0.1 -based cell. This study provides a strategy to synergistically improve the electrochemical reduction of CO 2 activity of SOECs by constructing an active heterogeneous interface and increasing the oxygen vacancy content. [Display omitted] • A composite of metal alloy and Ruddlesden-Popper perovskite formed. • An eCO 2 RR catalyst re-PSCFN 0.2 was developed. • A synergistic strategy for improving eCO 2 RR performance was constructed. [ABSTRACT FROM AUTHOR]

This study presents a comprehensive investigation into the impact of substituting rare earth elements on the magnetic properties of strontium hexaferrite. The samples, synthesized by the sol-gel Pechini method, followed the formula Sr 1-x Re x Fe 12 O 19 with Re = Gd, Sm, Nd, Pr, and La, for 0.025 ≤ x ≤ 0.100. The findings revealed that Re substitution promotes a considerable increment of the coercive field. However, the magnetic yield dropped with increasing the Re content. Therefore, the higher coercivity field, largest magnetization and maximum energy product (BH max) were reached for samples with x = 0.025. This tendency was consistent across all rare earth-substituted samples although the hexaferrite substituted with samarium and praseodymium showed the strongest hard-magnetic properties. This behavior has been attributed to a reduction of the interaction field due to the emergence of a monodomain structure, and to the limited solubility of rare earth elements within the structure of strontium hexaferrite. • Rare earth substitution in the strontium hexaferrite. • Improvement of the magnetic properties of the strontium hexaferrite. • Effects of Gd, Sm, Nd, Pr and La used as substitution elements in the Sr-M. • Hysteresis properties of the strontium hexaferrite substituted with rare earths. [ABSTRACT FROM AUTHOR]

This study has demonstrated that lithium niobate doped with praseodymium (LiNbO 3 :Pr), which initially did not exhibit persistent luminescence(PersL), can display significant PersL performance through the modulation of the lithium-to-niobium ratio (R LN). By adjusting the R LN to 1, LiNbO 3 :Pr achieved enhanced PersL, lasting several minutes, with the afterglow's duration further influenced by the R LN. Thermoluminescence (TL) assays and energy diagram analyses have elucidated that the presence and depth of oxygen vacancy defects are critical for both the emergence and longevity of PersL LiNbO 3 :Pr polycrystals. These insights enhance the understanding of PersL mechanisms in lithium niobate crystals and highlight their potential for application in optical information storage. • The lithium-to-niobium ratio effectively modulated the afterglow and thermoluminescence(TL) of LiNbO 3 :Pr polycrystals. • The lithium-to-niobium ratio of 1 resulted in the maximum persistent luminescent time constant and minimum defect depth. • TL experiments confirmed the depth of oxygen vacancy defects and elucidated their role in modulating the afterglow. [ABSTRACT FROM AUTHOR]

Silicate-Titania (SiTi) glass-ceramics doped with Pr3+ (0.6, 1.6, 2.4 and 3.6 mol%) ions were prepared by sol-gel technique. The materials were characterized by powder XRD, FTIR, TEM, EDX, Optical absorption and Photoluminescence spectroscopy. The identification of non-bridging oxygen (NBO) formation and the removal of OH groups are validated through analysis of the FTIR spectra. Additionally, measurements using XRD and TEM showed that the samples contain nano-sized crystallites. The three phenomenological Judd–Ofelt (J–O) intensity parameters Ω 2 , Ω 4 , and Ω 6 were obtained and used to analyze different radiative characteristics for the fluorescence levels of Pr3+ in the glass ceramic, including radiative lifetime, branching ratio, radiative transition probability and stimulated emission cross-section. Several emissions were observed in the visible region, among which the 1D 2 →3H 4 in the orange-red region is the most intense. All of these reported branching ratios, stimulated emission cross-sections, and visible emission spectra point to the possibility of employing them as red region lasers. The CIE chromaticity coordinates from all of the emission spectra were also assessed to determine if these materials are suitable for orange-red phosphors. According to CIE chromaticity investigations, 1.6 mol% of Pr3+ ion concentration is ideal for SiTiPr glass-ceramic for use as red phosphors and possibly red lasers. • SiO 2 –TiO 2 glass ceramics doped with Pr3+ are synthesized by sol-gel technique. • TiO 2 nanocrystals of size around 10–20 nm are formed. • Judd-Ofelt parameters and radiative parameters are calculated. • Strong emissions in the orange-red region are observed under blue excitation. • Cross-relaxation reduces luminescence at high Pr3+ concentration. [ABSTRACT FROM AUTHOR]

The RE 6 Fe 13 Ga phase (RE, Rare Earth) exhibits tremendous promise for achieving high-performance magnets. However, the challenge of controlling its formation and distribution hinders improvements in coercivity and squareness of Ga-doped magnets. In this study, we present a strategy to regulate the chemical composition of the RE-rich phase (0–9 at.% Cu, without Ga) and subsequently modify the phase transformation pathways of the RE 6 Fe 13 Ga phase in Ga-doped magnets by incorporating a Pr-rich Ga-Cu-containing aiding alloy. Remarkable magnetic performance was achieved, with values of B r =13.36 kGs, μ 0 H cj =20.82 kOe, (BH) max =43.75 MGOe, and μ 0 H k90 /μ 0 H cj =0.99. Through quantitative analysis of chemical and structural properties and phase fractions at grain boundary (GB) triple junctions, we elucidate the phase transformation pathways in the magnets. The reaction between amorphous RE-Ga-rich phases and the matrix phases, along with partial consumption of the RE-rich phases with the Mn 2 O 3 -type structure (space group Ia 3 ¯), led to the formation of the RE 6 Fe 13 Ga phase, accompanied by the presence of an amorphous Fe-rich transitional phase sharing a similar chemical composition. The gradual and partial involvement of the RE-rich phase improved the melt's wettability and delayed the formation of the RE 6 Fe 13 Ga phase. Consequently, a uniform microstructure was achieved, establishing the conditions for high magnetic performance. Thin metallic GBs and thick RE-rich, amorphous Fe-rich, and RE 6 Fe 13 Ga GBs were formed in the magnet. The former ensured squareness, while the sufficient coverage of the latter contributed to exceptional coercivity. The Pr-rich aiding alloy induces chemical heterogeneity, reinforcing the magnetic properties. This study advances our understanding of phase transformation pathways in Ga-doped magnets and introduces an effective approach for achieving high-performance magnets. [Display omitted] [ABSTRACT FROM AUTHOR]

Perovskite nanostructures of PrFe 1-x Mn x O 3 with and without Mn ions were hydrothermally processed and extensively studied as photocatalysts and photoelectrocatalysts. The significance of Mn ions on the intrinsic characteristics of perovskites were initially evaluated to be in orthorhombic pbnm structure. PrFe 1-x Mn x O 3 was also examined to be made up of fine particle like structures. The effective replacement of Mn ions was affirmed through several structural characterization routes. The bonding of Mn ions in the perovskite architecture and their capacity to replace the Fe sites was additionally studied using X-ray photoelectron spectroscopic (XPS) measurements. The absorbance spectra augmented the potential of PrFe 1-x Mn x O 3 to serve as an effective photocatalyst in treating organic pollutants. Mn ions were also found to improve the defect sites in the nanomaterials, which actually played a vital role in influencing the photocatalytic and photoelectrochemical activities. The photocatalytic efficacy of Mn based perovskites was noted to be much better than their pristine counterparts through the comparative photocatalytic studies. The density of photocurrent values studied via photoelectrochemical experiments also supported the active role of Mn ions in boosting the water splitting performance. The impedance data studied via electrochemical route suggested the aid of Mn ions in accelerating the migration of charges readily to result with the observed results. [ABSTRACT FROM AUTHOR]

The electrochemical performance and stability of infiltrated praseodymium nickelate (PNO) as the cathode for solid oxide fuel cell (SOFC) applications was studied. PNO cathode (Pr 2 NiO 4+δ) was infiltrated into gadolinium-doped ceria (GDC) scaffolds and tested in two different anode-supported cells with tubular geometry: i) tubular cell A with Ni-YSZ support, Ni-YSZ anode functional layer (AFL), and thin (∼7 μm) electrolyte and; ii) microtubular cell B with Ni-YSZ support, without AFL and thick (34 μm) electrolyte. Both cells were stable during 91 h and 260 h of stability testing at 650 °C and experienced a reduction in total polarization resistances. Post-mortem X-ray diffraction (XRD) analysis confirmed PNO's partial transformation into the Pr 4 Ni 3 O 10 phase with higher electrical conductivity and thermal stability. Improvement in the oxygen reduction reaction was confirmed using DRT analysis. This finding confirms that PNO infiltrated into GDC scaffold can be considered a promising cathode for SOFC applications. [Display omitted] • PNO was infiltrated into GDC scaffold and heat treatment temperature was studied. • Post-mortem XRD analysis showed Partial transformation of PNO cathode to Pr 4 Ni 3 O 10. • Cathode's oxygen reduction reaction improved during the stability tests. • SOFCs fabricated with PNO infiltrated cathodes were stable for 91 h and 260 h. [ABSTRACT FROM AUTHOR]

Materials capable of converting visible light into the ultraviolet C (UVC) region are promising candidates for antimicrobial technology and photocatalytic applications. In this work, the effective UVC upconversion phosphors ACaF 3 :Pr3+ (A = K, Rb, Cs) were synthesized using solid state reactions. Upconverted emissions in the range from 230 to 315 nm were obtained with 444 nm laser excitation. The dependence of upconverted luminescence on pump power, the concentration of Pr3+ ions, and the decay profiles of upconverted luminescence provide insights into the primary mechanisms responsible for upconversion. Among the obtained fluoroperovskites, the rubidium composition showed the most intense luminescence. Additionally, ACaF 3 :1 %Pr3+ exhibits a manifold increase in upconversion emission compared to the previously studied reference material LiYF 4 :1 %Pr3+, indicating the potential use of fluoroperovskites for surface decontamination. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work we report a thermal stress test executed on high efficiency diode pumped waveguide lasers based on Pr:LiLuF 4. Numerical simulations have been performed to estimate the core temperature. We demonstrated that no modifications in the output power, 275 mW at 604 nm and 310 mW at 721 nm, and in the bulk-level slope efficiency, 40% at 604 nm and 50% at 721 nm, have been observed with an estimated core temperature of 70 °C. We also executed stability measurements of the free running laser in thermally severe conditions, demonstrating output power fluctuations of mechanical origin as low as 10% of the peak value. • Direct femtosecond-laser-writing allows the fabrication of waveguides in dielectrics. • Praseodymium-based lasers can be used as metrological or medical-oriented sources. • Praseodymium-based waveguide lasers can be passively dissipated without power loss. • Passively-cooled devices play a key role in aerospace-oriented lightweight systems. [ABSTRACT FROM AUTHOR]

Lanthanum barium borate glasses doped with praseodymium were fabricated by a melt-quenching process, to study the effect of Pr 2 O 3 on their properties. The addition of Pr₂O₃ in glass increases its density, molar volume, and refractive index. XRD confirms an amorphous nature of glass network, and XANES approves the praseodymium character as Pr3+ oxidation state in glass. Glasses absorb photons in ultraviolet and near-infrared region by the Pr3+ transitions from 3H 4 ground state. The photoluminescence spectra of glasses exhibit the strongest emission at 602 nm (1D 2 → 3H 4) under 442 nm excitation (3H 4 → 3P 2). The optimal 0.5 mol% Pr 2 O 3 -doped glass possesses the highest emission intensity due to the concentration quenching effect. Judd-Ofelt theory was used to determine the Pr3+ site environment in glass and its dominant stimulated emission. Strong orange emission of this glass is suitable for orange solid-state lasers, LEDs, and emitting devices. • Strong orange emission of new Pr3+ doped lanthanum barium borate glasses for photonic materials. • The different emissions from multiple luminescence levels of Pr3+ ion were observed. • XANES obviously confirms the Pr3+ oxidation state and the variation of ion concentration in glass. [ABSTRACT FROM AUTHOR]

Scheme 1. PrCl 3 mediated B-Z transition in (CG) n DNA and reverse back by EDTA. [Display omitted] • Praseodymium shows sequence specific B-Z transition in pyrimidine-purine repeats. • PrCl 3 stabilizes left-handed DNA in (CG)n repeats but condensation in (GC)n DNA. • EDTA-based chelation of Pr results in Z-B reverse transition in CG-repeat. • Pr-induced Z-DNA in (CG)n exhibits close to neutral zeta potential and lower Tm. • Molecular dynamics simulation verifies the ability of Pr3+ to produce left-handed DNA. The present study investigates the impact of praseodymium chloride on the conformational transition between the B-form and Z-form of DNA. In the current communication, we employ a combination of biophysical techniques, including circular dichroism, isothermal titration calorimetry, fourier transform infrared, zeta potential and molecular dynamics simulations to elucidate the mechanism of B-Z transition. Our results reveal a praseodymium-dependent modulation of the DNA helical structure, leading to the conversion from the canonical B-DNA to the left-handed Z-DNA in (CG) n repeat and condensation in (GC) n repeat. Altered helical parameters, base pair stacking and overall DNA geometry upon praseodymium binding has been characterized using spectroscopic analysis. The decrease in Gibbs free energy during ITC indicates a spontaneous reaction and provides the specific binding sites and coordination geometry of praseodymium ions within the DNA double helix. Molecular dynamics simulation further complements our experimental findings, offering a dynamic perspective on the temporal evolution of the B-Z transition process. We observe that praseodymium plays a crucial role in stabilizing the Z-DNA conformation in (CG) n repeat, providing a foundation for understanding the thermodynamics and kinetics of this transition. [ABSTRACT FROM AUTHOR]

Sulfur hexafluoride (SF 6) from Gas Insulated Switchgear (GIS) will decompose and produce hydrogen sulfide (H 2 S) in the event of equipment failure. Therefore, the detection of H 2 S can determine whether the equipment has malfunctioned. Due to the low concentration of the SF 6 decomposition product H 2 S and its application in industrial environments, sensors must have a low detection limit and rapid response time. Considering that the oxides of rare earth elements can improve the sensing characteristics, praseodymium oxide (Pr 6 O 11)-indium oxide (In 2 O 3) was prepared. The impact of Pr 6 O 11 doping on In 2 O 3 was investigated through characterization methods. To validate its feasibility for use in GIS, the best sensor (F3) exhibits good sensing characteristics for H 2 S in the SF 6 and air ambient. The responses to 10 parts per million (ppm) H 2 S at 190°C were 146.6 in SF 6 and 190.8 in air. In SF 6 ambient, the F3 sensor demonstrated a low detection limit (50 parts per billion (ppb)). The good sensing characteristics are attributed to the doping of rare earth elements, which induces an increase in the proportion of defect oxygen and accelerate the chemical reaction. The sensing characteristics of the material can be attributed to the doping of Pr 6 O 11 and the electronic effect. This study provides a novel approach for detecting H 2 S generated from SF 6 decomposition. [Display omitted] • A rapid response (15 s) H 2 S gas sensor based on Pr 6 O 11 -In 2 O 3 nanocomposites. • A H 2 S gas sensor with an extremely low detection limit of 20 ppb. • Pr 6 O 11 -In 2 O 3 can achieve high response to H 2 S in air (190.8) and SF 6 (146.6). [ABSTRACT FROM AUTHOR]

[Display omitted] • Pr-doped ZnO nanostructured materials were prepared by electrospinning. • OTC photodegradation revealed a PSO rate constant of 1.165 × 10-1 L mg−1 min−1. • The process intensification led to a decrease in the half-life to 1 min. • TOC removal efficiency was found to be 60.79% • Excellent stability was found in the reuse tests for several cycles. Zinc oxide nanostructures doped with praseodymium (ZnO:Pr) at varying Pr content (0.05 % to 1.0 % w/w) were synthesized using the electrospinning-calcination technique. Comprehensive morphological and structural characterizations were conducted through SEM, XRD, and XPS analyses. In addition, diffuse reflectance and photoluminescence spectroscopy measurements were performed to assess the optical properties of materials. The produced photocatalysts (ZnO:Pr) were then employed for the degradation of methylene blue dye and oxytetracycline under visible-light irradiation. ZnO:Pr(0.1 %) demonstrated the best photocatalytic performance against methylene blue showing a pseudo-first-order rate constant of k = 3.630 × 10-2 min−1. Investigation of oxytetracycline photodegradation with ZnO:Pr(0.1 %) revealed a pseudo-second-order rate constant of k s = 1.165 × 10-1 L mg−1 min−1, resulting in a reaction half-life (τ ½) of approximately 1 min under optimal conditions. Total organic carbon and mass spectrometry analyses highlighted mineralization and identified the main reaction intermediates, respectively, for the oxytetracycline photodegradation. The photodegradation mechanism of oxytetracycline was proposed by the photocatalytic degradation measurements in the presence of scavengers such as hydroquinone and isopropanol. These nanostructures exhibited robust photocatalytic activity over multiple cycles, demonstrating excellent stability. This study underlines the promising potential of ZnO:Pr(0.1 %) as an efficient photocatalyst able to intensify the photodegradation of organic pollutants. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pr-doped In 2 O 3 microtubes are prepared by driving from MIL-68. • Pr-doping leads to the smaller average grain size and more lattice defects. • The gas-sensing performance is highly-enhanced by Pr-doping. • The better anti-humidity results from the transition of Pr3+→Pr4+ of 3Pr-In 2 O 3 sensor. • The high response value is due to the higher specific surface area and oxygen vacancies. Formaldehyde (HCHO) is a typical toxic gas that poses serious risks to human health and the environment. Gas sensors with reliable performance are momentous for accurate detection and timely monitoring of HCHO gas. Herein, Pr is doped into In 2 O 3 microtubes via deriving from metal-organic framework of MIL-68(In) to improve the HCHO sensing performance. All results indicate that Pr-doping hardly changes the phase structure, while the specific surface area, bandgap and oxygen vacancies are adjusted to some extent. More importantly, the gas-sensing properties of In 2 O 3 sensors towards HCHO gas are greatly enhanced due to Pr-doping. 3Pr-In 2 O 3 sensor exhibits the highest response value of 999.08 to 10 ppm HCHO gas at the optimized operating temperature of 210 °C, which is 8.15 times higher than that of In 2 O 3 sensor at 230 °C. Moreover, the selectivity, response time, stability and anti-humidity of Pr-doped In 2 O 3 sensors is also improved to a certain extent, which the HCHO gas concentration can be determined from the response value. The highly-improved gas-sensing performance should be attributed to the higher specific surface area, more oxygen vacancies, smaller bandgap, and Pr3+→Pr4+ transition for Pr-doped In 2 O 3 sensors. [ABSTRACT FROM AUTHOR]

[Display omitted] • Heteronuclear Pr 1 -Ni 1 active sites with Pr-N 4 C 2 and Ni-N 4 moieties were constructed. • Pr/Ni-NC shows 99.1 % FE CO with commercial-scale current density of 237 mA cm−2. • Pr site facilitates CO 2 activation and Ni site enables H 2 O dissociation for CO 2 RR. Lanthanide metals have attracted particular interest in the catalysis of electrochemical CO 2 reduction. The synthesis and precise spatial distribution of active sites are fundamental important but still formidably challenging owing to the strong oxygen affinity of lanthanide. Here, heteronuclear Pr 1 -Ni 1 single atoms are supported on the carbon matrix containing surface framework defects from lanthanide contraction. The Pr/Ni-NC catalyst exhibits a CO Faradaic efficiency of 99.1 % with a commercial-scale current density of 237 mA cm−2 and a turnover frequency as high as 18,038 h−1 at −1.1 V due to d-f coupling effect and electronic structure perturbation of Pr. Furthermore, mechanistic investigations unveil that the diatomic active sites effectively reduce the energy barrier of the crucial *COOH formation, in which the Pr site facilitates CO 2 activation and the Ni site enables H 2 O dissociation to accelerate the proton transfer process, thereby ensuring the synergy of catalytic sites to greatly facilitate CO 2 -to-CO conversion. [ABSTRACT FROM AUTHOR]

[Display omitted] • PWO was prepared by facile co-precipitation synthesis approach. • This fabricated sensor determined RD with a low LOD of 0.3 nM. • Our electrochemical sensor displayed good selectivity and excellent performance. • PWO sensor was utilized to monitor RD in spiked river water, spiked urine and tablet samples. Profligate consumption of antibiotics in animal and livestock husbandry indulged in antibiotic pollution. This collapses the natural balance of the ecosystem and results in various environmental health crises. Herein, we have developed an ultra-sensitive praseodymium tungstate (PWO) based electrochemical sensor to detect one such serious antibiotic, Ronidazole (RD). A facile synthesis strategy was applied to prepare PWO nanomaterial and their structural, functional, and elemental details were thoroughly examined with a wide range of spectroscopic measurements. The electrochemical properties were determined by performing impedance and voltammetry experiments. The high catalytic efficiency of the designed sensor was achieved by optimizing its performance under different parameters. Based on the outcomes, the designed PWO-based sensor offered an extremely low level of detection (0.3 nM) and exhibited a wide range of linearity (0.001 µM to 20.4 µM), high sensitivity (7.72 µA µM−1 cm−2), and good selectivity. Further, the performance of the electrochemical sensor was validated with good repeatability, reproducibility, and stability results. The practical applicability of the sensor was investigated by monitoring the RD in aquatic, biological, and pharmaceutical samples. The obtained results affirmed that the PWO sensor is an efficient platform for the real-time monitoring of RD. [ABSTRACT FROM AUTHOR]

This work reports on the influence of co-doping on the luminescence and persistent luminescence properties of BaAl 2 O 4 (BaO·Al 2 O 3) laser-sintered ceramics. The samples were doped with Eu and doubly co-doped with different rare earths (Dy, Er, Nd, Pr, and Tm) followed by laser-sintering without an atmospheric control, at a power density of 1.6 W/mm2. All sintered ceramics contained the hexagonal BaAl 2 O 4 phase and had a homogeneous microstructure. A photoluminescence emission band centered at 495 nm was observed, which was due to the 4f65 d1 → 4f7 Eu2+ transition in the BaAl 2 O 4 matrix. The persistent luminescence emission was monitored for 15 min after charging at 345 nm for 3 min. The combination of Nd and Dy co-doping led to substantial improvements in decay time and persistent luminescence intensity compared to individual co-doping. These results suggested that the two co-dopants interacted by modifying the trap configurations in the BaAl 2 O 4 matrix. • Laser sintering has proven effective in sintering BaAl 2 O 4 :Eu,RE ceramics, exhibiting persistent luminescence properties. • To achieve long-lasting persistent luminescence, it is crucial to choose the right co-dopants or trap depth. • The combination of Nd and Dy exhibits superior persistent luminescence results compared to samples co-doped individually. [ABSTRACT FROM AUTHOR]

Ho,Pr:CaYAlO 4 (Ho,Pr:CYA) crystal doped with 1 at.% Ho3+ and 0.1 at.% Pr3+ was successfully grown using the Czochralski method. Polarized absorption spectra, emission spectra, and fluorescence lifetime measurements were performed. The impact of Pr3+ co-doping on the ∼3 μm emission of Ho3+ ions was analyzed. The energy transfer efficiency from Ho3+:5I 7 to Pr3+:3F 2 energy level was calculated to be 60.66 %, indicating that Pr3+ effectively mitigated the self-termination effect in Ho,Pr:CYA crystals. The absorption cross-section at 645 nm was found to be 1.53 × 10−20 cm2 for σ polarization and 2.62 × 10−20 cm2 for π polarization. The emission cross-section at 2842 nm was calculated to be 0.86 × 10−20 cm2 for σ polarization and 1.33 × 10−20 cm2 for π polarization at 2908 nm, with a full width at half maximum (FWHM) of 139 nm and 88 nm, respectively. The fluorescence lifetimes of the 5I 6 and 5I 7 levels were measured to be 0.17 ms and 2.01 ms, respectively. These results collectively suggest that Ho,Pr:CYA crystals hold great potential as a candidate for 2.8 μm laser applications. • Ho3+,Pr3+ co-doped CaYAlO 4 crystal was grown by the Czochralski method. • The crystal structure, polarized absorption and emission spectra were investigated. • The intensity parameters were obtained using J-O theory. [ABSTRACT FROM AUTHOR]

• Metal production causes severe environmental impacts, that may increase in the future when demand for metals may rise. • We found that, e.g., greener electricity, higher recycling shares, or novel technologies may reduce impacts per kg metal. • Yet, this is probably insufficient to compensate for rising demand. Thus, demand-related impacts are likely to increase. • Knowledge is lacking about future impacts of many metals, especially minor metals essential for the energy transition. • Better understanding of future impacts of metals is needed, considering rising demand and impacts beyond GHG emissions. With the energy transition, the future demand for many metals is expected to sharply increase. We systematically reviewed studies which assessed future environmental impacts of metal supply chains. We evaluated their results regarding future impact trends, and their methods, i.e., modelling approaches, scenario variables, and data sources. Our review yielded 40 publications covering 15 metals: copper, iron, aluminium, nickel, zinc, lead, cobalt, lithium, gold, manganese, neodymium, dysprosium, praseodymium, terbium, and titanium. Metals crucial for the energy transition, e.g., lithium or neodymium, are rarely addressed, unlike major metals. Results for future environmental impacts of metals strongly depend on scenario narratives and assumptions. We found that specific impacts (per kg) may decrease driven by, e.g., greener electricity, higher recycling shares, or novel technologies. Nevertheless, this is probably insufficient to compensate for surging demand. Thus, future demand-related impacts are still likely to increase. We identified 15 scenario variables. The most common variables are background electricity mix, ore grade, recycling shares, demand, and energy efficiency. It is crucial to better understand future impacts of more metals, considering also rising demand and impacts beyond GHG emissions. We recommend improving research practices towards open and collaborative research, to enable more harmonised, reusable and accurate scenario assessments. [Display omitted] [ABSTRACT FROM AUTHOR]

• Results showed Ce oxide as cheaper than Ce carbonate for Al–Ce manufacturing. • This is because larger markets such as Ce oxide are more resistant to price shocks. • The cerium market saw its greatest increase in value when cerium metal was used. An imbalance problem exists in the rare earth element (REE) market with cerium and lanthanum being more abundant and less valuable than REEs used in permanent magnets such as neodymium, praseodymium, and dysprosium. Research has been conducted on new applications for abundant REEs to improve mining economics. However, potential market impacts of these applications on individual REE commodities are unknown. A system dynamics model was built to investigate the impacts of a new aluminum-cerium (Al–Ce) alloy that can theoretically utilize three separate cerium forms: cerium carbonate, cerium oxide, or cerium metal. Cerium carbonate currently possesses the lowest price of the three available forms making it initially the most favorable choice. However, model results showed that cerium oxide could provide the best economics for future Al–Ce alloy deployment because its larger market size buffers major shocks to price. [ABSTRACT FROM AUTHOR]

The synchronous removal of soot particles and NO x using high-performance catalysts is a research hotspot in the catalytic purification of diesel engine exhaust. In this paper, glucose is used as a complexing agent to successfully prepare a series of praseodymium and/or potassium doped La–Ni-based perovskite catalysts. The La 0.9 Pr 0.05 K 0. 05 NiO 3 catalyst exhibits the best catalytic performance when NO 2 is present in the environment, with values of T 10 , T 50 , and T 90 at 287, 331, and 361 °C, respectively. The CO 2 selectivity reaches over 98% and has good thermal stability. Through characterization experiments, it was found that the co-doping of Pr and K can lead to the formation of oxygen vacancies by changing the valence state of Ni atoms, thereby increasing the adsorption and activation centers of reactive oxygen species, and enhancing the oxygen storage capacity of the catalyst through the redox cycle between Pr3+ and Pr4+. • A novel porous soot catalytic material was prepared using bimetallic doped perovskite. • Bimetal doping increases the active oxygen and oxygen vacancy contents of perovskite. • Conduct comprehensive tests on the characterization and properties of materials. • The prepared materials exhibit excellent catalytic and thermal stability performance. • The required materials for preparation are cheap and green. [ABSTRACT FROM AUTHOR]

In the present work, novel ceria-based nanocatalysts containing different quantities of La and Nd were prepared via hydrothermal synthesis. The effects of doping on the structural and physico-chemical properties of ceria were examined with several techniques, such as XRD, FESEM, TEM, Raman spectroscopy, XPS, H 2 -TPR and O 2 /NH 3 /CO 2 -TPD. The catalytic activity of doped ceria towards CO, NO and soot oxidation was evaluated in different conditions; in particular, the role of the catalyst-soot contact and the influence of NO x and water on the soot oxidation performances were investigated. La and Nd ions were well incorporated in ceria structure, but the final morphology was significantly altered. The introduction of trivalent cations was also associated with a higher abundance of defects and oxygen vacancies, but an excessive oxygen deficiency detrimentally affected the material reducibility and catalytic activity for CO and NO oxidation. Conversely, soot oxidation benefited from La and Nd addition. In particular, the Ce-La equimolar oxide exhibited outstanding performances in all the tested conditions, thanks to its optimal morphology and surface acidity. A detailed comparison with equimolar ceria-praseodymia allowed to investigate how acid-base sites and redox properties control the different catalytic mechanisms involved in standard and NO x -assisted soot oxidation. [Display omitted] • La and Nd ions can be well incorporated in the lattice of ceria-based nanocatalysts. • Excessive oxygen deficiency and defectiveness negatively affect ceria reducibility. • Equimolar ceria-lanthana shows an outstanding activity towards soot oxidation. • Acid-base sites strength is closely related to doped ceria catalytic performances. • Different NO x -assisted soot oxidation pathways are promoted by La or Pr doped ceria. [ABSTRACT FROM AUTHOR]

In order to improve the catalytic formulations for soot removal in after-treatment emission control technologies for gasoline and diesel engine vehicle, an isotopic study was approached using transitory labeled oxygen response method over model catalysts that allows the unraveling of soot oxidation mechanism. Ce-based materials promote oxygen exchange associated with the high population of lattice oxygen species (O2-) denoted as O I type. The incorporation of praseodymium produces a Pr3+ enrichment that decrease the energy for oxygen release and increase oxygen mobility through surface and subsurface oxygen centers (O II type) depending on the synthesis procedure. For PtBaK catalyst, O III species are responsible for oxygen exchange. Gas-solid reaction between soot and gas phase molecular oxygen is responsible for direct uncatalyzed soot oxidation. For ceria containing catalysts, low-temperature soot removal takes place through the intervention of lattice atomic species and superoxide species. For DPNR model catalyst, PtBaK/Al 2 O 3 , the soot elimination occurs with the intervention of O III type centers. In the presence NO, the assisted and cooperative mechanism due to NO 2 and the intervention of the adsorbed nitrate species on the trimetallic catalyst enhances soot removal capacity. [Display omitted] • For CeO 2 catalysts the 18O 2 /16O 2 exchange prevails and Pr increases oxygen uptake. • PtBaK promotes single-atom exchange being 18O16O the main detected species. • Soot removal mechanism depends on oxygen species (O I , O II or O III type) mobility. • CePr mixed oxides are able to remove soot at low temperature under inert conditions. • DPNR catalyst is more efficient in the presence of NO due to nitrate intervention. [ABSTRACT FROM AUTHOR]

The photoluminescence and temperature sensitivities of Ca 3 Y 2 Si 3 O 12 :Pr3+ thermo-phosphors with silico-carnotite structure obtained by solid state reaction method were investigated. Pr3+ ions were accommodated in the A sites having coordination number of 9 in AB 2 C 2 (SiO 4) 3 to replace Y3+ ions. The typical sample consisted of microcrystals with an irregular structure and the surface of particles was smooth, which could enhance the luminescence due to reducing the scattering and non-radiation produced by rough surfaces. The band gap value of typical sample was about 4.01 eV. Dipole-dipole interaction could account for concentration quenching. The two thermometry strategies including normalized intensities from 3P 0 →3H 4 transition and Fluorescence intensity ration (FIR) of 3P 0 →3H 4 /3P 1 →3H 5 transitions were employed for temperature sensing in 298–573 K. The results revealed that Ca 3 Y 2 Si 3 O 12 :Pr3+ thermo-phosphors had good temperature sensitivity performance with maximum S r of 0.59% K−1@573 K and 0.762% K−1@298 K in the above two methods, respectively. Hence, Ca 3 Y 2 Si 3 O 12 :Pr3+ would be a promising candidate in the field of optical thermometry. [ABSTRACT FROM AUTHOR]

Activation cross sections of proton-induced reactions on 141Pr were measured. Stacked foil activation technique and γ-ray spectrometry were adopted to derive the cross sections. The production cross sections of 141,140,139mNd, and 139Ce were determined up to 30 MeV. The physical yield of 140Nd was deduced using the measured cross sections of the 141Pr(p,2n)140Nd reaction. The physical yields of the proton- and deuteron-induced reactions on 141Pr and 3He-induced reaction on natCe for 140Nd production were compared. [ABSTRACT FROM AUTHOR]

Nanoparticles of ZrO 2 :Pr stabilized with ytterbium in the range 0.5%mol.-20%mol. were synthesized. Crystallite sizes depended on Yb concentration. Red luminescence resulting from 1D 2 →3H 4 transition of Pr3+ is present in all the samples. Additionally in the samples calcined at 1200 °C blue-green luminescence from 3P 0 level of Pr3+ was found. This emission was more intense than red one. Intensity of the 3P 0 →3H 4 luminescence depended on ytterbium content and was found to be the highest at 20% mol. Yb. Luminescence study had shown, that ytterbium introduced additional lattice defects. Some quantity of praseodymium activator ions were found to be present at +4 state and changed its valence to +3 as ytterbium content had risen. [ABSTRACT FROM AUTHOR]