Praseodymium Oxide Research Articles

High transparent and stability indium praseodymium oxide thin-film transistors with tungsten doping by solution method

Indium-oxide-based thin-film transistors are widely investigated and exhibit higher carrier mobility than amorphous silicon. Lanthanide-doped Indium oxide TFTs show relatively high negative bias illumination stress (NBIS) stability but at the cost of mobility. To improve the NBIS stability by the solution method, we doped Tungsten (W) into Praseodymium-doped Indium oxide (InPrO) and fabricated InPrWO TFT. We proposed that W doping could densify the films and suppress oxygen vacancy. With the increase of W doping concentration from 0 to 3 mol%, the contact angle of precursor solutions first decreased and then increased, reaching minimums of ∼13° at 1 mol%. When the W doping concentration increased from 0 to 1 mol%, the density of films increased from 6.155 to 6.479 g/cm3. While doping concentration increased from 1 to 3 mol%, the density of films decreased. Transmittance of InPrWO films was higher than 90 % from 300 to 800 nm. The localized defects of InPrWO films were investigated by μ-PCD. With 1 mol% W doping, deep-level and shallow-level defects were relatively the least. XPS result revealed that W was successfully doped into the films. Besides, the oxygen vacancy ratio first decreased and then increased when the W doping concentration increased. InPrWO film with 1 mol% W doping had the least oxygen vacancy ratio, resulting in the highest stability. The TFT fabricated with optimal 1 mol% W doped InPrWO film showed excellent electrical characteristics (μsat = 5.4 cm2/Vs, Vth = -0.3 V, Ion/Ioff = 8.0 × 105, and SS = 0.30 V/dec). With the W doping concentration increased, the NBIS stability first increased and then decreased, having minimum shift ΔVth = -2.1 V at 1 mol%. We improved the quality of films and NBIS stability of TFT by doping W into InPrO and appropriate post-processing, satisfying the development trend of high transparency and high stability TFTs for future displays.

Tailoring activity on effect of loadings over praseodymium oxide catalyst in methanation

Most methanation reactions used basic catalysts to achieve high CO2 conversions. Therefore, in this study, praseodymium oxide was selected and synthesized using ratio Ru/Mn/Pr (5:30:65) and Al2O3 as support. From the result, it successfully converted 96 % of CO2 gas at calcination temperature of 800 °C using one series reactor. When the praseodymium-based loading is varied, the trend CO2 conversion is higher at 65 %wt and slightly decreased when increased to 85 wt%. Then, two series furnace reactors were applied and the Ru/Mn/Pr (5:30:65)/Al2O3 catalyst exhibited a slightly increased CO2 conversion with 98 %. According to X-ray diffraction analysis, the catalyst is amorphous with the presence of active species MnO2 and Pr2O3. In contrast, FESEM analysis showed that the catalyst surface was covered with large crystalline solids of irregular size which align with amorphous structure. Electron dispersive X-ray analysis shows the presence of all active element. Meanwhile, surface area of catalyst is ​​59.22 m2/g from Nitrogen analysis.

Fabrication and structural, physical, and nuclear radiation shielding properties for Oxide Dispersion-Strengthened (ODS) alloys through Erbium (III) oxide, Samarium (III) oxide, and Praseodymium (III) oxide into 316L matrix

We report a comprehensive investigation on customization process of Oxide Dispersion-Strengthened alloys through Sm2O3, Pr2O3, and Er2O3 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 (Er2O3), Praseodymium oxide (Pr2O3), and Samarium oxide (Sm2O3). 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 Er2O3 compared to other reinforced oxides. The detector counting value reached its minimum level when a 5% Er2O3 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 Er2O3 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.

Tribological characteristics of a functionally gradient iron-based wind turbine brake pads reinforced with praseodymium oxide

Tribological characteristics of a functionally gradient iron-based wind turbine brake pads reinforced with praseodymium oxide

Solid state synthesis and investigation of double oxides in х/6Pr6O11 – MoO3 (2 ≤ х ≤ 6) series

The polycrystalline samples of the x/6Pr6O11 – MoO3 (2 ≤ x ≤ 6) series were prepared by conventional solid-state route. The phase formation was studied by XRD analysis in the temperature range of 1000 – 1200 °C. After calcination at 1100 °С, the formation of praseodymium molybdate with Pr4MoO9+δ composition is observed, which decomposes into a mixture of Pr2MoO6 and Pr6MoO12+δ phases at 1200 °С. It was first established that Pr4MoO9+δ praseodymium molybdate has a monoclinic lattice with parameters a = 16.7211(9) Å, b = 11.9894(7) Å, c = 9.5588(5) Å, β = 109.6149(7) °, sp. gr. C 2/m. Crystal structure was refined by high resolution neutron diffraction data. The homogeneity regions of Pr4MoO9+δ and Pr6MoO12+δ were determined to be 4 < x < 4.2 and 4.57 < x < 6, respectively. It was shown that the conductivity of this molybdates increases with praseodymium oxide content in the Pr5Mo3O16+δ – Pr4MoO9+δ – Pr6MoO12+δ series.

Fabrication of highly efficient nanofiltration membranes decorated with praseodymium based triamino-functionalized MCM-41 for desalination and micropollutants removal

The nanofiltration membranes with a stable decoration of inorganic fillers such as zeolites are desperately required for enhancing the desalination performance of the membranes and hence three nanofiltration membranes were fabricated by decorating the membranes with praseodymium-based triamino-functionalized MCM-41 (Pr-(NH)2NH2-MCM-41). The membranes were applied for the removal of emerging pharmaceutically active micropollutants from water. The Pr-(NH)2NH2-MCM-41 was synthesized by using an in-situ approach where praseodymium oxide was chemically decorated in the framework of MCM-41 followed by simultaneous amine functionalization using N1-(3-Trimethoxysilylpropyl)diethylenetriamine (TMSPTA). A thorough characterization of the synthesized Pr-(NH)2NH2-MCM-41 was carried out by using HR-TEM, SEM, WCA, XRD, FTIR, BET, elemental and mapping analysis. Three different concentrations of synthesized Pr-(NH)2NH2-MCM-41 were decorated in the membrane active layer through interfacial polymerization in the presence of an aqueous tetra-amine solution and using terephthaloyl chloride as an organic crosslinker. Subsequently, the fabricated membranes were used for desalinating saline feed containing divalent (CaCl2, MgCl2, Na2SO4, MgSO4) and monovalent (NaCl) ions. The rejection of salts by PA/0.05-Pr-MCM@PSU/PET membrane was found to be the highest among all the fabricated membranes which were found to be 98 %, 96 %, 95 %, 87 %, and 82 % for CaCl2, MgCl2, MgSO4, Na2SO4 and NaCl, respectively. The permeate flux was found to be dependent on the applied feed pressure which was found to be 56 L m-2 h-1 (LMH) at 25 bar for PA/0.050-Pr-MCM@PSU/PET membrane. The rejection performance of the membranes was also evaluated by using different well-known pharmaceuticals (Caffeine, Sulfamethoxazole, Amitriptyline, and Loperamide) as micropollutants in the feed. All the pharmaceutical drugs were found to be highly rejected > 96 % by PA/0.5-Pr-MCM-41@PSU/PET membrane followed by PA/0.025-Pr-MCM-41@PSU/PET membrane. Therefore, the current approach of synthesizing functionalized zeolites is quite effective and efficient for the stable decoration of inorganic fillers in the membrane active layer and should be extended to other zeolites such as zeolites with antimicrobial potential.

Synergistic effects of nitrogen-doped carbon and praseodymium oxide in electrochemical water splitting

Hybrid materials featuring perovskite-type metal oxide in conjunction with heteroatom-doped graphene hold immense promise as alternatives to costly noble metal catalysts for electrochemical water splitting, facilitating the generation of environmentally friendly hydrogen. In this study, perovskite-type oxide containing praseodymium, barium, strontium, cobalt, and iron atoms dispersed in a carbon matrix as a catalyst is synthesized via annealing of the carbon material with substrates for the preparation of perovskite oxide. The mass ratio of reagents regulates the porous structure and elemental composition. The result of the hydrogen evolution reaction (HER), suggests that the hybrid catalysts exhibit intermediate HER kinetics compared to the commercial Pt/C and the catalyst without carbon. The Tafel slope for HER is lower for materials containing carbon, because of the improved reaction kinetics, facilitated proton transfer, and enhanced electrochemical surface area. Therefore, the study provides an effective strategy for the preparation of catalyst and their use as the active catalyst of water splitting.

Evaluating the Phosphorescence duration of Zn2P2O7 glass–ceramic activated by Dy3+/Pr3+ for LED applications

The present study focuses on investigating the phosphorescence efficiency of binary zinc–phosphate glasses co-doped with dysprosium and/or praseodymium oxides together with their corresponding glass ceramics. The studied glass series was prepared directly by the conventional melting and quenching method. Differential thermal analysis (DTA) indicated an exothermic peak at 550 °C that was applied to yield glass-ceramic samples. The major monoclinic phase of Zn2P2O7 was detected by X-ray diffraction (XRD). FTIR and SEM–EDAX were applied to identify the structural morphology of the prepared samples. The optical efficiency was characterized through UV–Visible–NIR absorption spectra and photoluminescence analysis. Both light emissions and their corresponding lifetimes were enhanced significantly in glass–ceramic. These samples display high CRI, low color temperature, and CIE values comparable to those expected for pure white-light and warm yellow emitting diodes.

Eco-friendly synthesis of mesoporous praseodymium oxide nanoparticles for highly efficient electrochemical sensing of carmoisine in food samples

Herein, a mesoporous Pr6O11 nanoparticle (NPs) has been prepared via a simple sonochemical process employing an eco-friendly capping agent, grape juice, and utilized for the development of a novel electrochemical sensor to measure carmoisine. Chronoamperometry, cyclic voltammetry (CV), and differential pulse voltammetry (DPV) have been used for the investigation of the electrochemical behavior of mesoporous Pr6O11/Ionic liquid/Carbon paste electrode (MP-Pr6O11/IL/CPE) in the presence of carmoisine. The oxidation behavior of carmoisine has been examined, and it has been discovered that there was a greater enhancing signal with the MP-Pr6O11/IL/CPE. A lowdetection limit of 12 nM in a linear range of 0.09–135 µM was achieved by the novel carmoisine sensor. Good selectivity, repeatability, stability, and reproducibility were all features of the newly constructed sensor. As a result, the suggested procedurewas appropriate for routine analysis and ought to serve as a viable option for analyzing food colorant.

Surface modification of praseodymium oxide/hematite doped into Polycaprolactone for enhanced wound management demands

Praseodymium oxide (Pr6O11), hematite (Fe2O3), graphene oxide (GO), and polycaprolactone (PCL) based polymeric nanocomposites (NCs) are fabricated, aiming their usage as bio-scaffold for medical purposes. Because of their distinctive light absorption and stability, Fe2O3 and Pr6O11 have been introduced as potential optical elements. The structure and size examination of NCs were executed by XRD, Raman, and FESEM. Pr6O11/Fe2O3/GO@PCL polymeric NC is exhibited Pr6O11, and Fe2O3 average size of 1.4, 0.4 µm, while average pores size 2.1 µm. As well, the Uv–Vis shows an absorption edge shifting along the x-axis that it begins with 3.1 eV for pure PCL, after that it declined to 1.7 eV for Pr6O11@PCL NC. Also, Pr6O11 @PCL, and Pr6O11/ Fe2O3@PCL NCs show the lowest similar contact angle with 38°. Regarding cell attachment evaluation test, the Pr6O11/Fe2O3/GO@PCL NC healing valuation is touched ∼ 80%. As a result, the structure enabled 3-dimensional the division of normal cells, so promoting wound healing.

Structural, optical, and magnetic studies on novel Pr- doped barium lithium fluoroborate glass system

The current study involves the spectral analysis of barium lithium fluoroborate glasses doped with Praseodymium Oxide (Pr6O11). The glass composition used in the study is (70-x) B2O3+20BaF2+10Li2O+xPr6O11 (where x = 0.0, 0.5, 1.0, 1.5 and 2.0 mole%) and was prepared using the traditional melt quenching technique. The amorphous nature of the prepared glasses was confirmed by the X-ray diffraction spectrum. The Raman spectroscopy demonstrated that the addition of Pr6O11 to the barium lithium fluoroborate glasses caused structural changes. The thermal analysis confirmed that Pr6O11 doping increases glass transition temperature and enhances glass thermal stability. The optical characteristics of the glasses that were prepared were analyzed through the use of UV, Vis, and NIR absorption. The calculation of the optical bandgap for both direct and indirect allowed transitions was conducted in order to gain insight into the electronic band structure, as well as to determine the Urbach energy values. The investigation includes an analysis of the refractive index and extinction coefficient across the whole range of wavelengths. The magnetic behavior of all samples was observed to be soft ferromagnetic. The glass material's ability to provide windows for optical fiber at a wavelength of 1550 nm suggests its potential as a viable source for waveguide lasers and its appropriateness for use in applications involving optical fiber amplification.

Electrochemical performance and stability of PrO1.833 as an oxygen electrode for solid oxide electrolysis cells

Significant efforts have recently been undertaken to develop highly efficient solid oxide cells for high-temperature steam electrolysis (SOEC). Implementing new materials and microstructures that would improve the performance and durability of this technology remains a major issue. For this purpose, a nano-structured PrO1.833 material coated by the electrostatic spray deposition (ESD) technique was studied as a promising active oxygen electrode for SOEC application. The study was performed considering the PrOx as the functional layer and strontium-doped lanthanum manganite (LSM) as the current collecting layer on a standard half-cell supported by a typical Ni-YSZ cermet, a YSZ electrolyte, and a gadolinium-doped ceria (GDC) barrier layer. The electrochemical characterizations showed promising initial performance at 700 °C in SOEC mode (− 1 A cm−2 at 1.4 V with H2O/H2 = 90 vol%/10 vol%). In addition, a reasonable degradation rate of ∼5.8% kh−1 was obtained at 700 °C within 1000 h of SOEC operation. The structural and elemental evolutions were analyzed with micrometer size resolution all along the functional layer thickness using synchrotron μ-X-ray diffraction and fluorescence. The electrode degradation was primarily attributed to the phase transitions of PrO1.833. In particular, the structural analyses of the sample aged under applied current revealed a small quantity of PrO1.5≤x≤1.7 phase at the GDC/AFL (active functional layer) interface which is expected to be less conductive than PrO1.833, along with PrO1.714 and GDC phases. Finally, additional structural characterizations were performed on samples annealed at different temperatures and dwell times: 700 °C for 1000 h and 800 °C for 700 h, respectively. The results are discussed to provide a better understanding of the stability of the praseodymium oxide.

Exploring the dielectric properties of Bi doped Pr0.01Zn0.97O nanoparticles using impedance spectroscopy

In our study, Pr0.01Zn0.97O (PZ) and Pr0.01Bi0.01Zn0.97O (PBZ) were synthesized by sol-gel method. The correlation among their structural and dielectric properties was investigated in details. We used the X-ray diffraction (XRD) along with Rietveld refinement to confirm the hexagonal wurtzite structure with P63mc space group and the existence of a secondary phase attributed to the praseodymium oxide (Pr6O11) in all samples. We have also used the impedance spectroscopy to find the impacts of temperature and frequency on dielectric properties of our samples. The dielectric properties revealed that the Pr0.01Zn0.97O sample shows a low tangent loss and a high conductivity compared with Bi doped Pr0.01Zn0.97O sample, which demonstrates the potential application of the Pr0.01Zn0.97O in microwave semiconductor devices.

5-Fluorouracil-loaded designed praseodymium oxide – poly- β-cyclodextrin nanorods for effectively inhibiting breast cancer cells

Breast cancer remains one of the commonly prevailing and challenging diseases. Lanthanide-based nanomaterials are fascinating depending on their unique properties and represent a preferable choice of drug transport, aimed at finding an agent for targeted therapy. It necessitates that lanthanide-based nanocarriers with suitable surface modification and desired physicochemical characteristics are developed for effective anticancer drug delivery, owing to their fascinating light absorption, magnetic, and morphological features. Herein, we report praseodymium oxide nanorods in combination with poly-cyclodextrin as a novel nanocarrier to deliver the chemotherapeutic drug 5-fluorouracil to breast cancer cells. The praseodymium oxide nanoparticles were prepared using a sonochemical method and characterized using routine analytical methods, including X-ray Diffraction, Transmission Electron Microscopy, and X-ray Photoelectron Spectroscopy. The monodisperse rod-shaped structures possess length and width of 200 ± 30 and 72 ± 10 nm, respectively. The nanoparticles are 64.33% crystalline, revealed by XRD. The polymer content in the nanoparticles is ∼37% by weight. Further, the nanoparticles' magnetic, light absorption and photoluminescence characteristics are studied. Low saturation magnetization and insignificant hysteresis properties are observed. Broad absorption and visible wavelength region photoluminescence arise from the praseodymium in the material. The continuous release of the drug cargo and the in vitro anticancer activity are discussed. The loaded drug (5-fluorouracil) is released sustainably, extending over 250 hours. The anticancer activity in vitro is observed with the portion of the drug released from the nanocarrier. The apoptotic action mode of the drug-carrier vehicle is analyzed. The inhibition of cells occurs mainly on the S-phase of the cell cycle. The nanomaterial can function as a drug carrier and is suitable for anticancer therapy. The results reported herein on praseodymium oxide nanoparticles are promising as a nanocarrier and pose the possibility of future in vivo studies.

Praseodymium Oxide Improving the Activity of a Silver-Loaded Calcium Titanate Photocatalyst for Carbon Dioxide Reduction with Water

Heterogeneous photocatalytic CO2 reduction with water has attracted great attention. Although the addition of Ag nanoparticles (NPs) as a cocatalyst on a semiconductor photocatalyst has been known to improve both the photocatalytic activity and reaction selectivity for CO2 reduction, the addition of Pr as Pr6O11 species on the surface of an Ag-loaded CaTiO3 (CTO) photocatalyst further improved the photocatalytic activity. The different calcination temperatures for the sample preparation changed the state of Pr species, and it strongly influenced the photocatalytic performance. The Pr6O11 species was found to be loaded between the CTO surface and Ag NPs on the Ag/Pr/CTO photocatalyst, proposing that it improves the electron migration from the CTO photocatalyst to Ag NPs via the Pr6O11 layer.

Ce-Pr-Nd]:CsPbI1.8Br1.2: Stability enhanced light harvester in perovskite solar cells, energy storage material for batteries, and an OER/HER electro-catalyst

Current work for the first time investigates the impact of the lanthanide co-doping strategy on the fully inorganic cesium lead halide (CsPbI1.8Br1.2) perovskite by using oxides of cerium, praseodymium, and neodymium forming [Ce-Pr-Nd]:CsPbI1.8Br1.2. The doped perovskite material expressed an enhancement in the opto-electronic, crystalline, and morphological aspects upon lanthanide addition besides gaining an impressive stability at the ambient conditions. The dark brown doped thin films heated at 200 °C succeeded in acquiring a bandgap energy of between 1.66 and 1.73 eV showing stable response for 28 days revealed by ultra-violet spectrophotometry. Furthermore, the desired black phase cubic crystalline geometry was exposed by x-ray diffraction with an average crystallite size of 62.61 nm. In terms of morphology, the doping treatment not only enhanced the performance of CsPbI1.8Br1.2 but also it acted as a passivator for curing the surficial defects. The performance of the pristine and doped perovskite material was assessed by utilizing it as the light trapping material inside perovskite solar cells where highly improved performance was obtained for the doped absorber layer with 15.53 % efficiency, 68 % fill factor, 15.01 mA cm−2 short circuit current, and an excellent open circuit voltage of 1.14 V. Furthermore, the perovskite undoped and doped materials were fabricated in the form of an electrode for assessment of charge storage potential for battery application. With the electro-active behavior signifying surficial faradic redox process, there was an augmentation in the battery capacity with doping which boosted from 228 to 311.3 mAh g−1. With the series resistance as lows as 0.62 Ω, faster reaction kinetics were revealed for doped electrode. The oxygen and hydrogen evolution potential of the developed pristine and doped materials as bifunctional catalysts was assessed by estimation of the overpotential values and Tafel slope values. The Tafel slope values of the doped electro-catalysts were lower in comparison to the pristine material suggestive of the synergism between perovskite and dopants giving rise to an excellent energy generation capacity. The Tafel slope for oxygen and hydrogen generation of the doped electrode were 256.4 and 120.6 mV dec−1 indicating excellent hydrogen evolution. The stability and endurance of the developed material reflected from their original characteristics retention makes them excellent materials for use in energy application, specifically, [Ce-Pr-Nd]:CsPbI1.8Br1.2 excelled over pristine material showing the profound impact of doping on host lattice.

Development of a voltammetric method of analysis using praseodymium oxide‐carbon nanotubes for the sensitive detection of dopamine in the presence of tramadol, paracetamol and ascorbic acid

AbstractA sensitive and selective method of analysis was constructed by the the combination of praseodymium oxide and carbon nanotubes. The charge transfer resistance (Rct) values of 109 in 1 × 10−3 M K3[Fe(CN)6] and 79 Ω in 5 × 10−6 M dopamine indicate that Pr6O11@MWCNTs/GCE enables an excellent electron pathway between electrolyte and electrode. The platform was successfully applied for the determination of dopamine in the presence of tramadol, paracetamol and ascorbic acid. The platform exhibited a remarkable decrease in ▵Ep for DA. A dynamic linear range from 1.2 × 10−9 M to 1.8 × 10−5 M was obtained with an LOD of 1.0 × 10−10 M. Such a sensitive and selective method of analysis makes Pr6O11@MWCNTs/GCE of high interest to observe trace level of DA with good accuracy and precision.

Impacts of praseodymium (III, IV) oxide on physical, optical, and gamma-ray shielding properties of boro-silicate glasses

The present work aims to study the influence of Pr3+ ions on the structural, optical, and gamma-ray shielding properties of borosilicate glasses. Therefore, a new series of boro-silicate glass reinforced by small concentrations of praseodymium oxide varied between 0 and 1 mol.%. The XRD was utilized to emphasize the amorphous phase of the fabricated glasses. Moreover, UV–Vis Spectroscopy is used to detect the absorbance which is used to evaluate the energy band gap (Eg, eV) and Urbach energy (Eu, eV). The optical results showed that the energy band gap for direct transition decreased from 3.508 eV to 3.086 eV and decreased for the indirect transition from 3.086 eV to 2.879 eV with raising the Pr6O11 concentration in the fabricated glasses. The Monte Carlo simulation method was applied to simulate the average track length of γ-photons inside the fabricated boro-silicate. The linear attenuation coefficient for the fabricated boro-silicate glasses was enhanced by factors of 2.56 times (at 26 keV), 2.68 (at 103 keV), and 1.05 times (at 511 keV) with raising the Pr6O11 concentration between 0 and 1 mol.%. The result depicts no considerable change in the γ-ray shielding properties observed at γ energy ≥511 keV.

Structural, morphological, and electrochemical studies of Mg2SiO4-Pr6O11 nanocomposite for energy storage applications

Owing to not only the high demand in the development of new materials for the energy storage applications but also the high abundance of magnesium orthosilicate (Mg2SiO4) belonging to olivine group of minerals in Earth, magnesium orthosilicate (called as MOS) nanoparticle and magnesium orthosilicate–praseodymium oxide (Mg2SiO4–Pr6O11) (MOS-PO) nanocomposite have been chosen to explore mainly their electrochemical characteristics. The MOS nanoparticle and MOS-PO nanocomposite were synthesized using sol-gel method. The characterization techniques such as x-ray diffraction (XRD), Scanning Electron Microscopy (SEM), energy dispersive x-ray (EDX) spectroscopy, Zeta potential analyzer, and Cyclic Voltammetry (CV) were used to investigate the structural, morphological, and electrochemical properties of the prepared samples. Using Scherrer’s equation, phase identification was performed for the samples of MOS nanoparticle and MOS-PO nanocomposite with crystallite sizes 43 nm and 52 nm, respectively. The respective average particle sizes of 39 nm and 50 nm were observed for MOS nanoparticle and MOS-PO nanocomposite, using SEM images, and these values along with the images revealed the formation of spherical nanoparticles along with some agglomerates. The Zeta potential of the samples was calculated to analyze the stability of the nanoparticles. The electrochemical characterization was performed using the sample coated Mg foil as the working electrode and 0.5 M of KOH solution as the electrolyte, with the help of cyclic voltametric technique. The CV analysis was conducted ranging from 1.5 to −1.5 V at various scan rates of 25, 50, 100, 200, and 300 mVs−1. For MOS-PO nanocomposite, the maximum specific capacitance of 1812 Fg−1 was observed at a scan rate of 25 mVs−1. The results showed the possibility of the usage of MOS-PO nanocomposite material in the application of energy storage devices.

Tribological characterization of functionally gradient wind turbine brake pads reinforced with rare earth metal oxide

Copper-based brake pad materials with various fractions of praseodymium oxide and yttrium oxide are fabricated through the powder metallurgy processing technique. The influence of praseodymium oxide and yttrium oxide on the microstructure, microhardness, and tribological characteristics of the fabricated specimens are analyzed. The specimen with desired density, high hardness, wear resistance, and optimal friction coefficient is fabricated with gradient layers (pure copper at the brake pad – brake caliper interface and composite at the brake pad – brake disc interface). The result suggested that as the load gradually increases, the wear rate also increases. The surface morphology, elemental composition, and phase composition of the fabricated specimen and worn surface were characterized using advanced instrumental characterization.