WO3 Content Research Articles

Characterization of photocatalytic hybrid TiO2–WOX thin films deposited via co-sputtering

Photocatalytic hybrids of titanium dioxide (TiO2) and tungsten oxide (WOX) can exhibit high photocatalytic activity under weak ultraviolet (UV) and visible-light irradiation. In this study, hybrid TiO2–WOX thin films deposited via co-sputtering are characterized using radiofrequency sputtering at various compositions, and their photocatalytic activity in the degradation of a methylene blue solution is evaluated. X-ray photoelectron spectroscopy measurements show enhanced W(4f) and decreased Ti(2p) signal intensities with increasing WOX content. Further, chemical shifts toward lower binding energies are observed as the compositions of TiO2 and WOX become equivalent. X-ray diffraction analysis reveal decreased anatase TiO2 peaks and monoclinic WOX peaks with the formation of amorphous structures as the compositions of TiO2 and WOX become equivalent. Atomic force microscopy images show homogeneous and flat structures on the surfaces of the hybrid TiO2–WOX thin films. The deposition rate decreases with decreasing WOX sputter power, whereas the optical bandgap decreases with increasing WO3 content. Furthermore, the photocatalytic activity under UV irradiation improves with increasing TiO2 content, whereas that under visible-light irradiation improves with increasing WOX content. This approach can provide the guidelines to fabricate the high-performance photocatalytic materials that can be used in different condensed thin-film devices.

A Non-Matrix-Matched Calibration Method for In Situ Major and Trace Element Analysis of Scheelite by Nanosecond LA-ICP-MS.

In this work, a reliable and robust in situ non-matrix-matched calibration method is proposed for element composition determination in scheelite samples. With external calibration against the silicate glass standard reference material NIST SRM 610, the concentrations of both major elements (Ca and W) and trace elements (Si, Fe, Mo, Y, rare earth elements, etc.) in scheelite are determined using an ArF 193 nm excimer nanosecond laser ablation-inductively coupled plasma mass spectrometer (LA-ICP-MS). Here, the ablation was performed by hole drilling under a helium (He) environment using a laser spot size of 35 μm and a laser repetition of 5 Hz, and the aerosols were then transported to a quadrupole ICP-MS by a mixture of He and make-up gas argon (Ar) with a total gas flow rate of 1.6 L/min. Results showed that there was no apparent matrix effect between the NIST SRM 610 and scheelite by this proposed method. With internal standardization against W, the obtained concentrations of CaO and WO3 were found to yield an average matrix CaO/WO3 mass fraction ratio of 0.245 (2σ = 0.003, n = 19), which agreed well with the value of 0.243 (2σ = 0.002, n = 15) from electron probe microanalysis (EPMA). Furthermore, the accuracy of trace element analyses with this proposed non-matrix-matched calibration in situ method was evaluated by comparing the concentration results with those from bulk analysis by solution nebulizer ICP-MS (SN-ICP-MS). It was found that the quantification results from LA-ICP-MS and SN-ICP-MS were comparable, in particular showing a relative concentration bias of the total ∑REE+Y contents of less than 2%. This confirmed that scheelites can be accurately analyzed in situ by LA-ICP-MS without matrix-matched calibration standards. By using this developed in situ method, the element compositions in a series of scheelite samples from different W-associated deposits in China were successfully quantified, promising further genetic process investigation and associated geologic activities of the polymetallic resources.

Nanofibers based on zein protein loaded with tungsten oxide for cancer therapy: fabrication, characterization and in vitro evaluation

Plant proteins have become attractive for biomedical applications such as wound dressing and drug delivery. In this research, nanofibers from pristine zein (plant protein) and zein loaded with tungsten oxide (WO3) were prepared (WO3@zein) using less toxic solvents (ethanol and acetic acid). Morphological and biological properties of the zein nanofiber were determined. Prepared nanofibers were defined by thermogravimetric analysis (TGA), X-ray diffraction (X-RD), Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy. The average fiber diameter was unchanged with an increase in WO3 concentration from 0.001 to 0.008%. FT-IR spectroscopy and X-RD indicated the presence of WO3 in WO3@zein nanofibers. In comparison to WO3-free, WO3@zein nanofibers showed higher safety and preserved the anticancer effect of WO3 against human melanoma cell line (A375) melanoma cells compared to WO3-free. Moreover, both WO3-free and WO3@zein caused a fourfold increase in the cellular proliferation of reactive oxygen species (ROS) in the treated A375 cells compared to untreated cells. ROS elevation led to apoptosis-dependent cell death of A375 cells as evidenced by up-regulating the expression of p53-downstream genes (p21 and Bax) (tumor-suppressor gene) while down-regulating the expression of key oncogenes (BCL2 and cyclin D). In conclusion, the prepared nanofiber represents a promising and safe candidate for anticancer applications.

One-Step Dry Coating of Hybrid ZnO-WO3 Nanosheet Photoanodes for Photoelectrochemical Water Splitting with Composition-Dependent Performance.

In this study, the potential of zinc oxide (ZnO), tungsten oxide (WO3), and their composites (ZnO-WO3) as photoanodes for photoelectrochemical (PEC) water splitting was investigated. ZnO-WO3 nanocomposites (NCs) were deposited on fluorine-doped tin oxide substrates at room temperature using a one-step dry coating process, the nanoparticle deposition system, with no post-processes. Different compositions of ZnO-WO3 NCs were optimized to enhance the kinetics of the PEC water-splitting reaction. Surface morphology analysis revealed the transformation of microsized particle nanosheets (NS) powder into nanosized particle nanosheets (NS) across all photoanodes. The optical characteristics of ZnO-WO3 photoanodes were scrutinized using diffuse reflectance and photoluminescence emission spectroscopy. Of all the hybrid photoanodes tested, the photoanode containing 10 wt.% WO3 exhibited the lowest bandgap of 3.20 eV and the lowest emission intensity, indicating an enhanced separation of photogenerated carriers and solar energy capture. The photoelectrochemical results showed a 10% increase in the photocurrent with increasing WO3 content in ZnO-WO3 NCs, which is attributed to improved charge transfer kinetics and carrier segregation. The maximum photocurrent for a NC, i.e., 10 wt.% WO3, was recorded at 0.133 mA·cm-2 at 1.23V vs. a reversible hydrogen electrode (RHE). The observed improvement in photocurrent was nearly 22 times higher than pure WO3 nanosheets and 7.3 times more than that of pure ZnO nanosheets, indicating the composition-dependence of PEC performance, where the synergy requirement strongly relies on utilizing the optimal ZnO-WO3 ratio in the hybrid NCs.

A three-dimensional fibrous tungsten-oxide/carbon composite derived from natural cellulose substance as an anodic material for lithium-ion batteries

To meet the ever-growing demands over electrochemical energy storage, tungsten trioxide (WO3) has aroused substantial attention as a promising anodic material for lithium-ion batteries due to its high theoretical capacity, abundant earth storage, and eco-friendliness. However, developing high-performance WO3-based electrodes is hampered by its restrictive conductivity and tremendous structural as well as the volumetric changes during the charge/discharge processes. Herein, a novel bio-inspired nanofibrous WO3/carbon composite was synthesized via a facile hydrothermal method employing pre-carbonized cellulose substrate (e.g., ordinary filter paper) as both the structural scaffold and the carbon source. The urchin-like WO3 microspheres with diameters of 3–6 μm assembled by nanorods were uniformly anchored on the surfaces of the cellulose-derived carbon fibers. The three-dimensional network structure of the composite was beneficial in alleviating the volume expansion of WO3 nanorods and enhanced the charge-transport kinetics of the electroactive materials. The composite with an optimized content of WO3 (26.36 wt%) exhibited superior lithium storage properties with an initial discharge capacity of 1470 mAh g−1 and an extraordinary long-term cycling performance of 682 mAh g−1 capacity retention after 300 cycles at 100 mA g−1. Furthermore, cyclic voltammetry, ex-situ XRD, and SEM measurements for mechanism studies were carried out to yield deeper insights into the synergism in the WO3/carbon electrodes, revealing the predominance of reversible pseudocapacitive intercalation of lithium-ions during the electrochemical reaction inside the WO3/carbon anode.

Composite-modified nano-TiO2 for the degradation of automobile exhaust in tunnels

To improve the degradation efficiency of automobile exhaust in highway tunnels, which have the special lighting conditions, nano-TiO2 based on the composite modification of metal ions (Fe), nonmetal ions (N), and semiconductors (WO3) was developed. Composite-modified nano-TiO2 was prepared via the sol–gel method, and its properties were characterized by X-ray diffraction, UV–Vis spectrophotometry, IR-spectroscopy, fluorescence spectra, and electron paramagnetic resonance. X-ray diffraction analysis showed that composite modification reduced the size of nano-TiO2 grains, which is conducive to the surface scale effect of nano-TiO2. UV–visible diffuse reflection showed that composite modification made the absorption band of nano-TiO2 red shift, and the absorption of visible light increased. Infrared spectrum analysis and electron paramagnetic resonance showed that the composite-modified nano-TiO2 was conducive to the formation of OH free radicals under the action of visible light, and the photocatalytic activity was enhanced. An orthogonal test scheme with three factors and three levels was designed, and the automobile exhaust degradation test was conducted by using homemade automobile exhaust degradation test device. Results showed that the composite modification improved the catalytic efficiency of nano-TiO2, and the addition of Fe3+ had the most considerable effect on the degradation of automobile exhaust. When the Fe3+ content was 1.69 %, the N content was 1.5 % the WO3 content was 6.12 %, the automobile exhaust degradation efficiency was the highest. Within 120 min, the maximum degradation efficiencies of CO and NO by composite-modified nano-TiO2 were 13.08 % and 69.18 % respectively.

Effect of WO3 on the attenuation parameters of TeO2–La2O3-WO3 glasses for radiation shielding application

The attenuation capability of tellurite glasses with composition of (100-x)TeO2–5La2O3-xWO3 where x = 10, 15, 20, and 25% was analyzed. Radiation attenuation parameters such as mass, linear attenuation coefficients (MAC, LAC) and effective atomic number were determined at various energies. The S4 glass sample, which contains the highest WO3 content and smallest TeO2 concentration, has the greatest MAC at all energies. The glasses with the highest densities also have the highest LAC values, with greater WO3 content leading to greater density in the glass system. The half value layer (HVL) values of the samples are positively proportional with the energy of the incoming radiation, greatest at the highest tested energy. The ratio between the tenth value layer (TVL) values for S1 and S4 are greater than one at all energies, which means that S1's TVL, the glass with the smallest WO3 content, is higher than S4's TVL. The mean free path values were shown to have an inverse trend with the WO3 content in the samples. The S4 sample, the glass with the highest WO3 content and lowest TeO2 content, has the greatest Zeff at all energies.

Fluffy ultrathin WO3 nanoneedle clusters in-situ grown in mesoporous hollow carbon nanospheres as advanced anode for lithium-ion batteries

Fluffy ultrathin WO3 nanoneedle clusters are in-situ grown in mesoporous hollow carbon nanospheres (MHCSs) via unique material impregnation and confined molten reaction in MHCS nanoreactors. Through transmission electron microscopy, scanning electron microscopy, X-ray diffraction, Raman spectra and X-ray photoelectron spectroscopy analyses, it can be found that WO3 nanoneedles with 5–10 nm in thickness and ∼140 nm in length are encapsulated within each MHCS with 150–250 nm in diameter and 30–40 nm in shell thick. Thermal gravimetric analysis reveals the WO3 content of 83.5 wt%. Lithium storage performance was evaluated by galvanostatic charge/discharge cycling, cyclic voltammogram and electrochemical impedance spectroscopy. The composite exhibits remarkable rate performance (average discharge capacity of 1352 mAh g−1 at 0.1 A g−1 and 105 mAh g−1 at 10 A g−1) and excellent cycling performance (1094 mAh g−1 at 0.2 A g−1 after 50 cycles, 760 mAh g−1 at 1 A g−1 after 500 cycles, 351 mAh g−1 at 5 A g−1 after 2000 cycles). The composite also presents outstanding kinetics properties, such as high Li+ diffusion coefficient, strong capacitive effect, and low electrochemical impedance. The superior electrochemical performance is attributed to unique “ship-in-a-bottle” structure. MHCSs facilitate electron transfer and ion diffusion, buffer volume change of WO3 and maintain the integrity of WO3. Furthermore, fluffy ultrathin nanoneedle cluster structure endows WO3 with high electrochemical activity.

Development of chitosan base graphene oxide/ WO3 hybrid composite for supercapacitor application

The use of non-renewable energy has brought to serious environmental problems for the planet. The amount of greenhouse gases rose immediately as the combustion of fossil fuels increased. As a result, sea levels are steadily rising and the Earth is becoming warmer. Research on renewable energy sources has been done extensively to provide a solution. However, in order to maximise energy utilisation, renewable energy needs an energy storage system, such as a super capacitor. For the development of sustainable supercapacitors for future energy systems, electrode material is a prospective target. The formation of desired electrode material is essential in order to fabricate supercapacitor with higher power density and longer life cycle than secondary batteries in electronic application. In this study, chitosan (CS) was isolated from crab shells, and graphene oxide (GO) was synthesized using a modified Hummers' process, followed by a chemical reduction approach. Based on the results, the synthesized GO exhibited higher capacitance as compared to GO that synthesized through single-step modified Hummers’ method. Continuous efforts have been exerted to further improve the electrochemical performance of GO/WO3 nanocomposite by incorporating an optimum content of WO3. In this manner, comprehensive investigations on different parameters, such as loadings of ammonium paratungstate (APT), hydrothermal temperature and reaction time were conducted in order to study the formation of GO/WO3 nanocomposite. WO3 and GO/WO3 nanocomposite were successfully synthesized through a simple hydrothermal method.

Influence of tungsten oxide concentration on structural, morphological, compositional, linear and non-linear optical properties, and vibrational properties on NiO:WO3 thin films

Mixed nickel-tungsten oxide, NiO:WO3 (90:10, 85:15) thin films with different tungsten oxide (WO3) concentrations of 10 and 15% were deposited using the radio frequency (RF) sputtering technique. An X-ray diffraction analysis reported the amorphous nature of the films. A SEM study showed smooth morphology. EDAX confirms the compositional purity, in which the nickel content decreases, while the tungsten and oxygen content increase with an increased WO3 concentration. The average transmittance of the NiO:WO3 (90:10, 85:15) films decreases from 79 to 75% as a consequence of increased thickness. The Urbach energy (Eu) enhances because of increased defects (localized states) inside the films induced by tungsten oxide addition. The energy bandgap decreases from 2.66 to 2.48 eV due to the formation of new localized energy states inside the band gap (Eg). The refractive index (n) acquired from different proposed models for the entire UV–Vis–NIR region has increased with increasing WO3 concentration, implying the escalation in densification (or packing density) of prepared films. The optical parameters like n, k, ε1, ε2, electronic polarizability (αp), optical conductivity (σop), electric conductivity (σe), volume and the surface energy loss function (VELF AND SELF) vary with WO3 concentration. The dispersion energy parameters (Eo, Ed), resulting from the Wemple and Didomenico (WD) model, decreases. The optical non-linear susceptibility, χ(3), decreased with increasing WO3 concentration. The photoluminescence (PL) emissions were perceived at 368 nm and 423 nm, assignable to 3 d8 Ni2+ ions transitions. Micro-Raman detected peaks at 570 cm−1 and 1100 cm−1 ascribing Ni–O bond vibrations, whereas the peak spotted at 870 cm−1 is ascribed to a W–O bond vibration. The deposited films are good enough for electrochromic and optoelectronic device fabrications.

Structural, mechanical, and thermal features of PVA/starch/graphene oxide nanocomposite enriched with WO3 as gamma–ray radiation shielding materials for medical applications

AbstractPolyvinyl alcohol (PVA)/starch/graphene oxide nanocomposites containing different ratios of tungsten oxide (WO3) were prepared for use in the medical field as low‐cost, facile, eco‐friendly, and biodegradable low‐energy γ‐ray shielding materials. The effect of different WO3 loading (0, 2, 4, 8, and 12 wt%) on nanocomposites' structural, mechanical, and gamma attenuation properties was studied. X‐ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscope verified the incorporation of WO3 into the nanocomposite matrix. The thermal stability and activation energy of the decomposition of nanocomposites showed continuous improvement with increasing WO3. The maximum tensile strength and elongation of nanocomposites were achieved by incorporating 4 wt% WO3 compared to the lowest tensile strength and elongation at 8 and 12 wt% of WO3, respectively. The good filler distribution inside the polymeric matrix at lower filler loading compared to the creation of voids and agglomeration at higher filler levels explains this behavior. It was found that nanocomposites' calculated mass attenuation coefficient μm (cm2/g) increased with increasing WO3 at different photon energies. Half‐value layer (HVL) and tenth‐value layer (TVL) values fall as WO3 concentration rises. The sample with 12 wt% of WO3 exhibits lower HVL and TVL values and higher μm, demonstrating a more remarkable gamma attenuation ability. Such results endorsed the prepared nanocomposites as low energy γ‐rays attenuation materials in medical fields.Highlights PVA/starch/graphene oxide nanocomposites with different WO3s were fabricated as shielding materials. The impact of WO3 on nanocomposites' mechanical and shielding characteristics was studied Thermal stability of nanocomposites showed continuous improvement with increasing WO3 μm increased with continuously increasing WO3 at different photon energies.

Improving the optical, photoluminescence, and electrical properties of PEO/NaAlg-WO3 nanocomposites for optoelectronic and nanodielectric applications

Nanocomposites based on polyethylene oxide (PEO)/Sodium Alginate (NaAlg) with varying content of tungsten trioxide nanoparticles (WO3 NPs) have been synthesized by using a green solvent casting method. Through the use of X-ray diffraction (XRD), Fourier transforms infrared (FTIR), and Ultraviolet–visible spectroscopy (UV–Vis.), the interaction of mixed components has been evaluated. Studies using spectroscopy have shown that WO3 nanoparticles and the blend's component parts interact strongly at their interfaces. XRD confirms the increasing amorphous propensity of the PEO/NaAlg film with increasing nanofiller loading. FTIR implies the development of molecular complex of the polymer with the nanofiller. From UV–Vis analysis, Tauc's relation was used to specify the direct and indirect bandgap energy. The Eg (direct) of pure PEO/NaAlg was considerably decreased from 4.23 to 3.04 eV by adding 2.0 wt% of WO3 NPs. The fluorescence for various WO3 NPs concentrations in PEO/NaAlg blend films was analyzed. The PEO/NaAlg blend's fluorescence intensity decreased with increased doped with WO3 NPs. The films made of nanocomposites also had their dielectric behavior and electrical conductivity examined. In contrast to the electrical conductivity (AC), the dielectric constant and dielectric loss of PEO/NaAlg-WO3 nanocomposites drop as the frequency of the electric field rises. The investigation revealed that an increase in WO3 concentration led to a corresponding rise in the nanocomposites' dielectric loss and dielectric constant values. The fabricated system of PEO/NaAlg-WO3 NPs nanocomposites films showing improved in AC conductivity and dielectric characteristics and could be suggested in optoelectronic and nanodielectric devices.

Performance evaluation of Falcon fluidized bowl and ultrafine (UF) bowl concentrators for the recovery of ultrafine scheelite particles

The recent developments in enhanced gravity concentrators, such as Falcon centrifugal separators, are proven beneficial in treating fine and ultrafine mineral particles. This concentrator is classified into a fluidized bowl concentrator and an ultrafine (UF) bowl concentrator based on the bowl design, which has considerable significance in facilitating the separation process. The present investigation concerns the recovery of ultrafine scheelite particles present in the gold mine tailing with an average WO3 content of 0.08%. The separation behaviour and application of different bowls concerning various particle sizes have been investigated. It is found that the Falcon UF concentrator can achieve a high recovery while the Falcon fluidized bowl can obtain a higher grade. Further, the fluidized bowl was found more effective at eliminating entrapped calcite mineral particles than the UF bowl. The effectiveness of both bowls is assessed in recovering heavy particles of various sizes, and the results show that the fluidized bowl performs better in recovering coarser heavy particles, while the UF bowl performs better in recovering fine heavy particles. Based on these findings, an integrated circuit (fluidized and UF bowls) has been designed, which resulted in achieving a higher (85%) recovery of WO3 values compared to individual bowls.

Mechanic-elastic properties and radiation attenuation efficiency of TeO2/WO3/K2O composite glass systems for nuclear and medical application

WO3 effects on neutron and ionizing radiation defending factors of ternary tellurite-based glass blocks with molecular formula 80TeO2 –(20-x)WO3 – xK2O; x = 0–20 mol% (denoted as TKW-glass) has been reported via Phy-X theoretical calculations and Geant4 simulation code. Correlations between shielding factors and kinetics properties of the investigated glasses at different photon energy have been examined. The highest values of mass (MAC) attenuation coefficient were noted at 15 keV of the examined TKW-glass materials with the values of 38.408, 44.388, 49.855, 54.872, 59.492 cm2/g for TKW-0, TKW-5, TKW-10, TKW-15, and TKW-20, respectively. Generally, these values of the TKW-glasses obey the sequence: (TKW-0)MAC< (TKW-5)MAC < (TKW-10)MAC < (TKW-15)MAC < (TKW-20)MAC. The highest mean free path (MFP) values of TKW-glasses were registered at 15 MeV with the values of 6.101, 5.591, 5.097, 4.647, and 4.302 cm for TKW-0, TKW-5, TKW-10, TKW-15, and TKW-20, respectively. The two parameters half value layer (HVL) and MFP follow the pattern: (TKW-0)HVL, MFP > (TKW-5)HVL,MFP > (TKW-10)HVL,MFP > (TKW-15)HVL,MFP > (TKW-20)HVL,MFP. The maximum values of effective atomic number (EAN) took place at gamma energy of 15 keV corresponding to 44.35, 48.86, 52.63, 55.83, and 58.58 for TKW-0, TKW-5, TKW-10, TKW-15, and TKW-20, respectively. The trend of the buildup factors was similar for all of the glass specimens. The fast neutron removal cross-section (ΣR) enhanced as WO3 content increased in the specimens. Thus, the peaked value of ΣR is 0.1059 cm−1 was noted in the TKW-20 sample. Mechanical properties, neutron and γ-rays protection parameters were observed to improve with enhanced WO3 mol% in the TKW-glasses. The current results bear their utilization for neutron and gamma protection purposes.

The effect of tungsten ions on the structural, elastic moduli, and shielding characteristics of arsenic lead phosphate glasses

A series of phosphate glass with the following formulation was manufactured using the melt quenching procedure: 3As2O3 – 37PbO – (60 − 𝑥𝑥) P2O5- 𝑥𝑥 WO3, 𝑥𝑥 = (0 ≤ 𝑥𝑥 ≤ 5 mol. %). The glasses' physical and other structural characteristics were examined in depth. The basic structural properties of the materials were examined using a variety of characterization procedures, such as XRD and FT-IR. With increasing WO3 concentration, the phosphate network evolves, leading to depolymerization of the glass network, according to the FT-IR analysis. With increasing WO3, the physical, mechanical, and structural parameters were enhanced like glass density, longitudinal and shear speeds, and all elastic moduli. Because of P–O–W bonds in the glass network are stronger than P–O– P bonds, the radiation characteristics were enhanced as the content of WO3 increased. The interpretation of the parameters showed that the glass in the statement is an excellent candidate for photon shielding applications.

Mineral forms of tungsten at the Porokhovskoe and Yugo-Konevskoe deposits (South Urals)

The ore hand specimens and technological ore samples from the Porokhovskoe and Yugo-Konevskoe W greisen deposits in the South Urals are studied. The major W minerals of primary ores at both deposits include hubnerite and scheelite. The secondary and accessory minerals are pyrite, chalcopyrite and molybdenite, rare minerals include sphalerite, galena, bismuthinite, aikinite, unidentifed chalcogenides and sulfosalts, magnetite, rutile, ilmenite, titanite and columbite. The veins are mainly composed of quartz and muscovite with subordinate calcite, dolomite and fuorite, rare chlorite and amphibole and accessory zircon, apatite and uraninite. No zonation in the distribution of wolframite with various Fe content is identifed relative to the Yugo-Konevsky granite pluton, however, wolframite of the Northern area of the Porokhovskoe deposit is enriched in Fe compared to that of the Central area and Yugo-Konevskoe deposit. In addition to veined wolframite and scheelite, the oxidized ores also contain Fe and Mn oxyhydroxides, malachite, pyromorphite and bromargyrite. Tungsten is part of Mn and Fe oxyhydroxides, which replace wolframite and less often sulfdes. The WO3 content of pseudomorphic Mn and Fe oxyhydroxides after hubnerite reaches 18 wt. %. Single grains of stolzite and russellite are found. According to the results of phase chemical analysis of technological samples, the amount of tungstite in oxidized ores is minor, therefore all ores of both deposits were ascribed to primary type. Keywords: South Urals, Porokhovskoe deposit, Yugo-Konevskoe deposit, tungsten, hubnerite, scheelite, stolzite, trace elements.

Effects of WO3 reinforcement on the properties of poly(lactic acid) composites for radiation shielding

During this work, efforts have been made to improve the gamma radiation shielding capabilities of poly(lactic acid) (PLA) by including tungsten trioxide (WO3). Simulations and theoretical analyses have been performed on the parameters of radiation shielding. They have been tested across a broad spectrum of energies, from 0.015 to 15 MeV. The values suggest that naturally occurring composites with a high WO3 content may be utilized to improve the gamma shielding properties of PLA/TO (TO ≡ tungsten trioxide) composites for protection applications; such composites can be employed as a covering for the solar cells to prevent damage. The composite samples made of PLA and WO3 were analyzed for a range of photon energies. The results showed rise of considerable proportions in the values of linear attenuation coefficient (μ) and mass attenuation coefficient μm at 0.08 MeV, due to the k-absorption edge of tungsten. In addition, μ and μm for all samples at selected photon energy are increase as the WO3 content increases and decreases with increasing photon energy. The half value layer (T0.5) decreased as the WO3 content increased, with the highest values seen at 15 MeV and the lowest values at 15 keV. The behavior of the mean free path (λ) was identical to T0.5 with regards to the amount of WO3 and the energy of the photon. The T0.5 values of the PLA-W7 were lower than other polymer materials, making it a more efficient material for filtering radiation. The Zeff values of the PLA/TO composite samples were the highest at 0.08 MeV and showed a trend of increasing with energy to 15 MeV. The exposure buildup factor (EBF) and energy absorption buildup factor EABF values were computed using the G-P fitting method and showed that the lowest values were presented for the PLA-W7. An increase in WO3 reinforcement in the PLA sample contributed to the decreased EBF-EABF values. The shielding parameters were determined through calculations done using both Phy-X/PSD and FLUKA, and the results from both are in good agreement with each other. The results of the study demonstrate the effectiveness of PLA-W7 as a material for radiation shielding.

Preparation of WO3/In2O3 heterojunctions and their performance on the CO2 photocatalytic conversion in a continuous flow reactor

This study investigated the CO2 conversion in the gas phase using the WO3/In2O3 photocatalysts synthesized by the solvothermal method at different WO3 content (5, 10, and 15 wt%). The experimental results in a continuous flow reactor demonstrated that carbon monoxide was the main product obtained from the photocatalytic reduction of CO2 using the coupled oxides and the individual semiconductors. However, in addition to CO, the WO3/In2O3 catalyst also produced CH4 and C3H6 hydrocarbons. The incorporation of WO3 into In2O3 inhibits the crystal growth and changes the preferentially formed cubic phase of In2O3 to the hexagonal phase structure, promoting the generation of hydrocarbons. The W15%/In coupled catalyst exhibited the best performance on methane and propylene production. This behavior was attributed to the enhanced interaction between the gas and the catalyst surface, and the improved charge separation promoted by the direct Z-scheme mechanism in the W15%/In heterojunction.

Unveiling the structural, optical, and electromagnetic attenuation characteristics of B2O3–SiO2–CaO–Bi2O3 glasses with varied WO3 content

This study provides insight into B2O3–SiO2–CaO–Bi2O3 glasses where novel results for the effects of WO3 content on its structural and optical properties have been demonstrated. Thus, provides useful data for developing new glasses for optical and electromagnetic shielding applications. The effect of WO3 content on the structural and optical properties of B2O3–SiO2–CaO–Bi2O3 glasses was investigated along with radiation shielding features which have been calculated by XCOM program. BSCB/W-00, BSCB/W-2.5, BSCB/W-5.0, BSCB/W-7.5, BSCB/W-10, BSCB/W-15, and BSCB/W-20 refer to seven samples of bismuth borosilicate glass system doped with 0.0, 2.5, 5, 7.5, 10, 15, and 20% of WO3, respectively, synthesized using the melt quenching technique. The density of the glasses decreased with increasing WO3 content due to the replacement of Bi2O3 with lower-density WO3. It was found that the absorption coefficient decreased with increasing WO3 content up to 10 wt%, but showed an opposite trend for samples with higher WO3 content. The optical band gap and the transition type were affected as the WO3 content increased. The electromagnetic wave decay or skin depth was also calculated. Overall, the shielding effectiveness of investigated samples BSCB/W-00, BSCB/W-2.5, BSCB/W-5.0, BSCB/W-7.5, BSCB/W-10, BSCB/W-15, and BSCB/W-20 has reduced with the enlargement of the WO3 concentration. BSCB/W-00, out of all the samples tested, has the highest shielding efficiency.

Preparation, characterization, and mechanical-optical properties of telluro-borate glasses containing tungsten

The current work is interested in the preparation, characterization, and mechanical-optical properties of the glasses in the (75-x)B2O3–10SrO–8TeO2–7ZnO−xWO3 system, with (x = 0 (BSTZW0), 1 (BSTZW1), 5 (BSTZW2), 10 (BSTZW3), 22 (BSTZW4), 27 (BSTZW5), 34 (BSTZW6), and 40 mol% (BSTZW7). The preparation of the glasses has involved the melt-quenching route. The new glasses are characterized by different characterization techniques using densimeter, microhardness, Raman spectroscopy, UV–visible absorption and emission, and X-ray diffraction. Photoluminescence can determine the impact of substituting B2O3 with WO3 on the mechanical-optical parameters and the structure of the present glasses. The prepared samples’ X-ray patterns showed amorphous states. The density value rises from 2.88 to 4.50 g/cm3, with the amount of WO3 rising from 0 to 40 mol% as a result of the difference in molecular weight between WO3 and B2O3. The Vickers microhardness (Hv) rises as the amount of WO3 increases as a result of a decrease in free volume and the formation of covalent bonds. The elastic moduli were found to increase when the WO3 concentrations increased from 0 to 40 mol%. This increase depends on the formation of bridging oxygen atoms. The Raman bands are designed to correspond to the bonds that form the structure of the current glass and detect the insertion of WO3 content by the attribution of the new W–O–W and W–O bonds. The UV–Visible spectroscopy analysis showed no band characteristic for the reduced species of W5+ ions identified by dark blue. However, the photoluminescence spectra showed emission bands (under excitation at 300 nm) that are associated with the active centers of W4+, W5+, and W6+ ions.