WO3 Addition Research Articles

Effect of Nanophotocatalyst WO3 Addition on PVDF Membrane Characteristics and Performance

The addition of photocatalyst materials in the membrane has great potential to increase membrane performance and characteristics. In this study, nano photocatalysts WO3 were added to the polyvinylidene fluoride (PVDF) membrane for process water treatment from rubber industry. The results of SEM and XRD showed the presence of nano photocatalyst WO3, indicating the successfully embedded nano photocatalyst in PVDF membranes. The addition of nano photocatalyst materials has increased hydrophilicity by increasing the membrane's water uptake ability and decreasing the membrane's contact angle. The PVDF-WO3-2%wt membrane showed the highest flux value at 64.29 L m−2 h−1 with 96.40%, 85.61%, and 93.88% of chemical oxygen demand (COD), total dissolved solid (TDS), and ammonia rejection, respectively. The photocatalytic degradation effect of PVDF-WO3 is proven by a significant difference in the filtration results under vis-light irradiation. Membrane resulted in a better performance in photo-filtration (visible light) than in the dark condition. The PVDF-WO3-2%wt membrane also showed an excellent reusability after being used for 8 hours of the photo-filtration process. This research is promising to increase the use of photocatalytic membranes in rubber wastewater treatment into clean water.

Visible light-driven TiO2-WO3@GO photocatalyst with catalytic memory for round-the-clock photocatalytic degradation of oilfield-produced water

The inability of most photocatalysts to continue the catalytic process after the removal of light irradiation is one of their major drawbacks. In this work, a ternary nanocomposite of titanium oxide (TiO2) supported with tungsten oxide (WO3) and hybridized with graphene oxide (GO) (TiO2-WO3@GO) photocatalyst with electron energy storage properties was synthesized for oilfield-produced water (OPW) treatment under visible light and in dark conditions. WO3 addition extended the light absorption range of TiO2 into the visible light while also serving as an electron storage material for dark catalysis (memory catalysis). The GO serves as an efficient electron acceptor and transporter to prevent charge carrier recombination, thereby enhancing interfacial electron transfer within the photocatalyst system. 2.5 wt%, 5 wt%, and 10 wt% of WO3 precursors were reacted with TiO2 precursor and GO was further added to synthesize the nanocomposites via a modified sol-gel and solution-based approach for the first time. The properties of the nanocomposite were assessed using a wide range of characterization. The nanocomposite containing 5 wt% WO3 showed the best photocatalytic activity with the total organic content (TOC) degradation of 27.7% within 4 h of photodegradation in visible light, which is better than 22 % in 5 h under UV light so far reported in the literature. The nanocomposite also exhibited electron energy storage properties for dark catalysis after pre-illumination, i.e., 16.6% TOC degradation in 3 h in dark conditions. This low % TOC degradation in the dark could be attributed to the complex nature of OPW. This work has further confirmed the possibility of the use of photocatalysts for dark catalysis.

Two-Phase Microstructure Generated by Reaction of Nano WO3 Addition and its Effect on Flux Pinning in Bi 2212 Composites

Two-Phase Microstructure Generated by Reaction of Nano WO3 Addition and its Effect on Flux Pinning in Bi 2212 Composites

The Modification of WO3 for Lithium Batteries with Nickel-Rich Ternary Cathode Materials

Nickel-rich ternary cathode materials (NRTCMs) have high energy density and a long cycle life, making them one of the cathode materials of LIB that are currently receiving much attention. However, it has shortcomings such as poor cycling performance (CP) and a high-capacity decay rate. Because of this, the study analyzed the modification effect of WO3 on NRTCM lithium batteries by preparing WO3-modified poly-crystal and single-crystal NCM622 materials under the existing conditions of better original cathode materials as reference samples. The results showed that in the morphology and structure testing, with the increase of WO3 addition, the c/a values of all NCM622-WO3 samples were greater than 4.95. In the analysis of cycling and rate performance (CRP), as W increased, the rate performance (RP) of the NCM622-W4.0 sample had a discharge specific capacity ratio of 86.2% at 10.0 C/1.0 C. In cyclic voltammetry testing, when the addition amount of WO3 was 1.0%, the polarization degree of SC-NCM622 sample was the weakest. In the AC impedance test, after six cycles, compared with the original sample, the Ret and R + Rct values of the NCM622-W sample modified with WO3 showed a significant downward trend. The above results prove that WO3 modification can lower the polarization of the material, effectively raising the CRP of the battery. It provides a reference path for the further progress of high capacity and stability ternary cathode materials.

The role of tungsten oxide in Er3+-doped bismuth-germanate glasses for optical amplification in L-band

A series of novel Er3+-doped bismuth-germanate glasses containing different tungsten concentrations with a molar composition of 97.5[(75 − x)GeO2–25Bi2O3–(x)WO3]–2Sb2O3–0.5Er2O3 (x = 5, 10, 15, 20, and 25 mol%) were fabricated. Their thermal properties are measured by differential scanning calorimetry. A structural investigation by Raman spectroscopy suggested that changes occurred in the glass network by WO3 incorporation. By laser excitation at 980 nm, a strong emission from Er3+ ions at 1532 nm is observed, while the WO3 addition caused changes in the emission spectra. The emission cross-section spectra of Er3+ are calculated by both McCumber and Füchtbauer–Ladenburg theories and their comparison showed these theories yielded slightly different results, but in both cases, the calculations showed that a gain signal in L-band can be achieved when 30% of the Er3+ ions are at the excited state. This study proves that the Er3+-doped bismuth-germanate glasses are suitable for optical fiber amplifier applications operating at C- and L-band.

Mechanical properties, elastic moduli, and gamma ray attenuation competencies of some TeO2–WO3–GdF3 glasses: Tailoring WO3–GdF3 substitution toward optimum behavioral state range

Abstract We report the mechanical properties, elastic moduli, and gamma ray attenuation properties of some TeO2–WO3–GdF3 glasses. Using the chemical composition of the selected glasses, the dissociation energy per unit volume (G t ) and the packing density (V t ) were calculated. Using the G t and V t values, Young’s, Shear, Bulk, Longitudinal Modulus, and Poisson’s ratio of the glasses are calculated. Next several fundamental gamma ray attenuation properties such as linear and mass attenuation coefficients, half value layer, mean free path, effective atomic number, effective electron density, effective conductivity, exposure, and energy absorption buildup factors are calculated in 0.015–15 MeV energy range. As a consequence of WO3–GdF3 substitution, the glass densities are observed in different values. The overall gamma ray attenuation properties are found to be enhanced through WO3 addition. Moreover, the increasing WO3 incorporation into glass configuration decreases the overall elastic moduli of glasses. It can be concluded that increasing WO3 may be a useful tool for enhancing the gamma ray attenuation qualities and decreasing the elastic moduli of TeO2–WO3–GdF3 in situations where a material with versatile mechanical properties is required.

Translocation of tungsten(vi) oxide/gadolinium(iii) fluoride in tellurite glasses towards improvement of gamma-ray attenuation features in high-density glass shields

Abstract This study investigates the effect of substituting tungsten(vi) oxide/gadolinium(iii) fluoride in tellurite glasses whose densities varies from 5.0879 to 5.3246 g/cm3 on gamma-ray absorption properties. A range of fundamental absorption parameters, including attenuation coefficients, half-value layer thicknesses, effective atom and electron numbers, effective conductivity, exposure, and energy absorption buildup factors, were studied for five different glass samples with varying substitution ratios. The ratio of tungsten(vi) oxide to gadolinium(iii) fluoride varied between 0 and 20 mol%, as well as the TeO2 ratio in the composition was maintained between 90 and 80 mol%. The sample with the composition of 80–20 mol% TeO2/WO3, which attained the maximum density value with 20 mol% WO3 addition, showed the highest gamma-absorption capabilities based on the obtained findings in the range of 0.015–15 MeV. In consideration of the mechanical and physical properties of WO3 in tellurite glasses, it can be concluded that WO3 incorporation is a crucial monotonic process that may be utilized to further improve the properties of glass shields.

A Promising Glass Type in Electronic and Laser Applications: Elastic Moduli, Mechanical, and Photon Transmission Properties of WO3 Reinforced Ternary-Tellurite Glasses

We report the symmetry of mechanical and gamma-ray attenuation properties for some tellurite glasses through elastic moduli, mechanical, and transmission properties as a function of varied WO3 amount in glass configuration. Four glass samples, along with different molar compositions as well as WO3/GdF3 substitution ratios, are investigated. Transmission properties using several essential parameters, such as attenuation coefficients, half-value layers, effective atomic numbers, effective conductivity, and buildup factors, are calculated in the 0.015–15 MeV energy range. Moreover, elastic moduli and Poisson’s ratios (σ) of the studied glass are calculated using the Makishima–Mackenzie model. The M4 sample with the highest WO3 addition is found with superior photon attenuation properties among the glasses investigated. Poisson’s ratio (σ) is increased, while all elastic moduli are decreased. Young’s modulus is reported as 62.23 GPa and 36.45.37 GPa at the highest and lowest WO3 mol%, respectively. It can be concluded that WO3 is a functional and monotonic tool in ternary-tellurite glasses for multiple modifications and enhancement purposes on gamma-ray attenuation, elastic moduli, and mechanical properties. It can also be concluded that increasing the WO3 amount in tellurite glasses may be considered a tool in terms of providing symmetry for mechanical and gamma-ray attenuation properties.

Flux Pinning in Composites of Bi 2212 Superconductors with Two-Phase Microstructure Generated by Reaction of Nano Wo3 Addition

Flux Pinning in Composites of Bi 2212 Superconductors with Two-Phase Microstructure Generated by Reaction of Nano Wo3 Addition

Structural and luminescence behavior of Eu3+ ions in ZnO-B2O3-WO3 glasses

Structure and luminescence properties of glasses with compositions 50ZnO:40B2O3:10WO3:xEu2O3, 0 ≤ x ≤ 10 mol% were studied using infrared, Raman and photoluminescence spectroscopic techniques. Physical properties like density, molar volume, oxygen molar volume and oxygen packing density of the glasses were also determined. The overall results obtained indicate the efficiency of the 50ZnO:40B2O3:10WO3 glass structure for the luminescence performance of doped Eu3+. The most intense luminescence peak observed at 612 nm and the high integrated emission intensity ratio (R) of the 5D0→7F2/5D0→7F1 transitions at 612 and 590 nm of 5.77 suggest that the glasses are potential materials for red emission. The results are compared to measurements of a glass without WO3 addition (50ZnO:50B2O3:5Eu2O3) and results from other publications of similar glasses.

Influence of CeO2 and WO3 Addition to Impregnated V2O5/TiO2 Catalysts on the Selective Catalytic Reduction of NOx with NH3

Influence of CeO2 and WO3 Addition to Impregnated V2O5/TiO2 Catalysts on the Selective Catalytic Reduction of NOx with NH3

Effect of WO3 addition on mechanical, structural, optical, and radiation shielding properties of lead boro phosphate glasses system using Monte Carlo simulation

This study, aims to investigate the effect of WO3 in a lead boro phosphate glasses system with the chemical composition of (100-x) [0.1B2O3-0.4 P2O5-0.5PbO]-xWO3 where x = 10–60 mol% WO3 (BPPW). This research was conducted to study structural, acoustic, (Young’s, shear, bulk, and longitudinal) and gamma radiation shielding parameters such as Mass Attenuation Coefficient (MAC), Half Value Layer (HVL), micro-hardness (H), for the BPPW glass systems with different molar composition. Radiation shielding parameters of the samples were investigated using Phy-X/PSD software and Geant4 simulation in the energies 0.826, 1.173, 1.28 and 1.33 MeV. As a result, the values of the Poisson's ratio (σ), Mass Attenuation Coefficient (MAC), Liner Attenuation Coefficient (LAC) and Half Value Layer (HVL) were found to decrease with the increasing of WO3 concentration. Also, the values of Elastic module with the increase of WO3 concentration have an increasing behavior. The simulated results, shown that the best recorded Mass Attenuation Coefficient for BPPW60 glass sample (ranging between 1.07975 and 0.36046 cm2/g for gamma photons ranging from 0.826 to 1.33 MeV, respectively). Furthermore, the MAC results have shown a good agreement between both programs.

Improving the production of furfural from cellulose catalytic pyrolysis using WO3/γ-Al2O3 composite oxides

Furfural is one of the top valuable building block chemicals, the selective production of furfural from biomass has attracted increasing concerns in recent years. In this work, a novel method for the selective production of furfural through cellulose catalytic pyrolysis with WO3/γ-Al2O3 was reported, and the synergistic effect between γ-Al2O3 and WO3 was explored. Compared with cellulose pyrolysis alone, the addition of γ-Al2O3 improved the selectivity of furans and greatly inhibited the formation of sugars; while, WO3 addition promoted the formation of levoglucosenone. When (20–40%) WO3/γ-Al2O3 were added, the amount of sugars was further reduced, and the yields of furans (furfural and 2-methylfuran, in particular) were further increased at the same time. Under the optimum conditions (temperature = 600 °C, residence time = 15 s, and catalyst to cellulose mass ratio of 4), 30%WO3/γ-Al2O3 showed the best performance, and the selectivity and yield of furfural were improved by nearly 100% and 300%, respectively, as compared with cellulose pyrolysis alone. In addition, compared with γ-Al2O3, the addition of 30%WO3/γ-Al2O3 further increased the yield of furfural and 2-methylfuran to about 50% and 200%, respectively. The high selectivity and yields of furans with WO3/γ-Al2O3 addition might be due to that WO3 crystals in the composite promote the formation of levoglucosenone, which is further converted to additional furans through the Lewis acid sites of γ-Al2O3. The study may provide some meaningful advices for improving the production of furfural from green catalytic pyrolysis of cellulose.

Evaluation of the Effect of Different Nano-Size of WO3 Addition on the Thermal Properties of HDPE Composite

Evaluation of the Effect of Different Nano-Size of WO3 Addition on the Thermal Properties of HDPE Composite

The effects of WO3 addition to NiO/ZrO2 oxygen carriers for chemical looping combustion of methane

Chemical looping combustion (CLC) is a promising combustion technology with inherent CO2 capture at low energy penalty. The success of CLC relies heavily on the development of an appropriate oxygen carrier. Mixed metal oxide supported oxygen carriers have been widely used to alleviate some of the disadvantages of monometallic based oxygen carriers. In this study, the effects of introducing WO3 into NiO/ZrO2 oxygen carriers were investigated for methane CLC using different synthesis methods and varying oxygen carriers’ compositions. Several characterization techniques such as ICP-OES, N2 adsorption-desorption, XRD, SEM/EDS, H2-TPR, and XPS have been used to understand the effects of preparation method, and oxygen carrier composition on methane CLC. The dual NiO-WO3/ZrO2 oxygen carriers exhibited enhanced oxygen capacity and lower carbon formation compared to their NiO/ZrO2 monometallic counterpart. Introduction of WO3 into NiO/ZrO2 lattice structure led to formation of an intermediate phase (NiWO4) which enhanced oxygen carriers’ reducibility and improved metal dispersion. This was mainly due to the high valence number of W6+ which created oxygen vacancy in the OC lattice structure due to charge balance difference. Coprecipitation and impregnation methods have been used to synthesize dual OCs, and impregnation method exhibited superior performance in terms of cyclic stability and coking resistance. Using impregnation synthesis method, WO3 and NiO loadings were optimized based on oxygen capacity and coke formation under cyclic redox experiments. Amongst the tested samples for methane CLC, NiO(60%)-WO3(25%)/ZrO2 showed the optimum performance with 15.6% oxygen carrying capacity and no carbon formation.

Photoelectrochemical properties of WO3-modified anatase TiO2 photoanodes and application for dye-sensitized solar cells

TiO2 electrodes were modified with different WO3 loadings and photoelectrochemical characterization revealed an increase in photocurrent density and decrease in interface charge transfer resistance with increasing amount of WO3. A decrease in green PL was observed with WO3 addition indicating more mobility of charges and therefore less probability of recombination. A series of TiO2 photoanodes modified by WO3 were designed with different geometrical configurations for dye-sensitized solar cell (DSSC) applications, WO3 was introduced successively in the screen-printed paste, as an undercoat and in the TiCl4 pretreatment bath. The results indicated a decrease in photovoltaic performance of all devices modified by WO3 compared to TiO2 reference cell. The highest conversion efficiency of the modified cells was observed for the configuration of WO3 introduced into the TiCl4 pretreatment bath. In this case, the optimized contact between the coupled semiconductors improved the charge transfer, also the direct contact of WO3 with the FTO substrate decreased the loss of electrons by confinement and recombination.

The tungsten oxide within phosphate glasses to investigate the structural, optical, and shielding properties variations

We prepared a series of sodium phosphate glasses by changing WO3/P2O5 content and investigated structure optical and radiation shielding features as a function of the glass composition. The average density ( $$\rho_{{{\text{exp}}}}$$ )was found to increase gradually from 2.49 to 3.07 g/cm3, while the average molar volume values reduced from 47.37 to 44.28 cm3/mol with WO3 addition. Also, the average field strength was also computed and found to increase with increasing WO3. The study of optical absorption spectra reveals that the absorption peaks in the visible region become higher compared to the peaks In the Ultraviolet region. This observation is accompanied by a color transformation of glasses from light to dark blue color, with more WO3 adding. The existence of a pentavalent tungsten state (W5+) is identified by this blue color; with WO3 addition an absorption band at around 350–390 nm is appeared. Moreover, this band is overlapped with the Urbach edge, which regularly produces an artificial edge-like feature at ~ 400 nm. A detailed deconvolution protocol is required for an appropriate understanding of these spectra and unraveling the hidden Urbach edge. Our analysis shows that, with increasing WO3/P2O5 content, the optical band gap decreases. This behavior can be elucidated in terms of a lower band gap of WO3 (2.7 eV) than that of P2O5 (8.5 eV) and the high polarizing power tungsten. Further, the radiation shielding parameters were investigated for the prepared glasses. WO3 addition improves these shielding parameters against radiation. Besides, upon the increase of WO3 concentration, the linear attenuation coefficient of glass material increases, which leads to decrease in have value layer values. Then it is deducible that the amount of WO3 in this glass sample has an important impact on the shielding capability at lower energy values and has a slight impact at higher energy values.

Dielectric barrier discharge plasma coupled with WO3 for bisphenol A degradation

Based on the difficulty of the refractory organic compounds degradation in water by the traditional wastewater treatment methods, the research relies on the technology of the dielectric barrier discharge plasma (DBDP) and the catalysis of the nano WO3, investigating the bisphenol A (BPA) degradation in the synergistic system of DBDP/WO3. The coupled degradation percentage of the BPA under different amounts of WO3 addition, different initial solution pH and carrier gas were investigated to confirm the catalysis of the WO3 in the DBDP system. It was obtained from the experimental results that the optimal additive amount of the WO3 was 175 mg L−1 and change of the solution pH value and the carrier gas variety could not change the catalysis of the WO3. The BPA degradation percentage could reach 100% after treating 30 min in the DBDP/WO3 system with 0.5 L min−1 O2 as the carrier gas. The WO3 still had a better catalysis after four times usage and the discharge had little effect on the microstructure of the WO3. The existence of the WO3 in the DBDP system could result in the reduction of the O3 concentration and the enhancement of the H2O2 concentration, which improve the catalysis of the WO3 in the DBDP system, while the experiments on the scavengers’ addition verified the major role of the OH on the BPA degradation. The catalytic mechanism of the WO3 as well as the BPA degradation pathway was also speculated in the research.

Effect of in situ formation of tungsten semicarbide on the microstructure and mechanical properties of medium carbon steel composites

Fabrication with the in-situ formation of W2C reinforced medium carbon steel (MCS) MMC’s was attempted using W or WO3and graphite addition to steel. The P/M route comprising milling, compaction and sintering at 1050 °C and 1120 °C respectively in 90% N2 + 10% H2atmosphere was adopted. Both SEM and BET studies revealed the particle size to be around 100, 7 and 40 µm for MCS, W and WO3, respectively. A complete conversion of tungsten into tungsten semicarbide (W2C) was noted in XRD for the tungsten additions of ∼6, 9 and 12 wt.% with stoichiometrically balanced C (graphite) addition of 0, 0.2 and 0.4 wt.%. However, WO3 + C addition (balanced as above) revealed the partial conversion of WO3to W2C. The peaks of Fe3C were observed only for MCS + W + C samples and not for MCS + WO3 + C samples in XRD. In SEM, the WO3phase appeared porous and partially converted, whereas, W2C phase was dense. Sintered density improved for the addition of W, whereas it monotonically reduced for WO3addition to MCS + C samples. Higher hardness, compressive strength, and wear resistance was noted for W addition than WO3to MCS+C samples.

Catalytic methane decomposition over ZrO2 supported iron catalysts: Effect of WO3 and La2O3 addition on catalytic activity and stability

A leading method of hydrogen production that is free of carbon oxides is catalytic methane decomposition. In this research, Fe supported catalysts produced by wet impregnation method were employed in the methane decomposition. The effect of doping ZrO2 with La2O3 and WO3 on the catalytic performance was studied. Different techniques were used to characterize the catalysts. It was discovered that support doped with WO3 gave the best performance in terms of CH4 conversion, H2 yield and stability at the test condition (800 °C, 4000 ml/hgcat space velocity). The initial H2 yield was found to be 58%, 81% and 92% on Fe/ZrO2, Fe/La2O3–ZrO2 and Fe/WO3–ZrO2 catalysts, respectively. These values were significantly decreased to reach 20% and 25% over the Fe/ZrO2 and Fe/La2O3–ZrO2 catalysts after running for 240 min. On the contrary, the Fe/WO3–ZrO2 catalyst maintained its catalytic activity and stability within the reaction time. The BET results showed remarkable increase in the specific surface area of Fe/La2O3+ZrO2 and Fe/WO3+ZrO2 compared to Fe/ZrO2 catalyst. TPR profiles revealed progressive change in the valency of Fe in its combined form to the zero valence free metal. The Fe/WO3–ZrO2 catalyst showed the highest reduction temperature among the tested catalysts, probably due to the strong metal support interaction. The Fe/WO3–ZrO2 gave the best performance and maintained stability during the time on stream. Its stability was attributed to the higher dispersion and stabilization of iron nanoparticles on the surface of WO3–ZrO2 support. TEM and TPO results indicated that the deposited carbon was multi-walled carbon nanotubes with tabular structure.