WO3 Content Research Articles

Evaluation of Thermal and Mechanical Properties of Bi-In-Sn/WO3 Composites for Efficient Heat Dissipation

Phase change materials (PCMs) offer promising solutions for efficient thermal management in electronic devices, energy storage systems, and renewable energy applications due to their capacity to store and release significant thermal energy during phase transitions. This study investigates the thermal and physical properties of Bi-In-Sn/WO3 composites, specifically for their use as phase change thermal interface materials (PCM-TIMs). The Bi-In-Sn/WO3 composite was synthesized through mechanochemical grinding, which enabled the uniform dispersion of WO3 particles within the Bi-In-Sn alloy matrix. The addition of WO3 particles markedly improved the composite’s thermal conductivity and transformed its physical form into a putty-like consistency, addressing leakage issues typically associated with pure Bi-In-Sn alloys. Microstructural analyses demonstrated the existence of a continuous interface between the liquid metal and WO3 phases, with no gaps, ensuring structural stability. Thermal performance tests demonstrated that the Bi-In-Sn/WO3 composite achieved improved thermal conductivity, and reduced volumetric latent heat, and there was a slight increase in thermal contact resistance with higher WO3 content. These findings highlight the potential of Bi-In-Sn/WO3 composites for utilization as advanced PCM-TIMs, offering enhanced heat dissipation, stability, and physical integrity for high-performance electronic and energy systems.

Advancing gamma radiation shielding with Bitumen-WO₃ composite materials

This research focuses on a manner in which bitumen-WO₃ (petroleum-derived bitumen mixed with tungsten trioxide nanoparticles) materials can be a good shielding candidate against gamma radiation. The objective we set in mixing WO₃ nanoparticles with bitumen was to take advantage of both the bitumen's natural qualities and the WO₃'s excellent shielding capabilities. The prepared composites were tested against various gamma-ray energies emitted from multiple gamma-ray sources to examine their shielding capabilities. The X-ray diffraction (XRD) analysis of the composites' structural properties verified the effective integration of the WO₃ with the bitumen structure. Scanning electron microscopy (SEM) showed that microstructural changes, such as an increase in material density and an improvement in particle dispersion, are caused by a rise in WO3 concentration, which is an essential step toward efficient shielding. Then, the Mean Free Path (MFP), Half-value Layer (HVL), and Linear Attenuation Coefficients (μl) were computed, showing that the composite's capacity to reduce gamma radiation is much enhanced by raising the WO₃ content, especially at lower gamma-ray energies. For instance, at 20 keV, the LAC of 50 wt% WO₃-bitumen composite increased to 9.18 cm⁻1 compared to pure bitumen's 0.40 cm⁻1, while the HVL decreased from 1.73 cm to 0.08 cm, and the MFP dropped from 2.3 cm to 0.1 cm” The results demonstrate the potential of bitumen-WO₃ composites as a sustainable and efficient material for radiation shielding, particularly highlighting their applicability in various sectors, including the development of building wall paints against gamma radiation.

Influence of WO3 Content in Phosphated Tungsten-Zirconium Oxide Catalysts on the Catalytic Pathways of Glycerol Transformation.

The catalytic performance of phosphate-stabilized WOx-ZrO2 compositions in gas-phase glycerol dehydration has been investigated. Results show that varying WO3 concentrations direct the process towards either acrolein or allyl alcohol formation. Catalysts with low WOx content exhibit strong Lewis acid sites (Zr4+ and W6+), where these metal ions likely function as redox sites, facilitating glycerol hydrogenolysis to produce allyl alcohol. Higher WO3 concentrations (exceeding 20 wt.%) lead to the shielding of some W6+ and Zr4+ sites by polytungstate surface complexes, which are strong Brønsted acid sites. This alteration promotes glycerol dehydration through the removal of two water molecules, thereby shifting the selectivity towards acrolein formation.

Recovery of Low-Concentration Tungsten from Acidic Solution Using D318 Macroporous Resin.

Tungsten is a crucial strategic metal that plays a significant role in various fields, such as the defense industry, fine chemicals, and the preparation of new materials. During the practice of numerous tungsten smelting processes, a large amount of acidic wastewater containing low concentrations of WO3 is generated. The adsorption method, known for its simplicity, effectiveness, and ease of operation, represents the most promising approach for tungsten recovery and is vital for the sustainable development of the tungsten industry. In this study, D318 macroporous resin was used as an adsorbent to investigate its effectiveness in adsorbing WO3 from acidic solutions. Static adsorption experiments revealed that the adsorption capacity of D318 resin for WO3 was 683 mg·g-1. Kinetic analysis indicated that the controlling step for the adsorption of WO3 from acidic solutions by D318 resin was intraparticle diffusion. Thermodynamic analysis demonstrated that the adsorption process was endothermic and could occur spontaneously. By fitting the isothermal adsorption equation, it was found that the Langmuir model was more suitable for describing the adsorption process of WO3 on D318 resin in acidic solutions. The results of dynamic adsorption experiments showed that under optimized conditions, the dynamic adsorption capacity for WO3 was 529 mg·g-1; when using NaOH as the desorbent for cyclic desorption, the desorption rate for WO3 was 98.21%. XPS and SEM-EDS testing and analysis confirmed that D318 macroporous resin exhibited excellent adsorption performance for tungsten in acidic solutions.

Novel Eu3+-Doped Glasses in the MoO3-WO3-La2O3-B2O3 System: Preparation, Structure and Photoluminescent Properties.

Novel multicomponent glasses with nominal compositions of (50-x)MoO3:xWO3:25La2O3:25B2O3, x = 0, 10, 20, 30, 40, 50 mol% doped with 3 mol % Eu2O3 were prepared using a conventional melt-quenching method. Their structure, thermal behavior and luminescent properties were investigated by Raman spectroscopy, differential thermal analysis and photoluminescence spectroscopy. The optical properties of the glasses were investigated by UV-vis absorption spectroscopy and a determination of the refractive index. Physical parameters such as density, molar volume, oxygen molar volume and oxygen packing density were determined. The glasses are characterized by a high glass transition temperature. Raman analysis revealed that the glass structure is built up mainly from tetrahedral (MoO4)2- and (WO4)2- units providing Raman bands of around 317 cm-1, 341-352 cm-1, 832-820 cm-1 and 928-935 cm-1. At the same time, with the replacement of MoO3 with WO3 some fraction of WO6 octahedra are produced, the number of which increases with the increasing WO3 content. A strong red emission from the 5D0 level of Eu3+ ions was registered under near-UV (397 nm) excitation using the 7F0 → 5L6 transition of Eu3+. Photoluminescence (PL) emission gradually increases with increasing WO3 content, evidencing that WO3 is a more appropriate component than MoO3. The integrated fluorescence intensity ratio R (5D0 → 7F2/5D0 → 7F1) was calculated to estimate the degree of asymmetry around the active ion, suggesting a location of Eu3+ in non-centrosymmetric sites. All findings suggest that the investigated glasses are potential candidates for red light-emitting phosphors.

Effect of low concentrations of WO3 on synthesis, structural, physical, optical, neutron attenuation, and charged particle absorption properties of B2O3+Na2O+BaO glassy composites

This study presents the physical, optical, and radiation shielding attributes of 75B2O3+5Na2O+(20-x)BaO+xWO3 glasses, with the aim of producing effective transparent and light shields. The well-known melting-and-quenching technique was used to prepare the transparent glasses for x = 0; 03; 10 mol%). The glasses were characterized by determining their density, molar volume, optical transmittance, bandgap, refractive index, dielectric constant, reflection loss, molar refraction charged radiation stopping powers, projected range, fast neutron removal cross section and thermal neutron total cross-section. All the estimated parameters showed variations with glass stoichiometry. The addition of WO3 triggered the BO4 → BO3 unit transformation which prompted the variations in the physical and optical parameters of the glasses. The optical transparency in the visible region and density of the glasses decreased with WO3 concentration while the molar volume increased. For electrons, the stopping powers were in the range, 1.436–11.76 cm2/g, 1.433–11.66 cm2/g, and 1.426–11.44 cm2/g, for BNB-W00, BNB-W03, and BNB-W10, respectively. For protons, alpha particles, and carbon ions, the mass stopping powers increased with WO3 content. Based on projected range data, particles with greater energy per nucleon penetrated the glasses deeper and the WO3- rich glasses had higher transmissivity for charged radiation. Compared to some existing neutron moderators, the investigated glasses displayed higher fast neutron cross-sections. The studied glasses can function well as barriers to moderate fast neutrons, attenuate thermal neutrons, and absorbed charged radiation.

Improve flotation efficiency of refractory tungsten ore and reduce carbon emission in flotation process: A case study of Sandaozhuang deposit in Henan, China

With the rapid consumption of tungsten ore resources which were easy to beneficiation, the low-grade refractory scheelite has become the main source of tungsten production. In this study, a new reagent recipe was proposed to improve scheelite flotation efficiency and reduce carbon emission in flotation process by taking Sandaozhuang strongly altered ore as an example. The mineralogical study indicated that the content of WO3 in this ore was 0.0952 %, and 83.16 % of WO3 occurred in scheelite. The high content of calcium-containing gangue, easy-argillation gangue and fine scheelite jointly made it difficult to recover scheelite efficiently. The batch flotation tests shown that under the conditions of Na2CO3 1800 g/t, SS 600 g/t, SG 60 g/t, engine oil 20 g/t and FX-8 180 g/t, a rough concentrate with WO3 grade of 1.503 % and WO3 recovery of 79.40 % can be obtained. The industrial tests and application shown that this new reagent recipe had good industrial applicability and stability, and was conductive to improve the efficiency of the whole flotation process. The economic and environmental benefits analysis found that the application of this new reagent recipe in a 10,000 t/d scheelite flotation plant can create annual additional economic value of more than CNY 20 million, and reduce annual carbon emissions by more than 5000 t. Therefore, this new reagent recipe was worth popularizing and applying in similar refractory scheelite flotation plants.

Characterization, potential valuable metals recovery and remediation of historic wolframite mining waste

The understanding of tungsten (W) mineral weathering and mobilization in nature remains limited due to W being a transition element with a wide range of oxidation states, which enables it to form a variety of complex chemical compounds. This study examined W mining waste at the abandoned Wolfram Camp mine in North Queensland, Australia, to address this gap. The mineralogical analysis showed the W tailings primarily consisted of silicates, including quartz, illite/mica, plagioclase, and K-Feldspar, with low WO3 content. Static acid mine drainage (AMD) tests indicated most tailings were non-acid forming, while groundwater samples exhibited acidification, with pH ranging from 3.8 to 5.2. The reprocessing trials using gravity separation and bioleaching demonstrated promising results, suggesting both techniques could effectively recover resource and decontaminate the mining waste. The gravity separation reprocessing test has successfully recovered 48.4% W from the tailings, with the resulting W concentrate achieving a 21.6% WO3 grade. On the other hand, the bioleaching reprocessing exhibited a remarkable 44-fold enrichment of W from the tailings, with 2.2% W in the AMD sediment. Synchrotron-based XFM/μ-XANES imaging analysis revealed significant wolframite weathering in reprocessed W concentrates. This study proposed a comprehensive approach, integrating environmental remediation and resource recovery technologies, to repurpose abandoned W mining waste. Passive treatment appears to be an economical option for remediating abandoned W mine sites. The findings provide valuable insights for sustainable W mining waste management and the rehabilitation of the abandoned Wolfram Camp W mine site.

The role of WO3 on the optical and radiation attenuation characteristics of ZnO–Na2O–B2O3 glasses

This works aims to investigate the role of the WO3 on the optical and radiation attenuation characteristics of ZnO–Na2O–B2O3 glasses which were called as ZNBW glasses using theoretical approach. The molar refractivity (Rmol), molar polarizability (αMol.), reflection loss (RLoss), static dielectric constant (εstatic), and optical dielectric constant (εoptical) of the ZNBW glasses enhance while optical transmission (TOpt.) and metallization criterion (M) of the ZNBW glasses reduce with enhancement of WO3 and decreasing of ZnO. The Rmol, αMol.,RLoss, εstatic and εoptical are the highest for ZNBW20 whereas they are the lowest for ZNBW0. The TOpt. and M are the highest for ZNBW0 while they are the smallest for ZNBW20. In terms of radiation attenuation characteristics, the linear attenuation coefficient, mass attenuation coefficient, effective atomic number, and effective electron density increase whereas half value layer, tenth value layer, mean free path and fast neutron removal cross section (FNRC) decline with the enhancement of WO3 and reducing of ZnO. The ZNBW20 which has the highest WO3 content possesses the greatest radiation attenuation properties and smallest FNRC whereas the ZNBW0 which has not WO3 content possesses the smallest radiation attenuation properties and the highest FNRC. Consequently, radiation attenuation characteristics of ZNBW glasses enhance whereas FNRC of ZNBW glasses decline with addition of WO3 and reducing of ZnO. The replacement of WO3 by ZnO has a positive effect on improving the radiation attenuation properties of the ZNBW glasses.

Influence of WO3 replacement for CaO on physical, optical, and γ-ray protection properties of borotellurite glasses: A comparative study

Glasses with WO3 in place of CaO with the chemical formula 45B2O3+15TeO2+(18-X)CaO+22Na2O + XWO3: X = 0 (W-0), 1.5 (W-1.5), 3 (W-3), 4.5 (W-4.5), and 6 (W-6) mol% were prepared using the melt quenching method. A comprehensive study of the structural, physical, optical, and γ-ray protection properties of the prepared glasses was investigated. Density (ρ), molar volume (Vm), UV–Vis measurements, the MCNP5 simulation code, and PhX software were employed to achieve the aims of this study. The density (ρ) of the W-X samples increased slightly from 2.45 g/cm3 to 2.62 g/cm3 as WO3 content increased from 0 to 6 mol%. The molar volume (Vm) evinced the same trend as ρ. In the UV range, significant absorption was observed, rising as the molar concentration of WO3 increased. The direct optical gap (Eopt.(dir.)) declined from 3.59 eV to 3.24 eV, while the indirect gap (Eopt.(indir.)) declined from 3.27 eV to 2.36 eV. The Urbach energies (ΔE) ranged from 0.35 to 0.71 eV. The refractive index (n) increased from 2.33 to 2.59 as WO3 content increased. The molar polarizability (αm) and molar refractivity (Rm) increased. The linear-attenuation absorption (μ) order is: W-0 < W-1.5 < W-3 < W-4.5 < W-6. The W-6 glass sample possessed the lowest half- (HVL), and tenth- (TVL) value layer, as well as the lowest mean free path (MFP). Therefore, the W-6 glass sample offers the best gamma radiation shielding capability among the prepared W-X glasses. Within the investigated energy range, the effective atomic number (Zef) varied from 30.773 to 13.234, 35.398–13.969, 39.089–14.670, 42.103–15.338, and 44.611–15.977 for the W-0, W-1.5, W-3, W-4.5, and W-6 glasses, respectively. At 0.080 MeV, the mass-attenuation absorption (μm) of the investigated W-X glasses was higher than for TBLMC-X (TeO2–B2O3–Li2O–MoO3–CuO) and TS-X (9SiO2–Al2O3–Na2O–B2O3–TeO2) glasses.

Structural and electrical conductivity studies of Polyaniline - WO3 hybrid nanocomposites for gas sensing applications

Abstract Conducting polymer – metal oxide based hybrid nanocomposites are a fascinating class of materials for miniaturized and flexible gas sensor devices. They exhibit enhanced physiochemical properties such as sensitivity, selectivity towards various volatile and hazardous chemical and bioanalytes. Our study focuses on conducting polyaniline (PANI) and WO3 nanocomposites, where different weight percentages (wt.%) of WO3 nanoparticles are embedded within the conducting PANI matrix using an in-situ oxidation polymerization synthesis technique. The surface morphology analysis indicated that the WO3 nanoparticles with an average grain size of ~200 nm are homogeneously distributed within the PANI nanofibers. The Fourier Transform Infra-Red (FTIR) spectrum analysis showed that the absorption peaks at 1111,1291, 1385, 1474, and 1560 cm−1 are typical of the conducting PANI emeraldine phase. We attribute the additional broad peak ranging between 840 to 720 cm−1 in the spectrum to WO3 phase, wherein, the intensity of the peak increases with WO3 content in case of hybrid composites. Current-voltage (I-V) characteristics for all our samples showed linear behaviour up to 1.2 volts. Temperature-dependent DC electrical conductivity (σ) studies measured from room temperature to 120°C for pure PANI, and PANI-WO3 composites showed an enhanced electrical conductivity of values up to 0.12 S/cm for PANI as compared to WO3 with σ ~ 1.4 x 10−3 S/cm. Pure PANI exhibits semiconducting behavior with an increase in electrical conductivity with temperature due to the charge carrier delocalization within the dispersed PANI backbone. The addition of higher concentrations of WO3 in composites leads to a metallic-like behavior, characterized by a decrease in electrical conductivity with temperature. These observations are attributed to the field-assisted band bending effects at the interfaces of PANI and WO3. Our composites show desired electrical characteristics suitable for gas sensing applications.

O vacancy-rich doped WO3/GF as a novel electrode for an aqueous DHAQ/ K4Fe(CN)6 redox flow battery

In this study, a graphite felt (GF) electrode was modified with N and S heteroatoms before being loaded with Ti-doped or Nb-doped WO3 to produce Ti-WO3/GF-N-S and Nb-WO3/GF-N-S electrodes. X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy were used to analyze the crystal structure, morphology, and elemental state of the modified GF electrodes and investigate the impact of nonmetallic and metallic element doping. The influence of metal doping on the electronic distribution of the oxide was determined using first-principle calculations. The electrochemical properties of the modified GF were studied using cyclic voltammetry, electrochemical impedance spectroscopy, and single-cell tests. The results showed that Ti or Nb doping changed the energy band structure, bond length, and bond angle in the WO3 crystal and formed O vacancies. The chemical properties of Ti and Nb resulted in different numbers of O vacancies for the two doped-WO3.The doping of N and S heteroatoms on the carbon fibres altered the O vacancy concentration of WO3. The synergism between the two doping methods accelerated electron transfer in the anthraquinone redox reaction. In addition, the N-containing functional groups provide lone-pair electrons, which accelerate electron transfer and anthraquinone adsorption. Therefore, compared to the pristine GF, the discharge capacities of the Ti-WO3/GF-N-S and Nb-h-WO3/GF-N-S graphite GF electrodes increased by 58 % and 41 %, respectively, and the Nb-h-WO3/GF-N-S graphite GF electrodes exhibited a good capacity retention rate. This study broadens the practical applications of aqueous anthraquinone redox flow batteries.

Effect of WO3 in the third-order optical nonlinearities of tungsten lead pyrophosphate glasses

The binary glassy system Pb2P2O7-WO3 demonstrates promising photonics applications owing to its high polarizability and chemical stability. The domain of glass's chemical state and linear and nonlinear optical properties have been investigated using X-ray photoelectron spectroscopy (XPS), UV–visible spectroscopy, and the Z-scan technique, respectively. The optical absorption spectra revealed that the absorption edge was redshifted with increased WO3 content, suggesting a decrease in bandgap energy. Nonlinear refractive index increased with the WO3 content from an average value of 0.70 x 10−19 m2 W−1 to 0.98 x 10−19 m2 W−1. Such an increase is due to the rise of non-bridging oxygens and the polarizability of W6+ and W5+ species. XPS studies found that a high concentration of WO3 leads to the transformation of the oxidation state of W6+ and W5+ related to the presence of oxygen vacancies. Therefore, our high nonlinear refractive index and polarizability results indicate that the glass system studied here is a potential candidate for photonic devices.

SiO2/WO3/ZnO based self-cleaning coatings for solar cells

The accumulation of pollution and any kinds of contamination on the glass cover of the solar cell affects the efficiency of the photovoltaic (PV) systems. The contamination on the glass cover can absorb and reflect a certain part of the sunlight irradiation, which can decrease the intensity of the light coming in through the glass cover. With the study, it was planned to develop self-cleaning coatings for the PV systems. It was aimed to prevent or reduce the contamination-induced efficiency loss of the existing PV systems. In the scope of the project, SiO2/WO3 and SiO2/WO3/ZnO composites were coated from their solutions on the glass substrates using a dip-coating technique. WO3 was selected as a photocatalyst semiconductor. Under the UV light irradiation, WO3 could absorb the photons of the UV light, generating the photoinduced charge carriers. The photoexcited charge carriers provide both the photoinduced hydrophilicity on the surface of the coating and the photocatalytic degradation of the organic contaminants accumulated on the surface of the coating, which allows water droplets to spread and flow on the surface of the cover glass to remove the contaminations. However, the recombination rate of the photoexcited charge carriers on the WO3 film was high. In order to suppress the recombination of the photoinduced charge carriers, WO3 was coupled with SiO2 and ZnO. Both of these semiconductors improved the photocatalytic activity of the WO3 film. Although SiO2 has superior features in terms of the light transmission, it was not very effective under UV light as a photocatalyst alone. The widely preferred photocatalyst ZnO was added into the composite film structure to enhance the photocatalytic activity. The self-cleaning mechanism of the film coatings on a solar cell was investigated through the photocatalytic dye removal efficiency on the as-prepared film samples. There was a slight decrease in the light transparency and the solar cell efficiency because of the WO3 content of the composite film. On the other hand, coupling the SiO2/WO3 film with ZnO enhanced the photocatalytic activity, and it suppressed the reduction effect of the WO3 phase on both the light transparency and the solar cell efficiency. The photocatalytic dye removal efficiency was increased to over 90% after 240 min of UVA light irradiation. In addition, the solar cell coated with the SiO2/WO3/ZnO film provided almost the same solar cell efficiency as the uncoated solar cell. The water contact angle measurement also exhibited the photocatalytic degradation of the model contamination on the glass cover of the solar cell under the UVA light irradiation.Graphical

Structural, morphological, thermal, mechanical, positron annihilation, and γ-ray shielding studies of nano-tungsten oxide/polyvinyl alcohol composites

Tungsten oxide nanoparticles were synthesized. Metal/polymer composites of nano-sized WO3 and poly vinyl alcohol were blended by the casting method with concentrations of WO3. The structural, morphological, thermal, and mechanical characteristics of the prepared samples were investigated. The γ-ray attenuation properties of the synthesized composites were examined using γ-ray spectrometers, and the γ-ray mass absorption coefficients were measured using 662 keV γ-ray of 137Cs radioactive source. The defects and microstructure changes of the composites were probed using positron annihilation lifetime and Doppler broadening techniques. The shielding performance and thermal stability improved with increasing the concentration of WO3, and some of the mechanical properties, in particular the elongation at break, deteriorate. The contribution of WO3 has a strong effect on reducing the relative fractional free volume, which in turn helps to increase the γ-ray absorption of the composites. The use of a 50–70 % WO3/PVA composite is recommended.

Scaling-Up of Solution-Processable Tungsten Trioxide (WO3) Nanoparticles as a Hole Transport Layer in Inverted Organic Photovoltaics

We reported the comparative studies of the optimization of solution-processable tungsten trioxide (WO3) as a hole transporting layer (HTL) in inverted organic photovoltaics (OPVs) using spin coating, slot-die coating, and spray coating technologies for scaling-up applications. To facilitate the technology’s transition into commercial manufacturing, it is necessary to explore the role of scalable technologies for low-cost and efficient device fabrication. We investigated the role of diluting WO3 with isopropanol as an HTL in inverted OPVs to solve the issue of poor wettability of the hydrophobic surface of the PBDB-T: ITIC bulk heterojunction layer. The optimal dilution ratios of WO3 with isopropanol were 1:4, 1:4 and 1:8 with spin coating, slot-die coating and spray coating techniques, respectively. We evaluated the device performance by conducting a current density–voltage (J-V) analysis, incident photon-to-current conversion efficiency (IPCE) measurements, and ultraviolet–visible (UV-Vis) absorbance spectra for various WO3 concentrations. The J-V characteristics revealed that slot-die coating resulted in the highest performance, followed by the spray coating technology. We further investigated the impact of the annealing temperature on device performance for both slot-die- and spray-coated diluted WO3. The highest device performance was achieved at an annealing temperature of 120 °C for both coating technologies. This research offers valuable insights into the scalable fabrication of inverted OPV devices, paving the way for cost-effective and efficient large-scale production.

Effect of MoO3/WO3 modulation on high-temperature wettability and crystallization behavior of glass and its application in solar cell

The role of glass in the metallization contact of crystalline silicon solar cells is crucial. Numerous studies have been conducted to investigate the reaction between the main components in glass and SiNx antireflection layer during sintering. Additionally, the low content component in glass plays an indispensable role in etching and wetting silicon base. The present study investigated the impact of ionic radius on glass properties through manipulation of the elemental composition of transition metals Mo and W. The results indicated a significant decrease in the characteristic temperature point of glass and an increase in wettability after the addition of MoO3 and WO3. Furthermore, the thermal expansion of glass was observed to increase with higher WO3 content. Screen printing for the preparation of silver electrodes revealed that glass-silver pastes had optimal printing properties. When the quality ratio of MoO3 and WO3 was 7:3, it effectively enhanced the precipitation of Bi2WO6 and Pb7.90Mo0.10O12.15 crystals in the glass, leaded to a reduction in the band gap of the glass. This resulted in an increased imprint of silver crystals within the glass layer, with more nano-silver crystals were deposited near the pyramid. Consequently, an optimal metallization contact was established between the silver grid and emitter. The average aspect ratio of silver grid improved from 0.415 for AG-1 to 0.469 for AG-3, which enhanced the photoelectric conversion efficiency of crystalline silicon solar cells.

Process and kinetics study on hydrolysis for the generation of Ti/W powders with controlled pore properties

The lack of research on the hydrolysis and calcination processes in the low-concentration Ti-W-H2SO4 system has been an obstacle to the recovery of titanium from the H2SO4 waste solution. This study proposes a feasible process for the synthesis of Ti/W powders from unconcentrated H2SO4 solutions containing Ti and W. The study explores the kinetics of hydrolysis and the influences of process parameters on the properties of Ti/W powders. Under optimum conditions, a Ti/W powder with a total TiO2 and WO3 content of 97.49%, and a specific surface area of 89.40 m2/g was obtained. The resynthesized SCR catalysts prepared using Ti/W powder demonstrated good denitrification activity. The hydrolysis efficiency of Ti conforms to the Avrami model. The homogeneous nucleation reaction occurred during hydrolysis with an activation energy of 191.97 kJ/mol. Based on the kinetic research, the temperature and time can be adjusted to fine-tune the microscopic morphology, pore properties, and particle size of the powder particles. This study demonstrates an effective technique for the stable preparation of high-value products from low-concentration Ti-W-H2SO4 solutions, which contributes to eco-friendly resource recovery.

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.