Tungsten Doping Research Articles

Surface Characteristics and Performance Optimization of W-Doped Vanadium Dioxide Thin Films

This study explores the surface characteristics evaluation and performance optimization of tungsten (W)-doped vanadium dioxide (VO2) thin films. W-doped vanadium dioxide films were deposited on B270 glass substrates using an electron beam evaporation technique combined with the ion beam-assisted deposition (IAD) method. The Taguchi method was used to analyze the performance optimization of VO2 thin films, and L16 orthogonal array design and Minitab software were used for optimization calculations. The surface roughness, visible light transmittance, infrared transmittance, and residual stress of un-doped and tungsten-doped (3–5%) VO2 thin films are set as the quality performance indicators of thin films. The goal is to identify the key factors that affect the performance of VO2 thin films during deposition and optimize their process parameters. The experimental results showed that a VO2 thin film with 3% tungsten doping, an oxygen flow rate of 60 sccm, a heating temperature of 280 °C, and a film thickness of 60 nm exhibited the lowest surface roughness of 2.12 nm. A VO2 thin film with 5% tungsten doping, an oxygen flow rate of 0 sccm, a heating temperature of 280 °C, and a film thickness of 60 nm had the highest visible light transmittance at 64.33%. When the oxygen flow rate was 60 sccm, the heating temperature was 295 °C, the film thickness was 150 nm, and the tungsten doping was 5%, the VO2 thin film showed the lowest infrared transmittance of 31.34%. A thin film with 5% tungsten doping, an oxygen flow rate of 20 sccm, a heating temperature of 265 °C, and a film thickness of 120 nm exhibited the lowest residual stress of −0.195 GPa.

Extrinsic tungsten doping to improve the intrinsic electrocatalytic activity of NiBP spheres for overall water splitting under high current density operation

Extrinsic tungsten doping to improve the intrinsic electrocatalytic activity of NiBP spheres for overall water splitting under high current density operation

Effect of Tungsten Doping on the Properties of Titanium Dioxide Dye-Sensitized Solar Cells

Tungsten-doped TiO2 thin films were prepared by sol–gel method on fluorine-doped tin oxide-coated substrates as working electrodes of dye-sensitized solar cells. The influences of different W doping (0, 2, 4, 6, and 8 at%) on the microstructure, optical, and photovoltaic properties of the W-TiO2 thin-film DSSCs were studied by the measurement of X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) analysis, and electrochemical impedance spectroscopy (EIS). An optimal DSSCs performance was observed with a 6 at% W-doped TiO2 thin film, resulting in a Voc of 0.68 V, a Jsc of 20.2 mA/cm2, an FF of 68.6%, and an efficiency (η) of 9.42%. The efficiency of DSSCs with 6 at% W-doped TiO2 photoanode improved by 75%. This is because the 6 at% W-doped TiO2 thin film increases the specific surface area and electron transfer rate.

Production of 1,3-propanediol via in situ glycerol hydrogenolysis in aqueous phase reforming using bimetallic W-Ni/CeO2.

The production of 1,3-propanediol via in situ glycerol hydrogenolysis and aqueous phase reforming is a promising technique to ensure high product yield with shorter reaction times and lower costs, as demonstrated in this study by investigating the effect of tungsten (W) doping on Ni/CeO2 catalysts. Physicochemical properties of catalyst were determined using XRD, H2-TPR, NH3-TPD, BET, and FESEM-EDX techniques, and the catalytic performance was investigated at 230 °C, 20 bar, and 5 wt.% glycerol in an autoclave batch reactor. W doping ranging from 1-7% improved the catalyst's performance, with 3% W in 10% Ni/CeO₂ (3W10NC) achieving the highest yield (2.4%), selectivity (33.3%), and a good conversion rate (72.18%). The effect of reaction parameter on the 3W10NC catalyst showed that increasing pressure and temperature from the initial parameters had a detrimental effect on 1,3-propanediol attributed to the phenomenon called over-hydrogenolysis. Increasing the glycerol concentration to 20 wt.% also had a positive effect, resulting in the highest 1,3-propanediol yield of 22.27%. The effect of reaction time study revealed that the yield of 1,3-propanediol continued to increase steadily, reaching 38.29% after 4 h of reaction under the optimal conditions of 230 °C, 20 bar, and 20 wt.% glycerol. The kinetic study confirmed that the reaction follows first-order reaction with activation energy of 20.104 kJ mol-1. The catalyst reusability test revealed a decrease in the yield of 1,3-propanediol to 32.55%, likely due to deactivation caused by sintering and leaching, as indicated by the FESEM micrograph, EDX spectra, and NH3-TPD.

Promoting homogeneous tungsten doping in LiNiO2 through a grain boundary phase induced by excessive lithium

Promoting homogeneous tungsten doping in LiNiO2 through a grain boundary phase induced by excessive lithium

Dual-Functional Tungsten-Doped NiO for Highly Sensitive Triethylamine Sensor with ppb Level Detection Limit.

In this study, the W-doped Nickel oxide (NiO) nanoflowers were synthesized using a straightforward hydrothermal method, significantly enhancing the sensing performance toward triethylamine through dual-functional tungsten doping. The optimal doping concentration not only increased the specific surface area of NiO from 25.54 to 189.19 m2 g-1 but also reduced the formation energy of oxygen vacancies. The sensor containing 4 at % W-doped NiO demonstrated exceptional sensitivity to triethylamine, achieving a detection level as high as 229.0 for concentrations of 100 ppm at 237.5 °C. This triethylamine sensor represents a 135-fold enhancement over sensors fabricated from undoped NiO, and offers a rapid response/recovery time of 8 and 30 s, respectively. Furthermore, at a lower triethylamine concentration of 50 ppb, indicating a lower detection limit.

Understanding the role of tungsten species in diamond-like carbon coatings for enhanced interaction with ionic liquids

Understanding the role of tungsten species in diamond-like carbon coatings for enhanced interaction with ionic liquids

Heterogeneous Photocatalytic Degradation of Selected Pharmaceuticals and Personal Care Products (PPCPs) Using Tungsten Doped TiO2: Effect of the Tungsten Precursors and Solvents.

Pharmaceuticals and personal care products (PPCPs) which include antibiotics such as tetracycline (TC) and ciprofloxacin (CIP), etc., have attracted increasing attention worldwide due to their potential threat to the aquatic environment and human health. In this work, a facile sol-gel method was developed to prepare tungsten-doped TiO2 with tunable W5+/W6+ ratio for the removal of PPCPs. The influence of solvents in the synthesis of the three different tungsten precursors doped TiO2 is also taken into account. WCl6, ammonium metatungstate (AMT), and Na2WO4●2H2O not only acted as the tungsten precursors but also controlled the tungsten ratio. The photocatalyst prepared by WCl6 as the tungsten precursor and ethanol as the solvent showed the highest photodegradation performance for ciprofloxacin (CIP) and tetracycline (TC), and the photodegradation performance for tetracycline (TC) was 2.3, 2.8, and 7.8 times that of AMT, Na2WO4●2H2O as the tungsten precursors and pristine TiO2, respectively. These results were attributed to the influence of the tungsten precursors and solvents on the W5+/W6+ ratio, sample crystallinity and surface properties. This study provides an effective method for the design of tungsten-doped TiO2 with tunable W5+/W6+ ratio, which has a profound impact on future studies in the field of photocatalytic degradation of PPCPs using an environmentally friendly approach.

Dual-engineering of tungsten doping and carbon incorporation in vanadium carbide arrays to accelerate the polysulfide conversion for lithium-sulfur batteries

Dual-engineering of tungsten doping and carbon incorporation in vanadium carbide arrays to accelerate the polysulfide conversion for lithium-sulfur batteries

Accelerated oxygen reduction kinetics in BaCo0.4Fe0.4Zr0.2O3-δ cathode via doping with a trace amount of tungsten for protonic ceramic fuel cells

Accelerated oxygen reduction kinetics in BaCo0.4Fe0.4Zr0.2O3-δ cathode via doping with a trace amount of tungsten for protonic ceramic fuel cells

Impact of cerium and tungsten doping on the structural and optical characteristics of NiO nanoparticles

Co-precipitation, a rapid and effective technique, was used to produce Ce- and W-doped NiO nanoparticles at pH values of 10 and 12. The FT-IR, UV-visible spectroscopy, and X-ray diffraction techniques were used to examine the structural and optical characteristics. The NiO nanoparticles’ distinct XRD pattern revealed their monoclinic shape and crystalline origin. According to the Debye-Scherrer formula, the crystallite size of NiO nanoparticles decreased to 5.94 nm and 7.12 nm, respectively, when 5% Ce and 5% W were added, from 20.41 nm for undoped. Using UV-VIS absorption spectra, the optical band gap and the wavelength of maximum absorption were found. It was found that both of these parameters were influenced by the pH level and the concentration of Ce and W metal dopants. It can be concluded that doping has a higher impact on Cerium compared to Tungsten and at pH 10 compared to pH 12. This work presents a comprehensive investigation of the effects of pH and dopant concentration on the properties of Ce and W-doped NiO nanoparticles.

Tungsten-Doped ZnO as an Electron Transport Layer for Perovskite Solar Cells: Enhancing Efficiency and Stability.

This study delves into enhancing the efficiency and stability of perovskite solar cells (PSCs) by optimizing the surface morphologies and optoelectronic properties of the electron transport layer (ETL) using tungsten (W) doping in zinc oxide (ZnO). Through a unique green synthesis process and spin-coating technique, W-doped ZnO films were prepared, exhibiting improved electrical conductivity and reduced interface defects between the ETL and perovskite layers, thus facilitating efficient electron transfer at the interface. High-quality PSCs with superior ETL demonstrated a substantial 30% increase in power conversion efficiency (PCE) compared to those employing pristine ZnO ETL. These solar cells retained over 70% of their initial PCE after 4000 h of moisture exposure, surpassing reference PSCs by 50% PCE over this period. Advanced numerical multiphysics solvers, employing finite-difference time-domain (FDTD) and finite element method (FEM) techniques, were utilized to elucidate the underlying optoelectrical characteristics of the PSCs, with simulated results corroborating experimental findings. The study concludes with a thorough discussion on charge transport and recombination mechanisms, providing insights into the enhanced performance and stability achieved through W-doped ZnO ETL optimization.

Tungsten Doping of Two‐Dimensional VO2 Nanoribbons for Rapid Zinc Ion Storage Channels

AbstractVanadium‐based oxides are promising candidates for use in aqueous zinc‐ion batteries owing to their open framework structure that facilitates rapid Zn2+ deintercalation. To improve the kinetics, a two‐dimensional nanoribbon‐shaped W‐VO2 cathode material was developed by pre‐embedding tungsten atoms into VO2(B) using a one‐step hydrothermal method. The large interlayer spacing in the W‐VO2 nanosheets aided in the deintercalation of hydrated Zn2+ ions. The 1 % W‐doped electrode exhibited stable cycling, reaching a high capacity of 365.8 mAh g−1 at 0.3 A g−1, with a 92.6 % capacity retention (338.8 mAh g−1) after 200 cycles. Impressively, 84.3 % of the capacity is retained after 1200 cycles at 1 A g−1. The zinc storage mechanism of W‐VO2 was elucidated through in situ X‐ray diffraction and X‐ray photoelectron spectroscopy, highlighting the benefits of tungsten doping on tunnel structure stability and Zn2+ deintercalation reversibility in VO2 electrodes.

Improving the structural stability and reaction kinetic of Na3V2(PO4)3 through tungsten doping towards the ultralong cycle performance and excellent temperature tolerance of sodium ion batteries

Improving the structural stability and reaction kinetic of Na3V2(PO4)3 through tungsten doping towards the ultralong cycle performance and excellent temperature tolerance of sodium ion batteries

Bulk doping of tungsten improves the structure stability and electrochemical performance of layered Ni-rich material

Bulk doping of tungsten improves the structure stability and electrochemical performance of layered Ni-rich material

An Enhanced Synaptic Plasticity of Electrolyte-Gated Transistors through the Tungsten Doping of an Oxide Semiconductor

Oxide electrolyte-gated transistors have shown the ability to emulate various synaptic functions, but they still require a high gate voltage to form long-term plasticity. Here, we studied electrolyte-gated transistors based on InOx with tungsten doping (W-InOx). When the tungsten-to-indium ratio increased from 0% to 7.6%, the memory window of the transfer curve increased from 0.2 V to 2 V over a small sweep range of −2 V to 2.5 V. Under 50 pulses with a duty cycle of 2%, the conductance of the transistor increased from 40-fold to 30,000-fold. Furthermore, the W-InOx transistor exhibited improved paired pulse facilitation and successfully passed the Pavlovian test after training. The formation of WO3 within InOx and its ion intercalation into the channel may account for the enhanced synaptic plasticity.

Theoretical Study on Ion Diffusion Mechanism in W-Doped K3SbS4 as Solid-State Electrolyte for K-Ion Batteries.

The development of a solid-state electrolyte (SSE) is crucial for overcoming the side reactions of metal potassium anodes and advancing the progress of K-ion batteries (KIBs). Exploring the diffusion mechanism of the K ion in SSE is important for deepening our understanding and promoting its development. In this study, we conducted static calculations and utilized deep potential molecular dynamics (DeepMD) to investigate the behavior of cubic K3SbS4. The original K3SbS4 exhibited poor ionic conductivity, but we discovered that introducing heterovalent tungsten doping created vacancies, which significantly reduced the activation energy to 0.12 eV and enhanced the ionic conductivity to 1.80 × 10-2 S/cm. The diffusion of K-ions in K3SbS4 primarily occurs through the exchange of positions with K vacancies. This research provides insights into the design of SSE with high ionic conductivity. Furthermore, it highlights the effectiveness of DeepMD as a powerful tool for studying the SSE.

Morphology and Structural Studies of Tungsten Doped Arsenic Tellurite Glass and Glass-Ceramics

Morphology and Structural Studies of Tungsten Doped Arsenic Tellurite Glass and Glass-Ceramics

The effects of tungsten doping on the thermoelectric properties of Bi2O2Se

In this study, we investigate the effects of tungsten doping on the structural, electronic, and thermoelectric properties of Bi2O2Se using density functional theory combined with Boltzmann transport theory. As the tungsten is doped at Bi-site, the introduced additional electrons modify the electronic structure of Bi2O2Se significantly and lead to the metallic character of Bi2O2Se. Meanwhile, tungsten doping improves the electrical conductivity and power factor of Bi2O2Se, and optimizes the figure of merit ZT. This study demonstrates that tungsten doping is an effective method to modify the thermoelectric transport properties of Bi2O2Se.

Effective formaldehyde elimination over pyrolusite-manganite hybrid catalysts promoted by Keggin acid decoration: Tungsten doping and chemically adsorbed active oxygen

Effective formaldehyde elimination over pyrolusite-manganite hybrid catalysts promoted by Keggin acid decoration: Tungsten doping and chemically adsorbed active oxygen