Nickel Tungsten Research Articles

Non-enzymatic electrochemical detection of sarcosine in serum of prostate cancer patients by CoNiWBO/rGO nanocomposite

Selective and sensitive sarcosine detection is crucial due to its recent endorsement as a prostate cancer (PCa) biomarker in clinical diagnosis. The reduced graphene oxide-cobalt nickel tungsten boron oxides (CoNiWBO/rGO) nanocomposite is developed as a non-enzymatic electrochemical sensor for sarcosine detection in PCa patients’ serum. CoNiWBO/rGO is synthesized by the chemical reduction method via a one-pot reduction method followed by calcination at 500 °C under a nitrogen environment for 2 h and characterized by UV-Vis, XRD, TGA, and SEM. CoNiWBO/rGO is then deposited on a glassy carbon electrode, and sarcosine sensing parameters are optimized, including concentration and pH. This non-enzymatic sensor is employed to directly determine sarcosine in serum samples. Differential pulse voltammetry (DPV) and linear sweep voltammetry (LSV) are employed to monitor the electrochemical behavior where sarcosine binding leads to oxidation. Chronoamperometric studies show the stability of the developed sensor. The results demonstrate a wide linear range from 0.1 to 50 µM and low limits of detection, i.e., 0.04 µM and 0.07 µM using DPV and LSV respectivel. Moreover, the calculated recovery of sarcosine in human serum of prostate cancer patients is 78–96%. The developed electrochemical sensor for sarcosine detection can have potential applications in clinical diagnosis.

Fast-switching electrochromic smart windows based on WO3 doped NiO thin films

Nickel oxide (NiO) is a very promising material for the counter electrode in electrochromic devices (ECDs). In the current research, WO3 incorporated NiO thin films were fabricated via RF sputtering to enhance the electrochromic performance of NiO thin films. An XRD analysis revealed that the addition of WO3 to the cubic NiO thin film disrupts its long-range crystalline structure, resulting in an amorphous state. FESEM revealed the formation of columnar structure which favours ECDs. XPS analysis revealed that the addition of WO3 into NiO enhanced the hole concentration by creating nickel vacancies (nickel defects). Compared to pristine NiO, WO3 mixed NiO thin films showed enhanced optical modulation (66 %) with rapid switching speed (0.6 s/1.0 s for bleaching/colouring). This is mainly because the defect- induced amorphous structure of the nickel tungsten oxide thin film can provide large number of diffusion channels which facilitates the rapid ion intercalation process, and can accommodate large number of ions, and hence enhances the electrochromic performance. This advancement might have a substantial impact on the development of nickel tungsten oxide as a potential counter electrode in high-performance energy saving smart windows.

Preparation of Porous Ni-W Alloys Electrodeposited by Dynamic Hydrogen Bubble Template and Their Alkaline HER Properties

Nickel–tungsten (Ni-W) alloys are gaining significant attention due to their superior hardness, wear resistance, anti-corrosion and electrochemical hydrogen evolution reaction (HER) activity. In this work, porous and crack Ni-W alloys with different W contents were prepared in a pyrophosphate bath. The key to forming a porous structure is a very high current density over 300 mA cm−2. The HER activity of porous and crack Ni-W alloys was studied by means of electrochemical technologies of linear sweep voltammetry (LSV), Tafel curves (Taf) and electrochemical impedance spectroscopy (EIS). Compared with the crack Ni-W alloy, the porous Ni-W alloy exhibits improved alkaline electrochemical HER performances, which can deliver a current density of 10 mA cm−2 at 166 mV (η10) vs. RHE (reversible hydrogen electrode).

Synthesis of Nickel–Tungsten Bimetallic Carbide Nanoparticles for the Hydrodeoxygenation of Benzofuran

Synthesis of Nickel–Tungsten Bimetallic Carbide Nanoparticles for the Hydrodeoxygenation of Benzofuran

Preparation of biomimetic reinforced modified carbon fiber composites and study of their friction properties

Because aluminum-based parts cannot be used for long-term applications in large load-wear environments, nickel–tungsten (molybdenum disulfide)/carbon fiber/aluminum composites were successfully prepared in this study for that purpose. By adjusting the plating solution ratio, nickel–tungsten was used as a carrier to introduce molybdenum disulfide nanoparticles, forming a nickel–tungsten/molybdenum disulfide composite coating on the surface of carbon fibers. To enhance the interfacial bonding strength between the carbon fiber and aluminum matrix, a laser was employed to induce the formation of a honeycomb-like structure on the surface of the aluminum base. This increased the contact area between the carbon fiber, aluminum matrix, and epoxy resin adhesives, forming a nickel–tungsten (molybdenum disulfide)/carbon fiber/aluminum composite material. The performance of this composite material was tested and analyzed. The results demonstrated that compared with the carbon fiber/aluminum composite material, the shear strength of the nickel–tungsten (molybdenum disulfide)/carbon fiber/aluminum composite material was increased by 129.7 %, and the friction coefficient and wear rate were reduced by 54.8 % and 83 %, respectively. Next, investigation of the mechanism underlying the honeycomb structure's contribution to the adhesive strength of the composites and their resistance to shear load revealed that the wear-resistant mechanism of molybdenum disulfide nanoparticles reinforced the nickel–tungsten composite coatings. The preparation and study of nickel–tungsten (molybdenum disulfide)/carbon fiber/aluminum composites provide a reference for expanding the applications of aluminum-based composite materials to meet the service requirements of complex environments.

Construction of Nickel Tungsten Oxide Anchored Carbon Nanofibers Modified with Glassy Carbon Electrode for Enhanced Electrochemical Detection of Metronidazole in Urine and Environmental Water Sample

Metronidazole (MTD) is an antibiotic that is commonly used to treat pathogens and protozoal infections, which have a highly harmful impact on human health and domestic animals. Hence, the detection of MTD is highly necessary to avoid environmental pollution. The hydrothermal technique has been utilized to prepare Nickel Tungsten oxide (NiWO4) nanosheets which were anchored with the carbon nanofiber (CNF) to produce CNF/NiWO4 nanocomposite, the nanocomposite coated on the glassy carbon electrode (GCE) and applied to the electrochemical detection of MTD. Besides, field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), energy dispersive X-ray analysis (EIS), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy. Moreover, electrochemical impedance spectroscopy (EIS), cyclic voltammetry studies (CV), and differential pulse voltammetry (DPV) were also handled for the identification of the electrochemical behavior of the GCE/CNF/NiWO4 electrode responses. Finally, the CNF/NiWO4 electrode shows a low detection limit of 0.4 μM, a wide linear response range of 0.01–650 μM, and a higher sensitivity of 0.274 μA μM−1 cm−2, with better repeatability, reproducibility, and excellent stability. Finally, the prepared GCE/CNF/NiWO4 electrodes were employed to detect MTD in tap water and urine samples with acceptable recoveries.

Influence of Cobalt content on the microstructure and texture evolution of hot-press sintered Tungsten nickel copper Alloy (W-Ni-Cu)

This study examines the effect of cobalt on the crystallographic texture and grain boundary evolution of hot-press sintered tungsten heavy alloy (W-4.9Ni-2.1Cu). Traditional tungsten heavy alloy with a Ni:Cu ratio of 7:3 has cobalt added (i.e., cobalt content increased from 0 to 1 wt% with a 0.25 wt% interval). The samples were produced using the hot press sintering method with the following parameters: 50 MPa pressure, 10 °C/min heating rate, 1450 °C temperature, and a 20-min hold time. The unalloyed cobalt WHA compact has a fibre texture in the (001) plane that is aligned in the 〈111〉 orientation. In addition, the cobalt-alloyed WHAs compacts exhibit a lower proportion of grain boundaries with low angles. Enhanced solid solution formation between cobalt and WHAs during liquid phase sintering led to increased compacts densification and randomised weak fibre development in cobalt-alloyed compacts. Texture deterioration (001) <111> in cobalt-added WHAs is caused predominantly by substructural recovery during liquid phase sintering. This study indicates that the addition of cobalt to the stoichiometry of WHAs resulted in the homogenous distribution of binder matrix within the compact during sintering. As a result, the W-4.9Ni-2.1Cu-1Co alloy exhibited improved microhardness (429.5 HV0.5), electrical conductivity (23.34% of IACS), and relative density (98.10%).

The hardfacing properties of the nickel-based coating deposited by the PTA process with the addition of wc nano-particles: Wear investigation

The impact of the addition of tungsten carbide (1 to 7 wt%) on the microstructure and wear characteristics of the nickel–tungsten carbide composite layer fabricated by the plasma transferred arc (PTA) process was studied. With the addition of nanoparticles, the degree of segregation becomes lower while heterogeneous nucleation increases and refining of the microstructure enhances. Wear rate and coefficient of friction for all samples with increasing the load from 1 to 5 N decrease and wear mechanism changes from abrasive to adhesive. The higher wear resistance for samples with 3%wt is due to a decrease in the porosity of the composite coatings, strong interfacial bonding, and promotion in the deposition efficiency at the same time.

Determining Hot Deformation Behavior and Rheology Laws of Selected Austenitic Stainless Steels

Due to their versatile properties, austenitic stainless steels have a wide application potential, including in specific fields, such as the nuclear power industry. ChN35VT steel is a chromium–nickel–tungsten type of steel stabilized by titanium, and it is suitable for parts subjected to considerable mechanical stress at elevated temperatures. However, the available data on its deformation behavior at elevated/high temperatures is scarce. The core of the presented research was thus the experimental characterization of the deformation behavior of the ChN35VT steel under hot conditions via the determination of flow stress curves, and their correlation with microstructure development. The obtained data was further compared with data acquired for 08Ch18N10T steel, which is also known for its applicability in the nuclear power industry. The experimental results were subsequently used to determine the Hensel-Spittel rheology laws for both the steels. The ChN35VT steel exhibited notably higher flow stress values in comparison with the 08Ch18N10T steel. This difference was more significant the lower the temperature and the higher the strain rate. Considering the peak stress values, the lowest difference was ~8 MPa (1250 °C and 0.01 s−1), and the highest was ~150 MPa (850 °C and 10 s−1). These findings also corresponded to the microstructure developments—the higher the deformation temperature, the more negligible the observed differences as regards the grain size and morphology.

In situ formed nickel tungsten oxide amorphous layer on metal–organic framework derived ZnxNi1−xWO4 surface by self-reconstruction for acid hydrogen evolution reaction

Noble metal free electrocatalysts for hydrogen evolution reaction (HER) in acid play an important role in proton exchange membrane-based electrolysis. Here, we develop an in situ surface self-reconstruction strategy to construct excellent acidic HER catalysts. Firstly, free-standing zinc nickel tungstate nanosheets inlaid with nickel tungsten alloy nanoparticles were synthesized on carbon cloth as pre-catalyst via metal–organic framework derived method. Amorphous nickel tungsten oxide (Ni-W-O) layer is in situ formed on surface of nanosheet as actual HER active site with the dissolution of NiW alloy nanoparticles and the leaching of cations. While the morphology of the free-standing structure remains the same, keeping the maximized exposure of active sites and serving as the electron transportation framework. As a result, benefiting from disordered arrangement of atoms and the synergistic effect between Ni and W atoms, the amorphous Ni-W-O layer exhibits an excellent acidic HER activity with only an overpotential of 46 mV to drive a current density of 10 mA cm−2 and a quite good Tafel slope of 36.4 mV dec−1 as well as an excellent durability. This work enlightens the exploration of surface evolution of catalysts during HER in acidic solution and employs it as a strategy for designing acidic HER catalysts.

Production of Single-Crystal Seeds [001] from Nickel–Tungsten Alloys by Directional Crystallization

Production of Single-Crystal Seeds [001] from Nickel–Tungsten Alloys by Directional Crystallization

Surface reconstruction and charge distribution enabling Ni/W5N4 Mott-Schottky heterojunction bifunctional electrocatalyst for efficient urea-assisted water electrolysis at a large current density

Urea-assisted water electrolysis is regarded as an energy-efficient strategy for hydrogen production, but its potential use is still limited by sluggish kinetics in both anodic urea oxidation reaction (UOR) and cathodic hydrogen evolution reaction (HER). Herein, we report the facile synthesis of nickel foam (NF) supported Ni/W5N4 Mott-Schottky heterojunction nano-microspheres as a highly active catalyst for both UOR and HER using a hydrothermal method followed by nitridation treatment. The as-prepared Ni/W5N4/NF catalyst with high electrochemically active surface area would reconstruct under oxidizing condition to form nickel tungsten oxyhydroxides to efficiently drive UOR, with a potential of only 1.34 V (versus reversible hydrogen electrode) at 10 mA cm−2. Impressively, thus-prepared catalyst benefited from charge redistribution only required an overpotential of 25 mV at 10 mA cm−2 for HER. In particular, the Ni/W5N4/NF catalyst couple used for urea-assisted water electrolysis just needed a cell voltage of 1.77 V at 1000 mA cm−2.

Effect of hBN on Corrosion and Wear Performances of DC Electrodeposited NiW and NiW–SiC on Brass Substrates

Crack-free and uniform nickel–tungsten (NiW) coatings and their composite coatings filled with ceramic particles such as silicon carbide (SiC) and hexagonal-boron nitride (hBN) were deposited on brass substrates by applying direct current (DC) waveforms. Among all coatings, NiW–SiC–hBN coatings displayed the noblest corrosion potential (−0.49 V) and lowest current density (4.36 × 10−6 A·cm−2). It also seems that addition of hBN and SiC ceramic particles to NiW matrix remarkably improved the wear performance of the NiW coatings. However, NiW–hBN exhibited the lowest wear volume (48.84 × 103 µm3) and the friction coefficient of 0.1 due to ultra–low friction coefficient of hBN particles.

Highly Regular Hexagonally-Arranged Nanostructures on Ni-W Alloy Tapes upon Irradiation with Ultrashort UV Laser Pulses.

Nickel tungsten alloy tapes (Ni—5 at% W, 10 mm wide, 80 µm thick, biaxially textured) used in second-generation high temperature superconductor (2G-HTS) technology were laser-processed in air with ultraviolet ps-laser pulses (355 nm wavelength, 300 ps pulse duration, 250–800 kHz pulse repetition frequency). By employing optimized surface scan-processing strategies, various laser-generated periodic surface structures were generated on the tapes. Particularly, distinct surface microstructures and nanostructures were formed. These included sub-wavelength-sized highly-regular hexagonally-arranged nano-protrusions, wavelength-sized line-grating-like laser-induced periodic surface structures (LIPSS, ripples), and larger irregular pyramidal microstructures. The induced surface morphology was characterized in depth by electron-based techniques, including scanning electron microscopy (SEM), electron back scatter diffraction (EBSD), cross-sectional transmission electron microscopy (STEM/TEM) and energy dispersive X-ray spectrometry (EDS). The in-depth EBSD crystallographic analyses indicated a significant impact of the material initial grain orientation on the type of surface nanostructure and microstructure formed upon laser irradiation. Special emphasis was laid on high-resolution material analysis of the hexagonally-arranged nano-protrusions. Their formation mechanism is discussed on the basis of the interplay between electromagnetic scattering effects followed by hydrodynamic matter re-organization after the laser exposure. The temperature stability of the hexagonally-arranged nano-protrusion was explored in post-irradiation thermal annealing experiments, in order to qualify their suitability in 2G-HTS fabrication technology with initial steps deposition temperatures in the range of 773–873 K.

Syntheis of Liquid Fuel Products by the Catalytic Hydroliquefaction of Sapropels Using Nickel and Nickel–Tungsten Catalysts

Syntheis of Liquid Fuel Products by the Catalytic Hydroliquefaction of Sapropels Using Nickel and Nickel–Tungsten Catalysts

Effect of pulse reverse current waveform on tribological and mechanical properties of electrodeposited nickel–tungsten alloys on brass substrate

ABSTRACT The precise control of tungsten content of electrodeposited nickel–tungsten (NiW) on brass substrate was achieved by applying a well-designed pulse reverse current waveform. A crack-free, uniform and, mirror-like finish surface was obtained by using a novel derivative of propargyl compound, propargyl-oxo-propane-2,3-dihydroxy, as a brightener and grain refiner into the electrodeposition bath. This study indicates that the electrodeposited nickel–tungsten alloys with an optimum tungsten content (32 wt%) possesses outstanding mechanical and, wear performance, also with very low friction of coefficient of 0.2.

Electrochemical Detection of Nitrite Using an Asymmetrically Substituted Cobalt Phthalocyanine Conjugated to Metal Tungstate Nanoparticles

AbstractThis paper explores the synthesis and characterisation of an asymmetrical Co phthalocyanine (CoPc), and its covalent linking to two tungsten nanoparticles: bismuth tungsten oxide (Bi2WO6) and nickel tungsten oxide (NiWO4). The nanoparticles were also mixed with the CoPc. The CoPc, nanoparticles and their respective conjugates were used as electrocatalysts in the electrochemical detection of nitrite. The electrocatalysts studied in this work had sensitivities ranging from 3–133 μA/mM while the limits of detection (LoDs) ranged between 0.063 μM and 1.7 μM. Bi2WO6 and its conjugate exhibited better LoD than corresponding NiWO4 and conjugate.

Cleaner Fuel Production via Co-Processing of Vacuum Gas Oil with Rapeseed Oil Using a Novel NiW/Acid-Modified Phonolite Catalyst

Clean biofuels are a helpful tool to comply with strict emission standards. The co-processing approach seems to be a compromise solution, allowing the processing of partially bio-based feedstock by utilizing existing units, overcoming the need for high investment in new infrastructures. We performed a model co-processing experiment using vacuum gas oil (VGO) mixed with different contents (0%, 30%, 50%, 70%, 90%, and 100%) of rapeseed oil (RSO), utilizing a nickel–tungsten sulfide catalyst supported on acid-modified phonolite. The experiments were performed using a fixed-bed flow reactor at 420 °C, a hydrogen pressure of 18 MPa, and a weight hourly space velocity (WHSV) of 3 h−1. Surprisingly, the catalyst stayed active despite rising oxygen levels in the feedstock. In the liquid products, the raw diesel (180–360 °C) and jet fuel (120–290 °C) fraction concentrations increased together with increasing RSO share in the feedstock. The sulfur content was lower than 200 ppm for all the products collected using feedstocks with an RSO share of up to 50%. However, for all the products gained from the feedstock with an RSO share of ≥50%, the sulfur level was above the threshold of 200 ppm. The catalyst shifted its functionality from hydrodesulfurization to (hydro)decarboxylation when there was a higher ratio of RSO than VGO content in the feedstock, which seems to be confirmed by gas analysis where increased CO2 content was found after the change to feedstocks containing 50% or more RSO. According to the results, NiW/acid-modified phonolite is a suitable catalyst for the processing of feedstocks with high triglyceride content.

Green Synthesis and Characterization of Nickel Tungsten Bimetallic Oxide Nanoparticles via Microwave Irradiation Technique

Nickel tungsten bimetallic oxide nanoparticles were synthesised in ethylene glycol using microwave irradiation technique. Nickel and tungsten oxide nanoparticles were synthesised separately using microwave assisted polyol synthesis method. The respective systems are combined together in ratio 1:1 molar and are subjected to microwave irradiation to get Ni-W bimetallic oxide. The structure and composition of nanoparticles were characterised by UV-Visible Spectroscopy, FT-IR Spectroscopy, X-Ray Diffraction (XRD), Energy Dispersion Spectroscopy (EDS), Transmission Electron Microscopy (TEM), Photoluminescence Spectroscopy (PL) and Magnetic Susceptibility measurements. From the XRD and FTIR measurements, nanocrystalline Wolframite structure of Ni-W bimetallic oxide nanoparticles was established. The emperical formula of the nanoparticle is found as Ni0.4W0.6O2.6. The composition may be varied by changing the ratio of Ni and W. A maximum absorbance of 385nm was obtained in UV-Visible spectrum and three emission peaks were obtained in the visible region of photoluminescent studies. Further studies can be done on the catalytic and electrochromic properties of the substance.

Fine patterned YBCO films grown on flexible nickel–tungsten substrates by photosensitive sol–gel method

In recent years, efforts devoted to the study of processing technologies for flexible devices have been increasing significantly. The fabrication of YBa2Cu3O7-x (YBCO) fine patterns on flexible nickel–tungsten (NiW) substrates is beneficial for the application of flexible superconducting electronic devices. The most challenging task is the simultaneous achievement of fine patterning and biaxial epitaxial growth of YBCO films on NiW substrates. This work reports the application of the photosensitive sol–gel lithography in combination with an all chemical deposition process to prepare fine patterned YBCO films on NiW substrates using gadolinium-doped lanthanum zirconate (LGZO) films as buffer layers. High-quality patterned YBCO films were epitaxially grown on LGZO–buffered NiW substrates, and the well-continuous YBCO patterns on flexible substrates could withstand bending deformations. The superconductivity remains good after the mechanical bending deformation process. These results are useful as guidance for the application of flexible superconducting devices.