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Understanding the behavior of intrinsic defects and helium (He) in tungsten oxides is useful for the application of tungsten (W) in a fusion environment because of the oxidation of W surfaces. The formation and diffusion energies of intrinsic defects and He in monoclinic γ-WO3 have been investigated using first-principles density functional theory calculations. The formation energy and diffusion activation energy of O defects are lower than W defects. O vacancy prefers to diffuse along the ⟨ 001 ⟩ direction, then followed by ⟨ 010 ⟩ and ⟨ 100 ⟩ directions; however, the W vacancy is immobile at temperatures lower than 2000 K. The stability of Schottky defects (SDs) is sensitive to their geometry and orientation. W interstitials prefer to move along the [100] direction, while O interstitials jump around W atoms rather than through the W quasi-cubic centers. He interstitial atoms are predicted to have a high solubility and an anisotropic diffusion mechanism in γ-WO3. In addition, the effect of biaxial strain on the solubility and diffusivity of He interstitials was investigated. He interstitials prefer to reside at individual sites rather than clusters. He atoms are weakly trapped by single vacancies or SDs. Vacancies assist the local migration of nearby He. Correspondingly, He self-clustering and bubble formation are less likely to form in γ-WO3 relative to bcc W. The energetics obtained in this work can be used to predict the microstructure evolution of the WO3 layer on a W substrate exposed to He plasmas at different temperatures. [ABSTRACT FROM AUTHOR]

The undesirable intrinsic activity of tungsten oxides derived from poor conductivity and adverse hydrogen absorption energy is insufficient for their practical application. Herein, the tungsten oxides with adjustable oxygen vacancies were synthesized by a facile pyrolysis of ammonium paratungstate hydrate in controllable atmospheres. The structural characterizations confirmed that oxygen vacancies and crystalline phases in tungsten oxides depend on the pyrolysis atmosphere. The electrochemical test indicated a strong dependence between catalytic activity and oxygen vacancies in tungsten oxides. Combining experimental results and density functional theory calculations verified that introducing oxygen vacancies into tungsten oxides effectively modulates the surface electronic structure. The enhanced electronic conductivity by reducing band gap accelerates the electron transfer from catalysts into the reactive species. The optimized hydrogen adsorption energy by electron migration from O into W promotes the activation of reactive species at W sites and the desorption from O sites, thereby accelerating the reaction kinetics. The regulated oxygen vacancies in tungsten oxides was availably achieved by controlling the annealing atmospheres for ammonium paratungstate hydrate. The as-prepared tungsten oxide catalysts exhibit a strong dependence between oxygen vacancies contents and catalytic activity for hydrogen evolution reaction. The experimental observations and theoretical calculations confirm that oxygen vacancies introduced into tungsten oxides can enhance the electronic conductivity and optimize the hydrogen adsorption energy to remarkably improve the catalytic activity. [Display omitted] • Oxygen vacancies in WO 3 were regulated by controlling annealing atmospheres. • WO 3 exhibits a strong dependence between oxygen vacancies and catalytic activity. • Introducing oxygen vacancies reduces band gap to improve electronic conductivity. • Oxygen vacancies optimize hydrogen adsorption energy on tungsten oxides. [ABSTRACT FROM AUTHOR]

In this study, tungsten oxide nanosheets loaded with nitrogen-doped graphene oxide quantum dots (NGQDs/WO3 NSs) were fabricated as SERS substrates. The promoted photo-induced charge transfer (PICT) and the strong π–π stacking effect resulting from the unique structure of the NGQDs contributed to the enhanced SERS signal. [ABSTRACT FROM AUTHOR]

Nano tungsten carbide (WC) was synthesized using loose yellow tungsten oxide (WO3) rods, which were derived from violet tungsten oxide (WO2.72) through calcination in dry oxygen. The WO3 rods were then subjected to ball milling with carbon black, followed by carbothermal reduction and carbonization. Unlike conventional methods such as hydrogen reduction or carbothermal reduction, this technique avoids the formation of hydrated tungsten oxides and addresses challenges related to precise carbon control and matching. This streamlined procedure produces nanoscale tungsten carbide particles approximately 150 nm in size, showing great potential for future industrial applications. [ABSTRACT FROM AUTHOR]

Electrochromic technology plays a pivotal role in various industries, offering significant benefits in energy efficiency and sustainability. By efficiently modulating sunlight, it reduces dependence on traditional climate control systems, thus decreasing overall energy consumption. Among electrochromic materials, tungsten oxide (WO 3) is highly favored for its outstanding stability and superior optical modulation amplitude. However, the escalating demands of commercial applications necessitate enhancements in electrochromic performance, achievable through doping or composite designs. This study investigates the electrochromic characteristics of novel niobium tungsten oxide (Nb 18 W 16 O 93) thin films, employing a gel electrolyte and examining their structural, optical, and electrochemical attributes. Compared to pure WO 3 , the Nb 18 W 16 O 93 -based electrochromic device exhibited a significant optical modulation of 55.1% in the visible spectrum and 31.3% in the near-infrared region. The gel-based device not only provides safety benefits over liquid electrolytes by mitigating leakage risks but also features rapid switching response times, with a coloration duration of 3.9 s and a bleaching interval of 3.6 s. Moreover, the device showcases exceptional long-term stability, retaining a ΔT of nearly 72% after 10,000 cycles. [ABSTRACT FROM AUTHOR]

Thin film technology is significant in technological progress and modern research because it allows for the production of optoelectronic devices with improved characteristics. Because of its superior chromatic efficiency, tungsten oxide (WO3) is one of the best candidates for energy-saving applications. In this study, undoped and tin (Sn)-doped WO3 films were grown on top of WO3 seed layers directly by a facile hydrothermal route at a temperature as low as 110∘C for 24 h. The seed layers were also deposited on top of glass substrates using spray pyrolysis. The results of tin doping on the structural, optical, and morphological characteristics of the WO3:Sn films were studied. X-ray diffraction patterns show that peak intensities increase significantly by adding Sn and the films' crystallinity was improved by rising Sn content. In the visible region, the average optical transmittance is around 13% and the optical bandgap changes from 2.61 eV to 2.81 eV, by increasing the dopant amount. Finally, the room temperature photoluminescence of samples shows intense green light emissions. The results of this research can be beneficial for the fabrication and performance optimization of electrical and optical devices such as gas sensors, electrochromic devices, and photosensors. [ABSTRACT FROM AUTHOR]

Tungsten oxides suffer from sluggish ion diffusion kinetics, limited ion storage capacity, and inadequate stability within the aqueous zinc ion electrolyte, thereby constraining their applicability in electrochromic energy storage devices (EESDs). Here, the amorphous hydrated tungsten oxide films with large optical modulation, fast response speed, large capacity, and high cycling stability are reported, enabled by tuning the contents of structural water and adjusting the pH value of aqueous zinc ion electrolyte. The enhancement of the electrochromic and ion storage performance is mainly due to the introduction of structural water which triggers pseudocapacitive behavior dominated by surface redox reaction, resulting in high electrochemical activity and fast electrochemical kinetics. Meanwhile, the relatively low pH value ensures the chemical stability of the hydrated tungsten oxide film, in synergy with surface redox that avoids ion trapping, leading to extraordinary cycling stability of up to 13000 cycles, marking the state‐of‐the‐art stability for tungsten oxide‐based materials in aqueous electrolyte. Based on the hydrated tungsten oxide films, high‐capacity and stable large‐size EESDs are constructed with the capability of visually monitoring energy status, recovering energy, and regulating light. This work provides a simple yet effective strategy for enhancing the performance of tungsten oxide‐based aqueous zinc ion EESDs. [ABSTRACT FROM AUTHOR]

This article explores the structuring sodium tungstate with sodium dodecyl sulphate (SDS) in water and characterizing the resulting products post-destabilization with hydrochloric acid and calcination. Utilizing nuclear magnetic resonance (NMR), small-angle X-ray scattering (SAXS), fluorescence spectroscopy with a pyrene probe, conductivity, and pH analyses, the study elucidates the system's structure and interactions. SDS serves as a structuring agent for tungstate anions in water, with sulphate anions interacting with tungsten d-orbitals. The presence of SDS significantly influences final structures after calcination. Higher precursor/structuring agent ratios result in higher proportion of tungsten oxide, alongside Na 2 W 2 O 7 and Na 2 W 4 O 13. Varying calcination temperatures yield different crystal structures and morphologies, including flower petals and roses at 500 °C and nanorods at 700 °C. These findings shed light on material structuring processes. The obtained materials exhibit to utilize solar radiation for chemical reactions. [ABSTRACT FROM AUTHOR]

The ability to actively control broadband light absorption and reflection ranging from deep‐ultraviolet (DUV) to near‐infrared (NIR), is crucial for various optical and optoelectronic applications. Herein, a novel type of ultrathin, lithography‐free, and broadband aperiodic thin‐film metamaterial coatings (metacoatings) is inverse‐designed from DUV to NIR (190–1700 nm), which is composed of a series of deeply subwavelength tungsten oxide layers with graded refractive index profiles (by varying the deposited Ar gas pressures from 0.1 to 3.0 Pa) above an opaque aluminum layer. Experimental results show that these proposed aperiodic metacoatings can realize a transition from broadband strong absorption (as‐deposited state) to high reflection (annealed state) from visible (VIS) to NIR (400–1700 nm), through thermal annealing techniques. The aperiodic metacoatings have an overall thickness of just ≈200 nm, with angle‐insensitive up to 70° as well as are polarization‐independent. Furthermore, vivid structural colors can be generated by rearranging the aperiodic tungsten oxide layers and finally employed in color display applications. These aperiodic metacoatings offer a very promising platform for many applications such as broadband photodetectors, thermophotovoltaics, information encryption devices, etc. [ABSTRACT FROM AUTHOR]

Tungsten oxide (WO3)-based memristors show promising applications in neuromorphic computing. However, single-layer WO3 memristors suffer from issues such as weak memory performance and nonlinear conductance variations. In this work, a functional layer based on the hybrids of WO3−x and TiO2 is proposed for constructing flexible memristors featuring outstanding synaptic characteristics. Applying diverse electrical stimulations to the memristor enables a range of synaptic functions, elucidating its conduction mechanism through the conductive filament model. The incorporation of TiO2 not only enhances the memristor's memory characteristics but makes its conductance more linear, symmetrical and uniform during the long-term changes. Furthermore, in view of the enhanced device performance by TiO2 doping, the potential of this device for simple behavioral simulation and processing of complex computing problems is explored. The "learning-forgetting-relearning" characteristics and device integrability are visually demonstrated. Applying the device to a convolutional neural network, the recognition accuracy of MNIST handwritten digits reaches 98.7%. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

An effective method capable of simultaneously providing antibacterial activity, blood glucose regulation, and angiogenesis promotion for healing bacteria‐infected diabetic wounds is not reported to date, but urgently required. In this study, a hydrogel composite (γ‐PGA/PDA/GOx/WOx (PPGW)), endowed with these desired attributes is fabricated by incorporating polydopamine (PDA), glucose oxidase (GOx), and tungsten oxide (WOx) nanowires into the poly(γ‐glutamic acid) (γ‐PGA) framework. The exceptional photothermal conversion properties of PDA facilitated notable antibacterial effects on bacteria‐infected diabetic wounds; GOx regulated high blood glucose by consuming glucose and generating hydrogen peroxide (H2O2); while WOx nanowires displayed remarkable photocatalytic abilities, converting H2O2 into oxygen (O2) when exposed to 808‐nm near‐infrared radiation. Density functional theory calculations and experiments are conducted to confirm the mechanism of WOx‐mediated photocatalytic degradation of H2O2 to produce O2. These transformations aided in alleviating the hypoxic conditions in wounds associated with diabetes, expediting angiogenesis, and fostering cell crawling and proliferation. Consequently, the multifunctional hydrogel dressing PPGW, featuring photothermal, antibacterial, and enzyme‐catalyzed activity reduces hyperglycemia at the wound site. Moreover, photocatalytic O2 production represents a promising strategy for addressing chronic bacteria‐infected diabetic wounds. [ABSTRACT FROM AUTHOR]

[Display omitted] • Successful construction of Pd/WO 3-x heterostructures. • Strong photoabsorption and high photothermal efficiency. • Efficient interfacial charge transfer and utilization of hot carriers. • High reactivity and selectivity for hydrodeoxygenation of vanillin under sunlight. The selective hydrodeoxygenation (HDO) of sustainable lignocellulosic biomass plays a pivotal role in the conversion of biomass into high-value fuels and chemicals. Nevertheless, HDO for biomass upgrading always demands high temperatures and high hydrogen (H 2) pressure. Photothermal catalysis has been recognized as an effective approach for boosting chemical reactions under mild conditions while maintaining superior selectivity. Herein, we report the design of palladium-decorated defective tungsten oxide (Pd/WO 3-x) catalysts with enhanced photothermal catalytic performances for the efficient HDO of vanillin. Pd/WO 3-x nanoflowers have been synthesized through a solvothermal/ in-situ reduction two-step strategy, and they exhibit notable photoabsorption in a wide range (200–1100 nm), high photothermal conversion and efficient charge separation efficiency. Under simulated sunlight irradiation (0.3 W cm−2), Pd/WO 3-x exhibits a maximum vanillin conversion up to 86.8 % with a 2-methoxy-4-methylphenol (MMP) selectivity of 100 %, which is obviously higher than that (vanillin conversion = 33.1 %, MMP selectivity = 100 %) in the oil bath at the same temperature. Such higher conversion efficiency and selectivity under sunlight should result from the synergistic integration of hot electrons and photothermal heating, both of which are derived from localized surface plasmon resonance (LSPR) in WO 3-x. Importantly, Pd/WO 3-x catalyst demonstrates good stability and high selectivity to MMP even after 5 cycles. This work may offer a novel viewpoint on the advancement of photothermal catalysts and the realization of photothermal catalytic biomass conversion under mild conditions. [ABSTRACT FROM AUTHOR]

In the present study, the effect of precursor concentration for WO 3 deposition by AACVD method was investigated. At the outset, H 2 WO 4 was synthesized as the precursor for the deposition process. In the next step, H 2 WO 4 solutions used in the AACVD process, with concentrations of 0.1, 0.5, and 1 M, were evaluated using a static wettability test. CV test revealed that at a concentration of 0.5 M, a higher number of charge carriers were involved in the redox process. CA and EIS tests were also employed to measure the impact of concentration on the electrochemical properties of the coated samples. Based on these findings, the concentration of 0.5 M was identified as optimal. Subsequently, Triton X-100 was added to the solution as a surfactant, and the deposition process was carried out. All the aforementioned tests were also conducted on the 0.5 M + Triton sample. Microstructural studies showed that the addition of Triton X-100 to the 0.5 M solution significantly improved the uniformity of the deposited tungsten oxide films. Based on optical measurements, the 0.5 M + Triton sample exhibited the optimal optical modulation (55.66 %), and coloration efficiency (40.37 cm2C-1) at the wavelength of 633 nm. [ABSTRACT FROM AUTHOR]

Direct photocatalytic conversion of benzene to phenol with molecular oxygen (O2) is a green alternative to the traditional synthesis. The key is to find an effective photocatalyst to do the trick. Defect engineering of semiconductors with oxygen vacancies (OVs) is an emerging strategy for catalyst fabrication. OVs can trap electrons to promote charge separation and serving as adsorption sites for O2 activation. However, the randomly distribution of OVs on the semiconductor surface often results in mismatching the charge carrier dynamics under irradiation, thus failing to fulfill the unique advantages of OVs for photoredox functions. Herein, we demonstrate that abundant OVs can be facilely generated and precisely located adjacent to the reductive sites on reducible oxide semiconductors such as tungsten oxide (WO3) via a simple photochemistry strategy. Such photoinduced OVs are well suited for photocatalytic benzene oxidation with O2 as they readily capture photogenerated electrons from the reductive sites of WO3 to activate adsorbed O2. The oxygen‐isotope‐labeling experiments further confirm that the OVs also facilitate the integration of oxygen atoms from O2 into phenol, revealing in detail the pathway for photocatalytic benzene hydroxylation. This study demonstrates that the photochemistry approach is an appealing strategy for the synthesis of high‐performance OVs‐rich photocatalysts for solar‐induced chemical conversion. [ABSTRACT FROM AUTHOR]

The essential raw materials, cyclohexanol and cyclohexanone, are derived from the selective catalytic oxidation of cyclohexane. Due to their closely matched boiling points, the efficient separation among the components remains a significant challenge in industrial catalysis. In this work, we employed DFT calculations to explore the adsorption behavior of CyH, CyOH, and Cy═O, on both clean and Ag‐modified ɦ‐WO3 (001) surfaces. The calculation results reveal that Ag4 exhibits the highest stability on the ɦ‐WO3 (001) surface. The organic species adsorbed onto the Agn‐WO3 surfaces through distinct host‐guest interactions: CyH via CH···Ag, CyOH, and Cy═O via HO···Ag and C═O···Ag, respectively. The optimal separation efficacy of CyOH and Cy═O on the Ag2‐WO3 surface results in CyOH as the preferred product, while on the Ag4‐WO3 surface, Cy═O serves as the ultimate outcome. Our theoretical calculations provided in this study offer a valuable theoretical foundation for the separation of the KA oil mixture. [ABSTRACT FROM AUTHOR]

Hydrogen, known for its high energy density and environmental benefits, serves as a prime substitute for fossil fuels. Nonetheless, the hydrogen evolution reaction (HER), essential in electrolysis, encounters challenges with slow kinetics and significant overpotential, which elevate costs and reduce efficiency. Thus, developing efficient electrocatalysts to reduce HER overpotential is vital to enhance hydrogen production efficiency and minimize energy consumption. Adjusting the electronic structure of transition metal oxides via elemental doping is a potent strategy to improve the effectiveness of electrocatalysts for hydrogen evolution. In this work, we synthesized a set of niobium‐doped tungsten oxides (Nbx‐W18O49) under anoxic conditions using a straightforward “one‐pot” solvothermal approach. After doping Nb, the oxygen vacancy content inside W18O49 was increased, which induced a synergistic effect with the active sites of tungsten. In acidic environments, the hydrogen evolution activity of the Nb0.6‐W18O49 electrocatalyst is second only by 20 wt % Pt/C. It attains a current density of −10 mA cm−2 at an overpotential of 102 mV. By comparison with W18O49, Nb0.4‐W18O49 and Nb0.5‐W18O49, Nb0.6‐W18O49 demonstrates a reduced charge transfer resistance, which significantly enhances its conductivity and the speed of electron movement across interfaces. Coupled with this feature are notably faster HER kinetics. Additionally, it exhibits excellent stability, meaning it maintains its performance and structural integrity over prolonged periods and under various operational conditions. This article provides a new perspective for discovering inexpensive and efficient hydrogen evolution electrocatalyst materials. [ABSTRACT FROM AUTHOR]

Once widely utilised in both human and veterinary medicine, tetracycline antibiotics are now recognised as major environmental pollutants with detrimental effects on the environment and human health. Concerns regarding allergic responses, gastrointestinal problems, and diseases resistant to antibiotics are raised by their persistence in soil, groundwater, and surface water. The production of a tungsten disulfide-graphene oxide nanocomposite for tetracycline degradation under varied light sources is presented in this work. The successful incorporation of tungsten disulfide on graphene oxide structures was confirmed by characterization using Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) and X-ray Diffraction (XRD). This revealed characteristic peaks for hydroxyl (3328 cm-1), carbonyl (1732 cm-1), alkene (1583 cm-1), and ether (1044 cm-1) bonds, as well as sulphur bonding (500 to 739 cm-1). With a D-spacing of 2.24 nm, the tungsten disulphide-graphene oxide nanocomposite had a strong peak at 2θ = 15.5°corresponds to the (002) plane, as shown by X-ray diffraction. A distinctive GO peak was found at 2θ = 10.1°, which corresponds to the plane (002). With light emitting diodes (95.67%), fluorescent lights (81.28%), and ultraviolet-visible light (88.09%), the nanocomposite in a photoreactor showed excellent photocatalytic efficiency. The better performance of the tungsten disulfide-graphene oxide nanocomposite under varying illumination circumstances, as determined by the Langmuir-Hinshelwood (LH) model, presents a viable and sustainable option for tetracycline degradation in water purification. This technique tackles a long-term strategy for tetracycline photocatalytic degradation in water purification under different illumination scenarios. [ABSTRACT FROM AUTHOR]

In this work, the surface reactions of the homemade explosive triacetone triperoxide on tungsten oxide (WO3) sensor surfaces are studied to obtain detailed information about the chemical reactions taking place. Semiconductor gas sensors based on WO3 nanopowders are therefore produced and characterized by scanning electron microscopy, X‐ray diffraction, and Raman spectroscopy. To analyze the reaction mechanisms at the sensor surface, the sensor is monitored online under operation conditions using Raman spectroscopy, which allows to identify the temperature‐dependent sensor reactions. By combining information from the Raman spectra with data on the changing resistivity of the underlying semiconductor, it is possible to establish a correlation between the adsorbed gas species and the physical properties of the WO3 layer. In the results, it is indicated that a Lewis acid–base reaction is the most likely mechanism for the increase in resistance observed at temperatures below 150 °C. In the results, at higher temperatures, the assumption of a radical mechanism that causes a decrease in resistance is supported. [ABSTRACT FROM AUTHOR]

The configurations, electronic attributes and dipole magnitudes of the TMWn–1O3n (TM = Mn, Fe and Co, n = 2 ~ 6) clusters have been calculated by using first–principles. The TM substitution significantly reduces the thermodynamic stability of tungsten oxide clusters. The position of tungsten atom substituted for the MnW4O15 clusters is different from those for the TMW4O15 (TM = Fe and Co) clusters. The MnW3O12, MnW5O18, FeWO6 and FeW5O18 clusters exhibit more kinetically stable than their neighbors. The charge transfer amounts (1.066 |e|, 1.104 |e|, 1.094 |e|, 1.138 |e| and 1.137 |e|) of the MnWn–1O3n clusters are more than those of the TMWn–1O3n (TM = F e and Co) clusters. Dipole magnitudes (1.6972 Debye, 1.342 Debye and 1.5261 Debye) of the MnW4O15, FeW3O12 and CoW3O12 clusters are larger than neighboring TMWn–1O3n clusters. [ABSTRACT FROM AUTHOR]

This study assessed tungsten-based materials with and without dispersed CeO2 for potential use as pH sensors. Specifically, three types of tungsten electrodes were characterized: tungsten electrodes without CeO2 but with native oxide, tungsten electrodes without CeO2 that were oxidized, and a tungsten electrode containing dispersed CeO2 that was oxidized, resulting in a mixture of WO3, CeO2, and Ce2O3. The characterization was performed using SEM/EDAX, X-ray photoelectron spectroscopy (XPS), and electrochemical techniques. The oxide coatings showed higher oxygen contents compared to native tungsten. XPS confirmed the presence of a thick layer of WO3 and cerium oxides. The electrodes exhibited good reproducibility and stability in pH measurements. A linear relationship was found between the open circuit potential and pH, with slopes of 44.9, 40.8, and 46.9 mV pH−1 for native oxide, WO3, and WO3 with CeO2 and Ce2O3, respectively. The latter showed the highest sensitivity and lowest hysteresis. The response times ranged from 14.5–23.5 s and were faster in acidic solutions. Overall, the inexpensive tungsten-based electrodes demonstrated promising capabilities for pH sensing, but in particular ceriated tungsten electrodes. [ABSTRACT FROM AUTHOR]

Electrochromic (EC) films are widely used in smart windows, automobile mirrors, and low-power displays due to their capability of reversibly changing color under an external potential. Transition metal oxides, due to their ability to switch between multiple oxidation states, are primarily used as EC films. They require low operating power and provide high coloration efficiency in EC applications. However, their thin-film fabrication through a low-cost and scalable process is still challenging. Here, nickel oxide (NiO) EC films have been synthesized by room-temperature electrochemical oxidation of Ni thin films. The Ni films were grown by electroless deposition and annealed at three different temperatures of 100°C, 200°C, and 300°C. The morphological, optoelectronic, and electrochemical properties of the films have been comparatively analyzed to obtain an optimized EC film. The NiO film annealed at 100°C exhibited superior properties with coloration and bleaching times of 1.8 s and 2.9 s, respectively, and a coloration efficiency of 20 cm2/C. This annealed film is further used to fabricate a EC device with NiO and tungsten oxide (WO3) as the electrode layers and a phosphoric acid-based gel as the electrolyte. The low-temperature deposition process used here can also be extended to flexible substrates. [ABSTRACT FROM AUTHOR]

This study investigates the corrosion products present on TiSi, AlTi, and WTi coatings deposited onto Ti6Al4V titanium alloy substrates using the RF sputtering PVD technique. Following deposition, the coatings underwent exposure to a temperature of 600 °C for 100 h. The corroded surfaces were meticulously characterized to identify the resultant corrosion products. Utilizing scanning electron microscopy (SEM), X-ray diffraction, optical profilometry, and XPS spectroscopy, the coatings were comprehensively examined. Furthermore, Raman mapping with multivariate analysis was employed to determine the spatial distribution of oxides in the coating post-high-temperature corrosion. Additionally, XPS spectroscopy unveiled the presence of species undetected by Raman spectroscopy, such as silicon oxide SiO2, aluminum oxide Al2O3, and tungsten oxide WO2, in oxidation studies on TiSi, AlTi, and WTi coatings, corroborated by XRD analysis. The results allowed us to propose the corrosion mechanisms of these coatings and to determine that the TiSi coating exhibits a superior high-temperature corrosion response compared to the AlTi and WTi coatings. The AlTi coating experiences aluminum depletion, whereas the WTi coating shows accumulations of tungsten oxides that resemble pitting. [ABSTRACT FROM AUTHOR]

Cs0.33WO3 (CWO) is a widely used inorganic material in window films and glass coatings, known for its excellent near-infrared radiation (NIR) blocking property and high visible light transmittance (Tvis). However, the stability of NIR blocking and the optical properties of CWO in the process of application is an urgent and important problem, because significant changes in optical results can impact the related products, such as window films, glass coatings, and so on. In this paper, the particle sizes and optical properties of CWO are tested to study the light stability and their relative relations. The results indicate that CWO particle sizes between 130 nm and 100 nm (D90, the point where 90% of the particles have a diameter smaller than the specified value) exhibit high stability in terms of NIR blocking and visible light transmittance (Tvis). CWO particles with D90 < 100 nm experience a greater reduction in NIR blocking, though this ability significantly recovers upon exposure to sunlight, making these coatings particularly suitable for use in tropical and subtropical climates. [ABSTRACT FROM AUTHOR]

Tungsten-based scandate dispenser cathodes are promising next-generation thermionic electron sources for vacuum electron devices, due to their excellent emission performance at temperatures lower than those required for conventional cathodes. There has been a significant recent effort to understand scandate cathode performance and to characterize the tungsten and other materials on the emitting surface, primarily via the study of cathodes before and after emission testing. Moreover, these scandate cathodes have typically been characterized at room temperature only. In situ observations of scandate cathodes is challenging, as these devices are thermionic emitters that operate in a high-vacuum environment, and because the sizes of relevant material features range from the micron (2.0 µm) to the nanometer (<50 nm diameter) length scales. In the current study, a series of in situ heating experiments was conducted on un-activated impregnated scandate cathode fragments, utilizing a micro-electro-mechanical system-based heater chip in a scanning electron microscope, enabling the real-time observation of cathode material evolution at elevated temperature (up to 1200 °C) under a pressure of 10−6 to 10−7 mbar. This study revealed how impregnant materials grow and migrate within the cathode matrix at elevated temperatures, and these observations are key to a thorough understanding of the behavior of scandate cathode materials. It also enabled direct observation of the incipient faceting of tungsten surfaces at high temperature while surrounded by impregnant materials. These are the first in situ observations of scandate cathode material evolution in relevant environmental conditions and at sufficiently high resolution to provide insights into the morphological and phase changes that occur in the near-surface regions of scandate cathodes. [ABSTRACT FROM AUTHOR]

Dual‐band electrochromic smart windows (DESWs), capable of actively and selectively modulate visible (VIS) light and near‐infrared (NIR) heat, have emerged as a practical technology for enhancing user comfort and reducing building energy consumption. However, the design and development of DESWs remain a significant challenge due to the difficulty in obtaining suitable materials and high‐durability electrolytes. Here, the first all‐solid‐state DESW based on an orthorhombic oxygen‐deficient tungsten oxide (o‐WO3‐x) film is presented. Benefiting from the synergistic effects of the efficient oxygen‐vacancy‐enhanced charge transfer process and the secure transfer pathway enabled by the orthorhombic crystal structure, the o‐WO3‐x film showcases remarkable dual‐band electrochromic properties, including selective modulation of VIS light and NIR heat, large optical modulation (89.1%), rapid response time (tb/tc = 6.8/17.9 s), high coloration efficiency (155.92 cm2 C−1), and ultrastable cyclic performance (8000 cycles) even in acidic aqueous electrolyte. Furthermore, the all‐solid‐state DESWs incorporating o‐WO3‐x deliver a significant and stable dual‐band electrochromic response with excellent thermal regulation and energy‐saving capabilities. These findings underscore the considerable potential of o‐WO3‐x films and their all‐solid‐state smart windows in decreasing building energy consumption. [ABSTRACT FROM AUTHOR]

Supercapacitors have captured the curiosity of researchers due to their extremely high energy storage capacity. Hybrid supercapacitors deliver high specific capacitance values compared to the exciting (electrical double layer capacitor) EDLC and pseudocapacitors. This work presents a simple and scalable synthetic method to design a hybrid ternary composite as electrode material. In this work, the combination of EDLC‐type behaviour material, i. e., sustainable biomass‐derived Nitrogen‐doped activated carbon (NAC) and pseudocapacitive behaviour electrode materials, i. e., metal oxides (tungsten oxide) and conductive polymer (polyaniline) are selected to achieve a high gravimetric capacity. The PANi/WO3/NAC (PWNAC) ternary composite is tested for symmetric and asymmetric supercapacitor (ASC). In a symmetric capacitor, PWNAC acts as both the positive and negative electrode, whereas in ASC, PWNAC acts as the positive electrode and NAC as the negative electrode. It is observed that the ASC shows a better capacitance value than symmetric. ASC operates at a potential range of 1.4 V in 1 M H2SO4 aqueous electrolyte, shows a maximum capacitance of 608.2 F/g at 0.5 A/g, and has long capacitance retention of 98.32 % of its initial capacitance after 2000 charge‐discharge cycles. [ABSTRACT FROM AUTHOR]

In this work, hydrothermal methods and deep eutectic solvents were combined for the first time to prepare tungsten trioxide nanoparticles in an easy and green manner improving their optical and photochromic properties. Characterization of the synthesized nanoparticles was performed via Fourier transform infrared spectroscopy, X-ray diffraction, ultraviolet visible spectroscopy, scanning electron microscopy, energy dispersive X-ray, transform electron microscopy, dynamic light scattering, thermogravimetric analysis, and X-ray photoelectron spectroscopy. The average size of the spherical nanoparticles was ca. 1.83 nm as shown by TEM, and the nanoparticles exhibited high thermostability at least until 900 °C, and photostability and photosensitivity when they were exposed to UV light. Additionally, synthesized tungsten trioxide nanoparticles were found to be nontoxic with maximum cell viability observed even at 100 μg mL−1, making them potential candidates for biomedical applications. [ABSTRACT FROM AUTHOR]

Complex oxides Eu2MeO6 (Me–Mo, W), Eu2W2O9 were obtained by a solid‐phase reaction between binary oxides. The thermodynamic and kinetic mechanisms of the reaction processes were established using a variety of physical‐chemical methods. All compounds obtained in this work crystallize in the low‐symmetry monoclinic system, forming complex framework structures, which determine a set of very valuable physical‐chemical properties. Comparison of experimental Kubelka‐Munk functions and DFT‐ calculated absorption spectra shows adequate agreement and reveals the origin of the fundamental absorption. In addition, the deficiency in DFT calculations in the part of mutual contribution of CTBs of Mo−O and W−O, from one side, and Eu−O contributions, from the other side, is reported. Calculations of absorption spectra are shown to be superior to band structure analysis in the determination of optical band gaps. Additionally, luminescent properties of Eu2MeO6 and Eu2W2O9 compounds were investigated. These studies provide a better understanding of the electronic and optical properties of the compounds Eu2MeO6 and Eu2W2O9, along with their potential applications in various areas. [ABSTRACT FROM AUTHOR]

The selective conversion of polyethylene (PE), polypropylene (PP), and mixtures of these two polymers to form products with high volume demand is urgently needed because current methods suffer from low selectivity, produce large quantities of greenhouse gases, or rely on expensive, single-use catalysts. The isomerizing ethenolysis of unsaturated polyolefins could be an energetically and environmentally viable route to propylene and isobutylene; however, noble-metal homogeneous catalysts and an unsaturated polyolefin are currently required and the process has been limited to PE. We show that the simple combination of tungsten oxide on silica and sodium on gamma-alumina transforms PE, PP, or a mixture of the two, including postconsumer forms of these materials, to propylene or a mixture of propylene and isobutylene in greater than 90% yield at 320°C without the need for dehydrogenation of the starting polyolefins. [ABSTRACT FROM AUTHOR]

The development of photoelectrochemical tandem cells for water splitting with electrodes entirely based on metal oxides is hindered by the scarcity of stable p-type oxides and the poor stability of oxides in strongly alkaline and, particularly, strongly acidic electrolytes. As a novelty in the context of transition metal oxide photoelectrochemistry, a bias-free tandem cell driven by simulated sunlight and based on a CuCrO2 photocathode and a WO3 photoanode, both unprotected and free of co-catalysts, is demonstrated to split water while working with strongly acidic electrolytes. Importantly, the Faradaic efficiency for H2 evolution for the CuCrO2 electrode is found to be about 90%, among the highest for oxide photoelectrodes in the absence of co-catalysts. The tandem cell shows no apparent degradation in short-to-medium-term experiments. The prospects of using a practical cell based on this configuration are discussed, with an emphasis on the importance of modifying the materials for enhancing light absorption. [ABSTRACT FROM AUTHOR]

Scanning transmission electron microscopy (STEM) and X-ray photoelectron spectroscopy analyses were combined to clarify the ultraviolet light-induced surface changes of WO3 in air. Identical-location STEM (IL-STEM) analysis showed that the WO3 particle surface was covered with an amorphous thin film after ultraviolet irradiation in air. X-ray photoelectron spectroscopy analysis showed that hydrocarbon decomposition and the formation of carboxyl/hydroxyl species occurred. These results suggested that the amorphous thin films consisted of photocatalytic oxidative species of hydrocarbon. The IL-STEM analysis could detect small light-induced changes. This technique will be useful for the microscopic characterization of photocatalysis or photoinduced hydrophilic conversion. [ABSTRACT FROM AUTHOR]

Recently, tungsten oxide (WO 3) and bismuth vanadate (BiVO 4) have been considered as an intriguing combination for constructing a heterojunction for efficient photoelectrochemical (PEC) applications. Herein, we report the preparation of ternary WO 3 /BiVO 4 /NiCo layered double hydroxide (LDH) photoanodes for boosting photogenerated carrier transport and promotion of catalytic activity. WO 3 /BiVO 4 heterostructures were synthesized by a hydrothermal process of WO 3 nanoplates on a fluorine-doped tin oxide (FTO) glass substrate, followed by spin-coating for BiVO 4 materials. We investigated the effect of a NiCo LDH catalyst on PEC performance by controlling the growth temperatures of the NiCo LDH via hydrothermal synthesis. Moreover, the X-ray diffraction (XRD), Fourier‒transform infrared (FTIR) and X‒ray photoelectron spectroscopy (XPS) analyses revealed that the WO 3 /BiVO 4 heterojunction was retained after the NiCo LDH growth process regardless of synthesis temperatures. The PEC results verified that the WO 3 /BiVO 4 heterostructure with the optimized NiCo LDH catalyst (WBN60) possessed the best photocurrent density of 3.2 mA/cm2 at 1.23 V vs. reversible hydrogen electrode (RHE), which created improved charge separation and surface oxidation kinetics of photogenerated carriers. Consequentially, the smallest charge transfer resistance and recombination rate were achieved in the WBN60 electrode compared to others, indicating a much lower photoelectrode‒electrolyte interfacial resistance and the enhancement of photogenerated carrier transport by suppressing recombination. [ABSTRACT FROM AUTHOR]

The complex dielectric permittivity of tungsten oxide at all stages of its colouration in a hydrogen-rich atmosphere was retrieved from measured VIS-NIR ellipsometric spectra of WO 3 /Pd bilayer. The retrieval was done by fitting the spectra with the Cody-Lorentz dispersion model, and, for optical absorption features, two Gaussian functions were added. The band gap edge, the Gaussian center energies, amplitudes, spectral widths and integrals were traced as the redox reaction progressed. Analysis of obtained data provides insight into mechanism of surface and bulk oxygen vacancies formation. We discuss these peculiarities in detail and show how they do affect the optical constants of WO 3 – x and potential sensors' response rates. • Ellipsometry for dielectric permittivity of WO 3 -x subjected to stepwise colouration in a hydrogen-rich atmosphere. • Absorption feature associated with WO 3 reduction was described by two competing processes fitted by Gaussians. • To elucidate the colouration mechanism, the Gaussians parameters were traced, illustrating oxygen vacancies formation. [ABSTRACT FROM AUTHOR]

Platinum (Pt)‐based compounds are the benchmarked catalysts for hydrogen evolution reaction (HER) but exhibit slow kinetics in alkaline environments. The *OH accumulation on Pt surface can block active sites, affecting proton reduction and water re‐adsorption. Alloying Ruthenium (Ru) with Pt sites can significantly modulate the adsorption and desorption of water dissociation intermediates. Choosing suitable supports and utilizing metal‐support interaction (MSI) is crucial for active site optimization. PtRu alloy anchored on tungsten oxide (WO3) with rich oxygen vacancies (OV) is prepared through an ultrafast microwave‐assisted approach. Benefiting from the coupling effects between alloying and MSI, PtRu/WO3‐OV exhibits exceptionally high HER activity. In 1 m KOH, 1 m KOH + seawater, and 0.5 m H2SO4, it requires ultralow overpotentials of 9, 26, and 6 mV to achieve 10 mA cm−2, respectively. The designed catalyst surpasses commercial Pt/C in mass activity and demonstrates considerable potential for intermittent energy integration. Density functional theory reveals that alloying Ru with Pt sites significantly reduces the energy barrier of dissociating *OH, modulating blockage on the surface and then promoting the overall alkaline HER process. This study offers insights into the rapid synthesis of non‐carbon supported catalysts with Pt site modulation for alkaline hydrogen generation. [ABSTRACT FROM AUTHOR]

In the article, electrochromic WO3 films were obtained from 25, 100, and 200 mM peroxytungstic acid (PTA) solution. A chronoamperogram of the cathodic reduction of tungsten oxide (WO3) through the stages of formation of a precursor film adsorbed on the surface of the ITO electrode and its subsequent staged reduction to WO3 and side formation of soluble reaction products is presented. The material yield of the WO3 film on ITO glass was within 50%, which is due to the parallel occurrence of side processes associated with hydrogen evolution and the reduction of tungsten complexes that were in the precipitation solution (WO3 reduction scheme). In this case, it was taken into account that thin WO3 films were the final product. The features of the synthesis of peroxytungstic acid have been studied. It has been shown that the reaction of W dissolution in 37% H2O2 proceeds exothermically. In this case, the reaction temperature reached 96°C within a few seconds, and its decline varied exponentially with the formation of reaction products. The dependence of the limiting current on the square root is obtained. The presented graphic dependence is characterized by linearity, while the beginning of the straight line does not coincide with the origin. The process of intercalation-deintercalation of protons (H+) (cathode-anode branches of CV) was a consequence of structural and reversible changes as a result of H+ intercalation. WO3 films obtained by electrochemical (cathodic) deposition can be recommended as an electrode material for electrochromic devices (cathode) and as a material for electrochemical sensors. Another promising direction is the development of a wide band gap anode based on WO3 for photovoltaic devices, which are energy efficient hydrogen generation systems. [ABSTRACT FROM AUTHOR]

A quantitative study of the composition of metastable acidic tungstate-vanadate solutions was carried out. The main polyanions coexisting in the solutions were determined by means of UV spectroscopy. Effect of the initial V: W ratio on the nature and concentration of polyanions was determined. Electrochemical deposition of hydrated tungsten oxide films from mixed solutions was carried out. The addition of 5–30 mol.% of vanadium leads to a significant increase in the deposition rate, and these rates are higher than in analogous solutions with the addition of H2O2. It is shown, that the growth of films in mixed solutions is associated with the formation of the Lindquist polyanions [VW5O19]3− and [V2W4O19]4− with high redox potentials. These polyanions are irreversibly destroyed upon reduction. The influence of various polyanions on the film growth was demonstrated in test experiments on the deposition from solutions prepared from individual salts of the polyanions. Films deposited from mixed tungstate-vanadate solutions contain a very low amount of vanadium as it was shown by elemental analysis. [ABSTRACT FROM AUTHOR]

Density functional theory-based characterization of crystalline tungsten oxide has been well established. Nonetheless, there remains a partial gap in theoretical studies concerning the electrochemical characterization of amorphous tungsten oxide. The electronic structure and diffusion kinetics of amorphous tungsten oxide require a systematic theoretical study. Therefore, we employed second-generation Car–Parrinello molecular dynamics simulations and the density functional theory with HSE06 exchange–correlation hybrid functional to investigate the electronic properties and lithium kinetics of amorphous tungsten oxide (α-WOx, x = 3, 2.5, 2) models. The precise electronic properties of these structures were computed using the HSE06 hybrid functions. The diffusion properties of lithium were determined in the range of 1 × 10−7 to 5 × 10−7 cm2/s by ab initio molecular dynamics. The computational findings provide a critical atomic-scale understanding and contribute to the development of tungsten oxide-based electrochromic devices for practical applications. [ABSTRACT FROM AUTHOR]

Fast and accurate detection of light in the near-infrared (NIR) spectral range plays a crucial role in modern society, from alleviating speed and capacity bottlenecks in optical communications to enhancing the control and safety of autonomous vehicles through NIR imaging systems. Several technological platforms are currently under investigation to improve NIR photodetection, aiming to surpass the performance of established III–V semiconductor p-i-n (PIN) junction technology. These platforms include in situ -grown inorganic nanocrystals (NCs) and nanowire arrays, as well as hybrid organic–inorganic materials such as graphene-perovskite heterostructures. However, challenges remain in NC and nanowire growth, large-area fabrication of high-quality 2D materials, and the fabrication of devices for practical applications. Here, we explore the potential for tailored semiconductor NCs to enhance the responsivity of planar metal–semiconductor–metal (MSM) photodetectors. MSM technology offers ease of fabrication and fast response times compared to PIN detectors. We observe enhancement of the optical-to-electric conversion efficiency by up to a factor of ∼2.5 through the application of plasmonically-active semiconductor nanorods and NCs. We present a protocol for synthesizing and rapidly testing the performance of non-stoichiometric tungsten oxide (WO 3 − x ) nanorods and cesium-doped tungsten oxide (Cs y WO 3 − x ) hexagonal nanoprisms prepared in colloidal suspensions and drop-cast onto photodetector surfaces. The results demonstrate the potential for a cost-effective and scalable method exploiting tailored NCs to improve the performance of NIR optoelectronic devices. [ABSTRACT FROM AUTHOR]

Mica-supported tungsten oxide (M/WO3) and neat WO3 nanoparticles (NPs) were synthesised through acid precipitation method and then used as photocatalysts for degradation of Methyl Violet (MV) dye in aqueous media. The scanning electron microscopy (SEM) shows that the majority of WO3 NPs have cubical shape. The SEM micrographs also illustrated that the particles are mostly present in dispersed form, while some are in agglomerated form. The transmission electron microscopy (TEM) presented that the size of the nanoparticles were below 100 nm. The formation of NPs were also confirmed by energy dispersive X-ray (EDX), X-ray diffraction (XRD) and Fourier transform infra-red (FT-IR). The photodegradation study presented that WO3 and M/WO3 NPs degraded about 87% and 97% of MV dye within 75 min irradiation time under UV light. The recovered and re-recovered M/WO3 and WO3 NPs also significantly degraded MV dye. Both WO3 and M/WO3 NPs showed significant bio-activities against two pathogenic bacteria (Citrobacter and Providencia). Further, both types of NPs showed effective antioxidant activity. [ABSTRACT FROM AUTHOR]

[Display omitted] Marigold analogues micro flowers of tungsten oxide (WO 3) have been grown in thin film form through simple and cost-effective solution chemistry approach on stainless steel substrate. Aqueous precursor involving WO 4 - 2 ions agglomerated as self-sacrificing template growing initially into the nano-petal, followed by self-assembly; leading to marigold analogues micro flower surface architecture. This enthralling morphology motivated us not only to fabricate supercapacitive electrode but also to design complete solid-state supercapacitor devices in dual configurations: flexible pouch cell and coin cell. Interestingly, both devices even in symmetric configuration yields remarkable potential window of 1.82 V when sandwiched by gel inclusive of Li+ ions dispersed in non-conducting polyvinyl alcohol matrix. Solid-state flexible pouch cell and coin cell delivered specific capacitances of 103.98 ± 3.59 and 30.09 ± 1.03 F/g respectively at a scan rate of 5 mV/s. Assembled electrode, coin-cell and flexible pouch-cells have been well assessed in-depth through specific capacitances using cyclic voltammetry and galvanostatic charge discharge, diffusive and capacitive contributions, mechanical bending tests, electrochemical active surface area, and electrochemical impedance analysis. Practical applicability has been demonstrated for designed flexible pouch cell to run small fan and light emitting diode panel whereas coin cell to run light emitting diode panel. [ABSTRACT FROM AUTHOR]

Machine learning (ML) is increasingly applied across various fields, including chemistry, for molecular design and optimizing reaction parameters. Yet, applying ML to experimental data is challenging due to the limited number of synthesized samples, which restricts its broader application in device development. In energy harvesting, photoanodes are crucial for solar-driven water splitting, generating hydrogen and oxygen. We explored electrodes like hematite and bismuth vanadate for photocatalytic uses, noting varied photoelectrochemical performances despite similar preparations. To understand this variability, we applied a data-driven ML approach, predicting photocurrent values and identifying key performance influencers even with limited experimental data in the research development of inorganic devices. We have utilized multiple machine learning algorithms to predict the target value in the calculation process, where the contributions of the dominant descriptors were unknown. We introduced a novel methodology, incorporating clustering to manage multicollinearity from correlated analytical data and Shapley analysis for clear interpretation of contributions to performance prediction. This method was validated on hematite and bismuth vanadate, showing superior predictability and factor identification, and then extended to tungsten oxide and bismuth vanadate heterojunction photoanodes. Despite their complexity, our approach achieved determination coefficients (R2) with a prediction accuracy over 0.85, successfully pinpointing performance-determining factors, demonstrating the robustness of the new scheme in advancing photodevice research. [ABSTRACT FROM AUTHOR]

Amorphous tungsten oxide (WO3) is widely exploited in the fields of photochromism and electrochromism. Despite its widespread use, the tractable synthesis of amorphous WO3 nanodots is still on the drawing board, even though the WO3 nanodots possess superior chromatic performance owing to their large surface‐to‐volume ratio. Therefore, a new efficient strategy to synthesize amorphous WO3 nanodots, which exhibit both excellent electrochromic and photochromic properties, is reported. For the first time, the ligand effects of the amorphous WO3 nanodots on chromatic applications are elucidated. The presence of the ligand on amorphous WO3 nanodots inhibits the electrochromic color switching, while promoting photochromic performance. As a proof of concept, zinc‐WO3 electrochromic devices, WO3‐polyvinyl alcohol (PVA) transparent hydrogels, and PVA/WO3 textiles are prepared for diverse rapid‐switching chromatic applications. These results present a new strategy for the synthesis of widely used amorphous WO3 nanodots and open new opportunities for the development of WO3‐based chromatic applications. [ABSTRACT FROM AUTHOR]

Electrochromic (EC) mirrors fabricated using the electrodeposition of metals can dynamically transition between reflective and transparent states via the deposition and dissolution of the employed metals. In particular, the incorporation of an EC counter electrode enables the realization of an absorptive state under optimized applied voltage. Herein, we present reversible EC mirrors composed of Ag and WO 3 layers as the two electrodes, highlighting their EC properties in three optical transformation modes: transparent, reflective, and absorptive. The formation of Ag layers under optimized deposition conditions was confirmed, and the electrodeposited WO 3 layers exhibited compact or porous structures depending on the deposition conditions. The prepared Ag–WO 3 EC mirrors showed substantial transmittance modulation during the reflecting (53.7%) and coloring (63.5%) process. Interestingly, in comparison to the compact WO 3 , the EC mirrors with porous WO 3 layers exhibited dark-gray coloration in the reduced state, which was attributed to the localized surface plasmon resonance effect caused by codeposited Ag particles. [ABSTRACT FROM AUTHOR]

Electrocatalytic upgrading of wasted plastic and renewable biomass represents a sustainable method to produce chemicals but is limited to carbohydrates, leaving other value‐added chemicals, such as organonitrogen compounds, being scarcely explored. Herein, we reported an electrocatalytic oxidation strategy to transform polyethylene terephthalate (PET) plastic‐derived ethylene glycol (EG) and biomass‐derived polyols into formamide, in the presence of ammonia (NH3) over a tungsten oxide (WO3) catalyst. Taking EG‐to‐formamide as an example, we achieved a high formamide productivity of 537.7 μmol cm−2 h−1 with FE of 43.2 % at a constant current of 100 mA cm−2 in a flow electrolyzer with 12‐h test, representing a more advantageous performance compared with previous reports for formamide electrosynthesis. Mechanistic understanding revealed that the cleavage of the C−C bond in the EG was facilitated by nucleophilic attack of in situ formed nitrogen radicals from NH3, with resultant C−N bond construction and eventually formamide production. Furthermore, this strategy can be extended to transformation of PET bottle and a series of biomass‐derived polyols with carbon number from three (glycerol) to six (glucose), producing formamide with high efficiencies. This work demonstrates a sustainable upgrading strategy of plastic and biomass that may have implications to more value‐added chemicals production beyond carbohydrates. [ABSTRACT FROM AUTHOR]

This research aims to determine and quantify the radiation shielding characteristics of high-density polyethylene/ tungsten oxide (HDPE/WO3) nanocomposites including the linear attenuation coefficient (µ), mass attenuation coefficient (µ/ρ), half-value layer (HVL) and tenth-value layer (TVL) for photons at various energies using Geant4, XCOM, and experiment. Thus, HDPE was chosen as the polymer matrix. Then, the samples at various concentrations of WO3 nanoparticles (0, 1, 2, 3, 4, 5, 6, and 9.5 wt.%), different graphene oxide (GO) weight percentages (0, 0.25, 0.5, and 1 wt.%), and 10 and 20 wt.% linear low-density polyethylene (LLDPE) were fabricated. An NaI (Tl) scintillation detector was used to measure the shielding quantities using the 201Tl, and 99mTc sources at three energies of 135, 140, and 167 keV. The experimental results demonstrated that the addition of GO and LLDPE to the HDPE matrix resulted in a more uniform sample. Incorporating 20% LLDPE into the HDPE polymer matrix for the 99mTc resulted in an 18% rise in µ compared to pure HDPE. Finally, the experimental results revealed a comparatively good agreement with the Geant4 and XCOM simulations. [ABSTRACT FROM AUTHOR]

Continuing our investigation of catalytic oxo/imido heterometathesis as novel water‐free method for C=N bond construction, we report here the application of classical transition metal oxides dispersed on silica (MOx/SiO2, M=V, Mo, W) as cheap, robust and readily available alternative to the catalysts prepared via Surface Organometallic Chemistry (SOMC). The oxide materials demonstrated activity in heterometathetical imidation of ketones, WO3/SiO2 being the most efficient. We also describe a new well‐defined supported W imido complex (≡SiO)W(=NMes)2(Me2Pyr) (Mes=2,4,6‐Me3C6H2, Me2Pyr=2,5‐dimethylpyrrolyl) and characterize it with SOMC protocols, which allowed us to identify the position of W on the oxo/imido heterometathesis activity scale (Mo

The development of the proton exchange membrane water electrolyzer (PEMWE) is still limited by the prohibitive cost and scarcity of iridium (Ir)‐based oxygen evolution reaction (OER) catalyst. This work presents a novel catalyst synthesized by precursor‐atomization and rapid joule‐heating method, successfully doping iridium atoms into polyvalent tungsten blends (W0, W5+, W6+) based on titanium substrate. The vacancy engineering of unsaturated tungsten oxide (W5+, W6+) reconstructs the electronic structure of the catalyst surface, which resulting in the low‐valence state iridium species, avoiding excessive oxidation of iridium and accelerating the catalytic kinetics. Meanwhile, metallic tungsten (W0) improves the conductivity of catalyst and guarantees the stable existence of oxygen vacancy. The TiIrWOx possesses excellent performance in acidic OER catalysis, requiring overpotential of only 181 mV to drive 10.0 mA cm−2, and exhibiting a high mass activity of 753 A gIr−1 at an overpotential of 300 mV. The membrane electrode assembly (MEA) with TiIrWOx as anode electrocatalyst can reduce the Ir consumption amount by >60% compared to commercial IrO2, and it can operated over 120 h at a current density of 1.0 A cm−2. [ABSTRACT FROM AUTHOR]

Regulating a material's crystal phase is difficult when using a solution-based method; however, this has far-reaching implications for the characteristics of the material. The current work reported herein represents an efficient realization of green synthesized adjustable layered tungsten oxide (WO3) nanosheets using β-Cyclodextrin (β-CD) biopolymer. Both nucleation process and sheet formation were greatly influenced by chelating ability of β-CD. These qualities allowed bonding between WO3 nanosheet and β-CD to occur after calcination at 450 °C yielding β-CD-assisted tungsten oxide nanosheets (WO3). Various analytical methods such as XRD, SEM, TEM, EDX, FTIR and UV–Vis spectrophotometry were employed to understand physicochemical properties of the prepared WO3 nanosheets. The main aim of this study was to investigate visible light-assisted photocatalytic degradation of Methylene Blue (MB). According to experimental results, within 24 min 98.8% decomposition efficiency towards MB was recorded under irradiation using visible light source in presence of 200 mg WO3 nanosheet catalysts. The experiment was conducted in two sets that is with and without addition of WO3 nanosheet catalysts respectively. Furthermore evaluation on antibacterial activity against Escherichia coli (E.coli), and Staphylococcus aureus (S.aureus) bacteria as well antioxidant power was performed for these nano sheets while anticancer and antioxidant effects were also evaluated which demonstrated all samples having significant antibacterial activities together with antioxidants performances in terms of WO3 nanosheets against different bacteria strains including E. coli, S. aureus. Moreover, it showed strong anticancer potentials coupled with their excellent free radical scavenging abilities thus making them perfect candidates for use as potential therapeutic agents. [ABSTRACT FROM AUTHOR]

Gamma radiation can cause structural defects in metal oxide thin films, affecting their conversion efficiency. This study focuses on synthesizing and characterizing Tungsten oxide (WO3) films for photo-electrochemical (PEC) water-splitting applications. The pristine WO3 film was irradiated with a Co-60 gamma source to improve its photocatalytic activity and was named G-WO3. The resulting G-WO3 thin films showed a decrease in the optical direct band gap and showed higher photocurrent density and lower charge transfer resistance for PEC applications. The carrier charge density (Nd) values were found to be increased after γ-radiation. The synthesized G-WO3 thin films possess good stability and reusability for photo-electrochemical water-splitting applications. [ABSTRACT FROM AUTHOR]