WO3 Nanorods Research Articles

Construction of WO3 nanowires artificial solid electrolyte interphase on silicon nanoparticles with sea urchin like structure for improving silicon anode stability

Giant volumetric variation of silicon during repeat lithiation/delethiation process leads to structure failure of silicon-based anodes and thus their initial high capacitance is hard to be maintained under long-run cyclic charging/discharging. Construction porous structure silicon composites and formation of artificial solid electrolyte interphase (SEI) coating on silicon particles are two effective ways to improve stability of silicon-based anodes. In this work, above two strategies are combined to construct a composite of inorganic artificial SEI WO3 nanowires/Si nanoparticles with sea urchin like porous structure via simple hydrothermal method. The silicon nanoparticles act as seeds for around 70 nm average diameter WO3 nanowires formation in compared with that of WO3 nano-rods around 500 nm diameter without Si nanoparticle seeds. The WO3 nanowire artificial SEI coating is found to be effective in preventing SEI overgrowth and their network provides spaces for volumetric variation of silicon nanoparticles in the bulk anode matrix during cyclic test, leading to reversible charging/discharging of stable bulk anode in compared with pure silicon anode of fast capacitance decay. The gravimetric capacitance of optimized composite reaches 1410.6 mAh·g−1 and its capacity remains 1039 mAh·g−1 after 200 cycles.

Nanorod-based smart windows with solid-gel electrolyte: An integrated electrochromic and pseudocapacitive technology for energy-saving and conversion

We fabricated two emerging nanorod-based smart windows with WO3 and NiO nanorods grown on the ITO/glass and ITO/muscovite mica (MM) substrates, respectively. The WO3/ITO/glass and WO3/ITO/MM substrates are excellent working electrodes, while the NiO/ITO/glass and NiO/ITO/MM substrates are exceptional counter electrodes. The nanorod-based WO3/Li+(s)/NiO@glass smart window consists of a WO3/ITO/glass working electrode, a NiO/ITO/glass counter electrode, and a solid-gel LiClO4 electrolyte (labeled as Li+(s)), respectively. The other nanorod-based WO3/Li+(s)/NiO@MM is comprised of a WO3/ITO/MM working electrode, a NiO/ITO/MM counter electrode, and a solid-gel LiClO4 electrolyte, respectively. Both the nanorod-based WO3/Li+(s)/NiO@glass and WO3/Li+(s)/NiO@MM smart windows have brilliant dual-band (red and near-infrared lights) electrochromic behaviors, such as large transmittance differences (ΔT), fast response times (bleaching time, tb, and coloration time, tc) at red (680nm) and near infrared (1000nm) lights and great electrochromic retention (4,000 cycles), and outstanding pseudocapacitive performances like good specific capacitances of ~18.4F/g and ~7.6F/g, intensive power densities of ~1779W/kg and ~2100W/kg with corresponding energy densities of ~5.4Wh/kg and ~2.2Wh/kg, enormous pseudocapacitive retention (10,000 cycles), and so on. Therefore, the brilliant dual-band electrochromic behaviors and outstanding pseudocapacitive performances make the nanorod-based WO3/Li+(s)/NiO@glass and WO3/Li+(s)/NiO@MM smart windows tremendous for use in multifunctional energy-saving-conversion devices.

Electrochemical sensor for acetylcholine detection based on WO3 nanorods-modified glassy carbon electrode

Acetylcholine (ACH) is one of the excitatory neurotransmitter in the human body. It is the most abundant neurotransmitter responsible for triggering the activation of postsynaptic neurons, leading to an excitatory response. ACH plays a crucial role in various physiological processes, including muscle contraction, autonomic nervous system regulation, and cognitive functions such as learning and memory. In this study, an electrochemical sensor was prepared based on WO3 nanorods modified glassy carbon electrode for the detection of ACH. The WO3 nanorods provided excellent properties for the electrochemical determination of ACH. The proposed sensor exhibited a wide linear detection range of (0.1 to 400.0 µM) and a low detection limit of 0.025 µM for ACH. These results demonstrate the sensor's high sensitivity in detecting this important neurotransmitter. In addition the developed sensor showed good ability for ACH determination in real samples. This study offers an innovative strategy for the electrochemical detection of ACH, showcasing the potential of nanomaterials in the development of advanced sensing technologies.

Light-driven methanol-to-olefins catalysis over W18O49/SAPO-34 hierarchical nanocomposite with strong photothermal effect

Solar-light-driven photothermal catalysis attracts attention because of the significant energy savings and environmental friendliness compared with thermal catalysis. In the present work, W18O49/SAPO-34 composite materials with hierarchical pore networks were constructed by a simple hydrothermal method, and applied into photothermal catalysis for methanol-to-olefins transformation. In combination of the broaden light absorption of W18O49 and moderate acid site of SAPO-34, the W18O49/SAPO-34 composite showed a rapid temperature rise on the surface of the catalysts due to the strong photo-to-thermal effect of W18O49. Methanol conversion of ∼ 90 % and ethylene selectivity of ∼ 60 % were achieved for the optimized W18O49/SAPO-34 catalyst, much higher than that of bare W18O49 and SAPO-34. The excellent methanol dehydration performance was attributed to the strong plasmonic absorption in the visible and near infrared light, the efficient photothermal conversion effect by localized plasmon heating on the W18O49 nanorods, and synergistic catalysis between W18O49 and SAPO-34. This photothermal catalyst showed great potential in the industrial applications of photocatalytic methanol-to-olefins conversion.

Biomimetic (Co, Ni, W)OxNy/WO3 photoelectrocatalyst for robust seawater oxidation

As an intriguing strategy for massive hydrogen production, photoelectrochemical (PEC) seawater splitting compels the anode to be highly hypochlorite-resistant. Inspired by algae, we designed a robust photoelectrocatalyst that WO3 nanorods (NRs) are covered by N/W co-doped (Co, Ni, W)OxNy nanosheets (NSs). The NSs expose (111) faces and are decorated by (Co, Ni)WO4 nanoparticles. DFT calculations reveal that Co and Ni atoms on the (111) surface of N/W co-doped NSs are more likely to adsorb OH-, while W atoms are more favorable to adsorb Cl-. Secondly, the lattice distortion and multi-crystal phases of NSs are triggered by doped W atoms, and the evacuation of 5d electrons makes W atoms as donor centers, leading to enhanced catalytic activity of CoNi atoms and corrosion resistance to Cl-. Furthermore, the N atoms expand the valence band of CoNiOx and elevate the conduction band of (Co, Ni)WO4, facilitating more electrons to participate in PEC reaction and the realization of seawater full-splitting. Resultantly, the N/W co-doped (Co, Ni, W)OxNy/WO3 hetero-NRs (HNRs) demonstrate a PEC current density about 0.35 mA/cm2 at 1.23 VRHE with durability over 100 hours in seawater. This work provides a practical strategy towards the durable PEC anode for seawater splitting.

Facile preparation of a highly efficient coin cell supercapacitor based on WO3 nanorods

Developing sustainable energy storage devices is challenging for the progress of energy storage applications. Here, nanotechnology represents a strategic route to reduce the amount of used critical materials, while continuing to take advantage of their properties, thanks to the high surface to volume ratio which characterizes nanostructures. WO3 nanostructures represent a promising active material for energy storage applications, thanks to their wide capability of small positive ions (H+ and Li+) intercalation and their high stability in acidic conditions. The coupling between WO3 nanorods and carbon black powder is studied to realize a highly efficient coin cell supercapacitor. The morphology of WO3 nanorods and carbon black is investigated by using a scanning electron microscope, and the energy storage performances were evaluated by performing cycling voltammetry and galvanostatic charge and discharge analysis, thus obtaining promising specific capacitance results (79 and 70 F/g at 5 mV/s and 0.5 A/g respectively). Moreover, the stability of the obtained coin cell was investigated, thus getting good capacity retention over 250 charge-discharge cycles. Energy and power densities were also calculated, obtaining the highest energy density of 39 Wh/kg at a power density of 500 W/kg. The WO3‑carbon black coin cells are used to power a red LED, so demonstrating the viability for practical applications.

Fabrication of WO3/Co3O4 nanorods as a p-n heterojunction photoanode for efficient photoelectrochemical oxygen evolution

Developing efficient photoelectrocatalysts is seen as a promising method for generating hydrogen through photoelectrochemical (PEC) water splitting. In this study, the WO3/Co3O4 heterojunction was fabricated on FTO substrates, serving as an effective photoanode for PEC water splitting. The p-type Co3O4 nanoparticles were loaded onto n-type WO₃ nanorods to create a p-n heterojunction, thereby reducing charge recombination due to the internal electric field at the heterointerface. Under LED illumination (∼80 mW/cm2), the photocurrent density of the WO3/Co3O4 photoanode reached 161.1 μA/cm2 at 1.23 V vs. RHE, which is 2.3 times higher than that of bare WO3 photoanode. The results show that loading Co3O4 onto WO3 nanorods significantly increased the absorption of visible light, boosted charge carrier density, and enhanced surface reaction kinetics. This work indicates the construction of p-n heterojunction photoanodes for achieving effective photoelectrochemical performance.

Correction: Promoting infrared light driven photocatalytic activity of W18O49 nanorods by coupling polypyrrole

Correction: Promoting infrared light driven photocatalytic activity of W18O49 nanorods by coupling polypyrrole

Itaconic acid modified carboxylic-acid functionalized (002) faceted monoclinic WO3 nanorods for electrochemical hydrogen evolution reaction

Itaconic acid modified carboxylic-acid functionalized (002) faceted monoclinic WO3 nanorods for electrochemical hydrogen evolution reaction

The interaction of light with oxygen-vacancy-rich W18O49 nanoparticles synthesized using different acid molarities for acidic and neutral water treatments

Toxic industrial compounds as a global difficulty can adversely impact people's health and the environment which motivates studies on the interaction of light and metal oxide nanoparticles to treat the water through adsorption or photocatalysis mechanism by nanoparticles. In the paper, oxygen-vacancy-rich W18O49 nanorods are successfully synthesized by a facile one-pot hydrothermal method using different molarities of hydrochloric acid (HCl) (2–12 M) as proposed candidates to treat the wastewater and solve the global difficulty related to treating the acidic water. The results declare that the change in acid molarity leads to noteworthy changes in the characteristic properties of the produced W18O49 nanorods, and the lowest acid molarity (2 M) causes the formation of uniform and pure monoclinic W18O49 nanorods with the high specific surface area (SSA) of 51.33 m2/g. Furthermore, the nanorods exhibit indirect and direct band gap energies in the range of 2.52–2.68 eV and 2.54–3.08 eV, respectively, as influenced by varying acid molarities (2–12 M). Furthermore, the impressive effects of acid molarity on the methylene blue removal efficiency of the nanorods under ultraviolet (UV) light are observed. The highest efficiency is obtained for W18O49 nanorods synthesized using the acid molarity of 2 M which can be explained by its high SSA, small band gap energy, generation of a large number of electron-hole pairs, and its efficient charge separation. The efficiencies of water treatment reach up to 99 % and 99.5 % at pH of 7 and 5, respectively, which is an excellent achievement and leads to proposing the mentioned W18O49 nanorods as an excellent candidate for treating wastewater and acid factory effluent which represents an appreciable breakthrough in addressing the issue.

Enhanced Electro‐Optical and Heat Regulation of Intelligent Dimming Films Using the Photovoltaic Effect of p–n Heterostructures

AbstractIn this paper, the effect of p–n heterostructures on the electro‐optical and heat regulation performances of polymer dispersed liquid crystal (PDLC) dimming films are studied. In detail, the WO3, Ag2O, and WO3/Ag2O p–n heterostructures are successfully synthesized via the co‐precipitation method. The products are analyzed by XRD, SEM, TEM, and XPS and the results demonstrated that the WO3 nanorods successfully grew on the surface of Ag2O. Compared to the primitive sample, the incorporation of p–n heterostructures into the composite films significantly enhances the electro‐optical properties. For a 20µm‐thick film, the saturation voltage (Vsat) decreases by 38.7% from 24.8 to 15.2 V, and the threshold voltage (Vth) is reduced by 22.9% from 12.7 to 9.8 V, while the contrast ratio reaches 132. Due to the molecular structure of the polymer monomers and the micro‐network structure of the film, the film exhibits high emissivity in the mid infrared spectrum, enabling enhanced dynamic cooling management through radiative cooling around the clock. Matrix & laboratory (MATLAB) calculations show that the maximum cooling power during the day and night reached 97.63 and 136.24W m‐2 K‐1, respectively. This research has great significance for the development of highly energy‐efficient smart windows.

Facile Synthesis of WS2/WO3 Materials in a Batch Reactor for the Hydrogen Evolution Reaction

In this study, a new and facile process was developed for the preparation of composite catalysts based on tungsten oxide (WO3) by batch reactor routes. The structures, morphologies, compositions, and characteristics of synthesized materials were investigated and confirmed. Using batch reactor processes, WO3 nanorods (WO3 NR), heterostructures of WS2/WO3 nanobricks (WS2/WO3 NB), and WS2/WO3 nanorods (WS2/WO3 NR) were successfully prepared. The prepared materials were then employed for hydrogen evolution reaction (HER) to investigate their catalytic performance. The results indicated that the electrocatalytic activities of WS2/WO3 NR are significantly improved compared to those of WO3 NR and WS2/WO3 NB. This improvement could be attributed to the formation of heterostructure between WS2 and WO3 elements in highly uniform materials, which could create the synergistic effect and further improve the catalytic activities of the catalyst. The data shows that the Tafel slope of WS2/WO3 NR (82.7 mV dec−1) is significantly lower than that of WO3 NR (112.5 mV dec−1) and WS2/WO3 NB (195.5 mV dec−1). Furthermore, the resistance of WS2/WO3 NR (397.7 Ω) is markedly decreased compared to those of WO3 NR (1816 Ω) and WS2/WO3 NB (3597 Ω). The results indicate that WS2/WO3 NR could be a great catalyst for electrochemical applications.

Laser-Printed Photoanode: Femtosecond Laser-Induced Crystalline Phase Transformation of WO3 Nanorods for Space-Efficient and Flexible Thin-Film Solar Water-Splitting Cells.

Despite its potential for clean hydrogen harvesting, photoelectrochemical (PEC) water-splitting cells face challenges in commercialization, particularly related its harvesting performance and productivity at an industrial scale. Herein, a facile fabrication method of flexible thin-film photoanode for PEC water-splitting to overcome these limitations, based on laser processing technologies, is proposed. Laser-induced graphene, a carbon structure produced through direct laser writing carbonization (DLWC), plays a dual role: a flexible and stable current collector and a substrate for the hydrothermal synthesis of tungsten trioxide (WO3) nanorods (NRs). To facilitate water-splitting, a femtosecond-pulsed laser (fs laser) is focused on the WO3 NRs, converting their crystalline phase from pristine orthorhombic to monoclinic structure without thermal damage. With NiFe layered double hydroxide (LDH) catalyst, the flexible thin-film photoanode exhibits good PEC performance (1.46mAcm-2 at 1.23 VRHE) and retains ≈90% of its performance after 3000 bending cycles. With its excellent mechanical properties, the flexible photoanode can be operated in various shapes with different curvatures, enabling space-efficient PEC water-splitting by loading larger photoanode within a given space. This study is expected to contribute to the advancement of large-scale solar water-splitting cells, introducing a new approach to enhance H2/O2 production and expand its application range.

Oxygen plasma treatment WO3 nanorods for Improvement H2S gas sensing

Herein, the oxygen (O2) plasma has been used to post-treat tungsten oxide (WO3) nanorods to improve the sensing performance of the H2S gas sensor. The reactive DC magnetron sputtering process with the glancing-angle deposition (GLAD) technique was used to prepare the WO3 nanorods. After deposition, the WO3 nanorod thin films were treated with O2 plasma at different treatment power from 100 – 200 W. The physical structure of as-deposition and treated WO3 nanorod thin films was investigated crystal structure and morphology by grazing incident X-ray diffraction (GIXRD), field-emission scanning electron microscope (FE-SEM), and high-resolution transmission electron microscope (HRTEM). The result indicated that the WO3 nanorod structure transformed to the monoclinic polycrystalline phase. FE-SEM and HRTEM observed slight changes in the shape of the WO3 nanorods. The H2S sensing properties were measured at 10 ppm at 150 – 350°C operating temperatures. At an operating temperature of 200 °C, the response to H2S of O2 plasma treated WO3 nanorods is increased by a factor of 5 – 15, and the maximum response to H2S is 15. The results showed that the O2 plasma treatment process improved the sensing response of the WO3 nanorods.

Carbon nitride interlayer-enhanced TiO2/WO3 nanorods with surface oxygen vacancies for durable photocathodic performance on 304 stainless steel in simulated seawater

To achieve a long-term photocathodic protective effect on metals in the marine environment, efficient charge mobility and electron storage are essential. Herein, we develop an oxygen vacancy (VO)-involved TiO2-wrapped WO3 nanorod composite by PPy-derived carbon nitride interlayer (TiO2/CNx/WO3) for the photoelectrochemical cathodic protection of 304SS in 3.5 % NaCl solution. The introduced CNx can serve not only as an electron channel to accelerate carrier migration but also as an efficient reductant to generate VO at the interfaces of TiO2 and WO3 during crystallization. The incorporated VO tunes the electronic structure and produces the mid-gap states, which lower the energy barrier for electron-hole separation. Meanwhile, WO3 nanorods as an electron self-storage pool make the photocathodic protection functional in darkness. Consequently, the as-prepared TiO2/CNx/WO3 photoanode yields a photocurrent density of 18.23 μA·cm−2 and a photoinduced cathodic polarization potential of −306 mV in simulated seawater. Even in the absence of light illustration, it can polarize 304SS to approximately −200 mV and continuously to 300 mV after 12h. This work will offer a universal strategy for the rational design and fabrication of highly efficient semiconductor composite materials in the field of photocathodic anticorrosion.

Black TiO2@Ag core-shell nanoparticles combined with WO3 nanorods on rGO nanosheets for PEC analysis

Well-coated black TiO2 and Ag core-shell nanoparticles (NPs) were prepared using a simple wet-chemical approach, which is combined with the WO3 nanorods over rGO nanosheets. The inherent properties of the composite nanostructures were examined thoroughly by diffuse reflectance spectroscopy, X-ray diffraction, Raman scattering, X-ray photoelectron spectroscopy, transmission electron microscopy, and photoelectrochemical (PEC) analysis. The formation of surface oxygen vacancies in the black TiO2 NPs facilitated tuning the optical properties in the visible region, which was enhanced by the surface plasmon resonance behavior of the Ag NPs. While combining the black TiO2@Ag core-shell NPs with intermediate bandgap WO3 nanorods and rGO nanosheets promoted PEC performance in the visible light irradiation. The composite nanostructure exhibited enhanced PEC efficiency (Jp=0.97 mAcm−2 and ABPE=0.62%) compared to the bare NPs. This work discusses the possible PEC mechanism based on the change in optical and structural properties.

Enhanced photocatalytic ammonia oxidation over WO3@TiO2 heterostructures by constructing an interfacial electric field

WO3 nanorods and xWO3@TiO2 (WO3/TiO2 mass ratio (x) = 1−5) photocatalysts were synthesized using the hydrothermal and sol-gel methods, respectively. The photocatalytic activities of xWO3@TiO2 for NH3 oxidation first increased and then decreased with a rise in TiO2 content. Among them, the heterostructured 3WO3@TiO2 photocatalyst showed the highest NH3 conversion (58 %) under the simulated sunlight irradiation, which was about two times higher than those of WO3 and TiO2. Furthermore, the smallest amounts of by-products (i.e., NO and NO2) were produced over 3WO3@TiO2. The enhancement in photocatalytic performance (i.e., NH3 conversion and N2 selectivity) of 3WO3@TiO2 was mainly attributed to the formed interfacial electric field between WO3 and TiO2, which promoted efficient separation and transfer of photogenerated charge carriers. Based on the results of reactive species trapping and active radical detection, photocatalytic oxidation of NH3 over 3WO3@TiO2 was governed by the photogenerated holes and superoxide radicals. This work combines two strategies of morphological regulation and interfacial electric field construction to simultaneously improve light utilization and photogenerated charge separation efficiency, which promotes the development of full-spectrum photocatalysts for the removal of ammonia.

Substantially Accelerated Response and Recovery in Pd-Decorated WO3 Nanorods Gasochromic Hydrogen Sensor.

The development of hydrogen (H2) gas sensors is essential for the safe and efficient adoption of H2 gas as a clean, renewable energy source in the challenges against climate change, given its flammability and associated safety risks. Among various H2 sensors, gasochromic sensors have attracted great interest due to their highly intuitive and low power operation, but slow kinetics, especially slow recovery rate limited its further practical application. This study introduces Pd-decorated amorphous WO3 nanorods (Pd-WO3 NRs) as an innovative gasochromic H2 sensor, demonstrating rapid and highly reversible color changes for H2 detection. In specific, the amorphous nanostructure exhibits notable porosity, enabling rapid detection and recovery by facilitating effective H2 gas interaction and efficient diffusion of hydrogen ions (H+) dissociated from the Pd nanoparticles (Pd NPs). The optimized Pd-WO3 NRs sensor achieves an impressive response time of 14s and a recovery time of 1s to 5% H2. The impressively fast recovery time of 1s is observed under a wide range of H2 concentrations (0.2-5%), making this study a fundamental solution to the challenged slow recovery of gasochromic H2 sensors.

Synthesis and characterization of WO3/BiS2/rGO composites for enhanced optoelectronic performance in photodetector applications

This research investigates into the fabrication and application of WO3/BiS2/rGO composites in enhancing the optoelectronic performance of photodetectors. The composite synthesis encompasses the acid oxidation of graphene oxide (GO), the hydrothermal generation of WO3 nanorods, and the subsequent amalgamation with bismuth sulfide (BiS2) and reduced graphene oxide (rGO). This study exploits the distinctive photoresponse characteristics of WO3, the narrow bandgap properties of BiS2, and the conductive attributes of rGO, meticulously examining their combined effect on improving the device's performance metrics. Extensive spectroscopic and microscopic investigations confirm the successful synthesis of the composites, uncovering detailed structural insights. The evaluation of key parameters such as responsivity, detectivity, photoresponsivity (3.74 A/W), and specific detectivity (1.38 × 1013 Jones) underscores the composites' superior performance over individual constituents and current composite materials. By strategically integrating WO3, BiS2, and rGO, this research addresses vital challenges in photodetection technology, significantly contributing to the development of advanced composite materials for optoelectronic applications. The comprehensive optimization and characterization of WO3/BiS2/rGO composites mark a pivotal step towards their incorporation in next-generation photodetectors, heralding promising advancements in sensing and imaging technologies.

Rational engineering WO3-X/CNTs@carbon fiber membrane for the high-efficient produce H2O2 via electrochemical two-electron water oxidation route

The electrochemical two-electron water oxidation reaction (2e-WOR) offers a promising avenue for hydrogen peroxide (H2O2) production. It is crucial to design electrocatalysts with high selectivity, yield, resource abundance, and environmental friendliness. In this paper, as a new generation 2e-WOR electrocatalyst, the WO3-X/CNTs@carbon fiber membrane nanostructure with abundant oxygen-rich vacancy (OV) has been discovered by a series of test techniques including XRD, FE-SEM, TEM, FT-IR, Raman and XPS, comprising interconnected carbon nanotubes and carbon fibers enveloped in WO3 nanorods with oxygen-rich vacancies. By comparing the specific surface area of WO3-x/CNTs@carbon fiber membrane at different temperatures, it was observed that the maximum value is 44.09 m2/g when the mass ratio of AMT to PAN was 3:2 at 600 °C. Furthermore, the WO3-X/CNTs@carbon fiber membrane can be directly utilized as an independent electrode. The electrochemical performance test revealed that the Faraday efficiency of the WO3-X/CNTs @CF-600-2 can reach 54 % (2.48 V vs RHE (reversible hydrogen electrode)), while the H2O2 yield can achieve 10.3 μmol· min−1·cm−2, nearly ten times higher than that of pure WO3. Furthermore, the stability testing demonstrated that after 12 h, the WO3-X/CNTs @CF-600-2 exhibited excellent stability with minimal change in its Faraday efficiency. This enhancement is attributed to the improved selectivity of WO3, excellent electrical conductivity, and mass transfer performance of carbon fiber. Finally, we proposed a mechanism for 2e-WOR and provided some perspectives on this reaction along with summarizing recent discoveries.