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Vanadium pentoxide (V2O5) nanoparticles exhibit diverse properties and have been studied for a wide range of applications, including energy storage, catalysis, environmental remediation, and material enhancement. In this work, we have reported the synthesis of vanadium pentaoxide (V2O5) nanoparticles using hydrothermal method. Ammonium metavanadate (NH4VO3) was used as a source of vanadium. These syntheses were carried out at four different concentrations of vanadium source. The hydrothermal reaction was conducted at a temperature of 180 °C for a duration of 24 hours, followed by an additional 24 hours period of natural cooling. Four samples were annealed in air using a muffle furnace at 500 °C for five hours. The x-ray diffraction technique was used to study the structural aspects. A comparative analysis of the microstructure was conducted utilizing the Scherrer method, the Williamson–Hall method and its various models, size-strain analysis, and the Halder–Wagner method. The crystallite size and microstrain were determined using these distinct methods, revealing a systematic correlation between the crystallite size and microstrain obtained through the different techniques. [ABSTRACT FROM AUTHOR]

In this work, the effect of heat treatment in the synthesis of vanadium pentoxide (V2O5) on its physicochemical properties was studied. Furthermore, the effect of liquid and viscous electrolytes based on lithium perchlorate (LiClO4) on the performance of electrochromic devices (ECDs) was evaluated using heat-treated V2O5 as electrochromic film. V2O5 was synthesized using the chemical bath technique. The V2O5 without and with heat treatment at 400 °C was characterized using FT-IR, UV-Vis, XRD, XPS, FESEM, AFM, and cyclic voltammetry (CV) techniques. Better physicochemical behavior was shown by the thermally treated V2O5, which is why it was used in the ECDs. Single ECDs were characterized using optical transmittance spectra, kinetic curves, and electrochemical impedance spectroscopy. A broadening of the absorption band towards the red and better electrochemical properties were observed when a thermal treatment was applied to the amorphous V2O5. A charge storage capacity of 1061.42 mC/cm2 was obtained for the crystalline V2O5 film (with heat treatment) compared to the charge storage capacity of 303.38 mC/cm2 obtained for the amorphous V2O5 film. A better distribution and decrease in grain size was observed for V2O5 with heat treatment. The CV curves showed higher stability of crystalline V2O5 compared to amorphous V2O5, even after several cycles and at different scan rates. A higher flow of ions between the working electrode and the counter electrode was achieved with the use of liquid electrolyte in the ECD, allowing a more efficient ECD with greater change in transmittance in the near-infrared region, compared to the use of viscous electrolyte. This research work contributes to the improvement of the physicochemical properties of V2O5. [ABSTRACT FROM AUTHOR]

Vanadium pentoxide nanowires were successfully fabricated using vanadium oxytrichloride oxidation with copper oxide nanoparticles serving as catalysts via atmospheric pressure chemical vapor deposition. Kinetic parameters such as temperature and flow velocity were proved to play important roles in the morphologic control of as-deposited product. Vanadium pentoxide nanowires with an average length of ∼10 μm and a diameter of 50–100 nm, were obtained under the optimum conditions. A root growth mechanism of nanowires was proposed that precursor was readily captured by catalyst nanoparticles at the beginning of deposition, forming nucleation sites. Subsequently, the anisotropic growth of vanadium pentoxide is primarily governed by energy minimization under the reaction rate limited conditions. The presence of oxygen vacancies in the nanowires was confirmed by Raman, XPS and photoluminescence characterization, indicating promising applications in functional materials manufacture. The novel route for preparing vanadium pentoxide nanowires provides an alternative pathway for transitioning traditional vanadium industry towards advanced functional materials development. [ABSTRACT FROM AUTHOR]

The extraction of vanadium from spent industrial catalysts is a widely practiced process globally due to the large quantities of material available with appreciable vanadium content. However, some of these spent catalysts are unresponsive to established extraction methods because they have different properties. Therefore, separate studies are necessary to deal with specific cases. This work demonstrates how the leaching step can limit the recovery of vanadium to the solution before the coprecipitation step. The NH4Cl‐H2SO4 synergetic system achieved a high vanadium leaching rate of up to 95 %, resulting in the preparation of high‐purity NH4VO3 with 75.45 % V2O5 content. This demonstrates the potential of the prepared V2O5 as a precursor for vanadium materials used in sodium‐ion batteries, allowing for the adjustment of the valence of vanadium. The Na3V2(PO4)3@C particles exhibit a discharge capacity of 110 mAh g−1 at a current density of 0.1 C and 90 mAh g−1 at 1 C. The synergistic leaching system provides a sustainable method for the recovery and reuse of vanadium from spent vanadium catalysts. This contributes to recycling efforts and the development of sodium‐ion batteries. [ABSTRACT FROM AUTHOR]

Progesterone (PGT) is a steroid hormone produced naturally by pregnant women. Advent of pharmaceuticals gave rise to synthetic production of PGT as a medicine for various pregnancy-related issues. As a result of synthetic production and high utilization rate of PGT, they have become an emerging contaminant in water sources worldwide. Conventional wastewater treatment is not competent enough to remove steroid contaminants. Hence, the current study attempted the degradation of 10 mg L−1 of PGT in water using photocatalysis (PC) followed by electrocatalytic oxidation (EC) using vanadium pentoxide (V2O5) and carbon-coated titanium (C/Ti) anode. Optimization studies found UV-C irradiation, pH 5, 50-mg L−1 catalyst dosage, 180-min PC followed by 300-min EC, and 69 mA cm−2 current density eliminating 96% COD and 71.5% TOC. Comparative studies showed that PC(UV-C) + EC was 50% and 25% more efficient than electrochemical oxidation and electrocatalytic oxidation for TOC removal. Photocatalytic pretreatment brought down current consumption of the process by 23 mA cm−2. High-resolution mass spectrometry (HRMS) studies were utilized to propose the degradation pathway that involved hydroxylation, demethylation, dehydroxylation, and decarboxylation mechanisms. [ABSTRACT FROM AUTHOR]

This study investigates the wear behaviour of aluminium, vanadium pentoxide and boron carbide, metal matrix composites. Specimens were prepared for various weight fractions of V2O5 particles added with aluminium and 2% B4C powder compaction using a suitable die assembly on a 1.0 MN capacity hydraulic press and sintering at 500°C. The use of powder metallurgy to create Al matrix composites reinforced with V2O5 particles has yet to be attempted. The ongoing study, which examined the wear behaviour of composites made up of Al–xV2O5–2B4C using the mechanical alloying method, discusses the function of reinforcement on the wear mechanism of metal matrix composite. The composites were analysed, X-ray diffraction was used for material characterization, scanning electron microscope analysis for worn surface characterization, and energy dispersive spectrum was used to determine the situation of the mechanically mixed layer and tested the friction coefficient and wear loss of the composites on a pin-on-disc tribometer. Addition of V2O5 with 2% B4C results in a good change in its specific wear rate, reduced coefficient of friction, and better formation of the mechanically mixed layer. [ABSTRACT FROM AUTHOR]

The increase in global temperature has led to a significant surge in energy consumption within the air conditioning industry, resulting in environmental deterioration. Electrochromic (EC) windows have emerged as a promising solution to address these challenges. Vanadium pentoxide (V2O5) stands out among all metal oxide materials due to its remarkable EC properties, including substantial Li+ ion insertion capacity and multicolor capabilities. Despite the potential of V2O5, there remains a lack of comprehensive research on the structural and optical properties of V2O5 films with varying thicknesses. Therefore, this study aims to investigate the structural and optical properties of V2O5 thin films with thicknesses ranging from 46 to 344 nm. By employing the sol-gel spin coating method, V2O5 thin films were fabricated and analyzed using X-ray diffraction (XRD) spectroscopy and ultraviolet-visible (UV-Vis) spectrophotometry. The fabricated V2O5 thin films with thicknesses of 46-274 nm demonstrated an average film transparency of 83%. XRD analysis further revealed that the V2O5 thin films reached their peak crystallinity at a thickness of 344 nm. Moreover, CV analysis revealed that the V2O5 device, with a thickness of 274 nm, exhibited a cathodic peak current of -1.63 mA, indicating its excellent ability to facilitate Li+ ion diffusion. Additionally, CA measurements displayed a high optical modulation of 37.78%. Ultimately, this research contributes to the development of energy-efficient solutions for sustainable environmental practices. [ABSTRACT FROM AUTHOR]

The hot corrosion resistance of 8 wt.% yttria‐stabilized zirconia (8YSZ) powder, modified with CaO, MgO, Ta2O5, and TiO2 at concentrations of 5, 10, and 15 wt.%, was systematically investigated in a molten vanadium pentoxide (V2O5) environment at 900°C and 1100°C for 48 h. The modified 8YSZ samples, coated with V2O5, underwent thermal cycling totaling 12 cycles. Results revealed susceptibility to hot corrosion for all doped 8YSZ powders, attributed to tetragonal ZrO2 destabilization, forming monoclinic ZrO2. Remarkably, 8YSZ/CaO demonstrated exceptional resistance to hot corrosion when exposed to a temperature of 900°C. The corrosion product found in the 8YSZ/Ta2O5 material was determined to be tetragonal Zr0.66Y0.17Ta0.17O2. Although, 8YSZ/TiO2 undergoes deterioration at 900°C, it exhibits improved resistance at 1100°C, resulting in the formation of TiVO4. [ABSTRACT FROM AUTHOR]

This work elucidates the synthesis of V2O5, Praseodymium (Pr) doped vanadium pentoxide Pr-V2O5 nanoparticles (NPs) and Pr-V2O5/rGO nanocomposite by green combustion method, using Manilkara zapota as a novel combustion fuel. The synthesised Pr-V2O5/rGO nano catalyst was characterized by various physicochemical techniques. Pr-V2O5/rGO exhibits an excellent electrochemical ability to detect Pb2+ with lower limit of detection 2.919 nM and sensitivity 0.8113 μA/nM cm2. Further, the Pr-V2O5/rGO employed for the photocatalytic degradation of MB dye displayed remarkable efficiency through swift degradation. Also, the conditions such as catalytic load, pH, and dye concentration were optimized to achieve most efficient degradation of the dye. Pr-V2O5 provides a greater number of catalytic sites and high ion transport channels, whereas rGO provides the conductivity and porosity to the nanocatalyst. By utilizing these synergic advantages, Pr-V2O5/rGO nanocatalyst effectively detects heavy metal ions (HMIs) and degrade methylene blue (MB) dye, befitting from unique morphology of Pr doped V2O5 nanoparticles wrapped into the two dimensional rGO nano sheets. The above results limelight that Pr-V2O5/rGO as the multifunctional catalyst for promising detection of hazardous metal ions and effective environmental remediation. [ABSTRACT FROM AUTHOR]

Rational Design of Amorphous Vanadium Pentoxide and Hollow Porous Carbon Spheres Hybrid for Superior Zinc-Ion Battery. [Display omitted] Aqueous zinc-ion batteries (AZIBs) are expected to be a promising large-scale energy storage system owing to their intrinsic safety and low cost. Nevertheless, the development of AZIBs is still plagued by the design and fabrication of advanced cathode materials. Herein, the amorphous vanadium pentoxide and hollow porous carbon spheres (AVO-HPCS) hybrid is elaborately designed as AZIBs cathode material by integrating vacuum drying and annealing strategy. Amorphous vanadium pentoxide provides abundant active sites and isotropic ion diffusion channels. Meanwhile, the hollow porous carbon sphere not only provides a stable conductive network, but also enhances the stability during charging/discharging process. Consequently, the AVO-HPCS exhibits a capacity of 474 mAh/g at 0.5 A/g and long-term cycle stability. Moreover, the corresponding reversible insertion/extraction mechanism is elucidated by ex-situ X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. Furthermore, the flexible pouch battery with AVO-HPCS cathode shows high comprehensive performance. Hence, this work provides insights into the development of advanced amorphous cathode materials for AZIBs. [ABSTRACT FROM AUTHOR]

The precise mechanism governing the reversible semiconductor‐to‐metal transition (SMT) in V2O5 remains elusive, yet its investigation is of paramount importance due to the remarkable potential of V2O5 as a versatile "smart" material in advancing optoelectronics, plasmonics, and photonics. In this study, distinctive experimental insights into the SMT occurring in amorphous V2O5 through the application of highly sensitive, temperature‐dependent, in situ analyses on a V2O5 thin film deposited on soda‐lime glass are presented. The ellipsometry measurements reveal that the complete SMT occurs at ≈340 °C. Remarkably, the refractive index and extinction coefficients exhibit reversible characteristics across visible and near‐infrared wavelengths, underscoring the switch‐like behavior inherent to V2O5. The findings obtained from ellipsometry are substantiated by calorimetry and in situ secondary ion mass spectrometry analyses. In situ electron microscopy observations unveil a separation of oxidation states within V2O5 at 320 °C, despite the thin film retaining its amorphous state. The comprehensive experimental investigations effectively demonstrate that alterations in electronic state can trigger the SMT in amorphous V2O5. It is revealed for the first time that the SMT in V2O5 is solely contingent upon electronic state changes, independent of structural transitions, and importantly, it is a reversible transformation within the amorphous state itself. [ABSTRACT FROM AUTHOR]

In recent years, vanadium pentoxide (V2O5) nanoparticles (NPs) have attracted considerable interest due to their potential medicinal applications, including cancer therapy, antibiotic resistance and antibacterial activity. Manufacturing V2O5 NPs is a crucial step in developing these applications, and laser ablation in solution has proven to be a particularly successful technique. Following fabrication, colloidal solutions were analyzed using ultraviolet–visible (UV–Vis) absorption spectra, Fourier transform infrared (FTIR) spectrum, transmission electron microscopy (TEM) and X-ray diffraction (XRD). In this work, XRD study revealed that the produced NPs had an orthorhombic phase. Based on the laser energy, nanosized vanadium pentoxide particles were created by laser irradiating a vanadium bulk submerged in a double deionized water (DDW), resulting in spherical particles with average sizes ranging from 15.4 to 33.8 nm, as shown by TEM micrographs. Conforming to the quantum size concept, the bandgap energy of V2O5 NPs is higher than that of bulk V2O5 due to the decrease in particle size. This study examined the effectiveness of V2O5 NPs against pathogenic bacterial strains Staphylococcus aureus as Gram's positive bacteria and Escherichia coli as negative Gram's bacteria. Then, we evaluated anticancer activity of V2O5 NPs against a breast cancer cell line (MCF-7 cells) using MTT assay. The results reveal that the activity of prepared V2O5 NPs against S. aureus is greater than that of E. coli. The findings suggest that prepared NPs can act as an anti-proliferative agent against MCF-7 cells. Subsequently, the produced NPs might be exploited as a future strategy for other biomedical applications. [ABSTRACT FROM AUTHOR]

Aqueous zinc ion batteries have attracted much attention due to their advantages of higher energy density, low cost and environmental friendliness. Among the commonly used cathode materials for zinc ion batteries, vanadium-based composites have a promising research prospect due to their multiple valence states (V5+, V1+, V3+, V2+) and different structural features, which provide high specific capacity when playing the role of cathode materials for zinc ion batteries. However, vanadium-based composites are limited in the application of zinc-ion batteries due to poor cycling stability and low electrical conductivity. To address this issue, nanoparticles with a larger specific surface area than commercial vanadium pentoxide (V2O3) were prepared in this study using a simple hydrothermal method. Such V2O5 nanoparticles as cathode materials for zinc ion batteries provide an excellent specific capacity of 364 mAh/g at lower current densities and exhibits a high reversible specific capacity of 156 mAh/g at high current densities. After 200 cycles, its capacity can still maintain 85% of the initial capacity, not only provide better cycling stability than commercial V2O5, but also possess higher specific capacity. Based on its simple preparation method and good electrochemical stability, the nanoparticles demonstrate potential applications in negative electrode materials for zinc ion batteries. [ABSTRACT FROM AUTHOR]

The present work reports the synthesis of pure V2O5 and Ni-doped V2O5 nanoparticles via co-precipitation method, exploring diverse concentrations of Ni2+ in V2O5 system. The valent reduction of V, Ni, Oxygen stabilization and formation of V2O5 and Ni-doped V2O5 nanoparticles were evident by characterization techniques such as X-ray diffraction, Fourier transform infrared spectroscopy, Photoluminescence and UV–Visible Diffuse Reflectance Spectroscopy. Bandgap variations and Crystallite size of pure V2O5 and Ni-doped V2O5 nanoparticles confirmed the reduction of Ni+ and V+ their difference was found to be ∆Eg = 1.52 eV and 24–43 nm, respectively. X-ray Photoelectron Spectroscopy analysis examined oxidation states and binding energies which is vital for understanding structural and compositional aspects. Evaluation of bacterial endurance against gram-positive (S. aureus) and gram-negative bacteria (E.coli), coupled with antioxidant activity measurements via 2,2-Diphenyl-1-picrylhydrazyl (DPPH) method, indicate the successful utilization of the synthesized nanoparticles for biomedical and wastewater treatment applications. In contagious diseases, Ni/V2O5 nanoparticles showed superior activity against both S. aureus and E. coli. Photocatalytic activity against MB (98%) and Rh–B (88%) dyes under visible light irradiation was also evaluated with Ni/V2O5 nanoparticles which is exhibiting enhanced performance. Pseudo-first-order kinetics revealed accelerated dye degradation upon Ni ion incorporation, suggesting improved electron–hole pair activity and ROS formation. The AOP facilitated by the photocatalyst holds promise for wastewater treatment, with advantages such as absence of secondary product formation and presence of activated electrons. The in-depth investigation about the properties of Ni2+ into V2O5 lead us towards the cost effective and multifunctional applications of these nanoparticles at industrial level. [ABSTRACT FROM AUTHOR]

Novel miniaturized Pb(II) paper-based potentiometric sensors are described using coumarin derivatives I and II as electroactive ionophores and nano vanadium pentoxide as a solid contact material for the sensitive and selective monitoring of trace lead ions. Density functional theory (DFT) confirms optimum geometries, electronic properties, and charge transfer behaviors of 1:2 Pb(II): coumarin complexes. The sensors are prepared by using two strips of 20 × 5 mm filter paper with two circular orifices. One orifice is coated with vanadium pentoxide (V2O5) nanoparticles in colloidal conductive carbon as a solid-contact, covered by a PVC membrane containing coumarin ionophore to act as a sensing probe. The other orifice is treated with Ag/AgCl in a polyvinyl butyral (PVB) film, to act as a reference electrode. Sensors with ionophores (I) and (II) exhibit Nernstian slopes of 27.7 ± 0.2 and 30.2 ± 0.2 mV/decade over the linear concentration range 4.5 × 10−7 to 6.2 × 10−3 M and 8.5 × 10−8 to 6.2 × 10−3 M, with detection limits of 1.3 × 10−7 M (26.9 ppb) and 2.1 × 10−8 M (4.4 ppb), respectively. The sensors are satisfactorily used for accurate determination of lead ions in drinking water, lead-acid battery wastewater, and electronic waste leachates. The results compare favourably well with data obtained by flameless atomic absorption spectrometry. [ABSTRACT FROM AUTHOR]

Lithium-sulfur batteries have high energy density and are one of the most promising secondary batteries to alleviating energy scarcity, but many aspects limit their practical applications. Among them, the shuttle effect produced when soluble polysulfides pass through the separator is a big reason for the slow progress in commercialization. In this study, N-doped vanadium pentoxide materials (SZV) were designed and synthesized as a functional material for separator. The SZV material provides abundant adsorption sites and catalytic sites and can effectively inhibit the shuttle effect of polysulfides. The first cycle discharge capacity was 982 mAh g−1 at 1 C, and the capacity decay was only 0.056% per cycle after 1400 cycles. The SZV separator battery have an initial capacity of 869 mAh g−1 at 4 C and retain a capacity of 648 mAh g−1 after 200 cycles. Notably, the modified separator batteries can adapt to temperature changes and show excellent cycling performance. The SZV separator battery has a capacity of 700 mAh g−1 at 60 °C and 864 mAh g−1 at 10 °C after 100 cycles at 0.5 C. [ABSTRACT FROM AUTHOR]

Developing the ecofriendly and high-fidelity electrocatalysts for the oxygen evolution reaction (OER) is essential to foster effective production of environmentally friendly hydrogen. Herein, we fabricated the highly efficient OER electrocatalysts of the activated carbon-decorated vanadium pentoxide (AC-V2O5) nanocomposites using a facile hydrothermal technique. The AC-V2O5 nanocomposites displayed an aggregated structure of the AC nano-sheet-anchored orthorhombic V2O5 nanorods. When performing the OER process in an alkaline electrolyte at 10 mA/cm2, AC-V2O5 exhibited the low overpotential (~230 mV), small Tafel slope (~54 mV/dec), and excellent stability. These substantial OER performances of AC-V2O5 could be ascribed to the synergistic effects from both the electrochemically active V2O5 nanorods and the highly conductive AC nanosheets. The results infer that the AC-V2O5 nanocomposites possess a substantial aptitude as a high-performance OER electrocatalyst for production of the future green energy source—hydrogen. [ABSTRACT FROM AUTHOR]

Background: Previous work from our group has shown that chronic exposure to Vanadium pentoxide (V2O5) causes cytoskeletal alterations suggesting that V2O5 can interact with cytoskeletal proteins through polymerization and tyrosine phosphatases inhibition, causing Alzheimer's disease (AD)-like hippocampal cell death. Objective: This work aims to characterize an innovative AD experimental model through chronic V2O5 inhalation, analyzing the spatial memory alterations and the presence of neurofibrillary tangles (NFTs), amyloid-β (Aβ) senile plaques, cerebral amyloid angiopathy, and dendritic spine loss in AD-related brain structures. Methods: 20 male Wistar rats were divided into control (deionized water) and experimental (0.02 M V2O5 1 h, 3/week for 6 months) groups (n = 10). The T-maze test was used to assess spatial memory once a month. After 6 months, histological alterations of the frontal and entorhinal cortices, CA1, subiculum, and amygdala were analyzed by performing Congo red, Bielschowsky, and Golgi impregnation. Results: Cognitive results in the T-maze showed memory impairment from the third month of V2O5 inhalation. We also noted NFTs, Aβ plaque accumulation in the vascular endothelium and pyramidal neurons, dendritic spine, and neuronal loss in all the analyzed structures, CA1 being the most affected. Conclusions: This model characterizes neurodegenerative changes specific to AD. Our model is compatible with Braak AD stage IV, which represents a moment where it is feasible to propose therapies that have a positive impact on stopping neuronal damage. [ABSTRACT FROM AUTHOR]

Emerging as a leading contender for economical, high‐security grid‐scale energy storage, rechargeable aqueous zinc‐ion batteries (AZIBs) are currently facing the challenge in its progression due to the absence of cathode materials with high energy density. In this study, we design a V2O5 ⋅ nH2O, GO and CNTs composite (HVO/GO‐CNTs) film through freeze‐drying and vacuum filtration. This binder‐free cathode for AZIBs exhibits remarkable electrochemical performance, featuring a high capacity of 387 mAh g−1 at 0.2 A g−1 and a high capacity retention of 82.6 % after 1000 cycles at 1 A g−1. This investigation offers a promising approach to electrode material design for the advancement of high‐performance AZIBs. [ABSTRACT FROM AUTHOR]

Total antioxidant capacity (TAC) can be evaluated by detecting the content of antioxidants, such as ascorbic acid, based on the enzyme-mimetic activity of nanomaterials. Herein, we fabricated a 3D-V2O5/NC nanocomposite using a self-templating strategy, which achieved ultrafine particles (∼2.5 nm), a porous carbon layer, large specific surface area (152.4 m2/g), N-doping and heterogeneous structure. The strong catalytic activity of 3D-V2O5/NC resulted from the integrated effect between the ultrafine structure of V2O5 nanoparticles and the 3D porous nitrogen-doped carbon framework, effectively increasing the number of active sites. This nanozyme presented a higher catalytic activity than its components or precursors in the nanocomposite (e.g., VN/NC, NC, V2O5, and VO2/g-C3N4). ROS scavenging experiments confirmed that the dual enzyme-like activity of 3D-V2O5/NC (catalase-like and oxidase-like) resulted from their co-participation of ‧O2-, h+ and ‧OH, among which ‧O2- played a crucial role in the catalytic color reaction. By virtue of the 3D-V2O5/NC nanoenzyme activity and TMB as a chromogenic substrate, the mixed system of 3D-V2O5/NC + TMB + H2O2 provided a low detection limit (0.03 μM) and suitable recovery (93.0-109.5%) for AA. Additionally, a smartphone-based colorimetric application was developed employing "Thing Identify" software to evaluate TAC in beverages. The colorimetric sensor and smartphone-detection platform provide a better or comparable analytical performance for TAC assessment in comparison to commercial ABTS test kits. The newly developed smartphone-based colorimetric platform presents several prominent advantageous, such as low cost, simple/rapid operation, and feasibility for outdoor use.

It is essential to improve thermal insulation. In this study, titanium dioxide (TiO2), magnesium oxide (MgO), and vanadium pentoxide (V2O5) were used as additives to modify phenolic novolac resin by the solution mixing method. Different weight percentages of resin nanoparticles (NPs) were added, and nanocomposites with different weight percentages were prepared. These nanocomposites were investigated by field emission scanning electron microscope (FE-SEM), X-ray diffraction spectroscopy (XRD), and oxyacetylene flame test (OFT). The FE-SEM images showed that the NPs were dispersed on the surface of the novolac resin at low concentrations. However, at high concentrations, the dispersion was suppressed in some cases by aggregation in the nanocomposites. The OFT test proved that by increasing the content of NPs in the nanocomposite, the back surface temperature of the sample decreased, thus improving the thermal insulation properties. [ABSTRACT FROM AUTHOR]

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Considering the importance of understanding the catalysis of metal oxides incorporated hydrogen storage system MgH 2 , in this study we tried to identify the chemical interaction between magnesium hydride (MgH 2) and the additive vanadium pentoxide (V 2 O 5). Two test samples, MgH 2 +0.25V 2 O 5 and 0.25MgH 2 +V 2 O 5 , were subjected to mechanical milling treatment for different times (15 min, 1h, 2h, 5h, 10h and 15h), and the phase change was monitored systematically. The detailed X ray diffraction analyses suggest that the phase evolution starts with the reduction of V 2 O 5 and it ends up with the formation of a rock salt structure, typified by Mg x V y O x + y. High-resolution transmission electron microscopy study coupled with energy dispersive spectroscopy suggest that the distribution of V, Mg and O in Mg x V y O x + y is homogenous, though V-rich spots/boundaries can be spotted across the rock salt particles. Further verification by X–ray photoelectron spectroscopy suggests that V exists in a mixed valence state in the end sample, 15h reacted MgH 2 +0.25V 2 O 5. Differential scanning calorimetry and hydrogen storage kinetics studies prove the improved hydrogen storage behavior of Mg x V y O x + y containing MgH 2 sample. We believe that the formation of Mg x V y O x + y rock salt particles with V enriched spots/interfaces is the key step in the catalysis of V 2 O 5 incorporated hydrogen storage system, MgH 2. • The catalytic interaction between MgH 2 and the additive V 2 O 5 makes Mg gets oxidized and V gets reduced. • The interaction also leads to the in-situ formation of V doped MgO rock salt particles. • Existence of V rich surface spots on the V doped MgO particles can be confirmed. • The particle surface contains V with variable oxidation states. • V doped MgO is catalytically active for MgH 2. [ABSTRACT FROM AUTHOR]

In this work, vanadium pentoxide (V2O5) nanoparticles-filled electrospun polyvinylpyrrolidone (PVP) nanofibers were investigated systematically at various nanofiller weight percentages (8 and 10 wt%) and input intensities to reveal the effective optical limiting feature in the visible spectrum. XRD analysis demonstrated the purity of the produced V2O5 nanoparticles. According to SEM findings, V2O5 nanoparticles were effectively integrated into the PVP nanofibers. Two distinct absorption bands were observed at around 400 and 217 nm. These bands were related to PVP and V2O5 nanoparticles in linear absorption measurements, respectively. Moreover, an increased Urbach energy value was obtained with an increase in V2O5 nanofiller content within PVP. Open-aperture Z-scan measurements were taken at 532 nm considering the band gap energy of the V2O5 nanofillers in PVP composite nanofibers. In 8 wt% V2O5 nanofilled PVP nanofibers, one-photon absorption (OPA) was the main nonlinear absorption (NA) mechanism, and the defect states of the V2O5 nanoparticles had no contribution to NA. On the other hand, sequential two-photon absorption was the main NA mechanism, and the defect states of the nanoparticles caused more efficient NA behavior in 10 wt% V2O5 nanofilled PVP nanofibers. The effective optical limiting behavior was obtained for this composite nanofiber with lower limiting threshold as 1.49 × 10–5 J/cm2. The V2O5 nanofilled PVP nanofibers presented strong potential optical limiters in the visible wavelength region. This was attributed to their high linear transmittance at low input intensities and their robust NA behavior at higher input intensities. [ABSTRACT FROM AUTHOR]

The combination of common semiconductors with porous materials has the potential to augment the splitting of electrons and holes, hence increasing the efficiency of photodetectors. In the current study, we present the efficient fabrication of photodetectors consisting of vanadium pentoxide (V2O5) and macroporous structures via the pulsed laser deposition technique. The structure, surface morphology, and optical properties of V2O5 nanostructures embedded in porous silicon were examined using an X-ray diffractometer, a field emission scanning electron microscope, and a UV–Vis–NIR diffuse reflectance spectrophotometer, photoluminescence emission spectra, and Fourier transformation infrared spectroscopy. The findings indicate that the V2O5 nanostructure exhibits an orthorhombic crystal structure, which tends to align along the (001) plane. These nanostructures were distributed on porous silicon surfaces, mainly within the pores, which range in size from 52.4 nm to 106.5 nm. The level of pore filling varies depending on the laser energy used, ranging from partial to almost complete filling. The room-temperature photoluminescence peaks of V2O5 nanostructure/porous silicon possess four distinct spectra characterized by their maximum emission wavelengths of around 461 nm and 664 nm.However, the electrical and spectral responsivity properties were measured before and after introducing V2O5 nanostructures into porous silicon. The ideality factor of porous silicon has decreased after embedding V2O5 nanostructure in porous silicon. The deposition of V2O5 nanostructures into porous silicon resulted in a significant rise in spectrum responsivity, particularly at a wavelength of 471 nm. Moreover, the spectral responsivity exhibited a rising trend with increasing laser energy, reaching a maximum value of 0.31 A/W. The external quantum efficiency found its highest value at 78.93% when more incredible laser energy was used. The V2O5 nanostructure/porous silicon device fabricated in this work, consisting of a V2O5 nanostructure integrated with porous silicon, has remarkable potential as a high-efficiency photodetector in several photoelectronic technologies. [ABSTRACT FROM AUTHOR]

In this research, an innovative Z-scheme vanadium pentoxide (V2O5)/graphitic carbon nitride (g-C3N4) photocatalyst was synthesised using a facile thermal treatment method, and its photodegradation performance and physicochemical properties were evaluated. The heterostructure provided high Brunauer–Emmett–Teller surface area and pore volume, which encouraged charge carrier separation and transfer, as well as supplied abundant micro-mesoporous structures and active sites for photocatalytic redox reactions. The successful incorporation of V2O5 between g-C3N4 layers can be proven by proposing the synthesis mechanism, as well as conducting morphology, crystal structure, elemental, and chemical analysis through scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy, respectively. Using these combined photocatalysts, ciprofloxacin (CIP) was successfully degraded up to 90.17% removal efficiency in the visible-light spectrum. The superior photocatalytic activity of g-C3N4 composite over V2O5 is primarily due to its increased light absorption capacity, as well as increased surface area, pore size, and volume, effective charge transfer, and optimal band alignment between g-C3N4 and V2O5. This research provides a significant future perspective for the utilisation of Z-scheme V2O5/g-C3N4 heterojunction photocatalyst for water treatment, especially those involving endocrine-disrupting compounds and antibiotics like CIP. [ABSTRACT FROM AUTHOR]

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Advanced energy storage technologies have been developed to achieve safe, high-capacity, and stable cathode materials for aqueous Zn-ion batteries. Vanadium oxide has lately become a popular cathode material thanks to its advantages of a sufficient operating voltage window and a highly reversible redox reaction. However, vanadium pentoxide has certain drawbacks, such as poor electrical conductivity and slow ion diffusion. To resolve these problems, V2O5 sheets with amorphous carbon were synthesized by an ultrafast (within one minute), lower temperature (180 ℃), one-step and large-scale combustion synthesis method. We demonstrate the introduction of carbon improves the conductivity and increases the content of low-valence vanadium, resulting in higher electrochemical activity and lower polarization of V2O5/C. Moreover, the introduction of C increases the concentration of oxygen defects in V2O5, further enhancing its conductivity and providing higher active sites for electrochemical reactions, thereby increasing its battery capacity. The synthesized V2O5/C sample exhibited a specific capacitance of 220 mAh g−1 (compared to 180 mAh g−1 for V2O5) in aqueous electrolytes at 4 A g−1, demonstrating a high specific capacity of 85.5% after 500 cycles with nearly 100% Coulomb efficiency. These results indicate improved specific capacitance and cyclic stability. [ABSTRACT FROM AUTHOR]

A gas sensor utilizing V2O5/Pd thin films has been successfully created by pulse laser deposition on porous silicon substrate, demonstrating rapid response times and superior sensitivity for detecting gases at low temperatures. The investigation of sensor response, selectivity, and stability demonstrates the impressive sensing capabilities of the thin films. Vanadium pentoxide films doped with palladium (V2O5/Pd) are fabricated through pulsed laser deposition technique, with varying laser pulse energy (600, 800, and 1000) mJ/pulse, for the purpose of sensing applications related to Hydrogen Sulfide (H2S) and Nitrogen Dioxide (NO2). The ablation procedure entails the utilization of a Q-switched Nd:YAG laser that operates at a specific wavelength of 1064 nm. The laser system exhibits pulse duration of 10 ns and a repetition rate of 1 Hz when operating on a porous silicon n-type Si (111) substrate. The X-ray diffraction, UV–Vis Spectroscopy, Raman scattering, Photoluminescence spectroscopy, and field emission-scanning electron microscopy techniques were employed to investigate the crystal structure, optical structure, and morphological properties of the V2O5/Pd NPs. As the energy of the pulse laser grows, the presence of well-defined peaks in the V2O5/Pd thin film indicates an enhancement in its crystalline structure. The size of the surface grains exhibit an augmentation, accompanied by an increase in the energy gap, leading to an elevated level of homogeneity. This study aimed to evaluate the influence of Pd on the development kinetics of vanadium pentoxide nanoparticles. The findings of this investigation demonstrated that the addition of Pd resulted in several notable effects, including improved sensitivity, reduced operational temperature requirements, and the capacity to maintain high sensitivity levels even at room temperature. [ABSTRACT FROM AUTHOR]

This study developed an effective and practical process for recovering vanadium as vanadium pentoxide (V2O5) from spent refinery catalysts. It involves four stages: leaching, purification, precipitation, and calcination. Vanadium was first leached using NaOH; then, the solution was purified by precipitation. Next, vanadium was recovered as ammonium polyvanadate, and finally, V2O5 was produced by calcination. The efficiency of the dissolution of vanadium reached 95% when the [NaOH] = 0.5 M, T = 25 °C, solid-to-liquid ratio = 1:10 g/mL, and time = 30 min. The pH of the leachate averaged ca. 10, but by decreasing it to 9, significant amounts of Al, Fe, and Si were removed from the solution. There was an estimated loss of 14% of vanadium during the precipitation of impurities, yet ca. 85% of it can be redissolved under the optimal leaching conditions. Finally, the purified leachate was subjected to the precipitation of vanadium by ammonium which was optimized using statistical software. The precipitation efficiency reached 76%; vanadium precipitated as ammonium polyvanadate. The resultant raffinate contained ca. 1.2 g/L of vanadium and was reconfigured for reuse within the process cycle. Next, the precipitate was calcined to produce V2O5 with a purity of over 99.5%. Experimental parameters were adjusted at each stage to optimize vanadium recovery while minimizing reagent consumption. By-products generated in each stage were reused in other processes, reducing waste production and vanadium loss. Finally, a life cycle assessment was conducted and revealed that the vanadium precipitation and calcination stages have the biggest impact on the environment in the developed process. [ABSTRACT FROM AUTHOR]

Herein, the composite of vanadium pentoxide and graphene oxide (V2O5/GO) was synthesized by the solgel method. The synthesized composite V2O5/GO was characterized by X-Ray diffraction analysis and Raman spectroscopy. After in situ reduction of GO, the electrochemical characteristics of V2O5/rGO were analyzed by cyclic voltammetry in Mg(NO3)2 aqueous solutions. The V2O5/rGO composite showed following intercalation capacities: initially 139.1 mA h g-1 and 101.8 mA h g-1 after the 10th cycle, which along with easy, fast and low-cost synthesis, make this composite a potentially good electrode material for application in secondary aqueous magnesium-ion batteries.

The fabrication of sponge-like vanadium pentoxide (V2O5) nanostructures using vertically aligned carbon nanotubes (VACNTs) as a template is presented. The VACNTs were grown on silicon substrates by chemical vapor deposition using the Fe/Al bilayer catalyst approach. The V2O5 nanostructures were obtained from the thermal oxidation of metallic vanadium deposited on the VACNTs. Different oxidation temperatures and vanadium thicknesses were used to study the influence of these parameters on the stability of the carbon template and the formation of the V2O5 nanostructures. The morphology of the samples was analyzed by scanning electron microscopy, and the structural characterization was performed by Raman, energy-dispersive X-ray, and X-ray photoelectron spectroscopies. Due to the catalytic properties of V2O5 in the decomposition of carbonaceous materials, it was possible to obtain supported sponge-like structures based on V2O5/CNT composites, in which the CNTs exhibit an increase in their graphitization. The VACNTs can be removed or preserved by modulating the thermal oxidation process and the vanadium thickness. [ABSTRACT FROM AUTHOR]

The paper examines the technological properties of diverse vanadium-containing raw materials, including titanium-magnetite concentrate, converter slag, dump sludge, neutralization sludge, slag from ferrovanadium smelting, fuel oil ash and slag, black shale, and spent catalysts. The existing chains of their formation and processing are described, considering the volume of raw materials underutilized for vanadium extraction, such as blast furnace slag, tailings, ilmenite concentrate, red mud, vanadium slag, and titanomagnetite concentrates. Most of these materials prove suitable for vanadium extraction. According to our estimates, annually produced industrial raw materials involve approximately 53.6 thousand tons of vanadium relative to V2O5. This includes 4.4 thousand tons of V2O5 suitable for extraction and 12.0 thousand tons of V2O5 potentially suitable for extraction. Additionally, about 28.5 thousand tons of vanadium relative to V2O5, found in titanium magnetite concentrates and converter slag, could be further engaged in processing. Consequently, the reserve of raw materials unused for vanadium extraction amounts to 45 thousand tons relative to V2O5. Processing these raw materials holds the potential to manufacture vanadium-containing products of a deeper degree of processing, including purified vanadium pentoxide V2O5, vanadium trioxide V2O3, and vanadium alloys, thereby reducing dependence on imported equivalents. [ABSTRACT FROM AUTHOR]

In this work we show high capacity and cycle‐life performance, for electrodeposited, crystalline V2O5 thin film cathodes protected by a 1 nm ALD alumina deposit for use with Li‐metal and ionic liquid electrolyte based microbatteries. Al2O3 coatings thicker than 1 nm are shown to decrease the performance of the V2O5 thin film cathodes. The ionic liquid outperforms an organic electrolyte at 1 C rates with an initial capacity of 148 mAh g−1 and capacity retention of 97 % at cycle 50. A polymer gel analogue of the ionic liquid electrolyte in combination with the 1 nm Al2O3 coated V2O5 had an initial capacity of 139 mAh/g with a capacity retention of 93.5 % to cycle 800, illustrating high capacity and extended cycle life. [ABSTRACT FROM AUTHOR]

The investigation into intercalation mechanisms in vanadium pentoxide has garnered significant attention within the realm of research, primarily propelled by its remarkable theoretical capacity for energy storage. This comprehensive review delves into the latest advancements that have enriched our understanding of these intricate mechanisms. Notwithstanding its exceptional storage capacity, the compound grapples with challenges arising from inherent structural instability. Researchers are actively exploring avenues for improving electrodes, with a focus on innovative structures and the meticulous fine-tuning of particle properties. Within the scope of this review, we engage in a detailed discussion on the mechanistic intricacies involved in ion intercalation within the framework of vanadium pentoxide. Additionally, we explore recent breakthroughs in understanding its intercalation properties, aiming to refine the material's structure and morphology. These refinements are anticipated to pave the way for significantly enhanced performance in various energy storage applications. [ABSTRACT FROM AUTHOR]

Although vanadium-based nanomaterials have found extensive use in industry, their influence on ecosystems and living organisms is not yet well investigated. In this study, hydrothermal methods were utilized for the synthesis of vanadium pentoxide nanoparticles (V2O5 NPs). The gained NPs were characterized using XRD, FT-IR, EDS, DLS, SEM and TEM techniques. Subsequently, the toxic effects of V2O5 NPs on the model green microalgae Chlorella vulgaris were evaluated. According to the obtained results, V2O5 NPs caused a significant reduction in cell number and biomass production of algae in a dose and time dependent manner. Moreover, flow cytometric analysis confirmed a reduction in the quantity of living cells. Scanning electron microscopy showed plasmolysis and deformation of the cells after exposure to nanoparticles. The photosynthetic pigments and phenolics content exhibited a decrease in comparison with the control sample. Although, non-enzymatic antioxidant system in C. vulgaris displayed an average action, antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) showed a dose dependent increasing trend. These intercellular reactions designated the activation of the antioxidant defense system in response to the induced oxidative stress by V2O5 NPs. [ABSTRACT FROM AUTHOR]

The present invention relates to a technique for synthesizing vanadium phosphorus oxide (VPO) catalyst employing an ultrasonic treatment approach while assessing phase composition and hydrocarbon oxidation activity to a conventionally synthesized catalyst. The ultrasonic treatment approach has been shown to produce a catalyst with improved surface constitution and accelerated hydrocarbon conversion in 3 h, as opposed to the typically heating process, which takes 24 h. Product selectivity is influenced by the nature of the catalyst, with an integration consisting of (VO)2P2O7 (V4+) and VOPO4 (V5+) being optimal for high rate of conversion. A 39 % conversion rate and 89 % maleic anhydride selectivity were achieved under optimum reaction conditions. [ABSTRACT FROM AUTHOR]

Copyright of Journal of University of Anbar for Pure Science is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copper metal is a promising anode in aqueous batteries due to its low price, noble reaction potential (0.34 V), high theoretical specific capacity, abundance and chemical stability. However, only a few copper ion storage materials have been reported. Herein, layered vanadium pentoxide is chosen to store copper ions for the first time. Ex situ XRD reveals a unique two phase transition process during cycling. The V2O5 electrode shows stable copper ion storage performance. It delivers 91.9 mAh g−1 for the first cycle with a cycle life of as high as 4000 cycles at 1.0 A g−1. This work provides an intriguing copper ion storage material and expands the available options of electrode materials for copper ion storage. [ABSTRACT FROM AUTHOR]

Oxygen vacancies are equilibrium defects in the vanadium pentoxide system that give rise to polaronic hopping transport via V4+ charge compensating defect. In this paper, we report the tunability of polaron formation, the hopping process, and their magnetic signature by substitution of isovalent (5+) phosphorus ions in the V5+ site. The powder x-ray diffraction data show a monotonous shift in lattice parameters with progressive P-doping, confirming the presence of a substitutional dopant. The polaron hopping energy reduced from 0.307 to 0.290 eV depicting a lower defect concentration in P-doping in V2O5. At low temperatures, it is found to obey the Efros–Shklovskii variable range hopping mechanism. The estimated hopping range increased to 1.6 ± 0.1 nm in doped V2O5 in contrast to ∼1.3 nm in the undoped one. The electron spin resonance measurements show a diminishing broad ferromagnetic signal and rising paramagnetic signal (g = 1.97) with progressive P-doping depicting predominant isolated electronic spins in the doped sample. The same is corroborated in room temperature M–H with a distinct hysteresis that diminishes with P-doping and a rise of a paramagnetic slope. Moreover, the reduced oxygen defects and lower V4+ relative occupancy together with fermi level fall toward intrinsic position are substantiated by photoelectron emission studies. [ABSTRACT FROM AUTHOR]

In this work, vanadium pentoxide nanoparticles (V2O5) derived by the chemical coprecipitation route were used to synthesize various vanadium-doped ZnO nanocomposite samples via the standard solid-state reaction process. The effect of V2O5 nanoparticles on the physicochemical properties of ZnO was discussed. The prepared samples were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy combined with energy-dispersive spectroscopy, and UV-visible spectroscopy. A diffuse reflectance spectroscopic approach is described to determine the bandgap energy (Eg) of the samples. The dielectric and photocatalytic characteristics are also examined. The photocatalytic performance of the prepared materials was tested under visible light using methylene blue (MB) as a pollutant dye model. As a result, it is found that the addition of V2O5 enhances the photodegradation of MB. The kinetics of the photodegradation reaction was found to follow a pseudo-first-order model. [ABSTRACT FROM AUTHOR]

Breast cancer is a commonly known cancer type and the leading cause of cancer death among females. One of the unresolved problems in cancer treatment is the increased resistance of the tumor to existing treatments, which is a direct result of apoptotic defects. Calculating an alternative to cell death (autophagy) may be the ultimate solution to maximizing cancer cell death. Our aim in this study was to investigate the potential of free nanoparticles (un‐drug‐loaded) in the induction or inhibition of autophagy and consider this effect on the therapy process. When the studies met the inclusion criteria, the full texts of all relevant articles were carefully examined and classified. Of the 25 articles included in the analysis, carried out on MCF‐7, MDA‐MB‐231, MDA‐MB‐231‐TXSA, MDA‐MB‐468, SUM1315, and 4T1 cell lines. Twenty in vitro studies and five in vivo/in vitro studies applied five different autophagy tests: Acridine orange, western blot, Cyto‐ID Autophagy Detection Kit, confocal microscope, and quantitative polymerase chain reaction. Nanoparticles (NPs) in the basic format, including Ag, Au, Y2O3, Se, ZnO, CuO, Al, Fe, vanadium pentoxide, and liposomes, were prepared in the included articles. Three behaviors of NPs related to autophagy were seen: induction, inhibition, and no action. Screened and presented data suggest that most of the involved free NPs (metallic NPs) in this systematic review had reactive oxygen species‐mediated pathways with autophagy induction (36%). Also, PI3K/Akt/mTOR and MAPK/ERK signaling pathways were mentioned in just four studies (16%). An impressive percentage of studies (31%) did not examine the NP‐related autophagy pathway. [ABSTRACT FROM AUTHOR]

A brand-new vanadium pentoxide (V2O5) functionalized starch (St) grafted poly(acrylonitrile) (PAN) adsorbent was synthesized via microwave-assisted graft polymerization method to remove methylene blue dye from water. FTIR, TEM, SEM, and XRD analysis were used to characterize the materials. Experiments on batch adsorption were conducted on the V2O5 and V2O5-St-g-PAN composite. The most significant removal efficiency of methylene blue (MB) by V2O5-St-g-PAN in water was 90% at a pH of 9 with an optimum adsorbent dose of 0.2 g in a 50 mL of 50 mg/mL MB concentration. The adsorption mechanism followed the Langmuir isotherm model with a correlation coefficient (R2) of 0.9996. The adsorption of MB onto V2O5-St-g-PAN was thermodynamically favorable at all temperatures (ΔGo = −56.371 KJ/mol to −56.164 KJ/mol). A negative enthalpy change (ΔHo) of −60.482 KJ/mol and a positive entropy change (ΔSo) of +0.0138 KJ/mol indicates an exothermic and highly ordered adsorption process. [ABSTRACT FROM AUTHOR]