VO2 Nanoparticles Research Articles

Exploration of Photoactive Cd2+ Substitutions on V2O5 Nanoparticles and Their Catalytic Potential Against the Toxic Dye

Exploration of Photoactive Cd2+ Substitutions on V2O5 Nanoparticles and Their Catalytic Potential Against the Toxic Dye

Coexistence of multiple magnetic interactions in oxygen-deficient V2O5 nanoparticles

This paper reports on the spin glass-like coexistence of competing magnetic orders in oxygen-deficient V2O5 nanoparticles with a broad size distribution. X-ray photoelectron spectroscopy yields the surface chemical stoichiometry of nearly V2O4.65 due to significant defect density. Temperature-dependent electrical conductivity and thermopower measurements demonstrate a polaronic conduction mechanism with a hopping energy of about 0.112 eV. The V2O5-δ sample exhibits strong field as well as temperature-dependent magnetic behaviour when measured with a SQUID magnetometer, showing positive magnetic susceptibility across the temperature range of 2-350 K. Field-cooled and zero-field-cooled data indicate hysteresis, suggesting glassy behaviour. The formation of small polarons due to oxygen vacancy defects, compensated by V4+ charge defects, results in Magneto-Electronic Phase Separation (MEPS) and various magnetic exchanges, as predicted by first-principle calculations. This is evidenced by the strong hybridisation of V orbitals in the vicinity of vacant oxygen site. An increase in V4+ defects shows an antiferromagnetic (AFM) component. The magnetic diversity in undoped V2O4.9 originates from defect density and their random distribution, leading to MEPS. This involves localised spins in polarons and ferromagnetic (FM) clusters on a paramagnetic (PM) background, while V4+ dimers induce AFM interactions. Electron paramagnetic resonance spectra measured at different temperatures indicate a dominant paramagnetic signal at a g-value of 1.97 due to oxygen defects, with a broad FM resonance-like hump. Both signals diminish with increasing temperature. Neutron diffraction data rules out long-range magnetic ordering, reflecting the composition as V2O4.886. Despite the FM hysteresis, no long-range order is observed in neutron diffraction data, consistent with the polaron cluster-like FM with MEPS nature. This detailed study shall advance the understanding of the diverse magnetic behaviour observed in undoped non-magnetic systems.

Toxicity and decomposition activity inhibition of VO2 micro/nanoparticles to white rot fungus Phanerochaete chrysosporium

Vanadium dioxide (VO2) is an excellent phase transition material widely used in various applications, and thus inevitably enters the environment via different routes and encounters various organisms. Nonetheless, limited information is available on the environmental hazards of VO2. In this study, we investigated the impact of two commercial VO2 particles, nanosized S-VO2 and micro-sized M-VO2 on the white rot fungus Phanerochaete chrysosporium. The growth of P. chrysosporium is significantly affected by VO2 particles, with S-VO2 displaying a higher inhibitory effect on weight gain. In addition, VO2 at high concentrations inhibits the formation of fungal fibrous hyphae and disrupts the integrity of fungus cells as evidenced by the cell membrane damage and the loss of cytoplasm. Notably, at 200 μg/mL, S-VO2 completely alters the morphology of P. chrysosporium, while the M-VO2 treatment does not affect the mycelium formation of P. chrysosporium. Additionally, VO2 particles inhibit the laccase activity secreted by P. chrysosporium, and thus prevent the dye decoloration and sawdust decomposition by P. chrysosporium. The mechanism underlying this toxicity is related to the dissolution of VO2 and the oxidative stress induced by VO2. Overall, our findings suggest that VO2 nanoparticles pose significant environmental hazards and risks to white rot fungi.

Coordination Compound Guided a Novel Composite Film with Zn2V2O7 Nanoflake and VO2@Zn2V2O7 Nanoparticle for Enhanced Thermochromism Smart Window.

Thermochromic vanadium dioxide (VO2) can intelligently modulate the transmittance of indoor solar radiation to reduce the energy consumption of air conditioning in buildings. Nevertheless, it remains a great challenge to simultaneously improve the luminous transmittance (Tlum) and solar modulation ability (ΔTsol) of VO2. In this study, a novel approach is employed utilizing a coordination compound to finely tune the growth of a VO2 based composite film, yielding a hierarchical film comprising Zn2V2O7 nanoflakes and VO2@Zn2V2O7 core-shell nanoparticles. Remarkably, the resulting composite films showcase exceptional optical performance, achieving a Tlum of up to 73.0% and ΔTsol of 15.7%. These outcomes are attributed to the antireflection properties inherent in the nanoflake structure and the localized surface plasmon resonance of well-dispersed VO2 nanoparticles. In addition, the Zn2V2O7-VO2 film demonstrates remarkable environmental durability, retaining 90% of its initial ΔTsol even after undergoing aging at 100°C under 50% relative humidity for a substantial period of 30 days - a durability equivalent to ≈20 years under ambient conditions. This work not only achieves a harmonious balance between Tlum and ΔTsol but also introduces a promising avenue for the design of distinctive composite nanostructures.

Transparent vanadium doped titania-silica films: Structural characterization and self-cleaning properties

Vanadium is one of the most promising dopants for titanium dioxide, as it has different oxidation states and comparable atomic sizes to titanium cation. In this article, vanadium-modified TiO2 was prepared at low temperatures and immobilized on glass for self-cleaning and superhydrophilic purposes. The synthesis was carried out at 80 °C under reflux for 48 hours and only 150 °C was required for complete immobilization on the glass surface using silica binder, which in turn formed 120 nm thick films. Such multilayered (3) films showed enhanced transparency in the visible region of the spectrum and exhibited strong superhydrophilic properties (water contact angle, WCA < 5°) even when not illuminated. Vanadium was present in interstitial regions, while the unbound vanadium formed V2O5 nanoparticles at higher concentrations. The presence of vanadium did not improve the photocatalytic properties for the degradation of fatty layers composed of stearic acid, which could be attributed to reduced migration of electrons and holes due to the trapping effects of vanadium species in such samples.

Structural, optical, and detailed photoluminescence characterization of solvothermal synthesized V2O5, ZrO2, and ZrV2O7 nanoparticles

It is indisputable that structural defects are pivotal in modulating the properties of materials. This study provides a comprehensive analysis of the structural, optical, and photoluminescence characteristics of V2O5, ZrO2, and ZrV2O7.These materials were chosen for their potential applications in various key technological domains. The XRD results revealed the formation of high-purity materials with no secondary phases. It was determined that ZrO2exhibits the most significant quantity of structural defects among the investigated materials. The variation in crystallite size as determined by XRD aligns with the variation in grain size observed through Scanning Electron Microscopy (SEM).The optical band gaps of V2O5, ZrO2, and ZrV2O7 were determined to be 2.27 eV, 5.19 eV, and 2.38 eV, respectively. X-ray Photoelectron Spectroscopy (XPS) analysis indicated the presence of constituent elements without any contaminants. A detailed examination of the photoluminescence (PL) emission characteristics in both UV–Vis and near-infrared (NIR) regions for all materials presented broad visible luminescence in the [450–650] nm range under UV excitation. Structural defects are crucial in determining the physico-chemical properties of materials. This is thoroughly examined for V2O5, ZrO2, and ZrV2O7.The infrared (IR) emission spectra, introduced for the first time in this study for V2O5, ZrO2, and ZrV2O7, are employed to elucidate the localization of structural defects within the band gap.

Synergistic Effects of V2O5 Nanoparticles Decorated By 2-Amino-1,3,4-Thiazole Derivatives Based Schiff Bases for High-Performance D-Glucose Sensing

V2O5 lamellar structure modifies its adsorption and conduction characteristics that makes it an extensively used biosensor for the detection of D-Glucose but its faster recombination rate limits its sensitivity. Here, V2O5 nanoparticles (NPs) decorated with 2-Amino-1,3,4-thiazole derivatives-based Schiff bases have been fabricated to enhance the sensing performance for D-Glucose detection. Decorated NPs exhibits unique physicochemical properties with enhanced surface area that attributes towards its better catalytic properties. Furthermore, modified V2O5 NPs surface with 2-Amino-1,3,4-thiazole derivatives facilitate efficient electron transfer and provides enhanced selectivity, sensitivity and repeatability towards glucose molecules that had been analyzed via. cyclic voltammetry and amperometry. Effect of different glucose concentration and scan rate at different time interval had been studied that illustrates the stability and sensitivity of NPs. Limit of detection (LOD), limit of quantification (LOQ), linear dynamic range (LDR), and durability has been acquired by a dependable current–voltage (I–V) process. Fabricated NPs shows potential for use in glucose sensing applications and advances biosensor technology to support the enzyme-free sensing technology.

A comprehensive study of laser irradiated hydrothermally synthesized 2D layered heterostructure V2O5(1−x)MoS2(x) (X = 1–5%) nanocomposites for photocatalytic application

Abstract It has been studied that both two-dimensional (2D) MoS2 and V2O5, which are classified as transition metal dichalcogenides and transition metal oxides, are good photocatalyst materials. For this purpose, the hydrothermal method was practiced to synthesize V2O5(1−x)MoS2(x) (X = 1–5% w/w) nanocomposites with different 1–5% w/w weight percent of MoS2 as a prominent photocatalyst under laser irradiation for 2, 4, 6, 8, and 10 min to tune photocatalytic degradation of industrial wastage water. The surface of the 2D molybdenum nanolayered matrix was efficaciously decorated with V2O5 nanoparticles. The crystal phase and layered structures of the V2O5(1−x)MoS2(x) (X = 1–5% w/w) nanocomposites samples were verified by X-ray diffraction and scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy respectively. In the range of the UV visible spectrum, the increment in light absorption from 3.6 to 14.5 Ω−1 cm−1 with an increase of active surface from 108 to 169 μ m 2 {{\rm{\mu }}{\rm{m}}}^{2} with increased MoS2 doping percentage. Furthermore, dielectric findings like the complex dielectric function, tangent loss, electrical conductivity, quality factors, and impedance of V2O5(1−x)MoS2(x) (X = 1–5% w/w) nanocomposites are studied. According to photoluminescence studies, the intensity of peaks decreases when laser irradiation time and doping percentages of MoS2 are increased. As a result, a small peak indicates a decrement rate of electron–hole pair recombination, which increases the capacity for separation. Thermo-gravimetric analysis and differential thermal analysis results revealed that weight loss decreased from 0.69 to 0.35 mg and thermal stability increased with increased doping concentrations. Methylene blue was degraded in 150 min, proving that the prepared MoS2-doped V2O5 material was a stable and economically low-cost nanocomposite for photocatalytic activity.

Comparative microstructural analysis of V2O5 nanoparticles via x-ray diffraction (XRD) technique

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.

Effect of annealing on properties of facile grown V2O5 nanoparticles and it’s application

Effect of annealing on properties of facile grown V2O5 nanoparticles and it’s application

A regenerated cellulose fiber with high mechanical properties for temperature-adaptive thermal management

The escalating global population has led to a surge in waste textiles, posing a significant challenge in landfill management worldwide. In this work, ionic liquid 1-butyl-3-methylimidazole acetate ([Bmim]OAc) and DMF (N, n-dimethylformamide) were used as solvents to dissolve waste denim fabric, then vanadium dioxide (VO2) nanoparticles were introduced into the spinning solution, and cellulose fibers were regenerated by dry-wet spinning process, to promote the recycling of waste cotton fabric. Finally, regenerated cellulose fibers with high added value were prepared by dry-wet spinning. Through this innovative strategy, on the one hand, because VO2 can form a large number of hydrogen bonds between the regenerated cellulose molecules, and realize the cross-networking structure of the molecular chains inside the fiber, the mechanical properties of the regenerated cellulose fibers are enhanced. On the other hand, due to the thermal phase transformation characteristics of VO2, it also endows the regenerated cellulose fiber unique intelligent temperature control function. Compared with the pristine regenerated fiber, the tensile stress of the regenerated fiber after adding VO2 nanoparticles (F-VO2) increased by 25.6 %, reaching 158.68 MPa. In addition, the F-VO2 fibric provides excellent intelligent temperature control, reducing temperatures by up to 6.7 °C.

Illuminating the Power of V2O5 Nanoparticles: Efficient Photocatalytic Degradation of Organic Dyes under Visible Light.

This research explores the synthesis, characterization, and application of Vanadium Pentoxide nanoparticles (V2O5 NPs), focusing on their efficacy in the photocatalytic degradation of organic dyes under visible light. Utilizing a co-precipitation method, we synthesized V2O5 NPs characterized by an orthorhombic crystal structure with a consistent average particle size of 28nm. The optical properties of V2O5 NPs, including their band gap, were thoroughly investigated to understand their light absorption capabilities, which are crucial for photocatalytic activity. In our study, Methyl Violet (MV) dye was employed as a model organic pollutant to assess the photocatalytic performance of the nanoparticles. Under visible light irradiation, the V2O5 nanoparticles demonstrated an exceptional photocatalytic degradation efficiency, achieving up to 85% degradation of the MV dye within 100min. This high level of efficiency is attributed to the nanoparticles' ability to effectively absorb visible light and generate electron-hole pairs, thereby facilitating a robust degradation process. Further analysis revealed that the photocatalytic activity led to the generation of reactive oxygen species (ROS) such as superoxide and hydroxyl radicals, which are integral to the dye degradation mechanism. These ROS play a critical role in breaking down the dye molecules, significantly contributing to the overall effectiveness of the photocatalytic process. The results of this study highlight the potential of V2O5 nanoparticles as a sustainable and effective photocatalytic material for environmental remediation applications, particularly in the treatment of wastewater containing organic dyes. This research not only advances our understanding of the photocatalytic properties of V2O5 nanoparticles but also demonstrates their practical application in addressing environmental pollution through innovative and efficient degradation of hazardous substances.

The combination of VO2 nanoparticle and flat films with enhanced thermochromic properties for smart windows

The combination of VO2 nanoparticle and flat films with enhanced thermochromic properties for smart windows

Microwave-synthesized V2O5 nanoparticles for ammonia sensing at room temperature

We introduce a process for synthesizing V2O5 nano particles directly from vanadium powder using a microwave oven in just 5 min. These nanoparticles are oval-shaped with an average diameter of 9 nm. These V2O5 nanoparticles are capable of detecting 1 ppm NH3 at room temperature with the response of 1.16 and the response/recovery times of 15 s and 326 s, respectively. Notably, the NH3 sensing characteristics of these V2O5 nanoparticles are almost unaffected by the humidity in the air and remain unchanged after at least 60 days of measurement. Therefore, V2O5 nanoparticles synthesized using microwave techniques are a material with great potential for application as low-energy NH3 sensors.

Unveiling the NIR modulation performance enhancement of VO2 endowed by oxygen vacancy elimination

Vanadium dioxide has emerged as a promising material for smart windows owing to the temperature-responsive variable near-infrared (NIR) transmittance. Yet, the poor NIR modulation ability challenges its efficiency in thermal management. In this study, by meticulously controlling the oxygen vacancy content at a low level, VO2 nanoparticles with excellent NIR modulation performance are achieved. Oxygen vacancy (VO) defects elimination leads to a remarkable decrease of reflectance in the monoclinic (M) phase, dramatically enhancing the near-infrared contrast of VO2 by 154 %. Density functional theory (DFT) calculations reveal that VO elimination favors low refractive index in the NIR region. The optimized experiment is carried out to prepare VO2 nanoparticles with low defects and high crystallinity. It shows the best NIR transmittance contrast at 1500 nm (ΔT1500 nm) of 24.4 %, simultaneously keeping a high luminous transmittance (Tlum) of 79.7 %. This study is believed to provide valuable guidance for the current defect and thermochromic performance study of VO2.

VO2 thin films: various microstructures for hysteresis manipulations

Vanadium dioxide reveals a phase change transition at 68 °C associated to typical hysteresis curves with strong variations in physico-chemical properties. The study presented here aims to investigate the influence of the structure and the microstructure of VO2 condensed matter on optical transmittance and electrical resistivity hysteresis curves during the metal-insulator transition. The characteristics of VO2 thin films synthesized through conventional laser ablation and of VO2 nanoparticle stacks generated via a laser vaporization cluster source are investigated. This study reveals the capability to modulate the transition temperature by as much as 20 °C, the transition width within the range of 4–30 °C, and the resistivity dynamics across the semiconducting-to-metallic phase transition by more than two orders of magnitude. These effects appear to arise because of the change of microstructure, the physical percolation of nanoparticles and associated collective effects.More complex hysteresis behaviors, taking benefit of the fabrication processes presented in this paper, and coupling the two previous distinct VO2 architectures (thin film and nanoparticles stack) lead to optical transmittance curves with three transition levels. This approach offers flexibility beyond binary responses, facilitating the design of innovative optoelectronic devices with n-stages modulation capabilities. Near room temperature applications of VO2 metal-insulator transition are underscored, highlighting opportunities for tailored architectures to exploit its properties effectively.

Polyvinyl alcohol based composite film modified with grapefruit peel waste and V2O5 nanoparticles

Polyvinyl alcohol based composite film modified with grapefruit peel waste and V2O5 nanoparticles

Electrochemical performance of V2O5/TiO2 nanocomposite: As an emerging electrode material for supercapacitor application

This scrutiny encounters the hydrothermal approach of binary nanocomposites V2O5/TiO2 (VT). The XRD pattern substantiated the formation of the binary composites with 18 nm of the crystallite size without any extraneous impurities. Whereas, HR-SEM implies the efficient bonding and homogeneous distribution between V2O5 and TiO2 nanoparticles, which provokes high electrochemical performances. Additionally, the BET analysis exposes the specific surface area to be 251 m2 g−1 with an average pore size of 3.14 nm for the VT nanocomposite. The electrochemical performances of the binary VT nanocomposite exhibit high specific capacitance of 443.7 Fg−1 at a current density of 1 Ag−1 with an excellent cyclic retention of 90 % even after successive 5000 cycles at 5 Ag−1. Therefore, the results obtained in this study clearly demonstrates that the binary nanocomposite VT would be a favorable electrode material for the commercial energy storage applications.

Enhanced durability of thermochromic film using VO2 nanoparticles with hybrid shell

Many progresses have been made for commercial application of adaptive VO2-based thermochromic smart window in the improvement of luminous transmittance (Tlum), phase transition temperature, solar regulation efficiency (ΔTsol), color modification, etc. The main obstacle for reaching this goal is relatively poor environmental durability of VO2. To address this issue, VO2 nanoparticle with hybrid shell (VO2@m-SiOx) was prepared by hydrolysis and polycondensation of the mixture of tetraethyl orthosilicate (TEOS) and Methyltriethoxysilane (MTES) using ammonia as catalyst in this paper. The optimized VO2@m-SiOx nanoparticle-based thermochromic films exhibited an ultra-high durability. The ΔTsol of thermochromic film in this study kept 44 % (from 19.0 % to 8.39 %) after 30 days in hyperthermal and humid environments, while the corresponding performance of film using uncoated VO2 nanoparticle disappeared completely after 2 days. This work provided a direct and effective way for improvement of stability of VO2 nanoparticle.

Revolutionizing photocatalysis: Synergistic enhancement of structural, optical, and photodegradation properties in Be-doped V2O5 nanoparticles for efficient methylene blue removal

This study focuses on the investigation of beryllium (Be) doping in V2O5 nanoparticles and the coordinated effects it has on the structural, optical, and photocatalytic characteristics of the material. XRD analysis reveals modifications in the orthorhombic structure upon Be doping, decreasing crystallite size (68.7–46.6 nm), and increased dislocation line density. Optimizing charge carrier mobility and separation is crucial for improving photocatalytic activity, and this is achieved via these adjustments. Raman spectra indicated increased crystallinity with Be doping. The optical analysis demonstrated an adjustable band gap (2.47–2.60 eV) and reduced refractive index (2.49–2.45), that enhance light absorption efficiency. More importantly, the study shows that Be-doped V2O5 nanoparticles have better photocatalytic activity for the breakdown of methylene blue, indicating its potential for environmentally friendly remediation. The present work contributes to the advancement of customized doping approaches for maximizing V2O5 functioning across a range of applications by clarifying the complex impacts of Be doping.