V2O5 Nanocomposites Research Articles

Preparation of MoS2/V2O5 nanocomposites for ciprofloxacin degradation and Cr (VI) reduction

In this study, MoS2/V2O5 nanocomposites are obtained by hydrothermal process, and used for photocatalytic system of Ciprofloxacin (CIP) degradation and Cr (VI) reduction. Owing to its novel characteristics, MoS2/V2O5 heterojunctions are revealed as potential semiconductors in this region. V2O5 photocatalyst acts as a charge acceptor, meantime MoS2 acts as an electron donor, therefore promoting charge carrier separation and enhancing photocatalytic efficiency. The MoS2/V2O5 nanocomposites displayed enhanced photocatalytic CIP (98.7 %) and Cr (VI) reduction (98.8 %) after 120 min and 100 min of visible light activity. In contrast, in the first cycle, the photocatalysis capability of the photocatalyst performed in six cycles is 93.8 %. The Kapp values of MoS2/ V2O5 nanocomposites displayed about 11.2 and 19.5-times improvement of photocatalytic of CIP degradation and Cr (VI) reduction, respectively. The MoS2/V2O5 nanocomposites exhibited an enhanced photocurrent density of 0.082 μA/cm−2 compared to a pristine MoS2 sample of 0.045 μA/cm−2. The distinguished heterojunction photocatalysis performance is due to the significant migration of interfacial charges and the inhibited recombination rate of electron-hole pairs. CIP Pollutants eventually decay into H2O, CO2, and small molecule intermediates by generating •O2-, •OH, and h+. The influences of reactive radicals follow the order of •O2- radicals > h+ radicals > •OH radicals. Then, the probable structures of intermediates and achievable photodegradation pathways were discussed for the removal of CIP and Cr (VI) reduction using nanocomposite with visible light response.

Novel bilayer 2D V2O5 as a potential catalyst for fast photodegradation of organic dyes

Two-dimensional (2D) materials have recently drawn interest in various applications due to their superior electronic properties, high specific surface area, and surface activity. However, studies on the catalytic properties of the 2D counterpart of V2O5 are scarce. In the present study, the catalytic properties of 2D V2O5 vis-à-vis bulk V2O5 for the degradation of methylene blue dye are discussed for the first time. The 2D V2O5 catalyst was synthesized using a modified chemical exfoliation technique. A massive increase in the electrochemically active surface area of 2D V2O5 by one order of magnitude greater than that of bulk V2O5 was observed in this study. Simultaneously, ~ 7 times increase in the optical absorption coefficient of 2D V2O5 significantly increases the number of photogenerated electrons involved in the catalytic performance. In addition, the surface activity of the 2D V2O5 catalyst is enhanced by generating surface oxygen vacancy defects. In the current study, we have achieved ~ 99% degradation of 16 ppm dye using the 2D V2O5 nanosheet catalysts under UV light exposure with a remarkable degradation rate constant of 2.31 min−1, which is an increase of the order of 102 from previous studies using V2O5 nanostructures and nanocomposites as catalysts. Since the enhanced photocatalytic activity emerged from the surface and optical properties of the catalyst, the current study shows great promise for the future application of 2D V2O5 in photo- and electrocatalysis.

Characterization and Corrosion Resistance Behavior Study of Pure Ni Coatings and Ni–V2O5 Nanocomposite Coatings Developed by Direct Current and Pulse Current Methods of Electrodeposition

Characterization and Corrosion Resistance Behavior Study of Pure Ni Coatings and Ni–V2O5 Nanocomposite Coatings Developed by Direct Current and Pulse Current Methods of Electrodeposition

Effect of copper oxide (CuO) and vanadium oxide (V2O5) addition on the structural, optical and electrical properties of corundum (α-Al2O3)

In this work, we prepared a pure α-Al2O3, α-Al2O3/CuO (AC) and α-Al2O3/V2O5 (AV) nanocomposite. The sol–gel method was used to prepare pure α-Al2O3, (AC) and (AV) samples at 1200 °C. Structural, electrical, and optical properties of the prepared samples were investigated using the X-ray diffraction (XRD), UV–Visible spectrophotometer, and conductivity meter, respectively. The XRD results confirmed the crystalline nature and the presence of the hexagonal structure of α-Al2O3, the rhombohedra structure of CuAlO2 and the tetragonal structure of V2O5. Moreover, the crystallite size of pure α-Al2O3 was 43.1 nm, while the crystallite size of α-Al2O3 in samples AC and AV nanocompsite was 24.05 nm and 34.84 nm respectively. The optical measurements showed that the band gap α-Al2O3 decreased significantly from 5.28 eV for pure to 3.7 and 3.4 eV to AC and AV respectively. The DC electrical conductivity (σd.c) values were measured for all prepared samples at room temperature. The electrical conductivity was 2.4 × 10–7 and 1.8 × 10–7 (Ω cm)−1 in AC and AV nanocompsite respectively, while ionic conductivity (σion) decreased from 3 × 10–10 in pure α-Al2O3 to 7 × 10–5 and 1 × 10–5 in AC and AV nanocompsite, respectively. The results showed an improvement in the structural, optical, and electrical properties, which may make these materials a candidate for use in many applications, such as photocatalytic, gas sensors, optoelectronics, microelectronics, semiconductor devices, ……etc.

Controlled synthesis of MWCNTs/V2O5 nanocomposite by hydrothermal approach for adsorption and photodegradation processes.

The current paper outlines the synthesis of pristine multi-wall carbon nanotubes (PMWCNTs)/Vanadium pentoxide V2O5 and functionalized multi-wall carbon nanotubes (FMWCNTs)/V2O5 nanocomposite for photocatalytic applications. The FMWCNTs were obtained by the oxidizing agents (H2SO4 and HNO3) to introduce the oxygenated functional groups. The samples were synthesized by hydrothermal approach and investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy analysis (EDX), and Fourier transform infrared spectroscopy (FTIR). The photocatalytic activity of multi-wall carbon nanotubes (MWCNTs), FMWCNTs/V2O5, and PMWCNTs/V2O5 nanocomposites was assessed via methylene blue (MB) degradation from water under visible light. The results demonstrated that the removal efficiency of MB by PMWCNTs, FMWCNTs/V2O5, and PMWCNTs/V2O5 could reach 90.4, 98.9, and 94.9%, respectively. It was noticed that MB adsorption and photodegradation tend to follow pseudo-second-order kinetics. The mechanism of MB photodegradation by FMWCNTs/V2O5 nanoparticles was explained. MWCNTs/V2O5 nanocomposites will allow further applications to remove other dyes and contaminants from wastewater.

Electrochemical evaluation of reduced graphene oxide anchored with ruthenium doped vanadium pentoxide nanostructures for supercapacitor applications

Ru doped vanadium pentoxide and reduced graphene oxide loaded Ru doped vanadium pentoxide nanostructures have been synthesized through the sol–gel route. The orthorhombic structure of rGO@Ru:V2O5 nanocomposite has been confirmed by using X-ray diffraction analysis and the appearance of O-V-O vibrational mode was confirmed by FTIR and Raman analysis. Furthermore, the scanning electron microscope and high-resolution transmission electron microscope images illustrate the formation of rGO@Ru:V2O5 nanomaterials as sheet-particles-rod shaped nature. Finally, the electrochemical performance of the rGO@Ru:V2O5 electrode exhibits outstanding electrochemical performance which illustrates the maximum capacitance value 1185 F/g at 1.25 A/g compared with the 2 %Ru:V2O5 electrode. Also, it shows high energy and power densities of 20.92 Wh/Kg and 570 W/Kg for Ru:V2O5 electrode and 66.65 Wh/Kg and 810.89 W/Kg for rGO@Ru:V2O5 electrode. Both electrodes are shows the maximum cyclic stability of 98 % & 94 % for Ru:V2O5 and rGO@Ru:V2O5 electrodes, respectively.

Synthesis and characterization of PANI doped V2O5 nanocomposites for supercapacitor application

The orthorhombic V2O5 nanorod-like structure and PANI are successfully prepared by hydrothermal and oxidative polymerization methods respectively and confirmed by XRD as well as FESEM. The electrochemical performance of electrodes with different mass-loadings of PANI doped V2O5 nanocompositeson nickel- foam has been checked by means of CV and GCD. The electrode with 2 mg mass-loading exhibits a high specific capacity of 889 Fg−1 at 5 mV/sec scan rate and 612.21 Fg−1 at 2 Ag−1 current density. The combined impacts of PANI and V2O5 can give an alternative path for developing cost-effective next-generation high-performance supercapacitor applications.

Structural transition and photoluminescence behavior of (V2O5)1-x (Ag0.33V2O5)x (x = 0 to 0.1) nanocomposites

The two phase (V2O5)1-x(Ag0.33V2O5)x (x = 0, 0.05, 0.075 and 0.1) nanocomposites were synthesized through one step hydrothermal process. The X-ray diffraction followed by two phase Rietveld refinement confirms the crystallization of V2O5 and Ag0.33V2O5 phases in the Pmmn (orthorhombic) and C21 (monoclinic) symmetry respectively without any impurity phase. Furthermore, the FE-SEM, EDX, PL, UV–vis and XPS characterization were carried out for microstructural, optical and chemical studies. The formation of Ag0.33V2O5 nano-belts with average length and width of 3–4 μm and 40–50 nm respectively, were observed in the electron micrograph. Moreover, the XPS study confirms the constituent element are in expected oxidation states with Vanadium in only + 5 (V+5) for V2O5 and in mixed states (V+5 and V+4) for 10 % Ag0.33V2O5 nanocomposite. The photoluminescence spectra of these nanocomposite depicts two broad emission peaks located around 570 nm and 707 nm due to indirect inter-band and mid-state energy states transitions, respectively. PL also prove the increase in oxygen vacancies by loading of Ag in V2O5 matrix. The optical absorption of Ag0.33V2O5 represents a decrease in the energy band gap (2.10–1.97 eV) by adding Ag concentration in the V2O5, which also proved the semiconductor to metal transition (SMT).

Synthesis of a novel visible-light active Gd2O3/GdVO4/V2O5 photocatalyst for rapid purification of industrial wastewater containing organic dyes and bacteria

In the past decades, population growth and industrial development have posed a significant threat to the aquatic environment and water pollution, considerably influencing our living standards. In the present study, novel visible light-responsive nano photocatalysts Gd2O3/GdVO4/V2O5 were synthesized by mechanical alloying and sintered at different elevated temperatures. All the structural and microstructural parameters of the mechanosynthesized C12.6N0.6VO3 phase have been modified from the reported values. XRD, TEM, SEM, XPS, and FTIR are employed to characterize the as-obtained nanocomposites with elemental mapping. The surface or grain boundary defects, bandgap, and Urbach energy of the nanocomposites are revealed by diffused reflectance spectroscopy (DRS) and BET analysis. The photodegradation and quantum efficiency of the samples are investigated by analyzing UV–Vis spectra, using Rhodamine B (RhB), Congo Red (CR), and Methylene Blue (MB) as model organic dye pollutants. Experimental results reflect that the 5 h milled and sintered sample shows better photocatalytic degradation efficiency of almost 100% within 150 min - nearly twice that of pure precursor materials. Scavenger tests ensure the oxidative radical species involved in the photodegradation mechanism. The antibacterial study reveals that the Gd2O3/GdVO4/V2O5 nanocomposite efficiently prohibits gram-positive bacterial growth in the wastewater. These Gd2O3 /GdVO4 /V2O5 nanocomposites may be utilized as an efficient tool for wastewater treatment in industrial areas and prohibiting bacterial growth in wastewater.

Electrochemical sensing platform for the detection of nitroaromatics using g-C3N4/V2O5 nanocomposites modified glassy carbon electrode

Rapid, reliable, cost-effective and trace-level detection of nitroaromatic toxins is becoming increasingly important because of their carcinogenic nature, and their presence in water sources as an environmental contaminant. The present study reports the development of an electrochemical sensing platform based on g-C3N4/V2O5 (VOCN) nanocomposites modified glassy carbon electrode (GCE) for the effective detection of nitroaromatics. The VOCN nanocomposites were synthesized via wet impregnation method, and were characterized by XRD, FT-IR, HRSEM and XPS techniques. The electrochemical behavior of four nitroaromatics (4-NP, DNP, DNT and TNP) were investigated on seven nanomaterials-based sensors using cyclic voltammetry, square wave voltammetry and chronoamperometry techniques. Under optimized conditions, the nitroaromatic compounds exhibited reduction peaks corresponding to the number of nitro-functional groups on an aromatic ring. The electrochemical studies revealed that the composite with 7 wt% V2O5 (VOCN7/GCE) exhibits higher sensitivity for the detection of 4-NP, DNP, DNT and TNP. The VOCN7/GCE recorded the limit of detection (LOD) as low as 0.85 nM, 3.3 nM, 3.4 nM and 11.0 nM in a linear range between 1.0 nM - 100.0 µM, 10.0 nM - 100.0 µM, 10.0 nM - 100.0 µM and 30.0 nM - 100.0 µM for 4-NP, DNP, DNT and TNP, respectively. The fabricated sensor showed high reusability and reproducibility, and could detect the four nitroaromatics in real water samples.

Organic Macromolecule regulated the structure of vanadium oxide with high capacity and stability for aqueous Zinc-ion batteries

The aqueous zinc-ion rechargeable batteries (AZIBs) have become a promising alternative for large-scale energy storage applications and triggered a great deal of scientific research due to low cost, high security, and eco-efficiency. Here, we report the successful synthesis of phytic acid coated/inserted V2O5 nano-composites (PHVO) by one-step hydrothermal method. On one hand, the surface of V2O5 nanosheets is uniformly coated by phytic acid to form an ultrathin layer, serving as a stabilizer to greatly enhance the structural stability by restraining the exfoliation of active materials during the cycling process. On the other hand, the phytic acid plays as the intercalary spacer to expand the V2O5 interlayer distance to 13.5 Å, which is beneficial to the diffusion kinetics of Zn2+ by offering expedited channels. With the abovementioned advantages, the overall electrochemical performance of PHVO has been significantly improved. It showed an excellent specific capacity of 406 mAh g−1 at 0.1 A g−1, and the capacity retention rate was 97.3% after 6000 cycles at 5 A g−1. This work paves the way to the design and fabrication of stable cathodes for AZIBs with excellent electrochemical performance.

Investigation of heterojunction between α-Fe2O3/V2O5 and g-C3N4 ternary nanocomposites for upgraded photo-degradation performance of mixed pollutants: Efficient dual Z-scheme mechanism

In this present work, a g-C3N4 decorated dual Z-scheme α-Fe2O3 and V2O5 heterojunction of magnetically recoverable GFV (g-C3N4/α-Fe2O3/V2O5) composite was rationally synthesized using facile calcination and hydrothermal approach. The crystal structure, surface morphology, chemical composition and optical properties of the as-obtained composite photocatalysts (PCs) were characterized by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectra high-resolution scanning electron microscopy (HR-SEM, high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS) measurement, UV-Vis diffuse reflectance spectra (DRS) and photoluminescence (PL) analyses respectively. Benefiting from these structural and compositional features, the optimum GFV heterostructured PCs sample revealed that the superior photo-degradation performance of methyl yellow (MY) and methylene blue (MB) mixed dye under visible-light, while the degradation rates were 93.4% for MY and 87.5% for MB dye at 90 min, respectively. Moreover, the enhanced photo-degradation performance of GFV composite PCs displayed an extended visible-light fascination due to lower bandgap, reduced recombination rates, high charge separation and good charge transfer capacity with the efficient dual Z-scheme heterojunction. Meanwhile, high photo-degradation stability is continued after five successive reusability tests. A possible photo-degradation mechanism of dual Z-scheme charge transfer paths was also been proposed. This study is also capable of emerging visible-light active facile heterojunction photocatalysts for various organic pollutants removal with great efficiency.

Graphitic carbon-encapsulated V2O5 nanocomposites as a superb photocatalyst for crystal violet degradation

To materialize the excellent photocatalyst for crystal violet dye-degradation, the graphitic carbon-encapsulated vanadium pentoxide (GC-V2O5) nanocomposites were synthesized through the simple sonication method by using the green tea waste-derived GC nanoflakes and the sonochemically synthesized V2O5 nanorods. The nanocomposites were confirmed to comprise an aggregated morphology, in which the orthorhombic V2O5 nanorods were well anchored with the intertwingled GC nanoflakes. Owing to the encapsulation of defective V2O5 by conductive GC, the GC-V2O5 nanocomposites exhibited the enhanced photocatalytic dye-degradation efficiency up to 98.4% within 105 min. Namely, the encapsulated GC nanosheets might compensate the native defects (i.e., charge traps) on the V2O5 surface; hence, the charge transport could be enhanced during the dye-degradation process while the photocarrier recombination could be suppressed. The results suggest the conducting layer-encapsulated semiconducting oxide nanocomposites (e.g., GC-V2O5) to be of good use for future green environmental technology, particularly, as a superb photocatalyst for dye degradation.

Construction of S-scheme 1D/2D rod-like g-C3N4/V2O5 heterostructure with enhanced sonophotocatalytic degradation for Tetracycline antibiotics

Pharmaceutically active compounds are an emerging water contaminant that resists conventional wastewater treatments. Herein, the sonophotocatalytic degradation of Tetracycline (TC) antibiotics as a model contaminant was carried out over a rod-like g-C3N4/V2O5 (RCN-VO) nanocomposite. RCN-VO nanocomposite was synthesized via ultrasound-assisted thermal polycondensation method. The results showed that the RCN-VO nanocomposite could completely remove the TC in water within 60 min under simultaneous irradiation of visible light and ultrasound. Moreover, the sonophotocatalytic TC degradation (a synergy index of ∼1.5) was superior to the sum of individual sonocatalytic and photocatalytic degradation using RCN-VO nanocomposite. Besides, the enhanced sonophotocatalytic activity of RCN-VO can be attributed to the 1D/2D nanostructure and the S-scheme heterojunction formation between RCN and VO where the electrons migrated from RCN to VO across the RCN-VO interface. Under irradiation, the built-in electric field, band edge bending and Coulomb interaction can synergistically facilitate the unavailing electron-hole pair recombination. Thereby, the cumulative electron in RCN and holes in VO can actively take part in the redox reaction which generates free radicals and attack the TC molecules. This study provides insight into a novel S-Scheme heterojunction photocatalyst for the removal of various refractory contaminants via sonophotocatalytic degradation.

Microwave-Assisted hybridised WO3/V2O5 rod shape nanocomposites for electrochemical supercapacitor applications

Electrochemical supercapacitors are prominent energy storage devices owing to their superior capacitive behaviour and matchless power and energy density with excellent cyclic stability. In this report, we have prepared the rod shape WO3/V2O5 nanocomposite by the microwave-assisted method. XRD analysis confirmed the rhombohedral and orthorhombic phase structure of V2O5 and WO3. Various functional groups associated with V2O5 and WO3 compounds were studied by FTIR spectrum. Surface and morphological image analysis demonstrated rod shape morphology. Surface area (22.798 m2/g), pore volume (0.137 cc/g) and particle size (18 nm) were analyzed by BET analysis. The pure V2O5 nanostructure exhibited maximum specific capacitance of 150F/g in 1 M H2SO4 electrolyte which was enhanced to 260, 265 and 386F/g respectively for various wt.% of WO3 added V2O5 nanocomposites. The long cyclic test showed 104 % of capacitance retention over 5,000 cycles with 99 % columbic efficiency.

Highly efficient tri-phase TiO2–Y2O3–V2O5 nanocomposite: structural, optical, photocatalyst, and antibacterial studies

Highly efficient tri-phase TiO2–Y2O3–V2O5 nanocomposite: structural, optical, photocatalyst, and antibacterial studies

Rapid photodegradation of methylene blue dye by rGO- V2O5 nano composite

Abstract Here we present rapid photo degradation of Methylene Blue (MB) dye using novel rGO-V2O5 nanocomposite synthesized through simple and fast methods. In the present work, rGO, V2O5 nanoparticles (NP’s) and rGO- V2O5 nanocomposite were synthesized through modified Hummer’s method, sol-gel method and sonochemical methods, respectively. The nano composite and other compounds were studied through X-ray diffraction, Raman spectroscopy and Scanning Electron Microscopy (SEM) to understand structural and morphological information. XRD studies confirm the formation of compounds in single phase where Raman spectroscopic results corroborate the XRD results. Micrographs of SEM show excellent distribution of V2O5 nanoparticle on rGO flakes. The photocatalytic activity of rGO-V2O5 nanocomposite was tested by photocatalytic degradation of methylene blue (MB) dye in visible light irradiation. A rapid degradation of the MB was observed where 71% degradation of MB happens in just 20 min duration. A concentration varying effect on the degradation is also being studied where 30 wt% solution of photocatalyst shows highest rate constant, 1.84 × 10−2 min−1 and rapid degradation of MB.

Structural, optical, dielectric and transport properties of ball mill synthesized ZnO–V2O5 nano-composites

In the present study composites of ZnO and V2O5 (3, 6 and 9 mol%) were synthesized by solid state reaction method and the influence of V2O5 on the structural, microstructural, optical, dielectric and transport properties of final product have been investigated. The characterization of samples has been carried out by employing various experimental techniques such as XRD, FESEM, RAMAN, UV–Visible spectroscopy and photoluminescence. Information regarding the phase and structural parameters has been extracted using Rietveld refinements and microstructural using Williamson–Hall (W–H) analysis. Samples were also investigated for dc and ac electrical behavior. The present study revealed that the presence of V2O5 in ZnO–V2O5 composite plays a significant role in altering its structural, optical, dielectric and transport properties. An effort has also been made to correlate the structure with optical, dielectric and conduction properties of synthesized composites.

Fabrication of room temperature liquid petroleum gas sensor based on PAni–CNT–V2O5 hybrid nanocomposite

Vanadium pentoxide (V2O5) nanoparticles have been synthesized by hydrothermal method. Polyaniline (PAni)—carbon nanotube (CNT)—V2O5 hybrid nanocomposite has synthesized by chemical polymerization of PAni in the presence of CNT—V2O5 nanocomposite. The band gap energy of the hybrid nanocomposite is calculated as 3.02 eV using UV–Vis absorption spectroscopy. Chemical composition and crystalline nature has been analyzed using fourier transform infrared spectroscopy and X-ray diffraction spectroscopy, respectively. Scanning electron microscope and transmission electron microscope are involved in the morphological analysis of the hybrid nanocomposite. Sensing electrodes are fabricated by spin coating of the sensing material on printed circuit board. The electrodes have been investigated for their sensing behavior towards oxygen, hydrogen and liquid petroleum gas (LPG) at room temperature. It has been observed that the electrode is selectively sensitive to the LPG with improved sensitivity (300%), response time (20 s) and recovery time (15 s) in the range of 10–50 ppm. The reproducibility of the response curve of the electrode is tested and it is 83.33% stable for the period of 50 days.

Preparation and comparison of hybridized WO3–V2O5 nanocomposites electrochemical supercapacitor performance in KOH and H2SO4 electrolyte

The rod shape WO3–V2O5 hybrid nanocomposites were prepared by microwave assisted wet chemical route. The electrochemical investigations of as-prepared composites were carried in two electrolytes such as KOH and H2SO4 for comparison. Their maximum capacitance was calculated as 44 F/g for WO3 and 173 F/g for WO3–V2O5 composites in KOH electrolyte and its efficiency is 100% up to 5000 cycles and its capacitance retention is ∼126% in KOH electrolyte. In H2SO4 electrolyte, the specific capacitance of WO3 was recorded as 246 F/g and WO3–V2O5 showed poor performance such as less than 12 F/g.