Showing papers on "Vanadate published in 2018"
165 citations
TL;DR: Vanadate quantum dots-interspersed graphitic carbon nitride (vanadate QDs/g-C3N4) can achieve efficient inactivation of Salmonella by harvesting a substantial visible light and the generation of high ROS could attack the bacterial cells membrane, and ultimately disrupt the cell metabolism through bacterial contents, which provided a feasible method for eliminating the microbial contaminated water.
Abstract: Photocatalytic disinfection, which is a readily reliable method in most climates, holds great promise to significantly reduce the microbial contamination in modern industry. Here we report that vanadate quantum dots-interspersed graphitic carbon nitride (vanadate QDs/g-C3N4) can achieve efficient inactivation of Salmonella by harvesting a substantial visible light. Detailed characterization through SEM-EDS, TEM, XRD, FT-IR, and XPS confirmed the formation of the composites. Owing to the efficient reactive oxygen species (ROS) production between vanadate QDs and g-C3N4, the bactericidal efficiency of AgVO3 QDs/g-C3N4 could reach 96.4% toward Salmonella in a concentration of 0.75 mg/mL after 10 min visible-light illumination. More importantly, scavenger experiments of different reactive species proved that the photoinduced electron generated at the oxidation site of AgVO3/g-C3N4 play a major role as oxidative species. Fluorescent-based cell live/dead test and membrane potentials were applied to demonstrate the integrity of cell membranes. Furthermore, the SEM technology, PCR and BCA protein assay were employed to verify the bacterial decomposition as well as leakage of bacterial cell contents toward Salmonella. Sterilization experiments of Staphylococcus aureus revealed that our composites have broad spectrum antimicrobial activity for both Gram-negative and Gram-positive bacteria under visible light. The results showed that the generation of high ROS could attack the bacterial cells membrane, and ultimately disrupt the cell metabolism through bacterial contents, which provided a feasible method for eliminating the microbial contaminated water.
159 citations
TL;DR: A layered iron vanadate Fe5V15O39(OH)9·9H2O nanosheet is first introduced to an aqueous zinc battery system as a cathode material, which delivers a high capacity and remarkable cycling performance at high current density.
153 citations
78 citations
TL;DR: This comprehensive analysis of PEC functionalities-including photon absorption, carrier separation, and heterogeneous charge transfer-informs strategies for improving PEC activity in the copper vanadate materials system and provides insights that may aid discovery, design, and engineering of new photoelectrode materials.
Abstract: To understand functional roles of constituent elements in ternary metal oxide photoanodes, essential photoelectrochemical (PEC) properties are systematically analyzed on a series of copper vanadate compounds with different Cu:V elemental ratios. Homogeneous and highly continuous thin films of β-Cu2V2O7, γ-Cu3V2O8, Cu11V6O26, and Cu5V2O10 are grown via reactive co-sputtering and their performance characteristics for the light-driven oxygen evolution reaction are evaluated. All four compounds have similar bandgaps in the range of 1.83–2.03 eV, though Cu-rich phases exhibit stronger optical absorption and higher charge separation efficiencies. Transient photocurrent analysis reveals a reduction of surface catalytic activity with increasing Cu:V elemental ratio due to competitive charge recombination at Cu-related surface states. This comprehensive analysis of PEC functionalities—including photon absorption, carrier separation, and heterogeneous charge transfer—informs strategies for improving PEC activity in...
63 citations
TL;DR: In this paper, vanadate and molybdate anions were intercalated into Zn-Fe layered double hydroxides (LDHs) by co-precipitation methods to obtain VO4-LDH and MoO4−LDH nanohybrids.
Abstract: In this study, vanadate and molybdate anions were intercalated into Zn–Fe layered double hydroxides (LDHs) by co-precipitation methods to obtain VO4-LDH and MoO4–LDH nanohybrids Powder X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), transmission electron microscopy (TEM), and X-ray energy dispersive spectroscopy (EDS) indicate the successful intercalation of vanadate and molybdate anions According to the results obtained from TEM and XRD, LDHs have a size in the nanometer scale with a plate-like morphology and high crystalline quality Moreover, the LDHs were used as an efficient electrocatalyst material for water oxidation in alkali solution In electrochemical water splitting, Zn–Fe–VO4 shows a superior OER performance compared to the bare glassy carbon electrode Zn–Fe–VO4-LDH exhibits good OER activity, which is expressed as a low onset overpotential, small Tafel slope, and large exchange current density At the overpotential of 046 (V vs SCE), the current density of the Zn–Fe–VO4-LDH nanosheets is about 18843 mA cm−2, which is much higher than that of the Zn–Fe–MoO4–LDH and Zn–Fe–NO3–LDH nanoparticles
61 citations
TL;DR: In this article, the authors provided insights into the recent progress in the development of efficient modified silver (meta)vanadate and their application in photocatalytic degradation of pollutant, water splitting, and bacteria disinfection.
57 citations
TL;DR: In this paper, the Na3Gd(VO4)2 (NGVO):RE3+ (RE3+) single doped phosphor materials were synthesized by a citrate-based sol-gel method, which confirmed a monoclinic phase with a space group of P21/c.
56 citations
TL;DR: In this paper, the deep eutectic solvent (DES)-aided synthesis of γ-CoV2O6 under modest reaction conditions using 1:1 choline chloride-malonic acid was reported.
Abstract: In this study, the deep eutectic solvent (DES)-aided synthesis of γ-CoV2O6 under modest reaction conditions using 1:1 choline chloride–malonic acid was reported. In the presence of DES, the reactio...
47 citations
TL;DR: In this paper, LiNiVO4 was used as a pseudocapacitor electrode material for the first time, and the phase purity, surface morphology and microstructure of the LiNiVo4 synthesized by both mechanochemical reaction and hydrothermal reaction followed by calcination were analyzed by X-ray diffraction and scanning electron microscopy techniques.
Abstract: This work describes lithium nickel vanadate (LiNiVO4) as a pseudocapacitor electrode material for the first time. The micro and nano-sized LiNiVO4 are synthesized via mechanochemical reaction and hydrothermal reaction followed by calcination, respectively. The phase purity, surface morphology and microstructure of the LiNiVO4 synthesized by both methods are analysed by X-ray diffraction and scanning electron microscopy techniques. The lithium ion intercalation-extraction behaviour of the LiNiVO4 electrode material is investigated in 1 M LiOH electrolyte solution. The results demonstrate an improved capacitive performance for nano-sized LiNiVO4 electrode synthesized via hydrothermal reaction due to the collective effect of small size and additional redox sites. The nanocrystalline LiNiVO4 electrode exhibits a high specific capacitance of 456.56 F g−1 at a current density of 0.5 A g−1. The cycle stability test reveals exceptional capacitance retention of 99.60% even after 1000 cycles owing to the unique structural feature which permit intercalation mechanism. These findings demonstrate the significance of lithium transition metal vanadate-based electrode material in the development of lithium ion intercalation pseudocapacitors.
37 citations
TL;DR: In this article, a series of CeVO4 catalysts were prepared by citric acid-assisted solvothermal synthesis and hydrothermal methods, and the Sn-CeVO4 exhibited superior NH3-SCR performance since abundant of cerium vanadate coexisting with a spot of CeO2 and a mass of surface acid sites forming.
TL;DR: In this paper, Li vanadate nanowires have been electrodeposited onto a titanium (Ti) foil by a direct current electrodeposition without template and the morphology, crystal structure, and the effects of deposition voltage, temperature and time on the prepared samples were tested and presented.
TL;DR: In this article, the additive effect of vanadate and phosphate in the NaCl electrolyte of Mg-air batteries was investigated through electrochemical tests and the battery performance was evaluated through constant-current discharging tests.
TL;DR: In this paper, the role of active site structure and support identity in determining the rate of ketone oxidation was investigated, and it was shown that the intrinsic activity of supported vanadates is sensitive to both vanadium oxide structure and the support identity.
TL;DR: The vanadium occurrence in stone coal, water leaching, and acid leaching residue was investigated by energy dispersive spectrometer (EDS) mapping and point analysis, and the vanadium transitions during roasting-leaching of stone coal were revealed as discussed by the authors.
Abstract: The vanadium occurrence in stone coal, water leaching, and acid leaching residue was investigated by energy dispersive spectrometer (EDS) mapping and point analysis, and the vanadium transitions during roasting-leaching of stone coal were revealed. In the roasting process, vanadium-bearing muscovite is converted to K-Na-feldspar, accompanying the liberation of vanadium. Most liberated vanadium reacts with sodium salt to generate water-soluble sodium vanadate, some reacts with calcite in stone coal to form water-insoluble calcium vanadate, and other liberated vanadium exists as free vanadium oxide. However, for coarse muscovite grains, the reaction of muscovite converted to K-Na-feldspar only occurs at the outer margin of muscovite grains, and the vanadium in the interior of muscovite grains is not liberated. During water leaching, the sodium vanadate is leached out. The calcium vanadate and free vanadium oxide are dissolved out in the process of acid leaching, and the vanadium, presenting in muscovite grains surrounded by K-Na-feldspar, still remains in the acid leaching residue. Two suggestions, including optimization of grinding-classification process and adopting microwave roasting, were proposed for improving vanadium recovery according to the vanadium transition rules.
TL;DR: In this paper, a simple and facile cation exchange method was used to obtain the silver vanadate/silver (Ag/Ag0.68V2O5) nanowires.
TL;DR: In this paper, the morphology and luminescence properties of InVO4:xEu3+ can be modulated by Eu3 + ion doping concentration using a post annealing process.
Abstract: Nanostructures of InVO4 and InVO4:Eu3+ were synthesized through a hydrothermal method with a post annealing process. The morphology and luminescence properties of InVO4:xEu3+ can be modulated by Eu3+ ion doping concentration. SEM and (HR)TEM studies indicated that different sizes of nanoparticles were obtained when the Eu3+ ion concentration ranged from 2 mol% to 30 mol%, and middle-concave nanodisks or nanoparticles with different sizes were obtained with the Eu3+ ion concentration ranging from 35 mol% to 45 mol%. Luminescence property studies indicated that the photoluminescence emission originated both from VO43− and Eu3+, and the emission of VO43− was blue shifted, affected by the doped Eu3+ ions. The CIE chromaticity diagram of Eu3+-doped indium vanadate exhibited green, blue-green, red, giving especially white light emission.
TL;DR: The synthesis of Eu3+-doped gadolinium orthovanadate nanocrystals (Eu:GdVO4-PAA) functionalized with poly(acrylic)acid (PAA), that are applicable as cell labeling probes for multimodal cellular imaging are described.
Abstract: In this work, we describe a simple solvothermal route for the synthesis of Eu3+-doped gadolinium orthovanadate nanocrystals (Eu:GdVO4–PAA) functionalized with poly(acrylic)acid (PAA), that are applicable as cell labeling probes for multimodal cellular imaging. The Eu3+ doping of the vanadate matrix provides optical functionality, due to red photoluminescence after illumination with UV light. The Gd3+ ions of the nanocrystals reduce the T1 relaxation time of surrounding water protons, allowing these nanocrystals to act as a positive MRI contrast agent with a r1 relaxivity of 1.97 mM–1 s–1. Low background levels of Eu3+, Gd3+, and V5+ in biological systems make them an excellent label for elemental microscopy by Laser Ablation (LA)-ICP-MS. Synthesis resulted in polycrystalline nanocrystals with a hydrodynamic diameter of 55 nm and a crystal size of 36.7 nm, which were further characterized by X-ray diffraction (XRD), photoluminescence spectroscopy (PL) and transmission electron microscopy (TEM). The multifu...
TL;DR: It is reported that a ubiquitous cellular metabolite, inorganic phosphate, stimulates RNAP exonuclease transcript cleavage activity nearly 2,000-fold, which represents a stunning example of how simple cellular molecules can reprogram an enzyme’s active center by providing functional groups and suggests an additional important role for in organic phosphate in cell biology.
Abstract: Inorganic P i is involved in all major biochemical pathways. Here we describe a previously unreported activity of P i . We show that P i and its structural mimics, vanadate and arsenate, enhance nascent transcript cleavage by RNA polymerase (RNAP). They engage an Mg 2+ ion in catalysis and activate an attacking water molecule. P i , vanadate, and arsenate stimulate the intrinsic exonuclease activity of the enzyme nearly 2,000-fold at saturating concentrations of the reactant anions and Mg 2+ . This enhancement is comparable to that of specialized transcript cleavage protein factors Gre and TFIIS (3,000- to 4,000-fold). Unlike these protein factors, P i and its analogs do not stimulate endonuclease transcript cleavage. Conversely, the protein factors only marginally enhance exonucleolytic cleavage. P i thus complements cellular protein factors in assisting hydrolytic RNA cleavage by extending the repertoire of RNAP transcript degradation modes.
TL;DR: In this paper, a peroxo-vanadium peroxide vanadium was used for selective oxidation of benzyl alcohol at low temperature and in presence of hydrogen peroxide, and the reaction was highly solvent selective and it proceeded well only in acetonitrile.
Abstract: Silver-sulphur hydroxo-peroxo vanadate species generated from silver-sulphur-oxido vanadium cluster favoured by the heterolytic dissociation of C-CN bond of acetonitrile was found to be highly active for selective oxidation of benzyl alcohol at low temperature and in presence of hydrogen peroxide. The in situ generated active peroxo-vanadium species was well characterized via electrospray ionization technique and various spectrochemical analyses. Benzyl alcohols with different substituents were successfully and selectively oxidized to its corresponding aldehydes. The reactions were highly solvent selective and it proceeded well only in acetonitrile. The formation of the product even in presence of free radical trapping agent revealed for the non-free radical mechanism. Density functional theory (DFT) calculations on the mechanism of benzyl alcohol oxidation suggested that Ag-π interaction played a significant role in stabilizing the intermediates and transition states.
TL;DR: In this paper, a simple and low cost method for synthesis of zinc oxide and zinc vanadate nanoparticles was proposed for photo degradation of methylene blue under visible light irradiation.
Abstract: In this work a new, simple and low cost method for synthesis of zinc oxide and zinc vanadate nanoparticles was proposed. The as-prepared nanoparticles were characterized using X-ray diffraction, Fourier transform infrared spectroscopy, Field emission scanning electron microscopy and electron dispersive X-ray spectroscopy. For evaluation of photocatalytic activity of these nanoparticles, some experiments under various conditions were carried out on the methylene blue as a pollutant model under visible light irradiation. Based on the obtained results, both photocatalysts have good efficacy for photo degradation of methylene blue, but zinc vanadate exhibits higher efficiency than zinc oxide for the decoloration of methylene blue. The higher visible-light-driven photocatalytic activity of zinc vanadate may be due to the more absorption of visible light by this nanoparticle. Zinc vanadate was also used successfully for the photo degradation of methyl red as a model of anionic dyes. Moreover, a preliminary kinetic study along with proposed photo degradation mechanism is included in this study.
TL;DR: In this paper, the authors demonstrated pressure and epitaxial stabilization of polar PbVO3 phases with perovskite-derivative crystal structures, and they demonstra...
Abstract: Recent experimental and computational studies have demonstrated pressure and epitaxial stabilization of polar PbVO3 phases with perovskite-derivative crystal structures. In this study, we demonstra...
TL;DR: In this paper, a commercial process was developed to treat a Ca-based Mo-V residue generated in Mo processing plant, where Vanadium was selectively leached using acetic acid and recovered as iron vanadate by hydro process.
TL;DR: In this paper, the effects of sodium ions, phosphorus, and silicon on the eco-friendly process of vanadium precipitation by hydrothermal hydrogen reduction were investigated to establish the suitable concentrated solution system for this ecofriendly process.
Abstract: The effects of sodium ions, phosphorus, and silicon on the eco-friendly process of vanadium precipitation by hydrothermal hydrogen reduction were investigated to establish the suitable concentrated solution system for this eco-friendly process The results showed that sodium ions had no negative effects on the vanadium precipitation process Phosphorus can reduce vanadate ion activity, and results in the decrease of vanadium precipitation percentage from 995% to 613%, as the phosphorus concentration in the feed solution increased from 005 g/L to 3 g/L As a result, the aimed products of V2O3 were hard to be obtained, and the purity of the precipitates was lowered Silicon can absorb in the form of H3Si3O7 on the surface of the precipitates, thus it was difficult for H (activity hydrogen atom) to react with the intermediate vanadium-bearing precipitates As a result, the vanadium precipitation percentage decreased from 995% to 862% as the silicon concentration in the feed solution increased from 01 g/L to 3 g/L The aimed products of V2O3 were not easy to be obtained, and only the intermediate vanadium-bearing precipitates containing sodium ions were obtained The upper limits of the concentrations of phosphorus and silicon in the feed V (V) solution were ascertained as 05 g/L and 01 g/L, respectively As the concentrations of phosphorus and silicon in the purified alkaline-concentrated V (V) solution extracted from vanadium-bearing shale are usually below the upper limits of the concentrations, the eco-friendly process of vanadium precipitation by hydrothermal hydrogen reduction has a great application prospect in the field of vanadium extraction from vanadium-bearing shale
TL;DR: Single crystals of the vanadate garnet Ca2NaCd2V3O12 (dicalcium sodium dicadmium trivanadate) were synthesized using the floating-zone method and the crystal structure was investigated using single-crystal X-ray diffraction, considering the effectiveness of substitution of the Y-site cation.
Abstract: Single crystals of the vanadate garnet Ca2NaCd2V3O12 (dicalcium sodium dicadmium trivanadate) were synthesized using the floating-zone method and the crystal structure was investigated using single-crystal X-ray diffraction. We considered the effectiveness of substitution of the Y-site cation with reference to previous structural studies of vanadate garnets. The structures of vanadate garnets are subject to geometric constraints similar to those of silicate garnets. These constraints force the tetrahedral-dodecahedral shared edge length in vanadate garnets to become shorter than the unshared dodecahedral edge length, as in ugrandite (uvarovite, grossular and andradite) garnets. However, the vanadate garnet Ca2NaCd2V3O12 exhibits the normal structural feature, similar to pyralspite (pyrope, almandine and spessartine) garnets, namely that the dodecahedral-dodecahedral shared edge length is shorter than the unshared dodecahedral edge length. With increasing ionic radius of the Y-site cation, the atomic coordinates x, y and z of oxygen adopt values which satisfy Pauling's third rule.
TL;DR: In this article, vanadium scavenging material comprising magnesium and yttrium oxides (Mg-Yoxide) was prepared and evaluated for vanadium capture under simulated FCC regeneration conditions for typical FCC process.
Abstract: Vanadium scavenging material comprising magnesium and yttrium oxides (Mg-Y-oxide) was prepared and evaluated for vanadium capture under simulated FCC regeneration conditions for typical FCC process. Vanadium trapping ability was measured using BET, XRD, FTIR, EDX coupled SEM and MAT. The results show that physiochemical properties, vanadium trapping and catalyst protection increase with amount of the trap material. SEM-EDX results confirm migration of vanadium as indicated by its presence in the passivator particle. Vanadium migrates within the catalyst particles by both inter and intra particles mechanisms. The XRD data further reveal high vanadium selectivity towards yttrium when passivator is incorporated after impregnation of vanadium, with the formation of crystalline yttrium vanadate (YVO4). Catalytic evaluation indicates improved activities of catalysts containing passivator which correlate with physiochemical parameters. In the passivation mechanism, mobile vanadic acid preferentially reacts more with Y2O3 in mixed metal oxide due to its higher activity (active sites), forming YVO4. These results therefore reveal that the passivator protects the catalyst by formation of immobile vanadate with mobile vanadic acid, thereby reducing hydrolysis of the catalyst framework and thus preserving important properties of the catalyst.
TL;DR: In this paper, the relationship between conductivity and structure was investigated by measuring the electric conductivity of the solution under different alkali concentrations and molar ratios of NaOH to V2O5.
TL;DR: Two genes, one designated as ABV1 (Alcian Blue staining, Vanadate resistance), which encodes a homologue of Saccharomyces cerevisiae Mnn4 responsible for attachment of mannosylphosphate to glycoside chains of secretory proteins, and the other designated as PHO87, encoding the plasma membrane low affinity phosphate sensor/transporter, highlight the dual function of this protein as a low affinityosphate transporter and an external phosphate sensor.
Abstract: The closely related yeasts Ogataea polymorpha and O. parapolymorpha differ drastically from each other by sensitivity to the toxic phosphate analog vanadate. Search for genes underlying this difference revealed two genes, one designated as ABV1 (Alcian Blue staining, Vanadate resistance), which encodes a homologue of Saccharomyces cerevisiae Mnn4 responsible for attachment of mannosylphosphate to glycoside chains of secretory proteins, and the other designated as its S. cerevisiae homologue PHO87, encoding the plasma membrane low affinity phosphate sensor/transporter. The effect of Pho87 on vanadate resistance was bidirectional, since it decreased the resistance on phosphate-depleted medium, but was required for pronounced protection against vanadate by external phosphate. This highlights the dual function of this protein as a low affinity phosphate transporter and an external phosphate sensor. Involvement of Pho87 in phosphate sensing was confirmed by its effects on regulation of the promoter of the PHO84 gene, encoding a high affinity phosphate transporter. The effect of Abv1 was also complex, since it influenced Pho87 level and enhanced repression of the PHO84 promoter via a Pho87-independent pathway. Role of the identified genes in the difference in vanadate resistance between O. polymorpha and O. parapolymorpha is discussed.