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Search results for: VANADATES
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Pressure in charge. Neglected parameter in hydrothermal synthesis turns out to be crucial for electrochemical properties of ammonium vanadates
PublicationAmmonium vanadates are of great interest as they exhibit unusual electrical and sensory properties.(NH4)2V6O16and (NH4)2V10O25$8H2O with various morphology were obtained in the hydrothermalsynthesis under controlled temperature and pressure. It was shown, that the pure (NH4)2V10O25$8H2Owas obtained under 50 bar of initial pressure, whereas lower pressure lead to the mixture of twocompounds. The influence of the pressure was studied...
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The valance state of vanadium-key factor in the flexibility of potassium vanadates structure as cathode materials in Li-ion batteries
PublicationPotassium hexavanadate (K2V6O16·nH2O) nanobelts have been synthesized by the LPE-IonEx method, which is dedicated to synthesis of transition metal oxide bronzes with controlled morphology and structure. The electrochemical performance of K2V6O16·nH2O as a cathode material for lithium-ion batteries has been evaluated. The KVO nanobelts demonstrated a high discharge capacity of 260 mAh g−1, and long-term cyclic stability up to 100...
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Insight into Potassium Vanadates as Visible-Light-Driven Photocatalysts: Synthesis of V(IV)-Rich Nano/Microstructures for the Photodegradation of Methylene Blue
PublicationPhotocatalysis is regarded as a promising tool for wastewater remediation. In recent years, many studies have focused on investigating novel photocatalysts driven by visible light. In this study, K2V6O16·nH2O nanobelts and KV3O8 microplatelets were synthesized and investigated as photocatalysts. Samples were obtained via the facile method based on liquid-phase exfoliation with ion exchange. By changing the synthesis temperature...
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Corrosion Inhibition of Aluminium Alloy AA6063-T5 by Vanadates: Local Surface Chemical Events Elucidated by Confocal Raman Micro-Spectroscopy
PublicationChemical interactions between aqueous vanadium species and aluminium alloy AA6063-T5 were investigated in vanadate-containing NaCl solutions. Confocal Raman and X-ray photoelectron spectroscopy experiments were utilised to gain insight into the mechanism of corrosion inhibition by vanadates. A greenish-grey coloured surface layer, consisting of V+4 and V+5 polymerized species, was seen to form on the alloy surface, especially on...
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Hydrothermal synthesis of vanadium ammonium compounds – the crucial role of the pressure
PublicationDue to the structural diversity and chemical activity, vanadium oxides and their derivatives are continuingly in the great interest of scientist. In a large family of vanadium compounds, one of the most interesting are ammonium vanadates (with the general formula (NH4)xVyOz). They have received much attention because of their promising application as cathode material in mono- and multivalent-ion batteries [1]. Hydrothermal synthesis...
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Tailoring the Size and Shape—New Path for Ammonium Metavanadate Synthesis
PublicationAmmonium metavanadate, NH4VO3, plays an important role in the preparation of vanadium oxides and other ammonium compounds, such as NH4V3O8, (NH4)2V3O8, and NH4V4O10, which were found to possess interesting electrochemical properties. In this work, a new route for the synthesis of NH4VO3 is proposed by mixing an organic ammonium salt and V2O5 in a suitable solvent. The one-step procedure is carried out at room temperature. Additionally,...
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New light on the photocatalytic performance of NH4V4O10 and its composite with rGO
PublicationSolar-driven photocatalysis has shown great potential as a sustainable wastewater treatment technology that utilizes clean solar energy for pollutant degradation. Consequently, much attention is being paid to the development of new, efficient and low-cost photocatalyst materials. In this study, we report the photocatalytic activity of NH4V4O10 (NVO) and its composite with rGO (NVO/rGO). Samples were synthesized via a facile one-pot...