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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. Sci Rep 2022; 12:18751. [PMID: 36335151 PMCID: PMC9637123 DOI: 10.1038/s41598-022-23509-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 11/01/2022] [Indexed: 11/07/2022] Open
Abstract
Potassium 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 cycles at 1 A g−1. The effect of the vanadium valence state and unusual construction of the nanobelts, composed of crystalline and amorphous domains arranged alternately were also discussed in this work. The ex-situ measurements of discharged electrode materials by XRD, MP-AES, XAS and XPS show that during the subsequent charge/discharge cycle the potassium in the K2V6O16·nH2O structure are replacing by lithium. The structural stability of the potassium hexavandate during cycling depends on the initial vanadium valence state on the sample surface and the presence of the “fringe free” domains in the K2V6O16·nH2O nanobelts.
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Nadolska M, Szkoda M, Trzciński K, Niedziałkowski P, Ryl J, Mielewczyk-Gryń A, Górnicka K, Prześniak-Welenc M. Insight into Potassium Vanadates as Visible-Light-Driven Photocatalysts: Synthesis of V(IV)-Rich Nano/Microstructures for the Photodegradation of Methylene Blue. Inorg Chem 2022; 61:9433-9444. [PMID: 35686953 PMCID: PMC9241143 DOI: 10.1021/acs.inorgchem.2c00136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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Photocatalysis 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 (20–80 °C), different
compositions, morphologies, and V4+/V5+ ratios
were obtained and investigated as photocatalysts for organic dye degradation.
Potassium vanadates’ structural, morphological, and optical
properties were characterized using X-ray diffraction(XRD), Fourier
transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy
(XPS), Physical Property Measurement System (PPMS), thermogravimetric
analysis (TGA) with mass spectrometry (MS), N2 adsorption,
scanning electron microscopy (SEM), photoluminescence (PL), and UV–vis
diffuse reflectance spectroscopy (DRS). Synthesized K2V6O16·nH2O and KV3O8 showed an efficient absorption in the visible
wavelength region with a narrow band gap energy of 1.80 and 1.91 eV,
respectively. Their photocatalytic activity was evaluated by the degradation
of methylene blue (MB) under simulated solar light illumination. The
KV3O8 microplatelets exhibited the greatest
photocatalytic activity, resulting in more than 90% degradation of
the dye within the first 30 min. It is suggested that the observed
excellent photocatalytic performance is attributed to the high content
of V4+ species. Furthermore, the influence of active species
was investigated, and the mechanism responsible for the photodegradation
of the MB dye was discussed for the first time for potassium vanadates. Potassium vanadates were synthesized
via the facile method
based on liquid-phase exfoliation with ion exchange. Different synthesis
temperatures (20−80 °C) resulted in various phase compositions,
morphologies, and V4+/V5+ ratios. The obtained
samples were demonstrated as efficient visible-light driven photocatalysts,
resulting in more than 90% degradation of methylene blue within the
first 30−60 min. The enhanced photoactivity is attributed to
the high content of V4+ species, which are beneficial for
the separation of photogenerated electrons and holes and their lifetime.
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Affiliation(s)
- Małgorzata Nadolska
- Faculty of Applied Physics and Mathematics, Institute of Nanotechnology and Materials Engineering, Gdansk University of Technology, Narutowicza 11/12, Gdansk 80-233, Poland
| | - Mariusz Szkoda
- Faculty of Chemistry, Gdansk University of Technology, Narutowicza11/12, Gdansk 80-233, Poland
| | - Konrad Trzciński
- Faculty of Chemistry, Gdansk University of Technology, Narutowicza11/12, Gdansk 80-233, Poland
| | - Paweł Niedziałkowski
- Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, Gdansk 80-308, Poland
| | - Jacek Ryl
- Faculty of Applied Physics and Mathematics, Institute of Nanotechnology and Materials Engineering, Gdansk University of Technology, Narutowicza 11/12, Gdansk 80-233, Poland
| | - Aleksandra Mielewczyk-Gryń
- Faculty of Applied Physics and Mathematics, Institute of Nanotechnology and Materials Engineering, Gdansk University of Technology, Narutowicza 11/12, Gdansk 80-233, Poland
| | - Karolina Górnicka
- Faculty of Applied Physics and Mathematics, Institute of Nanotechnology and Materials Engineering, Gdansk University of Technology, Narutowicza 11/12, Gdansk 80-233, Poland
| | - Marta Prześniak-Welenc
- Faculty of Applied Physics and Mathematics, Institute of Nanotechnology and Materials Engineering, Gdansk University of Technology, Narutowicza 11/12, Gdansk 80-233, Poland
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Huang X, Li Z, Liu H, Zhang M, Du X, Cui X, Wang Q, Wang H. Optimized cyclic and electrochemical performance by organic ion N(CH3)4+ pre-inserted into N(CH3)4V8O20 cathode and hierarchy distributive Zn anode in aqueous zinc ion batteries. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2022.140160] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Abstract
A novel vanadium–cellulose composite thin film-based on angular interrogation surface plasmon resonance (SPR) sensor for ppb-level detection of Ni(II) ion was developed. Experimental results show that the sensor has a linear response to the Ni(II) ion concentrations in the range of 2–50 ppb with a determination coefficient (R2) of 0.9910. This SPR sensor can attain a maximum sensitivity (0.068° ppb−1), binding affinity constant (1.819 × 106 M−1), detection accuracy (0.3034 degree−1), and signal-to-noise-ratio (0.0276) for Ni(II) ion detection. The optical properties of thin-film targeting Ni(II) ions in different concentrations were obtained by fitting the SPR reflectance curves using the WinSpall program. All in all, the proposed Au/MPA/V–CNCs–CTA thin-film-based surface plasmon resonance sensor exhibits better sensing performance than the previous film-based sensor and demonstrates a wide and promising technology candidate for environmental monitoring applications in the future.
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