JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2026
·Vol. 37
·期 18
·1391
·
IF 3.2
Zheng Zehan,Su Congxue,Wei Xiuzhen,Tao Wenlong,Liu Bochu,Pan Sisi,Fan Jun,Wang Ruijuan,Fang Liang,Lu Huidan
In this study, a strategy involving the incorporation of non-adjacent valence state cations into tetrahedral sites was employed. Microwave dielectric ceramics with the composition Ca 3 M 2 Ga 2.5 V 0.5 O 12 (M=Sn and Zr) were designed and synthesized using a solid-state reaction method. The crystal structure of these ceramics has been verified as cubic garnet with the Ia -3 d space group. Ca 3 Sn 2 Ga 2.5 V 0.5 O 12 and Ca 3 Zr 2 Ga 2.5 V 0.5 O 12 ceramics sintered at optimal temperatures exhibited favorable microwave dielectric properties, with Q × f values of 18, 571 GHz and 13,370 GHz, ε r of 9.65 and 9.34, and τ f values of − 43.1 ppm/°C and − 36.4 ppm/°C, respectively. The difference in ε r is primarily attributed to the ionic polarizability per unit volume and bond ionicity. The higher Q × f value of the Ca 3 Sn 2 Ga 2.5 V 0.5 O 12 ceramic correlates with its larger packing fraction, narrower Raman full width at half maximum, stronger average bond covalency, and higher total lattice energy. In contrast, the smaller | τ f | of Ca 3 Zr 2 Ga 2.5 V 0.5 O 12 is associated with its larger bond valence at the B-site, lower oxygen bond valence, and higher bond energy. Analysis using the Phillips−Van Vechten−Levine (P−V−L) theory and bond valence calculations demonstrates that the M 4+ cations occupying the octahedral sites have a significant impact on the microwave dielectric properties. Furthermore, a dielectric resonator antenna based on Ca 3 Sn 2 Ga 2.5 V 0.5 O 12 was designed for C-band communication (4−8 GHz).
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高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Tingyi Liu,Peng Wang,Zhong-Liang Wang
An effective complex of nanoscale zero-valent iron (NZVI) supported on zirconium 1,4-dicarboxybenzene metals-organic frameworks (UIO-66) with strong oxidation resistance was synthesized (NZVI@UIO-66) for V 5+ removal from wastewater. The results demonstrated that NZVI was successfully loaded on UIO-66 with a uniform dispersion, and then the composite was aged in the air which was named A-NZVI@UIO-66. V 5+ could be removed quickly and completely using A-NZVI@UIO-66 in a wider pH range except for the pH = 1 condition. The reaction between A-NZVI@UIO-66 and V 5+ was an endothermic process. Freundlich model with a better-fitted value showed the adsorption of V 5+ on A-NZVI@UIO-66 was multi-layer heterogeneous adsorption and the adsorbed amount of V 5+ was 397.23 mg V/g NZVI. Nitrate had a competitive inhibition on V 5+ removal by A-NZVI@UIO-66. Mechanisms of vanadium elimination from the aqueous phase by A-NZVI@UIO-66 included physical adsorption, reduction, and complex co-precipitation, particularly the reduction dominated. The subsistent Zr–O bond in A-NZVI@UIO-66 provided a possible double reaction path by playing an electron donor, storage, or conductor role. After acid leaching , A-NZVI@UIO-66 represented good reusability in the removal of V 5+ from the practical mine sewage.
研究领域:
环境科学
·
材料科学
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高影响因子
MOLECULES
·
2020
·Vol. 25
·期 4
·1000
·
IF 3.267
Rui Liu,Ziteng Liang,Yuxuan Xiang,Weimin Zhao,Haodong Liu,Yan Chen,Ke An,Yong Yang
Na3V(PO4)2was reported recently as a novel cathode material with high theoretical energy density for Sodium-ion batteries (SIBs). However, whether V3+/V4+/V5+multielectron reactions can be realized during the charging process is still an open question. In this work, Na3V(PO4)2is synthesized by using a solid-state method. Its atomic composition and crystal structure are verified by X-ray diffraction (XRD) and neutron diffraction (ND) joint refinement. The electrochemical performance of Na3V(PO4)2is evaluated in two different voltage windows, namely 2.5–3.8 and 2.5–4.3 V.51V solid-state NMR (ssNMR) results disclose the presence of V5+in Na2−xV(PO4)2when charging Na3V(PO4)2to 4.3 V, confirming Na3V(PO4)2is a potential high energy density cathode through realization of V3+/V4+/V5+multielectron reactions.Keywords:polyanion;energy density;multielectron reaction;solid-state NMR
研究领域:
材料科学
·
电化学
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高影响因子
Journal of Physical Chemistry Letters
·
2026
·Vol. 17
·期 31
·9085-9096
·
IF 4.5
Liu Hanbing,Wang Chao,Wu Min,Peng Zhangquan
The
redox kinetics of the V 4+ /V 5+ couple
govern the power density and stability of all-vanadium redox flow
batteries (VRFBs). Using electrolyte additives is the most common
strategy to accelerate the kinetics, but their underlying mechanisms
remain unclear. Herein, the electrochemical behaviors of the V 4+ /V 5+ couple in sulfuric acid (H 2 SO 4 ) with phosphoric acid (H 3 PO 4 ) and perchloric
acid (HClO 4 ) as additives were systematically investigated
using powder microelectrode (PME) techniques. Based on the in-depth
electrochemical analysis using the PME, the electrochemically active
species are identified as dimers, whose electron transfer (ET) kinetics
can be accelerated by H 3 PO 4 but inhibited by
HClO 4 . Fitting the PME-acquired Tafel plots with the Marcus–Hush–Chidsey
(MHC) ET theory demonstrates that H 3 PO 4 reduces
the reorganization energy and enhances electronic coupling strength,
while HClO 4 shows the opposite effect. Furthermore, H 3 PO 4 addition yields a lower-energy intervalence
charge transfer (IVCT) absorption band and a higher electronic coupling
matrix element, indicating that it not only reduces the formation
energy of the dimers but also enhances V 4+ /V 5+ electron transfer kinetics, which is further corroborated by Raman
spectroscopy. This work provides a reliable approach to evaluate ET
kinetics and offers theoretical guidance for designing high-performance
VRFBs.
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高影响因子
JOURNAL OF POWER SOURCES
·
2024
·
IF 8.1
Shuting Zhao,Wentao Qi,Chao Yang,Rui Ling
Na 3 V 2 (PO 4 ) 3 has received a lot of attention as a prospective cathode for sodium-ion batteries (SIBs) owing to its strong 3D wide-open architecture for Na + transport. However, the practical application is still hampered by its poor electronic conductivity and weak Na + diffusion kinetics . In this paper, a novel Mg 2+ -doped Na 3 V 2 (PO 4 ) 3 flower-like cathode (Na 3+x V 2-x Mg x (PO 4 ) 3 /C, x = 0, 0.02, 0.04, 0.06) with abundant mesoporous has been synthesized by a convenient template-assisted sol-gel method. Mg 2+ doping successfully triggers V 4+ /V 5+ reversible redox with improved voltage plateau and reversible capacity. The hierarchical mesoporous structure combined with carbon layers is beneficial to the fast transport of Na + and e − , which guarantee improved kinetic properties and enhanced conductivity. Attributed to these competitive advantages, significantly improved electrochemical properties of Na 3.04 V 1.96 Mg 0.04 (PO 4 ) 3 /C (NVMP-4) are acquired, including extremely high specific capacity (123.8 mAh g −1 at 1C), excellent rate performance (73.8 mAh·g −1 at 100C) and exceptionally stable energy output with 89.1 % capacity retention after 3000 cycles at 20C. Additionally, when assembled with a hard carbon anode (HC), NVMP-4||HC provides an exceptional energy density of 216.9 Wh kg −1 at 0.2C. By enhancing nanostructure and rational surface engineering, this project offers fresh perspectives for creating superior electrodes, increasing the energy density of SIBs.
研究领域:
材料科学
·
电化学
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高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Peng Wang,Jian Hu,Yidong Wang,Tingyi Liu
The ball-milling technology , a highly efficient and cost-effective method, had excellent application prospects for overcoming passivation issues of normal zero-valent iron (ZVI) to enhance the decontamination efficiency. In this work, we investigated the effects and mechanisms of pH, process control agents (PCA), and main process parameters on the removal of V 5+ using ball-milled zero-valent iron (ZVI bm ). The results showed that ZVI was successfully activated due to mechanochemical action. The enhanced proton conductivity of ZVI bm leaded to the rapid production of more Fe 2+ , thereby resulting in an order of magnitude higher elimination of V 5+ by ZVI bm than by ZVI under near-neutral conditions. In addition, the introduction of NaCl in the ball milling process could not only effectively alleviate the agglomeration phenomenon of ZVI bm , but also effectively enhance its activity. Unexpectedly, due to over-compaction and small size effects, excessive energy input weakened the reactivity of ZVI bm on V 5+ elimination. Various characterization results confirmed that the removal of V 5+ by ZVI bm was dominated by reduction and supplemented by adsorption. This work updated the basic understanding of the critical effects of process parameters and NaCl on ZVI bm in the remediation of vanadium-containing wastewater.
研究领域:
环境科学
·
化学工程
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高影响因子
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