Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 28
·16969-16978
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IF 10.733
Tianxing Wu,Miaomiao Han,Xiaoguang Zhu,Guozhong Wang,Yunxia Zhang,Haimin Zhang,Huijun Zhao
Deeply understanding the electrochemical activation and inactivation processes of an electrocatalyst is critically important for establishing a high-efficiency nitrogen reduction reaction (NRR) to synthesize an NH3 system. Here we report the utilization of a facile vapor-phase hydrothermal (VPH) method to directly grow ultrafine Nb3O7(OH) nanoparticles on commercial carbon fiber cloth (Nb3O7(OH)/CFC) for the NRR. The results demonstrate that the Nb3O7(OH)/CFC can afford an average NH3 yield rate of 622 μg h−1 mgcat.−1 with a high faradaic efficiency (FE) of 39.9% at −0.4 V versus the reversible hydrogen electrode (RHE) in 0.1 M Na2SO4 electrolyte (pH = 6.1) within 30 min of the NRR, surpassing the performance of most recently reported aqueous-based NRR electrocatalysts. The experimental and theoretical calculation results reveal that the in situ electrochemically converted NbO from Nb3O7(OH) during the NRR is the catalytic active phase with a N2 adsorption free energy of −0.97 eV; however with a reaction time over 30 min, the generated active *N atoms in the *N–NH3 → *N + NH3 hydrogenation step during the NRR are thermodynamically favourable for binding to the oxygen vacancies of NbO to form oxygen-containing NbN0.64 with reduced N2 adsorption free energy (−0.32 eV), resulting in significantly decreased NRR activity. Our studies suggest that although NbO possesses high NRR activity, it may not be a suitable NRR electrocatalyst, owing to easy formation of low active niobium oxynitride during the NRR.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2017
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IF 2.536
Xu Tang,Juan Han,Yun Wang,Xu Bao,Liang Ni,Lei Wang,Longhua Li
A fluorescence probe has been designed and synthesized, and applied with a combined theoretical and experimental study. Research suggests that the probe can be used to sense Zn 2 + and Hg 2 + through selective turn-on fluorescence responses in the aqueous HEPES buffer (0.05M, pH = 7.4). The limit of detection (LOD) were determined as 1.46 × 10 − 7 M (Zn 2 + ) and 2.50 × 10 − 7 M (Hg 2 + ). Moreover, based on DFT, the geometry optimizations of probe 1, [1-Hg 2 + ] complex and [1-Zn 2 + ] complex were carried out using the Gaussian 09 program, in which the B3LYP function was used. The electronic properties of free probe 1 and the metal complexes were studied based on the Natural Bond Orbital (NBO) analyses. The probe 1 has also been successfully applied to detection of Zn 2 + and Hg 2 + in living cells.
研究领域:
化学
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生物化学
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材料科学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
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2024
·
IF 4.3
Ziyan Lv,Rukang Li
A new noncentrosymmetric crystal Na12(NbO)3(PO4)7 was successfully synthesized in the niobium phosphate system. Its structure characterizes isolated and highly distorted NbO6 octahedra joining with isolated PO4 groups to form a unit of a (Nb6P6O12) hexagonal star by sharing O atoms. In (Nb6P6O12) hexagonal stars, all Nb and P atoms are in a hexagonal star-like arrangement and all Na atoms are also in a hexagonal star-like arrangement, except for Na(3) and Na(10) atoms. Notably, it exhibits a strong phase-matched second harmonic response: 3 × KDP, which is rare in known niobium phosphate systems. Meanwhile, it also has a wide optically transparent window (0.29–4.44 μm) and a high laser-induced damage threshold (3.5 GW/cm2). More importantly, Na12(NbO)3(PO4)7 is a congruent melting compound that has the potential to be grown into large-sized single crystals by the Czochralski method. These excellent properties make it a promising candidate as a mid-infrared nonlinear optical crystal.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
IONICS
·
2021
·Vol. 28
·期 2
·779-788
·
IF 2.817
Guo Zhihao,Wu Yuqi,Li Xinhai,Wu Xianwen,Hu Qiyang,Wang Zhixing,Guo Huajun,Peng Wenjie,Yan Guochun,Wang Jiexi
Employing the solid polymer electrolyte (SPE) instead of traditional liquid electrolyte is an effective way to develop high safety and high-energy density solid-state lithium batteries. Herein, for the first time, the Ni 3 B 2 O 3 (NBO) nanorods are incorporated into polyethylene oxide (PEO)-based SPE. Particularly, the optimized NBO-embedded SPE shows a high ionic conductivity of 8.5 × 10 −5 S cm −1 at 30 °C, lowering the operating temperature of PEO-based SPE substantially. The corresponding LiFePO 4 /Li battery demonstrates a high discharge capacity of 154 mAh g −1 after 80 cycles at 0.2 C under 30 °C, with favorable capacity retention of 97.5%. The remarkable properties are attributed to the high ionic conductivity of modified SPE at ambient temperature, which is resulted from the decreased crystallinity and melting transition point, increased movement of PEO chain, and promotion of lithium salt dissociation, as well as the formation of the lithium ion migrating pathway on the interface between PEO and NBO nanorods.
研究领域:
材料科学
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电化学
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能源存储
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 46
·26513-26523
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IF 10.733
Peng Huang,Min Huang,Hai Hu,Yuan Zhong,Chao Lai,Shulei Chou
The push for high performing electronic devices with long battery lives has rapidly advanced the field of energy storage systems. Niobium oxides have stood out as promising candidates to improve the storage and rate performance of anodes in lithium- and especially sodium-ion batteries due to their larger interplanar lattice spacing and patulous framework. Herein, we report the first synthesis of a nanosized metal/metal oxide hybrid composite coated by N-doped carbon and anchored onto reduced graphene oxide (NbO/Cu@NC-RGO) through in situ carbonizing of Cu-doped polyoxoniobate precursors. The strong synergistic effects between the uniformly distributed NbO/Cu hybrid nanoparticles, the N-doped carbon coating layer, and graphene substrates not only ensure efficient electron and ion transport, but also boost pseudocapacitive charge storage. The resulting composite exhibits a maximum reversible charge capacity of 580 mA h g−1 after 100 cycles at a current density of 100 mA g−1 when utilized in lithium-ion batteries (LIBs), and 203 mA h g−1 when utilized in sodium-ion batteries (SIBs). For SIBs in particular, a long-lifetime of 1012 cycles is observed when cycled at a high current density of 800 mA g−1. This work represents a promising step forward in the design and preparation of metal oxide composite anodes for LIBs and SIBs.
研究领域:
材料科学
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电化学
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纳米能源
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储能技术
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无机化学
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先进电池材料
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Qi Chen,Baole Li,Junli Wang,Haowei Zhu,Xiwen Chen,Yifu Hu,Jia Zhou,Wentao Wang,Weifang Zheng,Taihong Yan
In this work, the solvent extraction and complexation behaviors of U(VI) by two novel asymmetrical tetra-alkylcarbamides, N,N’-butyl-N,N’-hexylurea ( L1 : SBHU ) and N,N’-butyl-N,N’-pentylurea ( L2 : SBPU ) in HNO 3 media were systematically investigated. Both two ligands extract U(VI) more effectively than other metals such as Pu(IV), Np(IV), and Th(IV) in a wide range of acidity. Under 5 mol/L HNO 3 , D U reached 5.25, while D Pu = 1.08, D Np = 0.11, D Th = 0.13.. Additionally, no third-phase was present by the extraction of highly uranium concentration solution with SBHU even under 7 mol/L HNO 3 after four cycles demonstrating good acid resistance and resistance to the formation of the third phase. Slope analyses and FT-IR indicate that the U(VI) complexes are a form of UO 2 (NO 3 ) 2 ·2 L for the two ligands during the extraction. Additionally, based on the DFT calculations, the NBO analysis, and topological analysis were analyzed in detail. The results demonstrate that the interactions between ligands and U(VI) are shown mainly as ionic characteristics, and the ligand-to-metal charge transfer was also observed. This study enriches the coordination chemistry of actinides: Th(IV), U(VI), Np(IV), Am(III), and Pu(IV) by tetra-alkylcarbamides, which may shed light on the design and synthesis of novel U(VI) selective ligands.
研究领域:
配位化学
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锕系元素化学
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溶剂萃取
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理论化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）