Nano Energy
·
2017
·
IF 12.343
Haoxiang Yu,Hua Lan,Lei Yan,Shangshu Qian,Xing Cheng,Haojie Zhu,Nengbing Long,Miao Shui,Jie Shu
Hollow microstructure always exhibits some special properties in the field of electrochemistry . Here, this study reports the rational design and preparation of TiNb 2 O 7 nanofibers with one dimensional hollow structure via co-electrospinning. The as-electrospun TiNb 2 O 7 hollow nanofibers show high intercalation potential, low charge-charge resistance and fast electrochemical kinetics . The electrochemical results exhibit that the TiNb 2 O 7 hollow nanofibers deliver a reversible capacity of 210.1 mAh g −1 after 150 cycles at a current rate of 0.4 C, and 158.4 mAh g −1 after 900 cycles even at a current rate of 10 C with an outstanding capacity retention of 80.6%. The excellent electrochemical performance of nanofibers can be related to the unique morphology of hollow structure. Furthermore, the lithium ions storage mechanism of TiNb 2 O 7 hollow nanofibers is also systematically analyzed, which is related to one two-phase coexistence and two solid-solution processes during the whole charge-discharge cycle. In addition, it is also demonstrated by in situ and ex situ observations that TiNb 2 O 7 hollow nanofibers have outstanding structural stability and electrochemical reversibility. Therefore, the TiNb 2 O 7 hollow nanofibers can be applied as an alternative promising electrode material for the next rechargeable lithium ions batteries .
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
无机功能材料
✓ 已验证
DOI
高影响因子
MATERIALS & DESIGN
·
2017
·
IF 4.364
Puhong Wen,Lili Ai,Fenyan Wei,Dengwei Hu,Jingjing Guo,Fangyi Yao,Taotao Liu
The crystalline hexagonal Nb 2 O 5 (H-Nb 2 O 5 ) nanobelt clusters dominantly exposed (− 110) facet are firstly synthesized by a hydrothermal topological reaction with a precursor of fiber-like K 2 Nb 2 O 6 ·H 2 O. The structure and morphology of samples obtained at different temperatures and times are investigated. There are two steps in the synthesis process. One is the acid-exchanging reaction transforming into amorphous phase protonated niobate (HNO), and the other is dehydration reaction transforming into H-Nb 2 O 5 , and simultaneous dissolution reaction which forms nanobelt cluster morphology from the fiber-like particle. The formation mechanism of H-Nb 2 O 5 nanobelt clusters has been proposed in detail. After photo-reduced reaction between the H-Nb 2 O 5 nanobelt clusters and AgNO 3 solution, the dominantly exposed (− 110) facet of H-Nb 2 O 5 nanobelt is homogeneously covered by Ag nanoparticles . The photo-electrochemical performance of the obtained H-Nb 2 O 5 nanobelt clusters and Ag deposited H-Nb 2 O 5 (Ag-Nb 2 O 5 ) nanobelt clusters as photocatalysts are evaluated by splitting water under simulated sunlight illumination, and the generated photocurrent of Ag-Nb 2 O 5 sample is 10.73 μA, which is 535 times that of the H-Nb 2 O 5 sample. The results demonstrate that the Ag-Nb 2 O 5 nanobelt clusters have a high photo-electrochemical performance as well as good sunlight photoelectric conversion efficiency.
研究领域:
材料科学
·
纳米科技
·
光催化
·
能源化学
·
半导体材料
·
电化学
·
太阳能转换
✓ 已验证
DOI
高影响因子
Green Energy & Environment
·
2021
·Vol. 8
·期 2
·589-600
·
IF 8.207
Liuting Zhang,Farai Michael Nyahuma,Haoyu Zhang,Changshan Cheng,Jiaguang Zheng,Fuying Wu,Lixin Chen
Nb 2 O 5 nanoparticles with an average particle size of 10 nm supported on a rhombic dodecahedral metal organic framework (MOF) were successfully synthesized by a facile one-pot hydrothermal reaction and subsequent calcination process. Experimental results demonstrated that the prepared catalyst drastically improved the hydrogen storage behavior of MgH 2 . 7 wt% Nb 2 O 5 @MOF doped MgH 2 started to desorb hydrogen at 181.9 °C and 6.2 wt% hydrogen could be released within 2.6 min and 6.3 min at 275 °C and 250 °C, respectively. The fully dehydrogenated composite also displayed excellent hydrogenation by decreasing the onset absorption temperature to 25 °C and taking up 4.9 wt% and 6.5 wt% hydrogen within 6 min at 175 °C and 150 °C, respectively. Moreover, the corresponding activation energy was calculated to be 75.57 ± 4.16 kJ mol −1 for desorption reaction and 51.38 ± 1.09 kJ mol −1 for absorption reaction. After 20 cycles, 0.5 wt% hydrogen capacity was lost for the MgH 2 +7 wt% Nb 2 O 5 @MOF composite, much lower than 1.5 wt% of the MgH 2 +7 wt% Nb 2 O 5 composite. However, the addition of Nb 2 O 5 @MOF had limited effect on reducing the dehydrogenation enthalpy of MgH 2 . Microstructure analysis revealed that Nb 2 O 5 particles were uniformly distributed on surface of the MgH 2 matrix and synergistically improved the hydrogen storage property of MgH 2 with MOF.
研究领域:
材料科学
·
无机化学
·
纳米催化
·
能源存储
·
氢能源
·
固态储氢
✓ 已验证
DOI
高影响因子
Nano Select
·
2021
·Vol. 2
·期 11
·2135-2147
·
IF 0
Puhong Wen,Xiaowen Jiang,Qian He,Dengwei Hu,Lijun Ren,Weixing Zhao
The tetragonal phase Nb 2 O 5 (T-Nb 2 O 5 ) nanobelts with preferentially exposed the (010) facet have been successfully prepared for the first time by insitu topological reaction using the KNb 3 O 8 nanobelts as the precursor. Meanwhile, the transformation mechanism of the crystal structure and morphology from the layered KNb 3 O 8 nanobelt to the T-Nb 2 O 5 nanobelt was revealed in detail by using XRD, FE-SEM, TEM, HRTEM, SAED, UV-vis DRS, EDX, XPS, and Raman spectra. In addition, Ag deposited T-Nb 2 O 5 (Ag/T-Nb 2 O 5 ) nanobelts were prepared by photo-reduction reaction. The photoelectrochemical properties of the T-Nb 2 O 5 nanobelts and Ag/T-Nb 2 O 5 nanobelts as a photocatalyst were evaluated by splitting water under simulated sunlight. The results show that the photocurrent density generated by the prepared Ag/T-Nb 2 O 5 sample is 48.1 µA∙cm −2 , which is 2.3 times that of the T-Nb 2 O 5 sample, and the prepared tetragonal phase T-Nb 2 O 5 nanobelts produce a photocurrent value 1.5 times that of the contrast orthogonal phase O-Nb 2 O 5 nanosheets. It indicates that the (010) facet of the tetragonal phase Nb 2 O 5 is one of the highest photocatalytic active surfaces, and the visible light utilization efficiency of the T-Nb 2 O 5 nanobelt with Ag deposited on the surface has been significantly improved, which implies that it has potential applications in the field of photocatalysis.
研究领域:
材料科学
·
纳米科技
·
光催化
·
能源化学
·
半导体材料
·
表面科学
✓ 已验证
DOI
危险品化学品经营许可证（带存储）