Inorganic Chemistry Frontiers
·
2018
·Vol. 5
·期 5
·1126-1132
·
IF 5.106
Congjie Lv,Yi Peng,Jing Yang,Xiaochuan Duan,Jianmin Ma,Taihong Wang
Nb-Doped LiNi0.4Co0.2Mn0.4O2 (Nb-NCM) nanobelts have been successfully fabricated for the first time through a facile electrospinning method by the delicate control of PAN pyrolysis and Nb-NCM formation (including nucleation and subsequent growth processes). According to the experimental evidence from temperature-dependent characterization and isolation of the intermediates, the formation of nanobelts undergoes a morphology evolution from nanofibres to nanotubes, and finally to the nanobelts composed of subunit nanoparticles. When used as a cathode for lithium-ion batteries, the as-electrospun Nb-NCM nanobelts exhibit superior electrochemical performances, which could be attributed to their unique features, such as their 1D nanostructure, well-crystallized nature and Nb-doping. These features can improve the ionic conductivity of Nb-NCM nanobelts and stabilize the electrode/electrolyte interface. Therefore, the 1D Nb-NCM nanobelts developed in this study not only provide an excellent model to investigate the fabrication of multi-element oxides using the electrospinning method, but also open up a facile route for designing 1D layered cathodes with a complex component for high performance lithium-ion batteries.
研究领域:
材料科学
·
纳米技术
·
电化学
·
能源存储
·
无机合成
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2019
·Vol. 8
·期 3
·1143-1150
·
IF 6.641
Zhizhen Wang,Zhen Song,Lixin Ning,Quanlin Liu
Warm-color persistent luminescent materials are strongly desired for signage markings and medical imaging in comparison with green or blue counterparts. Herein we report a novel yellow long-persistent phosphor, Nb-doped Sr3SiO5:Eu2+, with a peak wavelength of ∼580 nm and persistence time of more than 14 hours at the 0.32 mcd m−2 threshold value after UV radiation. A combination of thermoluminescence (TL), thermoluminescence excitation (TLE), electron paramagnetic resonance (EPR) measurements and density functional theory (DFT) calculations reveals that the persistent luminescence enhancement is attributed to a significant Nb-induced increase of oxygen vacancies that act as electron trapping centers with appropriate trap depths. Groups of time-dependent color-change images are realized with this material, which has potential applications as anti-counterfeit and indicator marks. This investigation also expands the application of transition metal (TM) ions to the field of persistent luminescence and would motivate further exploration of TM substitutions to design and improve silicate or aluminosilicate persistent phosphors with superior performance.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
iScience
·
2023
·
IF 5.8
Ying Zhang,Yuying Wan,Xiaoxu Liu,Kai Chen,Ke Chu
Electrocatalytic reduction of nitrite to ammonia (NO 2 RR) is considered as an appealing route to simultaneously achieve sustainable ammonia production and abate hazardous nitrite pollution. Herein, atomically Nb-doped NiO nanoflowers are designed as a high-performance NO 2 RR catalyst, which exhibits the highest NH 3 -Faradaic efficiency of 92.4% with an NH 3 yield rate of 200.5 μmol h -1 cm -2 at -0.6 V RHE. Theoretical calculations unravel that Nb dopants can act as Lewis acid sites to render effective NO 2 - activation, decreased protonation energy barriers, and restricted hydrogen evolution, ultimately leading to a high NO 2 RR selectivity and activity.
研究领域:
材料科学
·
环境科学
·
催化化学
✓ 已验证
DOI
PubMed
高影响因子
Materials
·
2022
·Vol. 15
·期 19
·6929
·
IF 3.748
Shenghao Li,Xiaohuan Wang,Zhiming Shi,Jun Wang,Guojun Ji,Xinba Yaer
Ferrous titanate (FeTiO3) has a high theoretical capacity and physical and chemical properties stability, so it is a potential lithium anode material. In this study, FeTiO3nanopowder and nanosheets were prepared by the sol–gel method and the hydrothermal method. In addition, niobium-ion doping was carried out, the radius of Nb close to Ti so the Nb can easily enter into the FeTiO3lattice. Nb can provide more free electrons to improve the electrochemical performance. Then, the effects of the morphology and niobium doping on the microstructure and electrochemical properties of FeTiO3were systematically studied. The results show that FeTiO3nanosheets have a better lithium storage performance than nanopowders because of its high specific surface area. A certain amount of niobium doping can improve the electrochemical performance of FeTiO3. Finally, a 1 mol% niobium-doping FeTiO3nanosheets (1Nb-FTO-S) electrode provided a higher specific capacity of 782.1 mAh g−1at 50 mA g−1. After 200 cycles, the specific capacity of the 1Nb-FTO-S electrode remained at 509.6 mAh g−1. It is revealed that an increased specific surface area and ion doping are effective means to change the performance of lithium, and the proposed method looks promising for the design of other inorganic oxide electrode materials.Keywords:FeTiO3;niobium doping;microstructure;lithium storage performance
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Seokyoung Choi,Wuliang Feng,Zhongzhu Liu,Yongyao Xia
Spinel LiMn 1.5 Ni 0.5 O 4 (LMNO) is one of the promising cathode materials for the next generation Li-ion batteries due to its voltage platform. However, the dissolution of the transition metal at high voltage is the biggest obstacle that LMNO suffers from. In this study, we successfully suppressed transition metal dissolution in LMNO by the morphology control from regular octahedron to spherical. Niobium was integrated as a dopant, which restricted the growth of (1 1 1) crystal face, and increased the indices of crystal faces by homogenizing the surface energy. By changing to a smaller surface area with spherical morphology, the contact area with the electrolyte was reduced, thus suppressing the dissolution of the Mn ion. Consequently, the niobium-doped LMNO exhibited superior rate performance, capacity retention with 74.1% at 1C after 500 cycles in half-cell, and thermal stability compared to pristine LMNO.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 39
·22559-22566
·
IF 3.049
Hao Chen,Changteng Zhang,Ya Pang,Qianhong Shen,Yang Yu,Yuxuan Su,Jiabang Wang,Fang Zhang,Hui Yang
Novel Nb-doped Bi2WO6 nanosheets have been successfully synthesized by a simple hydrothermal method. XRD, Raman spectra, XPS and SEM were adopted to analyze the structure and morphology of the samples, then the structure-dependent optical properties, photoelectric behavior and photocatalytic activities were investigated, and the structure–property relationship was also discussed. The results show that doping Nb5+ can increase the oxygen vacancies in the Bi2WO6 lattice and reduce the optical band gap of Bi2WO6. The oxygen vacancies also act as electron traps, which promote the separation of photogenerated carriers. Hence, compared with the pure Bi2WO6, the as-prepared Nb-doped Bi2WO6 nanosheets exhibit enhanced visible-light photocatalytic activity for removing contaminants in water such as rhodamine B and tetracycline.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Jingyao Zeng,Jinqiang Gao,Weishun Jian,Haoji Wang,Wenyuan Li,Ningyun Hong,Baichao Zhang,Jiangnan Huang,Bai Song,Chaolun Gan,Sedat Yasar,Wentao Deng,Guoqiang Zou,Hongshuai Hou,Xiaobo Ji
Na 4 Mn 1.5 Fe 1.5 (PO 4 ) 2 P 2 O 7 (NMFPP), with its low cost and high energy density, is essential for accelerating the commercialization of sodium-ion batteries. However, its practical application is limited by serious voltage hysteresis and detrimental Jahn-Teller distortions. Herein, a high operating voltage and superior stable Nb-doped NMFPP with fewer intrinsic anti-site defects are elaborately designed by the reconstruction of the crystal lattice and electronic distribution. By introducing higher charge density Nb─O bonds, the lengths of Mn-O bonds are shortened, enhancing lattice stability. As a result, the lattice volume contracted during Na + extraction/insertion is decreased with niobium-modified Na 4 (Mn 0.5 Fe 0.5 ) 2.94 Nb 0.06 (PO 4 ) 2 P 2 O 7 , mitigating lattice distortion from the Jahn-Teller effect and increasing the capacity retention after 1000 cycles from 57.5% to 82.3%. More importantly, the delayed effect of Mn 2+ involvement in redox reactions is significantly reduced, raising the average operating voltage from 3.32 to 3.64 V and increasing the overall energy density by 13%. This study opens new avenues to develop advanced sodium-ion battery cathode materials with high energy density and long calendar life for energy storage.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2024
·Vol. 14
·期 7
·608
·
IF 4.4
Wei Liu,Yang Zou,Yuang Chen,Zijian Lei,Lili Zhao,Lixin Song
This work involves the introduction of niobium oxide into lanthanum aluminate (LaAlO3) via a conventional solid-state reaction technique to yield LaAlO3:Nb (LaNbxAl1−xO3+δ) samples with Nb5+doping levels ranging from 0.00 to 0.25 mol%. This study presents a comprehensive investigation of the effects of niobium doping on the phase evolution, defect control, and reflectance of LaNbxAl1−xO3+δpowder. Powder X-ray diffraction (XRD) analysis confirms the perovskite structure in all powders, and XRD and transmission electron microscopy (TEM) reveal successful doping of Nb5+into LaNbxAl1−xO3+δ. The surface morphology was analyzed by scanning electron microscopy (SEM), and the results show that increasing the doping concentration of niobium leads to fewer microstructural defects. Oxygen vacancy defects in different compositions are analyzed at 300 K, and as the doping level increases, a clear trend of defect reduction is observed. Notably, LaNbxAl1−xO3+δwith 0.15 mol% Nb5+exhibits excellent reflectance properties, with a maximum infrared reflectance of 99.7%. This study shows that LaNbxAl1−xO3+δpowder materials have wide application potential in the field of high reflectivity coating materials due to their extremely low microstructural defects and oxygen vacancy defects.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Qun Ma,Zhigui Zhang,Pengzu Kou,Dan Wang,Zhiyuan Wang,Hongyu Sun,Runguo Zheng,Yanguo Liu
Two-dimensional layered MXene material with high conductivity and good mechanical flexibility has gained wide attention in the field of energy storage. However, the practical application of MXene was hampered by its limited specific capacity and the unstable structure. Herein, a composite of in-situ grown niobium-doped TiO 2 nanosheet arrays on a double transition metal MXene TiNbCT x (TiNbC@NTO) was successfully obtained via a hydrothermal pretreatment followed by in-situ partial oxidation strategy. The prepared TiNbC@NTO combines multiple advantages of both MXene and oxide, including high conductivity derived from the unoxidized MXene TiNbCT x , superior structure stability from the in-situ produced oxide between the MXene layers, which prevents structural collapse and restacking during charging and discharging, and the large layer space which promotes lithium-ion transport. The degree of oxidation of MXene can be adjusted by controlling the reaction temperature, and the oxide nonosheet turn dense with the increase of the temperature. All the oxidized MXenes show improved electrochemical performance compared with the pure TiNbCT x , and the TiNbC@NTO-500 with the appropriate degree of oxidation exhibits the highest reversible capacity, best cycling stability of 261 mAh g −1 after 500 cycles at 1.0 A g −1 among all the as-prepared composites. Furthermore, an extraordinary rate performance (148.5 mAh g −1 at 2 A g −1 ) was obtained based on the pseudocapacitance dominated mechanism. This work provides a new insight into improving the performance of MXene-based anode material for lithium-ion batteries.
研究领域:
材料科学
·
能源存储
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2021
·Vol. 105
·期 3
·2020-2028
·
IF 3.784
Yuanyuan Wang,Hongbo Liu,Tingnan Yan,Jianwei Zhao,Shifeng Guo,Rong Sun,Zhilun Lu,Dawei Wang
In this work, Nb-doped 0.75SrTiO 3 -0.25BiFeO 3 (ST-BF) lead-free ceramics are designed and synthesized using a conventional solid-state reaction method. The influence of Nb doping on the microstructure, dielectric, and electrical properties are systematically investigated. With the increase of Nb concentration, the crystal structure of ST-BF remains pseudo-cubic as exhibited in the X-ray diffraction patterns. The grain size is found to increase from 0.33 to 6.23 μm, and then decrease to 1.88 μm by Nb doping, along with a clear heterogeneous core–shell microstructure. A relatively low dielectric loss (∼0.1, at 1 kHz) and a stable dielectric constant (∼700, at 1 kHz) are obtained for the 0.03 Nb-doped ST-BF composition at room temperature. Impedance spectroscopy analysis shows that Nb doping in ST-BF increases the total resistivity, forming an electrically conductive core and a nonconductive shell, with enhanced activation energy. The results may provide a feasible approach to develop novel ST-based lead-free dielectric ceramics for capacitor applications.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Liang Dan,Hui Wang,Xiaobao Yang,Jiangwen Liu,Liuzhang Ouyang,Min Zhu
The practical applications of MgH2 as a high-density hydrogen carrier depend heavily on efficient and low-cost catalysts to accelerate the dehydriding/hydriding reactions at moderate temperatures. In the present work, this issue is addressed by synthesizing Nb-doped TiO2 solid-solution-type catalysts that dramatically improve the hydrogen sorption performances of MgH2. The catalyzed MgH2 can absorb 5 wt % of H2 even at room temperature for 20 s, release 6 wt % of H2 at 225 °C within 12 min, and the complete dehydrogenation can be achieved at 150 °C under a dynamic vacuum atmosphere. Density functional theory calculations reveal that Nb doping introduces Nb 4d orbitals with stronger interaction with H 1s into the density of states of TiO2. This considerably enhances both the adsorption and dissociation ability of the H2 molecule on the catalysts surface and the hydrogen diffusion across the specific Mg/Ti(Nb)O2 interface. The successful implementation of solid solution-type catalysts in MgH2 offers a demonstration and inspiration for the development of high-performance catalysts and solid-state hydrogen storage materials.
研究领域:
材料科学
·
催化化学
·
能源存储
✓ 已验证
DOI
高影响因子
Nano Energy
·
2025
·
IF 17.1
Weiguang Han,Xiaodong Zhang,Hui Li,Yang Fu,Boxiong Shen,Sheng-Qi Guo,Tianyi Ma
Activating the inherent piezoelectric effect of materials as an auxiliary driving force for photocatalytic performance is considered a reliable approach for developing a new generation of efficient photocatalytic systems, but research on modification strategies for optimizing piezoelectric performance is still in its infancy. In this work, we developed Nb-doped NaNbO 3 (N-NNO-4) piezoelectric based on self-doping strategy. Under the combined action of ultrasonic vibration and solar light irradiation, N-NNO-4 can generate high concentrations of hydroxyl radicals (•OH) in water environment, thereby achieving excellent oxidation performance. N-NNO-4 exhibits excellent piezo-photocatalytic performance in water pollution control applications. The reaction kinetic coefficients of its use as a piezo-photocatalyst for purifying common plasticizers dimethyl phthalate are 8.5 times and 6.8 times those of its use as a photocatalyst and piezocatalyst, respectively, and 17 times that of undoped NaNbO 3 (NNO) piezo-photocatalyst. Mechanism analysis shows that the excellent piezo-photocatalytic performance is not only attributable to the efficient charge separation efficiency induced by Nb-doped and the improved charge transfer ability, but also originate from the synergistic effect of band tilt caused by piezoelectric effect and efficient activation of interface H 2 O caused by Nb-doped. The synergistic effect opens up new channels for •OH generation and significantly intensifies the formation of •OH. The present study explores the feasibility of constructing an efficient piezoelectric photocatalytic system based on self-doping strategy, providing theoretical reference and experimental basis for utilizing green energy in nature to achieve sustainable environmental protection and development.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）