Scientific Reports
·
2016
·Vol. 6
·期 1
·1-12
·
IF 5.228
Huan Yu,Wang Xiaohui,Koruza Jurij,Wang Ke,Webber Kyle G.,Hao Yanan,Li Longtu
Miniaturization of domains to the nanometer scale has been previously reported in many piezoelectrics with two-phase coexistence. Despite the observation of nanoscale domain configuration near the polymorphic phase transition (PPT) regionin virgin (K 0.5 Na 0.5 )NbO 3 (KNN) based ceramics, it remains unclear how this domain state responds to external loads and influences the macroscopic electro-mechanical properties. To this end, the electric-field-induced and stress-induced strain curves of KNN-based ceramics over a wide compositional range across PPT were characterized. It was found that the coercive field of the virgin samples was highest in PPT region, which was related to the inhibited domain wall motion due to the presence of nanodomains. However, the coercive field was found to be the lowest in the PPT region after electrical poling. This was related to the irreversible transformation of the nanodomains into micron-sized domains during the poling process. With the similar micron-sized domain configuration for all poled ceramics, the domains in the PPT region move more easily due to the additional polarization vectors. The results demonstrate that the poling process can give rise to the irreversible domain configuration transformation and then account for the inverted macroscopic piezoelectricity in the PPT region of KNN-based ceramics.
研究领域:
材料科学
·
物理学
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DOI
高影响因子
Journal of Materials Chemistry C
·
2026
·
IF 5.1
Jian Luo,Chenkai Jin,Juan Cai,Yan Lei,Juncheng Huang,Chao Fang,Lixin Song,Haining Na,Jin Zhu
Carbon nitride materials are promising for photocatalysis and optoelectronics owing to their earth-abundant composition and tunable electronic structure, yet they often suffer from limited charge separation and poor photothermal stability. However, achieving high-temperature luminescence retention together with long-term UV durability, especially in polymer-processable forms, remains challenging. Here, we introduce a dual-alkali co-doping concept (K/Na) that enables a carbon nitride phosphor with simultaneously improved thermal endurance and UV durability, and we further demonstrate its processability into transparent polymer composites. We report a potassium/sodium co-doped carbon nitride (CN–K/Na) synthesized by a solid-state route using 3-AT, NaOH, and KOH. Structural analyses indicate that K/Na incorporation modulates the local structure of the CN framework, which is consistent with synergistic regulation of defects and charge transport. The co-doped material shows a narrowed optical bandgap (2.23 eV), enhanced photoluminescence, and an increased TRPL lifetime (τ_avg ≈ 1.42 ns, from multi-exponential fitting), and significant thermal stability, retaining 90.8% emission at 475 K and ~75% at 625 K. Under extended UV exposure, the emission exhibits a non-monotonic evolution, reaching 1.7× of the initial intensity and maintaining 43% after 192 h, indicating notable optical durability. When incorporated into a polymer matrix, CN–K/Na effectively suppresses UV-induced degradation of PMMA, maintaining stable emission with minimal spectral drift. The improved UV durability of the composites is consistent with UV attenuation by the filler and reduced photodegradation of the polymer matrix. These results establish K/Na co-doping as a practical and scalable route to robust carbon nitride luminescent materials and UV-durable transparent composites for optoelectronic applications.
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产品关联
DOI
高影响因子
IONICS
·
2016
·Vol. 22
·期 11
·2087-2093
·
IF 2.119
Yang F.,Yu Z.,Meng B.,Zhu Y. J.,Yang Q. Q.,Lin Z. L.,Zhou H. M.,Liang X. L.
The Sr 1 − x
Na
x
SiO 3 − x /2 samples (SNS, x = 0.2, 0.3, 0.4, 0.45) were prepared by spark plasma sintering (SPS) at a lower sintering temperature of 850 °C for a shorter holding time of 5 min. All SNS samples by SPS are composed of single monoclinic SrSiO 3 phase, and the grain sizes are in the range of 1.9 ± 0.5 μm. The measurement results of the electrical properties show that the conductivities of SPS samples are one order of magnitude higher than those of the samples by traditional sintering method. The ion transference numbers of SNS samples by SPS are all higher than 0.99 in the temperature range of 500∼650 °C, which demonstrates that the SNS has met the requirements as solid oxide fuel cell electrolytes and the SPS process is a promising candidate for preparations of SNS electrolytes.
研究领域:
材料科学
·
陶瓷
·
固态离子学
·
能源材料
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DOI
高影响因子
ChemCatChem
·
2019
·Vol. 11
·期 20
·5098-5107
·
IF 4.495
Ning Xiang,Yaqin Hou,Xiaojin Han,Yulin Li,Yaoping Guo,Yongjin Liu,Zhanggen Huang
Room temperature HCHO catalytic oxidation over inert support loaded Pd catalysts remains a significant challenge. Herein, a series of alkali Na (1–4 wt.%) modified 1Pd/SBA-15 catalysts were prepared by a co-impregnation method and used for HCHO catalytic oxidation at room temperature. Results showed that alkali Na significantly improved the HCHO oxidation performance of 1Pd/SBA-15 and the optimal Na loading was 2 wt.%. BET, XRD, STEM, XPS, H 2 -TPR, O 2 -TPD and in situ DRIFTS were performed to reveal the promotion role of alkali Na. As a consequence, alkali Na addition could stabilize well dispersed Pd particles which then facilitated the O 2 activation and accelerated the decomposition of formate intermediates species, thus a superior HCHO catalytic oxidation performance was obtained. This study first clearly illustrated the promotion mechanism of alkali Na without the implication of active support and provides an efficient and facile way to achieve high dispersion of Pd particles on inert support and tremendously expands the selected range of supports for room temperature HCHO catalytic oxidation. Graphical Alkali promoted : A series of Na alkali-promoted 1Pd/SBA15 catalysts were prepared by a co-impregnation method and tested for HCHO catalytic oxidation at room temperature. Addition of alkali Na stabilized well-dispersed Pd particles which facilitated O 2 activation and accelerated formate species decomposition rate, leading to superior HCHO catalytic oxidation performance of 2Na-1Pd/SBA-15.
研究领域:
催化化学
·
环境科学
·
材料化学
·
表面科学
·
大气污染控制
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DOI
高影响因子
Green Energy & Environment
·
2024
·Vol. 10
·期 2
·374-381
·
IF 10.7
Dan Lv,Liehao Wei,Cheng Wang,Mingyue Wang,Zhongchao Bai,Yameng Fan,Dongdong Wang,Nana Wang,Jian Yang
Sodium-ion batteries (SIBs) hold great promise for large-scale energy storage in the post-lithium-ion battery era due to their high rate performance and long lifespan, although their sluggish Na + transformation kinetics still require improvement. Encouraged by the excellent electrochemical performance of titanium-based anode materials, here, we present a novel titanium vanadate@carbon (TVO@C) material as anode for SIBs. Our TVO@C material is synthesized via a facile coprecipitation method, with the following annealing process in an acetylene atomosphere. The opened ion channel and the oxygen vacancies within TVO@C facilitate the diffusion of Na + ions, reducing their diffusion barrier. Thus, an ultrahigh rate of 100 A g −1 and long life of 10,000 cycles have been achieved. Furthermore, the TVO@C electrode exhibits stable performance, not only at room temperature, but also at temperatures as low as −20 °C. The TVO@C||Na 3 V 2 (PO 4 ) 3 @C full cells have also achieved stable discharge/charge for 500 cycles. It is believed that this strategy provides new insight into the development of advanced electrodes and provides a new opportunity for constructing novel high rate electrodes.
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 53
·期 11
·8385-8397
·
IF 2.993
Zhang Hui,Zhao Yanming,Wen Mingming,Dong Youzhong,Fan Qinghua,Kuang Quan,Liu Huatao,Lian Xin
A new sodium ferrous orthophosphate Na
x
Fe 4 (PO 4 ) 3 (1.1 ≤ x ≤ 1.2) with P 2 1 / n symmetry has been successfully synthesized via a solid-state reaction for the first time. The structure consists of FeO 5 pyramids, FeO 6 octahedron, and PO 4 tetrahedra which form large six-sided tunnels along \( \vec{b} \) direction and three- or four-sided tunnels running along \( \vec{a} \) direction. When evaluated as the anode materials for sodium-ion batteries, the first discharge and charge capacities of 553 and 264 mAh g −1 for Na 1.1 Fe 4 (PO 4 ) 3 /C and 583 and 315 mAh g −1 for Na 1.2 Fe 4 (PO 4 ) 3 /C, respectively, can be obtained at 10 mA g −1 current density. Compared to the Na 1.1 Fe 4 (PO 4 ) 3 /C, Na 1.2 Fe 4 (PO 4 ) 3 /C exhibits a better cycling performance, where the charge capacity of about 100 mAh g −1 can still be maintained after 15 cycles. The electrode kinetics are investigated further by the electrochemical impedance spectroscopy.
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DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 93
·90455-90461
·
IF 3.289
Peng Lu,Xiaobing Huang,Yurong Ren,Jianning Ding,Haiyan Wang,Shibiao Zhou,Yuandao Chen,Xiang Ding
Na+ and Zr4+ co-doped lithium titanates with the formula Li4−xNaxTi5−xZrxO12 (x = 0, 0.01, 0.03, 0.05, 0.10, 0.15 and 0.20) were successfully synthesized via a solid-state reaction in air. XRD analysis indicates that Na+ and Zr4+ co-doping does not change the spinel structure of Li4Ti5O12 and the lattice parameter slightly increases with the enhancement of doping amount. Smaller particle size and larger BET surface areas are obtained for Na+ and Zr4+ co-doped Li4Ti5O12 samples. The four-point probe method and electrochemical impedance spectroscopy (EIS) results demonstrate that the Na+ and Zr4+ co-doped Li4Ti5O12 samples possess higher electrical conductivity and smaller charge transfer resistance compared with undoped Li4Ti5O12, resulting in improved electrochemical performance. Particularly, Li3.97Na0.03Ti4.97Zr0.03O12 exhibits the best rate capability and cycling stability. Even at 20C, it delivers a discharge capacity of 140 mA h g−1, and after 100 cycles at 10C, 97.7% of its initial capacity is retained.
研究领域:
材料科学
·
电化学
·
储能技术
·
锂离子电池
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Yunzhao Liu,Xiaowei Chi,Qi Han,Yuexiu Du,Jianhua Yang,Yu Liu
Sodium–oxygen (Na−O 2 ) batteries are being extensively studied because of their higher energy efficiency and lower cost compared to those of lithium–oxygen (Li–O 2 ) batteries. However, highly efficient and durable cathode catalysts are very limited, thus considerably hindering the application of Na–O 2 batteries. Herein, a vertically self-standing C@NiCo 2 O 4 nanoneedle arrays (C@NiCo 2 O 4 -NAs) have been delicately designed and fabricated by a facile hydrothermal method . The NiCo 2 O 4 nanoneedles are in-situ grown on the carbon paper , forming an unique urchin-like structure, which is directly used to Na–O 2 batteries as a self-standing and binder-free cathode for the first time. Under a current density of 50 mA g −1 , the Na–O 2 battery containing C@NiCo 2 O 4 -NAs cathode shows a high initial discharge capacity of 6500 mAh g −1 (based on NiCo 2 O 4 material mass) and low over-potential of 0.6 V due to the numerous catalytic sites and high electron mobility of C@NiCo 2 O 4 -NAs. SEM, XPS and FTIR tests have confirmed the formation of thin film-like Na 2 O 2 discharge product on the surface and gaps of NiCo 2 O 4 nanoneedles, and the special film-like structure can facilitate the decomposition of Na 2 O 2 in the subsequent charging process and reduce the over-potential notably. Meanwhile, the robust urchin-like structure of C@NiCo 2 O 4 -NAs renders the Na–O 2 battery a high cyclic stability up to 120 cycles when the specific capacity is limited to be 800 mAh g −1 .
研究领域:
储能
·
材料科学
·
电化学
·
纳米材料
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DOI
高影响因子
DALTON TRANSACTIONS
·
2021
·Vol. 50
·期 37
·13052-13058
·
IF 4.39
Hui Zheng,Changhao Ding,Han-Shu Xu,Lulu Tang,Huimin Liu,Lianwei Wei,Kaibin Tang
Several FeS-derived intercalated compounds (C2H8N2)xFeS and Ax(C2H8N2)yFeS (A = Li, Na) were successfully synthesized via a novel ammonothermal method. The powder X-ray diffraction (XRD) measurements reveal that the FeS intercalated samples have the same tetragonal crystal structure as the parent FeS. After intercalation, these three as-synthesized samples do not show superconductor behavior, which is confirmed by the magnetization and the electrical resistivity measurements. (C2H8N2)xFeS exhibits paramagnetic semiconductor behavior, while the newly synthesized Ax(C2H8N2)yFeS (A = Li, Na) shows antiferromagnetic semiconductor behavior. The absence of superconductivity in these FeS-derived compounds should be closely related to the iron vacancies in the FeS layer.
研究领域:
材料科学
·
固体化学
·
凝聚态物理
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Xiaowei Li,Xing Shen,Junmei Zhao,Yang Yang,Qiangqiang Zhang,Feixiang Ding,Miao Han,Chunliu Xu,Chao Yang,Huizhou Liu,Yong-Sheng Hu
Na-ion batteries (NIBs) have been considered as potential candidates for large-scale energy storage, where O3-type Na-based layered oxide cathodes have attracted great attention due to their high capacity and low cost. However, O3-NaxTMO2 materials still suffer from insufficient air stability, which could lead to deteriorative electrochemical properties and thus hinder their practical application. In this work, a series of Al-doped O3-NaFe(1/3–x)Ni1/3Mn1/3AlxO2 cathodes prepared by a co-precipitation method were investigated to enhance their electrochemical performance and air stability through stabilizing their structural and interface chemical properties. The Al-doped O3-NaFe(1/3–0.01)Ni1/3Mn1/3Al0.01O2 (NFNMA0.01) cathode delivers a comparable capacity of 138 mAh g–1 and keeps a capacity retention of 85.88% after 50 cycles at 0.2 C, while the undoped O3-NaFe1/3Ni1/3Mn1/3O2 (NFNM) can only keep a capacity retention of 71.02%, although with an initial capacity of 141 mAh g–1 at 0.2 C. For the air stability, the capacity decay rates are 58.87 and 5.07% for the undoped NFNM and Al-doped NFNMA0.01 after the air exposure for 30 days, respectively. The greatly decaying electrochemical performance could be due to the formation of carbonates during air exposure, which can be efficiently suppressed by Al doping. The doped Al3+ has been confirmed to be inserted into the NFNM crystal lattice, inducing the reduced values of lattice parameters a and c due to the smaller ionic radius of Al3+ (53.5 pm) vs Fe3+ (55.0 pm). This study demonstrates that Al doping plays an important role in the air stability and cycling stability for layered cathode materials, which offers an efficient strategy to optimize the material design for their practical application in NIBs.
研究领域:
储能
·
材料科学
·
电化学
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DOI
高影响因子
DALTON TRANSACTIONS
·
2018
·Vol. 47
·期 48
·17486-17492
·
IF 4.099
Fangfang He,Lei Wang,Cuifang Hu,Jing Zhou,Qian Li,Ling Huang,Daojiang Gao,Jian Bi,Xin Wang,Guohong Zou
Four antimony fluoride sulfates named A2SO4·SbF3 (A = Na+, NH4+, K+, Rb+) have been successfully synthesized using a hydrothermal method by introducing Sb3+ cations with a stereochemically active lone pair in sulfates and subsequently tuning the structure through the second monovalent cations. All of the title compounds are stoichiometrically equivalent materials which share a common structural motif composed of a distorted SO4 tetrahedron and an asymmetric SbF3 polyhedron. However, the macroscopic centricities of these four compounds are significantly influenced by the size and coordination environment of cations; Na2SO4·SbF3 crystallizes in centrosymmetric space groups Cmca and (NH4)2SO4·SbF3 in Pbca, while K2SO4·SbF3 and Rb2SO4·SbF3 crystallizes in noncentrosymmetric space group P212121. Complete characterization including thermal analyses, infrared and UV-vis spectroscopy, and theoretical calculations is also reported. Powder second harmonic generation measurement for noncentrosymmetric K2SO4·SbF3 and Rb2SO4·SbF3 indicated that both of them are type I phase-matchable.
研究领域:
无机化学
·
材料科学
·
非线性光学
·
晶体工程
·
固态化学
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DOI
高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 11
·期 33
·17491-17502
·
IF 11.9
Qingyuan Liu,Jianchao Chen,Danni Du,Shuxian Zhang,Chunyan Zhu,Zhiwei Zhang,Chengxiang Wang,Longwei Yin,Rutao Wang
Sodium-ion capacitors (SICs) have long been pursued as economically favorable alternatives to their well-developed lithium-ion counterparts. However, their commercialization suffers from the immature pre-sodiation technology in existence, primarily due to the increased cost and risk invoked by the use of highly reactive metallic sodium and sodium containing additives as sodium sources. Herein, we uncover a unique approach based on the use of prelithiated carbon as the anode for SICs. The prelithiated hard carbon anode with the preformed solid-electrolyte-interphase (SEI) layer can effectively compensate the large irreversible capacity loss and greatly improve the initial coulombic efficiency of SICs. Besides, the preformed Li-based SEI layer is effective in controlling the Na-ion intercalation behavior of the carbon anode, as confirmed by the reversible capacity that is mainly contributed by the extended slope region without the low-potential plateau region, thus avoiding the safety issues from Na metal plating. These features endowed by the pre-lithiation strategy enable us to use a slope region-dominated soft carbon anode for high-safety SICs with high capacity and superior rate capability. This work possesses far-reaching potential to implant the mature pre-lithiation technology into sodium-ion energy storage systems to resolve the scientific bottleneck from the immature pre-sodiation technology.
研究领域:
能量存储
·
材料科学
·
电化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）