DALTON TRANSACTIONS
·
2022
·Vol. 51
·期 41
·15990-15995
·
IF 4.569
Jianlong Huang,Chengfa Wu,Jianbang Chen,Zhiyong Guo,Wenjuan Ma,Feng Yu,Bin Dai
A new rare-earth borate Na3YB8O15 was fabricated by the flux method. The compound crystallizes in the P group, and shows a three-dimensional network built by [B8O17] fundamental building blocks (FBBs) with [NaO6], [NaO7], and [YO7] polyhedra. The [B8O17] FBBs are composed of five planar BO3 and three BO4 tetrahedra and connected via corner-sharing to construct a unique one-dimensional (1D) [B8O15]∞ infinity chain that is observed for the first time in the Na2O–Y2O3–B2O3 system compound, enriching the structural diversity of rare-earth borate. The title compound exhibits a short ultraviolet (UV) cutoff edge of ∼195 nm and a wide experimental band gap of 5.50 eV. DFT calculations indicate that Na3YB8O15 is a direct band gap compound with a calculated GGA band gap of 5.14 eV, and the band gap is mainly determined by B 2p and O 2p orbitals. The results update the phase diagram of Na2O–Y2O3–B2O3 and enrich the diversity of rare-earth metal borates.
研究领域:
无机化学
·
材料科学
·
固体化学
·
光电功能材料
·
晶体工程
✓ 已验证
DOI
高影响因子
Small
·
2021
·Vol. 18
·期 8
·2105599
·
IF 13.281
Wuhong Xue,Qitao Jiang,Fakun Wang,Ri He,Ruixue Pang,Huali Yang,Peng Wang,Ruilong Yang,Zhicheng Zhong,Tianyou Zhai,Xiaohong Xu
2D ferroelectrics with robust polar order in the atomic-scale thickness at room temperature are needed to miniaturize ferroelectric devices and tackle challenges imposed by traditional ferroelectrics. These materials usually have polar point group structure regarding as a prerequisite of ferroelectricity. Yet, to introduce polar structure into otherwise nonpolar 2D materials for producing ferroelectricity remains a challenge. Here, by combining first-principles calculations and experimental studies, it is reported that the native Ga vacancy-defects located in the asymmetrical sites in cubic defective semiconductor α‑Ga 2 Se 3 can induce polar structure. Meanwhile, the induced polarization can be switched in a moderate energy barrier. The switched polarization is observed in 2D α‑Ga 2 Se 3 nanoflakes of ≈4 nm with a high switching temperature up to 450 K. Such polarization switching could arise from the displacement of Ga vacancy between neighboring asymmetrical sites by applying an electric field. This work removes the point group limit for ferroelectricity, expanding the range of 2D ferroelectrics into the native defective semiconductors.
研究领域:
材料科学
·
凝聚态物理
·
纳米电子学
·
功能材料
·
半导体物理
✓ 已验证
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2016
·Vol. 18
·期 28
·19165-19172
·
IF 4.449
Lihong Bao,Xiaoping Qi,Tana,Lumen Chao,O. Tegus
Multiple nanocrystalline rare-earth hexaborides La1−xBaxB6 have been synthesized via a single step solid-state reaction. The Ba doping effects on crystal structure, grain morphology, magnetic and optical absorption properties were investigated using XRD, FESEM, HRTEM, SQUID magnetometry and optical measurements. The results show that all the Ba-doped hexaborides crystallize in the CsCl-type single phase, indicating the Ba atoms occupied the lattice sites of LaB6. The optical absorption results indicate that the absorption valleys of LaB6 are red-shifted from 622 nm to 780 nm when the Ba doping content increases to x = 0.8. The first-principle calculation results reveal that Ba doping reduces the total kinetic energy of the electrons of LaB6, which lead to the absorption valleys moving toward a higher wavelength. Meanwhile, the band gap of BaB6 obtained from optical absorption is in good agreement with the theoretical calculation results. The magnetic measurements results showed that Ba doping lead to room-temperature ferromagnetism of LaB6 due to the different ionic radii of La3+ and Ba2+ causing intrinsic crystal defects, which is directly observed experimentally by HRTEM. This is the first time that we have found the tunable optical and ferromagnetic behavior of Ba doped nanocrystalline LaB6. Thus, nanocrystalline La1−xBaxB6, as multi-functional materials, should open up a new route to extend the optical and magnetic applications of LaB6 nanopowder.
研究领域:
材料科学
·
凝聚态物理
·
纳米材料
·
功能材料
·
磁学
·
光学材料
✓ 已验证
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2017
·
IF 2.446
Tengchao Guo,Guoyue Xu,Shujuan Tan,Ning Liu,Jianchao Zhang,Xiangxiong Zeng,Juan Liang
The electronic properties and infrared emissivity of Zn 1-x Mg x O (x = 0, 0.0625, 0.125) were systematically investigated by using the first-principle calculation s based on density functional theory (DFT). The Zn 1-x Mg x O (x = 0, 0.0625, 0.125) powders were prepared by sol-gel method and their infrared emissivity in the wavelength of 8–14 μm was characterized. The results indicate that the infrared emissivity increases with the increase in Mg concentration, which is attributed to the reduction in conductivity and in the real part of dielectric function. Furthermore, the variation in conductivity and dielectric function has been well studied, and a reasonable method to calculate infrared emissivity of semiconductors has been established. It is expected that this method can be used for designing materials with different infrared emissivity and also applied for effectively guiding the experimental investigation.
研究领域:
材料科学
·
凝聚态物理
·
计算材料学
·
功能材料
·
半导体物理
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2016
·Vol. 46
·期 1
·193-199
·
IF 4.177
Dongdong Xu,Fangfang Zhang,Yanzhou Sun,Zhihua Yang,Binghua Lei,Lili Liu,Shilie Pan
A new rare-earth borate LiRb2LaB2O6 (LB-1) has been synthesized using a high-temperature solution method. Interestingly, it shares its topological structure with the famous porous material MOF-5, which is formed from Zn4O(BDC)3 (BDC = 1,4-benzenedicarboxylate). The nodes [OZn4] and organic linkers [BDC] of MOF-5 are carefully substituted with La3+ rare-earth cations and the inorganic linkers [BO3] and [LiO4], respectively, in order to construct a pure inorganic open framework. LB-1 exhibits good thermal and water stability. Moreover, it possesses a short cut-off edge (<190 nm) and moderate birefringence (exp. 0.040@589.5 nm, cal. 0.038@589.5 nm). Further insights into the cut-off edge were given by first-principles calculations. The factors that influence the birefringence of LB-1 were discussed in view of the spatial arrangement of the [BO3] anionic groups.
研究领域:
无机化学
·
材料科学
·
晶体工程
·
光学材料
·
固体化学
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2019
·Vol. 43
·期 44
·17502-17510
·
IF 3.069
Jie Ren,Zhenguo Wang,Yu Feng,Bangjun Guo,Ke Yu,Ziqiang Zhu
In this work, we report the first-principles investigation and synthesis method for a hollow-MoS2/C heterostructure applied to a hydrogen evolution catalytic material. First principles investigation was used to calculate the free energy of hydrogen ion adsorption at the heterostructure interface at different surface adsorption ratios. The change of the density of states before and after carbon coating proved that carbon coating improves the conductivity of the catalyst. Higher reactivity areas and higher conductivity can significantly improve hydrogen evolution catalytic performance, which is also demonstrated by electrochemical testing. Hollow-MoS2/C exhibits a low onset overpotential of 96 mV and a low Tafel slope of 67.4 mV dec−1, as well as good catalytic stability. The composite catalyst prepared by a two-step method has a larger specific surface area and a larger porosity, can significantly suppress the collapse and stacking effect caused by the electrode circulation process, and improve the cyclic reversibility and stability of the material. This work is expected to provide a meaningful reference for solving the problem of cycling performance degradation of non-precious metal-catalyzed hydrogen evolution materials.
研究领域:
材料化学
·
电化学
·
纳米材料科学
·
催化化学
·
能源材料
·
理论计算化学
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2023
·Vol. 52
·期 29
·10109-10114
·
IF 4
Juhe Liu,Yuwei Chen,Mengran Sun,Wenhao Liu,Xianghe Meng,Jiyong Yao
A new complex rare earth borate K7PbLu2B15O30 was prepared by the spontaneous crystallization method. K7PbLu2B15O30 is crystallized in the chiral trigonal space group R32 with cell parameters a = b = 13.0893(3) Å, c = 15.2379(6) Å, α = β = 90°, γ = 120°, and Z = 3. The basic structure of the crystal can be seen as composed of B5O10 groups and LuO6 polyhedra sharing oxygen atoms, while K+ and Pb2+ fill the space to balance the charge. The UV transmission cut-off edge of K7PbLu2B15O30 was less than 300 nm, and the powder SHG response was roughly 1.1 times that of KDP. Furthermore, a first-principles analysis was performed to see more about the relationship between the crystal structure and optical characteristics.
研究领域:
无机化学
·
材料科学
·
晶体工程
·
光学材料
·
固体化学
✓ 已验证
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2018
·Vol. 20
·期 27
·18455-18462
·
IF 3.906
Xiangyang Duan,Chao Ma,Wentao Jin,Xiaoman Ma,Lu’an Guo,Su-Huai Wei,Jinying Yu,Yelong Wu
A simple and efficient top-down strategy, the chemical vapor etching method, is reported for synthesizing corrugated ZnO nano/micro rods (NRs). The stabilization mechanism of this unique nanostructure has been determined through a combination of aberration-corrected field emission scanning electron microscopy, high-resolution transmission electron microscopy, and first-principles calculations. The experimental data are in good agreement with the theoretical calculations, and a remarkable nonpolar-to-polar surface faceting transition is demonstrated. The corrugated-shaped structure results from the remarkable stability of the defect-induced reconstructions (O vacancy, Zn–Zn dimer), which makes the high-index polar {301} and {10} planes lower in energy compared to the nonpolar {100} plane. Based on the results of first-principles surface calculations, a general formula is established to provide an accurate description of the unusual size effect of the length of the corrugated unit vs. the NR diameter, and it also offers direct explanations for certain experimental observations. The present study deepens our atomic-level understanding of the detailed structure and stability of polar surface decorated corrugated ZnO NRs, and points to a viable path towards designing polar-stable wurtzite structures.
研究领域:
材料科学
·
纳米科技
·
表面科学
·
凝聚态物理
·
计算材料学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Shuya Wang,Yaxin Chen,Bin Cui,Bo Li,Shuxuan Wang,Yanhua Cui,Zhicheng Ju,Quanchao Zhuang
Computer simulation accelerates the selection and application of new electrode materials. The First-principles calculations based on density functional theory (DFT) are performed to evaluate the performance as cathode for Potassium ion batteries (PIBs) on the structure, electronic conductivity and ionic diffusion of O-doped KMnF 3 . After taking comprehensive consideration of the calculation results, the nanostructured O-doped KMnF 3 was synthesized and the structure and electrochemical properties were further improved by carbon coating. Here, we report a new etch pathway to create a new class of carbon-coated perovskite fluoride to improve the performance of PIB in terms of rate capability and cycle stability. These new material design concepts will help discover and synthesize new materials for PIBs.
研究领域:
材料科学
·
电化学
·
计算材料学
·
能源存储
·
无机化学
·
纳米材料
·
固体物理
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·Vol. 47
·期 16
·22776-22785
·
IF 4.527
Kaidan Wu,Yefeng Feng,Jin Ke,Bingwen Yang,Zhiling Guo,Deping Xiong,Miao He
Graphite nanosheets coated by LiF/SnO 2 composites are designed to obtain a lithium ion anode material with excellent performance. LiF nanoparticles play a significant role in improving the electrochemical performance by inhibiting electrolyte decomposition and providing excess Li sources during cycling. The obtained LiF@SnO 2 @C electrode shows an outstanding capacity of 951.9 mAhg −1 at 0.2 Ag -1 after 370 cycles and excellent long cycling performance of 650.0 mAhg −1 at 1.0 Ag -1 after 930 cycles. First-principles calculations demonstrate that F-doped SnO 2 (−2211.8 eV) has a lower free energy compared to SnO 2 (−1937.4 eV), resulting in a robust composite architecture that gives rise to high cycling stability.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
计算材料学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Chen Zhou,Hui Zhang,Jianian Cheng,Hongyi Li,Sadeh Beysen
Two new isostructural lead borates , Pb 8 Mg(BO 3 ) 6 and Pb 8 Ca(BO 3 ) 6 , have been synthesized via high temperature solution method. The single crystal structures of title compounds contain ∞ [Pb 8 B 6 O 18 ] 2- double layers composed of planar BO 3 triangles, Pb(2)O 9 and distorted Pb(1)O 5 polyhedra, these layers condense in c -axis, and the MgO 6 (or CaO 6 ) polyhedra fill into the layers, forming a three-dimensional framework. The stereochemical activity of lone pair (SCALP) electrons were found in the Pb(1)O 5 polyhedra, which combine with the BO 3 units, generating strong optical anisotropy . The calculated birefringences of Pb 8 Mg(BO 3 ) 6 and Pb 8 Ca(BO 3 ) 6 using first-principles method are 0.15@1064 nm and 0.12@1064 nm, respectively, which are comparable to the commercial α -BaB 2 O 4 (α-BBO) crystal and imply that they probably can be used as birefringent materials. The electronic structures, density of states of title compounds were calculated by density functional theory (DFT). Meanwhile, the TG-DSC curves, infrared spectral and UV–Vis–NIR diffuse reflectance spectral were measured.
研究领域:
无机化学
·
材料科学
·
晶体工程
·
非线性光学材料
·
固体化学
✓ 已验证
DOI
高影响因子
Advanced Energy Materials
·
2016
·Vol. 7
·期 8
·1602149
·
IF 15.23
Shanshan Yao,Jiang Cui,Ziheng Lu,Zheng-Long Xu,Lei Qin,Jiaqiang Huang,Zoya Sadighi,Francesco Ciucci,Jang-Kyo Kim
Carbon-coated van der Waals stacked Sb 2 S 3 nanorods (SSNR/C) are synthesized by facile hydrothermal growth as anodes for sodium ion batteries (SIBs). The sodiation kinetics and phase evolution behavior of the SSNR/C anode during the first and subsequent cycles are unraveled by coupling in situ transmission electron microscopy analysis with first-principles calculations. During the first sodiation process, Na + ions intercalate into the Sb 2 S 3 crystals with an ultrafast speed of 146 nm s −1 . The resulting amorphous Na x Sb 2 S 3 intermediate phases undergo sequential conversion and alloying reactions to form crystalline Na 2 S, Na 3 Sb, and minor metallic Sb. Upon desodiation, Na + ions extract from the nanocrystalline phases to leave behind the fully desodiated Sb 2 S 3 in an amorphous state. Such unique phase evolution behavior gives rise to superb electrochemical performance and leads to an unexpectedly small volume expansion of ≈54%. The first-principles calculations reveal distinctive phase evolution arising from the synergy between the extremely low Na + ion diffusion barrier of 190 meV and the sharply increased electronic conductivity upon the formation of amorphous Na x Sb 2 S 3 intermediate phases. These findings highlight an anomalous Na + ion storage mechanism and shed new light on the development of high performance SIB anodes based on van der Waals crystals.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
固态物理
·
计算材料学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）