Minerals
·
2024
·Vol. 14
·期 4
·360
·
IF 2.2
Gaofeng Wang,Bowen Ling,Xiaoliang Liang,Jie Xu,Shichang Kang,Jingming Wei,Wei Tan,Runliang Zhu,Jianxi Zhu,Hongping He
Electrokinetic mining (EKM) is a novel method for rare earth element (REE) mining that can achieve green and efficient recovery of REEs. However, as yet, there is no accurate model for describing the electrokinetic transport of REEs in weathering crusts, and this hinders the wider application of EKM. The conventional model fails to capture the microscale transport physics occurring in the nanochannels that exist ubiquitously in weathering crusts. Consequently, the existing models cannot distinguish the mobilities of different REEs. Here, we report a new model for a more faithful description of the electrokinetic transport of REEs in weathering crusts that considers the ionic size, which has previously been neglected. We reveal that the electrokinetic transport of heavy REEs (HREEs) is faster than that of light REEs (LREEs) in weathering crusts, which is contrary to the predictions of conventional models. Our model was validated experimentally by measurements of the electrokinetic transport of two LREEs (La and Sm) and an HREE (Er) in weathering crusts. The speed of electrokinetic transport follows the order Er > Sm > La. Our findings suggest that the ionic size is a non-negligible factor affecting the electrokinetic transport of REEs in weathering crusts containing nanochannels. This work offers a constitutive model to describe the electrokinetic transport of REEs in weathering crusts, which promotes both theoretical developments and practical applications of EKM.
研究领域:
环境科学
·
矿物工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2022
·
IF 5.436
Ruixin Guo,Xingxing Jiang,Shu Guo,Mingjun Xia,Lijuan Liu,Zheshuai Lin,Xiaoyang Wang
Birefringence, as one of the most important factors for birefringent materials, governs their performances in applications. In this study, two previously unreported beryllium borates, BaCdBe2(BO3)2F2 (BDBBF) and NaMgBe2(BO3)2F (NMBBF), have been rationally designed by modulating interstitial cations. When smaller sizes of the cations are used, the crystal structure of NMBBF exhibits closer-packed 2D [Be6B6O12F3]∞ double layers rather than the 2D [Be3B3O6F3]∞ single layers in the crystal structure of BDBBF. The ultraviolet (UV) transmittance spectrum indicates that the short UV absorption edges of BDBBF and NMBBF are below 200 nm. The results from both theoretical calculations (theo.) and experimental characterizations (exp.) reveal enlarged birefringence from BDBBF (0.067 at 589 nm from theo. and 0.059 at 546.1 nm from exp.) to NMBBF (0.078 at 589 nm from theo. and 0.081 at 546.1 nm from exp.). Because of its excellent structure-based optical properties, NMBBF has the potential to be a deep-UV birefringent material. Our structural comparison and discussion provide a scope to aid in the design of potential deep-UV birefringent materials with large birefringence.
研究领域:
材料科学
·
光学
·
晶体学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2018
·
IF 4.7
Weiwei Cao,Xiaoyan Yang,Fengqi Lu,Wenfeng Zhu,Laijun Liu,Xiaojun Kuang,Mathieu Allix
Isovalent substitution of Zr4+ for smaller Ti4+ was performed in the 8-layer twinned hexagonal perovskite (referred to as 8H) tantalate Ba8Ti3Ta4O24, which stabilizes a 10-layer twinned hexagonal perovskite (referred to as 10H). The formation of the 10H phase occurs at low substitution concentration (x = 0.1) in Ba8ZrxTi3–xTa4O24 at 1300 °C and reverts back to the 8H phase upon heating at elevated temperatures. Such a 10H-to-8H phase transformation is suppressed at higher Zr-substitution contents (x > 0.1). The approach combining simulated annealing and Rietveld refinement with compositional constrain indicates that the 10H Ba8Zr0.4Ti2.6Ta4O24 (x = 0.4) composition adopts a simply P63/mmc disordered structure with Zr cations preferably located in corner-sharing octahedral (CSO) sites compared to face-sharing octahedral (FSO) sites. This 8H-10H phase competition, dependent on the substitution of Zr4+ for Ti4+ and firing temperature, is discussed in terms of the FSO B–B repulsion controlled by the cationic size, as well as the stacking periodicity which affects the thermodynamic stability. Both 8H- and 10H-phase pellets of Ba8ZrxTi3–xTa4O24 exhibit comparable and poorer microwave dielectric properties than the parent 8H Ba8Ti3Ta4O24, which is characterized by cationic disorder and FSO B–B repulsion. The 8H and 10H Ba8ZrxTi3–xTa4O24 ceramics display electrical insulator behavior but with electrically heterogeneous microstructure on the bulk grains. This study demonstrates the opportunity to control the stacking periodicity for the twinned hexagonal perovskites via tuning the B-cationic size and the firing temperature.
研究领域:
材料科学
·
无机化学
✓ 已验证
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2025
·Vol. 51
·期 20
·31430-31441
·
IF 5.6
Lei Wang,Yilin Wu,Jinsheng Li,Fengxu Li,Xudong Liu,Mu Zhang,Xiaoguo Bi,Xiaodong Li,Mengjia Xu,Xudong Sun
Donor-acceptor co-doped TiO 2 -based materials have attracted consideration attention because of their excellent dielectric properties , however, the effect of different acceptor ions on the dielectric properties of TiO 2 single crystals has been the subject of little study. In this paper, (Nb 0.5 A 0.5 ) 0.5 % Ti 99.5 % O 2 (A = Ga, Sc, La, Nd) single crystals were prepared by the Verneuil method, and their dielectric properties were investigated. It was found that the dielectric properties of co-doped single crystals do not become superior with increasing radius of the doped ions as in the case of TiO 2 ceramic samples. In contrast, as the radius of the acceptor ion increases, the ions encounter greater difficulty in entering the TiO 2 lattice. In addition to electron-pinned defect-dipole (EPDD) polarization, hopping polarization occurs in (Nb 0.5 Sc 0.5 ) 0.5 % Ti 99.5 % O 2 single crystal, while interfacial polarization occurs in (Nb 0.5 La 0.5 ) 0.5 % Ti 99.5 % O 2 and (Nb 0.5 Nd 0.5 ) 0.5 % Ti 99.5 % O 2 single crystals, both of which adversely affect the dielectric properties. In the (Nb 0.5 Ga 0.5 ) 0.5 % Ti 99.5 % O 2 single crystal, the defect clusters of triangular structure Ga 2 3 + V O · · Ti 3 + and diamond structure Nb 2 5 + Ti 3 + X Ti (X = A 3+ /Ti 3+ /Ti 4+ ) are interspersed with each other. This results in the formation of large defect dipole clusters, where EPDD polarization is the primary polarization mechanism and the optimal dielectric properties are obtained (ε′ = 1.003 × 10 5 , tanδ = 0.0342 under 1 kHz). This work contributes to a better understanding of the effects of diverse polarization mechanisms on the dielectric properties of TiO 2 -based materials, thereby facilitation a more scientific design of TiO 2 -based giant dielectric materials .
✓ 已验证
产品关联
DOI
高影响因子
Nano Energy
·
2021
·
IF 17.881
Yousheng Wang,Hui Ju,Tahmineh Mahmoudi,Chong Liu,Cuiling Zhang,Shaohang Wu,Yuzhao Yang,Zhen Wang,Jinlong Hu,Ye Cao,Fei Guo,Yoon-Bong Hahn,Yaohua Mai
Stabilization of perovskite phases and interfaces in stacked perovskite photovoltaics are critical for their efficiency, operational stability and perovskite solar modules (PSMs). Herein, A-site cation-size mismatch processed perovskite-composition films with less crystal defects are formed by incorporating larger cations formamidinium and methylammonium with smaller cations, i.e., potassium and cesium . The interface stabilization can be achieved by inserting Poly[bis(4-phenyl) (2,4,6-trimethylphenyl) amine], mesoporous alumina , phenethyammonium ligands and atomic-layer-deposition tin oxides at desired interfaces in inverted perovskite solar cells (PSCs). Thus, the interface defects, non-radiative recombination and ion migration can be remarkably suppressed, resulting in improvement of interface contacts and hole/electron transport. As a result, both cation-size mismatch and interface stabilization (CM-IS) strategies enable hysteresis-free, reproducible 21.9% and 16.9% efficient NiO x -based inverted PSCs and PSMs. Moreover, a high V oc of 1.16 V and 8.05 V can be obtained in large-area PSCs (1 cm 2 ) and PSMs (11.2 cm 2 ) with 7 subcells connected in series. Additionally, the measured T 85 lifetime (the time as a function of PCEs decrease to 85% of its initial value) of unencapsulated PSCs under continuous AM 1.5G light illumination is approximately 1000 h.
研究领域:
材料科学
·
光伏技术
·
能源研究
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Mengmeng Zhu,Junbo Wang,Lei Hou,Yiwen Yuan,Lili Liu,Yaoqing Chu,Chunmei Huang
The design and syntheses of new birefringent crystals will be of great importance in commercial applications and materials science. A series of ultraviolet (UV) birefringent crystals, AX·(H2SeO3)n (A = K, Cs; X = Cl, Br; n = 1, 2), with large sizes up to 23 × 6 × 3 mm3, was successfully synthesized by simple aqueous solution method. These four compounds belong to three different space groups. Isomorphic KCl·(H2SeO3)2 and CsCl·(H2SeO3)2 crystallize in the P1¯ space group, while CsBr·(H2SeO3)2 and CsCl·H2SeO3 crystallize in the P21/m and P21/c space groups, respectively. They exhibit cocrystal structures composed of [2(H2SeO3)]∞ and [AX]∞ frameworks, ingeniously inheriting the large optical anisotropy of selenite and the wide band gap of alkali metal halide. And it proves that these compounds indeed possess large birefringence (0.1–0.17 at 532 nm) and short UV cutoff edges (227–239 nm), achieving a balance of optical properties. This research affords a simple and viable strategy for the design and syntheses of new UV birefringent crystals. Besides, it is also found that the n value and ionic size (A and X ions) have important influences on the crystal structures and optical properties of AX·(H2SeO3)n. And this will promote further understanding of the alkali metal halide selenite family.
研究领域:
材料科学
·
晶体工程
·
光学材料
·
无机化学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2025
·
IF 4.7
Chao Wei,Danyang Dou,Bingbing Zhang,Ying Wang
Birefringent materials are a pivotal category of optical functional materials; however, finding a new birefringent material that can operate in the deep-ultraviolet (DUV) region remains elusive. Through structural integration of [B3O6] with [AlO3F] units, fluoroaluminoborates have emerged as a chemically tunable platform for engineering birefringent materials. In this study, we report the first demonstration of cation-size-driven crystal structure evolution and birefringence modulation within fluoroaluminoborate systems. Two polymorphic potassium fluoroaluminoborates, α- and β-KAlB3O6F, were successfully synthesized through a high-temperature melting method. Both phases exhibit remarkable DUV optical performance, achieving wide band gaps coupled with exceptional birefringence (α: 0.093 @ 546 nm, β: 0.110 @ 546 nm). By combining the crystal structure analysis and the first-principles calculation results, we reveal cation-size-dependent alignment of [B3O6]/[AlO3F] groups as the origin of birefringence enhancement. This work establishes an effective strategy for simultaneously optimizing birefringence while maintaining DUV transparency through cation structural engineering.
研究领域:
材料科学
·
光学
·
无机化学
·
固态化学
·
晶体学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Science China-Chemistry
·
2014
·Vol. 57
·期 5
·662-668
·
IF 1.516
Chai YunFeng,Pan YuanJiang
Protonation and alkali-metal cation adduction are the most important ionization processes in soft-ionization mass spectrometry. Studies on the fragmentation mechanism of protonated and alkali-metal-cationized compounds in tandem mass spectrometry are essential and helpful for structural analysis. In some cases, it was often observed that a compound attached by different alkali-metal cations (or proton) exhibits similar fragmentation patterns but the relative abundances of product ions are different. This difference was considered to derive from the different electrostatic interactions of alkali-metal cations (or the bonded effect of proton) with the analyte. The alkali-metal cation with a smaller ionic radius shows stronger electrostatic interaction with the molecule because of its higher charge density. In addition, the bonded effect of the proton is stronger than the electrostatic interaction of the alkali-metal cation. In the present study, which used McLafferty-type rearrangements of even-electron ions ([M + Cat] + , Cat = H, Li, Na, K) as model reactions, the effect of cation size in mass spectrometric fragmentation reactions is highlighted. These considerations were also successfully applied to interpret the similar but distinct fragmentation behavior of proton and alkali-metal cation adducts of a synthetic compound (2-(acetamido(phenyl)methyl)-3-oxobutanoate) and a drug (entecavir).
研究领域:
分析化学
·
质谱学
·
药物代谢
·
分子结构解析
·
有机质谱
·
电离机制
✓ 已验证
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2019
·Vol. 6
·期 11
·3125-3132
·
IF 5.934
Qian Wang,Lei Wang,Xiaoyu Zhao,Ling Huang,Daojiang Gao,Jian Bi,Xin Wang,Guohong Zou
By introducing Sb3+ cations with a stereochemically active lone pair in the sulfate system, two antimony fluoride sulfates with the same stoichiometric ratio, namely, K2SO4·(SbF3)2 and Rb2SO4·(SbF3)2, were successfully synthesized via mild hydrothermal reactions. The cooperative effects of the alkali metal cation size and lone pairs resulted in a different symmetry for these two title compounds. The compound K2SO4·(SbF3)2 crystallized in a centrosymmetric (CS) space group of P21/c, while Rb2SO4·(SbF3)2 crystallized in the noncentrosymmetric (NCS) space group of P21. Though both of these two compounds consisted of similar structural building units, [SbF3O2]4− tetragonal pyramid complexes and [SO4]2− tetrahedra, they displayed discrepant helix columns in the crystal structure due to the different steric hindrance forces produced by the alkali metal cations. The alkali metal cations K+/Rb+ provided a charge balance and connected the different helix columns to form the three-dimensional framework. The detailed characterizations revealed that Rb2SO4·(SbF3)2 was a potential ultraviolet nonlinear optical material. In addition, theoretical calculations were performed.
研究领域:
无机化学
·
晶体学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）