Nature Communications
·
2022
·Vol. 13
·期 1
·1-9
·
IF 17.694
Cao Peisheng,Zheng Haoyue,Wu Peng
Designing organic fluorescent and phosphorescent materials based on various core fluorophore has gained great attention, but it is unclear whether similar luminescent units exist for inorganic materials. Inspired by the BX 6 octahedral structure of luminescent metal halide perovskites (MHP), here we propose that the BX 6 octahedron may be a core structure for luminescent inorganic materials. In this regard, excitation-dependent color-tunable phosphorescence is discovered from α-AlF 3 featuring AlF 6 octahedron. Through further exploration of the BX 6 unit by altering the dimension and changing the center metal (B) and ligand (X), luminescence from KAlF 4 , (NH 4 ) 3 AlF 6 , AlCl 3 , Al(OH) 3 , Ga 2 O 3 , InCl 3 , and CdCl 2 are also discovered. The phosphorescence of α-AlF 3 can be ascribed to clusterization-triggered emission, i.e., weak through space interaction of the n electrons of F atoms bring close proximity in the AlF 6 octahedra (inter/intra). These discoveries will deepen the understanding and contribute to further development of BX 6 octahedron-based luminescent materials.
研究领域:
材料科学
·
光学材料
·
无机化学
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2020
·
IF 2.726
Dehai Liang,Xin Lian,Xianli Li,Binbin Luo
Two dimensional (2D) hybrid metal halide perovskites (MHPs) with broadband emission have attracted enormous attention, which is highly promising for single-component solid state lighting. However, it remains a challenge to unveil the underlying origin of broadband emission and achieve high quantum yield (QY). Herein, 2D single-layered [NH 3 (CH 2 ) 4 NH 3 ]CdBr 4 (Cd–P) has been successfully prepared. By partially replacing Cd 2+ with Pb 2+ , the energy band of Cd–P shows a transformation from indirect to direct, supported by the density functional theory (DFT) calculations. Benefiting from the change of energy band, alloyed Cd x Pb 1-x -P shows an intensive broadband emission spanning the whole visible range with a maximum of photoluminescence (PL) QY of 58%. Temperature-dependent and time-resolved PL uncover that the broadband emission origins from the coupling between free excitons (FEs) and [CdBr 6 ] 4- octahedra , instead of [PbBr 6 ] 4- . These findings provide a deep insight into the origin of STEs emission and an effective approach to promote the broadband emission for Cd-based MHPs.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Materials Horizons
·
2021
·Vol. 9
·期 3
·1002-1009
·
IF 13.266
Lu Wang,He Qi,Botao Gao,Ye Liu,Hui Liu,Jun Chen
The development of high-performance lead-free piezoceramics for replacing Pb-based perovskites has attracted lots of attention, and comparable room-temperature piezoresponse has been realized in (Na,K)NbO3 and BaTiO3-based ceramics with local structure heterogeneity via adjusting polymorphic phase boundary. In this work, a new method of oxygen octahedron tilt design is used in NaNbO3-based lead-free ceramics, which usually shows complex oxygen octahedron tilt information inherited from NaNbO3. The substitution of Ba(Fe0.5Nb0.5)O3 and BaTiO3 with high tolerance factor into NaNbO3 leads to a gradual elimination of anti-parallel cation displacement and anti-phase tilt along the three axes; as a result, a single tetragonal phase with P4bm space group and only in-phase tilt along c axis is achieved in 0.88NaNbO3–0.04Ba(Fe0.5Nb0.5)O3–0.08BaTiO3 ceramic. Accompanying the decreased oxygen octahedral tilt degree, a drastically improved d33 up to 367 pC N−1 (over ten times that of NaNbO3 ceramic) is obtained, reaching a record high in NaNbO3-based lead-free ceramics. Together with temperature insensitive piezoresponse originating from thermally stable oxygen octahedral tilt structure, the studied NaNbO3-based materials show large potential for replacing Pb-based ceramics in some electronic devices. The oxygen octahedron tilt engineering would be used for designing more high-performance lead-free ceramics with high piezoresponse and excellent thermal stability simultaneously.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
KEY ENGINEERING MATERIALS
·
2014
·
IF 0
Li Min Qian,Jie Zhou,Chu Zheng,Di Chen,Bi Shen,Yong Kun Liu,Li Xiao Wang,Yan Hua Tong
Cu2O, a p-type semiconductor, has broad potential applications, especially as a visible-light photocatalyst. This paper presents a simple water-bath reflux to prepare Cu2O micro/nanoparticles. The morphology evolution from intact octahedrons to surface-pitted spheres was obtained by adjusting reducing agent and additive. Reflectance spectra show similar photo-absorption intensity and the same range from 250 nm to 650 nm. However, they perform different photocatalytic activity. Intact octahedron has the best photodegradation ability and next is vertex-and edge-damaged octahedron, the lowest for vertex-free polyhedrons and surface-pitted spheres. The enhanced photocatalytic activity for intact octahedrons should to be attributed to its surface characteristics of high index. Our study not only provides a simple method for controllable preparation of Cu2O micro/nanoparticles with different morphologies but also confirms the effect of morphologies on photocatalytic activity.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
Materials Today Chemistry
·
2024
·
IF 6.7
Yifei Chen,Zhihui Qian,Qin Zhu,Ling Xia,Wei Bai,Mingwu Xiang,Yujiao Guo,Shulei Chou,Ping Ning,Junming Guo
Rapid capacity fade of spinel LiMn 2 O 4 cathode material limits the application of lithium-ion batteries. Herein, the introduction of La/B elements achieves the dual-modification of surface coating and single-crystal truncated morphology, ensuring the compatibility of rate capability and cycling stability. The La and B introduction enables the in situ formation of LaBO 3 coating layer. Both the LaBO 3 coating and truncated morphology prevent the direct exposure of the cathode to the electrolyte, decreasing the Mn dissolution and providing the additional Li + diffusion channels. The increase of La and B modification partially restrains the development of {110} crystal planes. The refinement manifests that the La 3+ /B 3+ doping partially replaces Mn 3+ of the LiMn 2 O 4 , inhibiting the Jahn-Teller effect and stabilizing the [MnO 6 ] skeleton. Consequently, the optimized LiMn 2 O 4 @0.04LaBO 3 with the favorable LaBO 3 coating thickness and two truncated octahedrons exhibits the excellent electrochemical properties at high current rate. The first discharge capacities of 109.1, 104.2 and 96.9 mAh⋅g −1 are obtained, whilst the capacity retentions of 64.8 % (after 2000 cycles), 65.8 % (after 2000 cycles) and 80.5 % (after 1000 cycles) can be maintained at 5 C, 10 C and 20 C, respectively. Even at 5 C and 55 °C, the high initial discharge capacity of 113.6 mAh⋅g −1 and good cycling lifespans can be achieved. This modification strategy provides valuable insight for preparing the advanced LiMn 2 O 4 cathode materials for lithium-ion batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Cheng Yu Xu,Shu Yi Ma,Tian Yuan Dong,Ji Ming Liu,Jin Sha Wei,Hong Tao Jiang,Ping Ni,Ge Ge Fan,Jia Yun Guo
Triethylamine (TEA) is typical hazardous volatile organic gas (VOCs), it is particularly important for us to effectively detect triethylamine in complex places. In this work, high efficiency triethylamine gas sensor based on SmVO 4 was successfully obtained by means of hydrothermal reaction and assisted calcination. Characterization of analytical materials, SmVO 4 octahedral nanoparticles formed clusters similar to pomegranate fruits. There is a trace +4 valence state of vanadium in the material, which contributes to the oxidation-reduction reaction between the target gas and the surface of the material. Gas sensitive test results found that the SmVO 4 sensor still has a 2.45 response to the target gas (triethylamine) at low concentrations (1 ppm). SmVO 4 shows excellent selectivity for triethylamine, with a response value more than three times that of other gases. In 25 days, it shows excellent stability and fast response recovery time (15 s/40 s). In addition, the gas sensing mechanism is analyzed.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
ACS Applied Electronic Materials
·
2021
·
IF 3.314
Xiu Li,Chen Chen,Faqiang Zhang,Hanliang Fang,Xintang Huang,Zhiguo Yi
Developing photostrictive materials with wide visible light response and desirable photostriction strength remains a great challenge in view of practical applications. Ferrites with rich physical and chemical properties have great potential in this regard. Here, the photostrictive performances of three ferrite materials, CdFe2O4, CaFe2O4, and YFeO3, with different crystal structures are systematically investigated. A large photostriction around 0.1% with a decent photostrictive efficiency of ∼10–11 m3/W is obtained for all the three ferrites under 405, 520, and 655 nm laser illumination. Further investigation reveals that the photothermal effect-induced expansion and the light-induced nonthermal part contribute almost equally to the measured shape deformation. In situ X-ray diffraction with external laser illumination in conjunction with the laser power-dependent Raman spectra analysis indicates that the strong photostriction is not a uniform deformation microscopically, which is closely related to the various degrees of response of the lattice planes to light and mainly attributed to the light-induced distortion of FeO6 octahedrons. Further analysis suggests a bond length rule to account for both the difference between their photostrictive performances and the screening of materials.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Yu Yan,Rongzun Zhang,Yadong Yu,Zhimei Sun,Renchao Che,Bin Wei,Alec P. LaGrow,Zhongchang Wang,Wei Zhou
It remains a great challenge to balance the activity and stability of platinum and Pt-based hydrogen evolution reaction (HER) catalysts in alkaline electrolyte. Herein, two-dimension monolayer Ti 3 C 2 MXene sheets were introduced to support PtNi octahedrons (PtNi@Ti 3 C 2 MXene), which optimizes the activity and stability of PtNi nanoparticles (NPs) through interface interactions between PtNi and Ti 3 C 2 MXene. It shows a small overpotential of 36 mV with a Tafel slope of 59 mV dec −1 at 10 mA cm -2 in 1 M KOH. It also exhibits excellent mass activity of 6.31 mA μg Pt -1 at an overpotential of 70 mV, which is ∼7.1 times that of commercial Pt/C and better than many recent reported Pt-based alkaline HER catalysts. Meanwhile, the PtNi@Ti 3 C 2 MXene gives an increased overpotential of ∼4 mV while the PtNi gives ∼25 mV during a long-time continuous CV cycles. A series of characterizations disclose these interfaces could promote the stability by alleviating the Ni atoms dissolution from surficial PtNi through uniformly lattice strain dispersion of PtNi. Simultaneously, they could keep the activity by interfacial electron transfer from PtNi to Ti 3 C 2 MXene demonstrated both by experimental tests (UPS, electrostatic potential and charge density distribution) and DFT calculation. It could decrease the energy barrier of H 2 O adsorbing and dissociating into hydrogen intermediates, further accelerating the recombination of hydrogen intermediates to H 2 . Under acidic and neutral medium, the electrocatalyst also exhibits improved HER performance compared to its counterparts. This work provides an interface optimization route for developing high-efficiency pH-universal especially alkaline HER electrocatalysts.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Nano Research
·
2015
·Vol. 8
·期 6
·2115-2123
·
IF 7.01
Long Ran,Wu Di,Li Yaping,Bai Yu,Wang Chengming,Song Li,Xiong Yujie
Heterogeneous catalysis occurs through a process of interfacial reactions; therefore, both surface facet and size control can increase catalytic efficiency. Octahedral Pd nanocrystals, enclosed by {111} facets, should be the ideal geometrical shape for Heck coupling reactions; however, it is challenging to synthesize 5 nm Pd octahedrons with a relatively uniform size distribution using existing capping-agent techniques. Here, we used palladium as a model system to investigate how the kinetics of atomic addition could be precisely controlled using a syringe pump. As a result, our method produced Pd octahedrons as small as 5 nm, which increased the catalytic efficiency of Heck coupling reactions while reducing the weight of catalyst used.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
APL Materials
·
2020
·Vol. 8
·期 6
·
IF 3.819
Li Xiu,Chen Chen,Zhang Faqiang,Huang Xintang,Yi Zhiguo
Photostrictive effect that has been discovered for over half a century is getting renewed interest in recent years in view of the great potentials for optomechanical applications. Ferroelectric materials represented by lead lanthanum zirconated titanate have been widely studied in this field because of their relatively large photostriction and fast photoresponse, but their wide bandgaps with limit response to visible light hinder further practical application. Here, visible-light-driven photostrictions of the order of 10 −3 are discovered in Bi(Ni 2/3 Nb 1/3 )O 3 –PbTiO 3 (BNNPT) ferroelectric solid solutions. Three BNNPT compositions with different phase structures, exhibiting notably different piezoelectric and photovoltaic properties, are selected to conduct the photostriction investigation, and their analogous photostrictive behaviors contradict with previous acknowledgment that the photostriction of ferroelectrics originates from the photovoltage-induced inverse piezoresponse. The nonuniform shifts of the XRD diffraction peaks under external laser illumination and the redshifts of the laser power dependent Raman modes disclose that the photostriction is mainly attributed to the light-induced distortion of BO 6 octahedra. This study sheds insight into the mechanism of the photostriction of ferroelectrics.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Jingtong Xie,Congmian Zhen,Lu Liu,Li Ma,Denglu Hou,Hanqing Pang,Dewei Zhao
A series of FeCo 2 O 4 powders was initially synthesized using a hydrothermal method and subsequently calcined at various temperatures to produce the final product. Pure phase FeCo 2 O 4 powders can only be formed in the temperature range of 950–1050 °C. In this work, we study the cation occupation, cation valence, bond length and bond angle changes of the pure phase FeCo 2 O 4 powders formed in such a narrow temperature range. Octahedral lattice distortion in the pure phase FeCo 2 O 4 samples has been observed. More tetrahedral Fe 3+ and octahedral Co 2+ are excited and exchanged their sites as the calcination temperature increases from 950 °C to 1000 °C, and part of Co 3+ ions are reduced to Co 2+ in the sample calcined at 1050 °C. The structure of the sample calcined at 1000 °C is close to that of the ideal FeCo 2 O 4 spinel. Magnetic measurements show that ferrimagnetism and anti-ferromagnetism coexist in the pure phase FeCo 2 O 4 samples. Interaction changes between ferrimagnetism and antiferromagnetism caused by the structural changes of the samples have been studied. Due to the pinning of the local anti-ferromagnetism to ferrimagnetism in the sample, the sample shows a Barkhausen jump below 150 K. As the measurement temperature increases further, the system enters into a reentrant spin glass state.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2021
·Vol. 14
·期 19
·5534
·
IF 3.623
Wen Jiang,Liwei Cheng,Jianghui Gao,Shiyu Zhang,Hao Wang,Zhihao Jin,Zhongfeng Tang,Cheng Peng
Substantial effort has been devoted to fabricating nanocrystalline lanthanum ferrite (LaFeO3), and calcination is the crucial process of crystallization in both high-temperature strategies and wet chemical methods. Lowering the calcination temperature gives the ability to resist the growth and agglomeration of nanoparticles, therefore contributing to preserve their unique nanostructures and properties. In this work, we prepared crystalline LaFeO3nanoparticles with a calcination process at 500 °C, lower than the calcination temperature required in most wet chemistry methods. Correspondingly, the experimental conditions, including stoichiometric ratios, pH values, precipitants, complexant regent, and the calcination temperatures, were investigated. We found that the crystalline LaFeO3was formed with crystalline NaFeO2after calcination at 500 °C. Furthermore, the structure of FeO6octahedra that formed in coprecipitation was associated with the process of crystallization, which was predominantly determined by calcination temperature. Moreover, an illusion of pure-phase LaFeO3was observed when investigated by X-ray diffraction spectroscopy, which involves amorphous sodium ferrite or potassium ferrite, respectively. These findings can help prepare nanostructured perovskite oxides at low calcination temperatures.Keywords:crystalline LaFeO3nanoparticles;coprecipitation;calcination;FeO6octahedra;perovskite
研究领域:
材料科学
·
纳米技术
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）