JOURNAL OF ALLOYS AND COMPOUNDS
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2018
·
IF 3.779
Abdul Basit,Junyou Yang,Qinghui Jiang,Zhiwei Zhou,Jiwu Xin,Xin Li,Sihui Li
Here, the intellectual challenges for thermoelectric materials revolves around the strategy of point defect engineering to regulate the electrical and thermal transport nature of Mn 1.06- x Sn x Te ( x = 0, 0.03, 0.035, 0.04, 0.045) materials. The power factor increases with substitution of Sn into the lattice of Mn 1.06 Te leading to enhance the carrier concentrations due to reduction of the band gap. Meanwhile, the thermal conductivity has also been remarkably reduced due to diverse phonon scattering and mass fluctuation by Sn substitution. As a result, a maximum ZT ∼0.93 for Mn 1.06- x Sn x Te ( x = 0.04) sample has been achieved at 873 K, which increases by 56% in comparison with the un-doped sample.
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高影响因子
Journal of Materials Chemistry C
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2019
·Vol. 7
·期 15
·4459-4465
·
IF 6.641
Yang-Jie Lin,Bin-Wen Liu,Run Ye,Xiao-Ming Jiang,Long-Qi Yang,Hui-Yi Zeng,Guo-Cong Guo
Two new infrared (IR) nonlinear optical (NLO) chalcogenides, SrCdSnQ4 (Q = S and Se) (1 and 2), were obtained by mixing NLO-active metal chalcogenides and d10 metal tetrahedral motifs in an alkali metal-containing system. Their structures are constructed with edge- and corner-sharing CdQ4 and SnQ4 (Q = S and Se) units to form two-dimensional (CdSnQ4)2− layers, between which are embedded with Sr2+. Compounds 1 and 2 have moderate band gaps of 2.05 and 1.54 eV, respectively. They exhibit strong second-harmonic generation intensities that are comparable to that of the benchmark AgGaS2 using a 2040 nm laser. Furthermore, their laser-induced damage thresholds are 10 and 5 times higher than that of AgGaS2, respectively. The strong NLO efficiency of these two compounds can be ascribed to SnQ4 tetrahedra with a synergetic enhancement in the large distortion of CdQ4 tetrahedra, shedding light on the exploration of new IR NLO materials with mixed NLO-active and synergetic distorted motifs.
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高影响因子
Advanced Optical Materials
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2019
·Vol. 7
·期 5
·1800579
·
IF 7.125
Yuting Ye,Yuehui Xian,Jiawen Cai,Kaicheng Lu,Zhengzheng Liu,Tongchao Shi,Juan Du,Yuxin Leng,Rongfei Wei,Weiqi Wang,Xiaofeng Liu,Gang Bi,Jianrong Qiu
Monochalcogenides of group IV elements have been considered as phosphorene analogs due to their similar crystal and electronic structure. Here, few-layer SnSe nanosheets are synthesized by a sonication-assisted liquid phase exfoliation process and their linear and nonlinear optical properties are examined. The as-exfoliated few-layer (FL) SnSe demonstrates layer thickness from 2 to 10 nm and lateral size of 150 nm with high crystallinity. Optical measurement confirms the layer-number dependent bandgap, which is also corroborated by first-principle calculation. In addition, the FL SnSe shows a transition from saturable absorption to reverse saturable absorption with the increase of pumping power, and the nonlinear absorption is characterized by an ultrafast response time of picosecond scale. The nonlinear optical response in FL SnSe could be explained by defect-involved recombination of photogenerated carriers as well as the Auger scattering process, which is further enhanced by structural two-dimensionality.
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高影响因子
CARBON
·
2018
·
IF 7.082
Suhang Chen,Yue Tang,Hongsheng Yu,Xinyan Guan,Luigi T. DeLuca,Wei Zhang,Ruiqi Shen,Yinghua Ye
Hydroxyl-terminated polybutadiene (HTPB) is extensively used in propulsion; however, it's trapped in low regression rate, partly related to poor thermal transfer from combustion. Carbon nanotubes (CNT) act as an energy transfer media, potentially accelerating the heat transfer and combustion performance of HTPB. Herein, multiwall CNT (MWCNT)/HTPB composites were prepared by dispersing MWCNT and surfactant into HTPB and toluene solvent through ball milling . Low MWCNT content (≤1%) promoted combustion, and excess MWCNT (≥2%) depressed, despite MWCNT shifting the HTPB-O 2 reaction to higher temperatures. (0.5%, 1%, 2% and 3%) MWCNT/HTPB composites reinforced the instantaneous regression rate by 11.2%, 31.6%, −21.3%, and −39.7% at Gox = 365 kg/m 2 ·s; by 27.0%, 25.0%, −26.4%, and −36.6% at Gox = 150 kg/m 2 ·s; while strengthened the average regression rate by 0.9%, 8.5%, −17.4%, and −36.7% at Gox = 365 kg/m 2 ·s; and by 5.4%, 8.9%, −8.3%, −22.6% at Gox = 100 kg/m 2 ·s. Specifically, the optimal MWCNT level was 1%, as demonstrated by the optimized reinforced thermal conductivity and slightly reduced energy release, since excessive MWCNT (>2%) hinders combustion through heat dissipation, high viscosity of the melting layer, low energy release and an attached carbon layer on the burning surface blocking the energy transfer.
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高影响因子
ACS Applied Materials & Interfaces
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2018
·
IF 8.097
Wangen Zhao,Fengyang Yu,Shengzhong Frank Liu
The development of Cu2ZnSn(S,Se)4 (CZTSSe) solar cells determines the prospect of thin-film photovoltaic devices because of some of their strengths. However, the usual solution fabrication processes of CZTSSe absorbing layers are either too tedious or highly toxic. Here, we have developed an alternative strategy to prepare kesterite CZTSSe absorber films with a simple and low-toxicity solution process by replacing the commonly employed thiol-based compounds using the glycolic acid aqueous solution, which significantly reduces the environment pollution and toxicity, providing a possibility toward the green solvent process. The power conversion efficiency of 6.81% has been acquired based the aqueous solution-processed CZTSSe thin film via optimizing the fabrication technology.
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PubMed
高影响因子
Materials Today Physics
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2018
·
IF 0
Y. Zhou,H. Wu,D. Wang,L. Fu,Y. Zhang,J. He,S.J. Pennycook,L.-D. Zhao
The ternary diamond-like compound Cu 2 SnSe 3 is a potential thermoelectric material . Its Cu-Se conducting network leaves Sn as a likely doping site to optimize the carrier concentration without much deterioration to the carrier mobility . Thus, the precise determination on the intricate phase structures of Cu 2 SnSe 3 is critical. Here, we first use the atomically resolved scanning transmission electron microscopy and reveal an unusual phase coexistence (monoclinic and orthorhombic phases) in Ag-doped Cu 2 SnSe 3 . Owing to coexisting phases and the order–disorder transition in the orthorhombic phase, the Ag-doped Cu 2 SnSe 3 shows an unusual three-stage behavior in its temperature-dependent electrical transport properties and achieves record high power factors in this system. The observed three-stage behavior due to the phase coexistence is supported by the first principle calculations, Hall measurements, and optical diffuse reflectance measurements . To fully understand the band structures and the coherent interface between these coexisting phases, a band contact model is proposed that could well explain the three-stage electrical transport behavior. Moreover, the phase coexistence is observed at the nanoscale regime, thus providing a high density of phase boundaries. Such coexisting nanophases play an important role in lowering the lattice thermal conductivity . As a result, the ZT value obtained in Cu 2 Sn 0.93 Ag 0.07 Se 3 is double that of undoped Cu 2 SnSe 3 .
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ACS Applied Nano Materials
·
2019
·
IF 0
Fei Luo,Dongya Wang,Jindong Zhang,Xiaona Li,Dongmei Liu,Hai Li,Min Lu,Xiaoji Xie,Ling Huang,Wei Huang
Preparing few-layer black phosphorus flakes, in a scalable, fast, and benign way, is a key step to promote both the fundamental research and practical applications of black phosphorus. Although the electrochemically assisted liquid exfoliation of bulk black phosphorus is a promising strategy, it is still challenging to obtain few-layer black phosphorus flakes in polar protic solvent through cathodic exfoliation. In this work, we demonstrate an ultrafast approach to exfoliate bulk black phosphorus, under a cathodic potential, in an aqueous solution of hexadecyltrimethylammonium chloride. Particularly, the exfoliation can be trigged within ∼20 s, and the obtained flakes exhibit satisfactory quality. Further detailed mechanical explorations reveal that the cathodic intercalation of hexadecyltrimethylammonium cations and their subsequent decomposition contribute to the ultrafast expansion and exfoliation of bulk black phosphorus crystals. In addition, the as-exfoliated flakes show improved stability due to the protection of hexadecyltrimethylammonium chloride. This exfoliation method, together with the findings, should shed light on the development of new exfoliation methods for preparing few-layer black phosphorus flakes in various liquid systems, thus facilitating the future applications of black phosphorus.
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APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Limin Chang,Zheng Yi,Zhaomin Wang,Limin Wang,Yong Cheng
SnO 2 is regarded to be promising for both Li-ion and Na-ion batteries. Thus, it is imperative to fabricate SnO 2 -based anode with improved lithiation reaction kinetics using simple but effective method. Herein, we develop a one-pot hydrothermal route to fabricate two-dimensional SnO 2 nanosheets and the graphene supported SnO 2 nanosheet composite with decreased SnO 2 nanosheet of about 5–10 nm. The ultrathin nanosheet structure anchored on graphene supporting can effectively accelerate the conversion/alloying reaction. Electrochemical researches demonstrate that the reaction kinetics of the lithiation/delithiation reaction can be significantly enhanced by the graphene supported SnO 2 nanosheets. As a result, a capacity of 817.2 mAh g −1 after 100 cycles in the potential window of 0.01 to 3 V are achieved at 500 mA g −1 . The full cell performance and the sodium storage performance are both demonstrated to be good. These promising results suggest that such strategy to fabricate two-dimensional SnO 2 -based anode is of great interest for next-generation Li-ion and Na-ion batteries.
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高影响因子
TRIBOLOGY LETTERS
·
2019
·Vol. 67
·期 3
·1-11
·
IF 2.235
Zeng M. Q.,Hu R. Z.,Song K. Q.,Dai L. Y.,Lu Z. C.
An in situ displacement reaction was used to prepare an Al–12 wt% Sn nanocomposite alloy from mechanically alloyed Al–SnO 2 –MgH 2 . The nanoscaled Sn phase was mostly 30–50 nm in size and was distributed uniformly in the Al matrix. The wear properties of the Al–SnO 2 –MgH 2 composite were enhanced significantly compared to those of an Al–Sn–MgH 2 composite. These improvements stemmed from the high-strength and nanoconfined Sn-phase lubrication, which moved the peak stress far below the surface, released strain localization at the uppermost sliding surface layer, and suppressed cracking and surface roughening. The dispersion strengthening of the Al–SnO 2 –MgH 2 composite favored the maintenance of a stable tribolayer, which resulted in an integrated worn surface and an excellent wear performance.
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高影响因子
ACS Applied Energy Materials
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2019
·
IF 0
Tiancun Liu,Jiulin Hu,Chilin Li,Yong Wang
Li metal anode is deemed the most promising candidate anode for high-energy battery systems such as Li-sulfur and Li-fluoride batteries. However, some severe challenges, for example, facile formation and growth of Li dendrites, large volume evolution of hostless Li ,and low Coulombic efficiency of Li plating/stripping, still hinder the commercialization of Li-metal batteries (LMBs). Herein, a free-standing and highly flexible 3D current collector made of carbon nanofibers (CNFs) conformally coated by continuous Sn layer is synthesized by electrospinning method. Sn layer enables a lithiophilic and alloyable carbon skeleton surface and provides uniform and continuous Li nucleation sites, leading to unusual conformal Li plating behavior and effective inhibition of Li dendrites. The spatial confinement of Li plating mitigates the volume expansion and network distortion of CNFs. The electric contact reinforced by Sn interlayer achieves highly reversible Li stripping for more than 850 h for CNF-Sn@Li symmetric cell. The small nucleation overpotential (28 mV) and potential polarization (14 mV for symmetric cell) benefit from the low energy barrier of Li–Sn alloying and following Li nucleation on Li–Sn layer. For CNF-Sn@Li-LiFePO4 full cell, the capacity retention ratio is as high as 92.2% after 150 cycles at 0. 5C and the reversible capacities are maintained at 134.3 and 106.7 mAh g–1 at 2C and 5C respectively. The design of 3D lithiophilic current collector instead of planar Cu is a potential solution to highly safe LMBs.
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Materials
·
2019
·Vol. 12
·期 9
·1501
·
IF 2.972
Hongdan Zhang,Ludan Zhu,Jun Cheng,Long Chen,Chuanqi Liu,Shuanglong Yuan
In recent years, all-inorganic lead-halide perovskites have received extensive attention due to their many advantages, but their poor stability and high toxicity are two major problems. In this paper, a low toxicity and stable Cs2SnCl6double perovskite crystals were prepared by aqueous phase precipitation method using SnCl2as precursor. By the XRD, ICP-AES, XPS, photoluminescence and absorption spectra, the fluorescence decay curve, the structure and photoluminescence characteristics of Ce3+-doped and undoped samples have been investigated in detail. The results show that the photoluminescence originates from defects. [SnSn4+2++VCl] defect complex in the crystal is formed by Sn2+substituting Sn4+. The number of defects formed by Sn2+in the crystal decreases with Ce3+content increases. Within a certain number of defects, the crystal luminescence is enhanced with the number of [SnSn4+2++VCl] decreased. When Ce3+is incorporated into the crystals, the defects of [Ce3+Sn4++VCl] and [SnSn4+2++VCl] were formed and the crystal show the strongest emission. This provides a route to enhance the photoluminescence of Cs2SnCl6double perovskite crystals.Keywords:lead-free perovskite;Cs2SnCl6;doping;photoluminescence
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PubMed
高影响因子
Aerospace
·
2019
·Vol. 6
·期 4
·47
·
IF 0
Suhang Chen,Yue Tang,Wei Zhang,Ruiqi Shen,Hongsheng Yu,Yinghua Ye,Luigi T. DeLuca
The low regression rates for hydroxyl-terminated polybutadiene (HTPB)-based solid fuels and poor mechanical properties for the alternative paraffin-based liquefying fuels make today hybrid rocket engines far from the outstanding accomplishments of solid motors and liquid engines. In this paper, a survey is conducted of several innovative methods under test to improve solid fuel properties, which include self-disintegration fuel structure (SDFS)/paraffin fuels, paraffin fuels with better mechanical properties, high thermal conductivity fuels and porous layer combustion fuels. In particular, concerning HTPB, new results about diverse insert and low-energy polymer particles enhancing the combustion properties of HTPB are presented. Compared to pure HTPB, regression rate can be increased up to 21% by adding particles of polymers such as 5% polyethylene or 10% oleamide. Concerning paraffin, new results about self-disintegrating composite fuels incorporating Magnesium particles (MgP) point out that 15% 1 μm- or 100 μm-MgP formulations increase regression rates by 163.2% or 82.1% respectively, at 335 kg/m2·s oxygen flux, compared to pure paraffin. Overall, composite solid fuels featuring self-disintegration structure appear the most promising innovative technique, since they allow separating the matrix regression from the combustion of the filler grains. Yet, the investigated methods are at their initial stage. Substantial work of refinement in this paper is for producing solid fuels to fulfill the needs of hybrid rocket propulsion.Keywords:hybrid;regression rate;self-disintegration;HTPB;paraffin;low-energy polymer;magnesium
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