International Journal of Applied Ceramic Technology
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2023
·
IF 2.1
Xinzhu Gan,Bin Tian,Zhigang Wang,Yong Xu,Ling Li,Lin Wang,Chonghe Xu
This study aimed to prepare YAlO 3 fibers doped with 2 mol% Er 3+ using electrospinning and a carbon-free sol system as the precursor. X-ray diffraction, thermal gravimetry and differential thermal analysis, and Fourier transform infrared were employed to characterize the thermal behavior and crystallization process of the precursor fibers. Scanning electron microscope analysis showed that the Er 3+ :YAlO 3 fibers had a uniform diameter of 1 μm, a dense and crack-free surface, and a non-porous cross-section. Upon excitation at 450 and 488 nm, upconverted luminescence spectra were obtained from the Er 3+ :YAlO 3 fibers. This observation indicates their potential as upconversion luminescent agents capable of converting visible light into ultraviolet light. These properties make the Er 3+ :YAlO 3 fibers promising candidates for various upconversion luminescence applications.
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高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Linjing Qiao,Jianqiang Bi,Yao Yang,Guandong Liang,Shaoyin Wang,Hongyi Wang
Nowadays, the increasingly severe electromagnetic (EM) wave pollution requires high-performance EM wave absorbing materials. Multi-principal-element materials are acknowledged as promising for broadening the applications owing to their tunable chemistries and structures in many fields, including as EM wave absorbers. Herein, we prepared a high-entropy MXene , (Mo 0.25 Cr 0.25 Ti 0.25 V 0.25 ) 3 C 2 T x . Furthermore, multi-principal-element (Mo 0.25 Cr 0.25 Ti 0.25 V 0.25 ) 3 C 2 T x /FeCoNi and (Mo 0.25 Cr 0.25 Ti 0.25 V 0.25 ) 3 C 2 T x /FeCoNiCu composites were synthesized via an in-situ hydrothermal process by combining high-entropy MXene with medium-entropy magnetic alloys . In contrast with the relatively narrow effective absorption bandwidth (EAB) of (Mo 0.25 Cr 0.25 Ti 0.25 V 0.25 ) 3 C 2 T x MXene (2.56 GHz), (Mo 0.25 Cr 0.25 Ti 0.25 V 0.25 ) 3 C 2 T x /FeCoNi composite with 50 wt% MXene can attain an optimum EAB of 4.88 GHz with the matching thickness of only 1.73 mm. As for (Mo 0.25 Cr 0.25 Ti 0.25 V 0.25 ) 3 C 2 T x /FeCoNiCu composites, both the absorption efficiency and absorption bandwidth are significantly enhanced. The combination of multi-principal-component strategy and composite construction endows the composites with synergistic dielectric and magnetic losses, optimized impedance matching as well as enhanced attenuation ability, thus improving EM wave absorption performances. In addition, radar cross section (RCS) simulation confirms that the prepared composites have broad application prospects as radar stealth materials.
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高影响因子
RARE METALS
·
2023
·Vol. 42
·期 11
·3829-3838
·
IF 8.8
Liu Xue-Feng,He Jiang-Feng,Li Ya-Ge,Li Hang,Lei Wen,Jia Quan-Li,Zhang Shao-Wei,Zhang Hai-Jun
Porous SiC ceramics (PSCs) are promising lightweight and efficient thermal insulators that can evade infrared detection by reducing the surface temperature of the protected object, which plays a crucial role in the development of new military equipment. However, the controllable synthesis of PSCs with both hierarchical pore structure and thermal/mechanical stability remains challenging. In this work, such PSCs were prepared by a facile foam-gelcasting/solid-state reaction method, using silicon powders and glucose-derived carbon as starting materials. The favorable dispersibility and wettability of hydrophilic carbon microspheres and the in-situ formed SiC guarantee the highly porous structure (92.8% porosity), comparable bulk density (0.20 g·cm −3 ) and reasonable mechanical property of the product. The designed PSCs performed outstanding high-temperature performance, especially thermal insulation in both oxidizing and inert atmospheres. More importantly, the composite architecture of PSCs and low emissivity layer (Al foil) exhibited desirable infrared stealth property (at a temperature up to 1100 °C), significantly extending the operating temperature range of thermal camouflage material. The unique combination of excellent properties would make PSCs a potential candidate material for future thermal protection and infrared stealth applications in an extreme environment. Graphical abstract
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SOLID STATE SCIENCES
·
2023
·
IF 3.5
Guang Yang,Hengwei Yan,Zhanwei Liu,Wenhui Ma,Shenghui Guo,Yonghui Yang
In this study, aluminothermic reduction and molten salt electrolysis were combined to prepare titanium powder. In this combined method, titanium dioxide was first deoxidized to produce titanium–aluminum alloy through an aluminothermic reduction reaction, and then the titanium–aluminum alloy was separated through chloride molten salt electrolysis to generate titanium powder. The obtained titanium powder, titanium aluminum alloy and slag was analyzed using several techniques, including X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy. A mass ratio of 2:3 of titanium dioxide and aluminum was suitable for the production of titanium–aluminum alloys. A large amount of alumina generated through the aluminothermic reduction reaction was separated into slag phases using cryolite. Then, the phases were electrolyzed into aluminum and cryolite, which were reused as raw materials. The final titanium–aluminum alloy product was electrolyzed in a chloride molten salt system to separate titanium and aluminum and produce titanium powder. Therefore, the combination of thermal reduction and molten salt electrolysis is efficient and has great potential for producing high-purity titanium powder.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Huanhuan Zhang,Qunying Sun,Linyan Bian,Qiuming Peng,Shumin Han,Baozhong Liu,Yanping Fan
Developing noble-based catalysts with high activity is the key to realizing high-efficiency hydrogen generation. Herein, PdRh alloys with different ratios supported on active Ti 3 C 2 is designed by microwave-assisted reduction to enhance the dissociation of NH 3 BH 3 and H 2 O. Specially, Pd 1 Rh 4 /Ti 3 C 2 conveys an optimal turnover frequency ( TOF ) of 338 min −1 and activation energy ( E a ) of 33.8 kJ mol −1 at room temperature. The TOF of Pd 1 Rh 4 /Ti 3 C 2 is 7.3 times than that of Pd/Ti 3 C 2 and 4.8 times of Rh/Ti 3 C 2 because of the construction of dual-active sites of PdRh alloy and active Ti 3 C 2 . The introduction of a small number of Pd changes the chemical environment of catalysts and presents significant excitation effect on catalytic activity. Experimental investigation reveals PdRh alloy and active Ti 3 C 2 are beneficial for the adsorption and dissociation of NH 3 BH 3 and H 2 O (active Ti 3 C 2 activates H 2 O, PdRh activates NH 3 BH 3 ). This research provides experimental foundation for the design of noble-based catalysts with high catalytic activity.
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JOURNAL OF ALLOYS AND COMPOUNDS
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2023
·
IF 6.2
Jiaqi Wang,Xin Ding,Tongtong Gao,Huiling Zheng,Xuejiao Wang,Qiushi Wang,Cailong Liu
Due to the characteristics of non-contact, high sensitivity and spatial resolution, nanoscale optical thermometry is necessary in many applications such as micro/nano electronics, integrated optics and biomedicine. Herein, we report the synthesis of Nd 3+ /Yb 3+ co-doped AlN (AlN:Nd 3+ /Yb 3+ ) nanorods using an arc discharge method and investigate their phase, composition and morphology using XRD, Raman, XPS, EDS, ICP, SEM and TEM. The nanorods with rectangular cross-section are highly single crystalline and have a uniform smooth surface. Upon excitation at 980 nm, AlN:Nd 3+ /Yb 3+ nanorods exhibit up-conversion (UC) visible emission bands (around 544, 595 and 667 nm) and near-infrared emission bands (around 755 and 806 nm), which correspond to intra-4f electron transitions of the Nd 3+ ions. Later, the temperature dependence of UC luminescence behavior was systemically studied using luminescence intensity ratio (LIR) technique. It was verified that LIRs with non-thermally coupled levels ( 4 G 7/2 / 4 F 5/2 or 4 G 7/2 / 4 F 7/2 ) are suitable for temperature sensing. The maximum relative sensitivity based on 4 G 7/2 / 4 F 7/2 is 4.63% K −1 at 298 K, which is one of the highest values reported for optical thermometers. This work provides an efficient method for synthesizing wide-band gap semiconductors with doped size-mismatched functional atoms that can be used for high-sensitivity optical thermometry.
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Advanced Science
·
2023
·Vol. 10
·期 31
·2303815
·
IF 15.1
Junli Ma,Zhenzhen Guo,Xu Han,Heng Lu,Kaixin Guo,Jianguo Xin,Chaoyong Deng,Xianbao Wang
Water evaporation is a ubiquitous and spontaneous phase transition process. The utilization of solar-driven interface water evaporation that simultaneously obtains clean water and power generation can effectively alleviate people's concerns about fresh water and energy shortages. However, it remains a great challenge to efficiently integrate the required functions into the same device to reduce the complexity of the system and alleviate its dependence on solar energy to achieve full-time operation. In this work, a multifunctional device based on reduced graphene oxide (RGO)/Mn 3 O 4 /Al 2 O 3 composite nanomaterials is realized by an asymmetric strategy for effective solar-thermal-electro integration that can induce power generation by water evaporation in the presence/absence of light. Under one sun irradiation, the solar-driven evaporation rate and output voltage are 1.74 kg m −2 h −1 and 0.778 V, respectively. More strikingly, the nine-grid evaporation/power generation array integrated with multiple devices in series has the advantages of small volume, large evaporation area, and high power generation, and can light up light-emitting diodes (LEDs), providing the possibility for large-scale production and application. Based on the high photothermal conversion efficiency and power production capacity of the RGO/Mn 3 O 4 /Al 2 O 3 composite evaporation/generator, it will be a promising energy conversion device for future sustainable energy development and applications.
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PubMed
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2021
·
IF 5.302
Juan Jiang,Na Ni,Weiwei Xiao,Xiaofeng Zhao,Fangwei Guo,Xiaohui Fan,Qi Ding,Wei Hao,Ping Xiao
Ceramic electrospun nanofibrous membranes (ENMs) are ideal candidates for ultrafiltration applications in harsh environments. However, it has been a great challenge to fabricate ceramic ENMs with sufficient strengths to withstand the water pressure duo to their intrinsic brittleness . In this study, we report an ultra-strong Y 3 Al 5 O 12 -Al 2 O 3 ENM employing graphene oxide (GO) as a sacrificing additive for the first time. The optimized membrane exhibits tensile strengths of 5.63 ± 0.31 MPa after sintering at 900 °C and 3.48 ± 0.44 MPa at 1000 °C. The high strength of the membrane ensures it to be used independently under a pressure up to 160 K Pa. An excellent nano-particle filtration performance is achieved with a high permeation flux of 5718–8494 L m −2 h −1 bar −1 and high rejection efficiencies above 99.75 % in both neutral and acidic water conditions. The work demonstrates a facile route for effective strengthening of ceramic ENMs with their great potential in harsh-environment self-standing ultrafiltration applications.
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MATERIALS CHEMISTRY AND PHYSICS
·
2021
·
IF 4.094
Faqiang Shi,Limeng Liu,Jiandong Wu,Junfeng Hou,Yujin Wang
TaC x (x = 0.5, 0.55, 0.6 and 0.7) ceramics with 20 mol% Al addition were prepared by hot pressing TaC, Ta and Al powder mixtures. Effects of the overall C:Ta ratios and the Al addition on constituent phases, microstructures and mechanical properties of the consolidated materials were examined. Results showed that O impurity contained in the starting powders was collected in form of Al 2 O 3 due to strong affinity of O with Al. The TaC x -Al composites were easy to densify due to presence of molten Al at its melting point ( T m = 660 °C) and a transient Al–Ta eutectic liquid at higher temperatures. After densification, the metallic liquids were eliminated ultimately by formation of refractory Ta 4 AlC 3 via reaction of Al, Ta and TaC. Reactions between the remnant Ta and TaC after Ta 4 AlC 3 formation resulted in ζ-Ta 4 C 3-z or h-Ta 2 C depending on the initial C:Ta ratio. The Ta 4 AlC 3 compound was compatible with the tantalum carbides. Microstructures of the TaC x -Al (x = 0.5–0.7) composites were consisted of ζ-Ta 4 C 3-z and Ta 4 AlC 3 fine lamellar grains to benefit the mechanical properties of the composites. The TaC 0.7 –20mol% Al composition had satisfying mechanical properties (flexural strength 613 ± 28 MPa and fracture toughness 11.2 ± 0.8 MPa m 1/2 ). TG-DSC evidenced an increase in oxidation resistance of the TaC x ceramics by the addition of 20 mol% Al.
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Materials Today Physics
·
2021
·
IF 9.298
Y. Wu,D. Lei,C. Wang
Lithium metal has been regarded as an ideal anode to meet the rapidly growing requirements on high energy density batteries , owing to their highest gravimetric capacity and their lowest redox potential . However, lithium metal batteries persistently suffer from serious issues, such as the unstable solid electrolyte layer and uncontrolled dendrite growth during plating/stripping, especially under high current density . Herein, we developed an innovative method to prepare dense LiAl 5 O 8 nanowires membrane and designed a LiAl 5 O 8 nanowires membrane/poly (vinylidene fluoride-co-hexafluoropropylene)-based gel polymer composite electrolyte (LPH-GPE) to address these issues. On the interface of LPH-GPE and lithium anode, uniformly dispersed aluminum is in situ generated by reducing LiAl 5 O 8 nanowires, which brings both superlithiophilic sites and uniform lithium ion flux, and thus enables the lithium ion depositing in plates rather than forming sharp lithium dendrites . The solid-state lithium/lithium symmetric cells with LPH-GPE exhibit significantly improved lifespan at 0.5 mA cm − 2 and short-circuit does not occur even at current density up to 4 mA cm − 2 .
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高影响因子
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
·
2021
·
IF 5.234
Xiaoping Cai,Xuanru Ren,Changcheng Sang,Lu Zhu,Zhoujun Li,Peizhong Feng
To meet the requirements of energy-efficiency and high quality joining in the emerging industries field, a novel thermal explosion (TE) joining method was developed. The dissimilar Ni/316SS joint was first obtained by the TE reaction technology. The Ni-Al mixed powder was selected as TE reaction system, and the reaction product was used as interlayer. The effect of temperature (800, 850 and 900 °C), hold time (5, 10, 15 and 20 min) and joining pressure (0, 10, 20 and 30 MPa) on interfacial microstructure, diffusion behavior and mechanical properties of Ni/316SS joint were investigated. The maximum combustion temperature of Ni-Al interlayer during heating process was 1655 °C and a significant exothermic phenomenon was lasted for 2 s. 316SS(Al), Fe 2 Al 5 (Ni, Cr) and serration-like Ni 5 Al 3 and Ni 3 Al were detected at the interface containing a reaction layer because of element diffusion. The maximum shear strength of the Ni/316SS joint was 65.2 MPa, and the failure is characterized by typical brittleness fracture. The fracture mode is the combination of partial spalling and fracture of the interlayer. The post heat-treatment assisted TE joining technique significantly shortened the bonding process of the dissimilar Ni/316SS joint at moderate temperatures, realizing the low energy and efficient joining between Ni and 316SS.
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Journal of Materials Chemistry A
·
2021
·Vol. 9
·期 8
·5016-5025
·
IF 12.732
Lin Yang,Dongxiao Kan,Chunxiang Dall'Agnese,Yohan Dall'Agnese,Baoning Wang,Ajay Kumar Jena,Yingjin Wei,Gang Chen,Xiao-Feng Wang,Yury Gogotsi,Tsutomu Miyasaka
The unique properties of MXenes that arise from terminating functional groups and oxidation of MXenes make them attractive for application in photovoltaic devices like perovskite solar cells (PSCs). Here, oxidation of Ti3C2Tx hydrocolloid was carried out to tune its properties desirable for an electron transport layer (ETL) in low-temperature processed PSCs. The calculations of the energy levels were carried out using the Vienna ab initio simulation package (VASP) code based on density functional theory (DFT). Oxidation of Ti3C2Tx can generate Ti–O bonds and effectively reduce the macroscopic defects of the film fabricated by spin-coating, while a transition from metallic material to semiconductor occurred after heavy oxidation. A better matching of energy levels between perovskite and ETL layer in the case of a hybrid of oxidized and pristine Ti3C2Tx renders a champion power conversion efficiency (PCE) of 18.29%. The improvement in PCE can be attributed to the increased electron mobility in the ETL, which promotes electron transport and reduces the electron–hole recombination. Hence, by presenting a simple method for high performance in PSCs by MXene-derived materials, this work demonstrates the great potential of these materials for applications in low-temperature processed PSCs and other photovoltaic technologies.
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高影响因子
危险品化学品经营许可证（带存储）