Nano Energy
·
2019
·
IF 15.548
Zirui Lou,Dachao Yuan,Fengyu Zhang,Yichen Wang,Yaguang Li,Liping Zhu
CO oxidation is one of the most important catalytic reactions and it has to be run at relatively high temperature. Photothermal catalysis system could convert light as heat to drive CO oxidation rather than their conventional counterparts that use only thermal stimulus. But the light intensity required in this photothermal catalysis system is much higher than the solar intensity, restricting the application of photothermal CO oxidation. Here we present a Fe 3 Si based photothermal converted system to assist Co 3 O 4 rhombus-shaped nanorods catalysts for achieving efficient photothermal CO oxidation just under weak solar irradiation . Based on photothermal experiments, we conclude that Fe 3 Si based photo-thermal converted system can convert 0.3–0.35 kW m −2 solar irradiation into a temperature as high as 160 °C, 3 times higher than existing photothermal catalytic systems , which able to excite the activity of Co 3 O 4 rhombus-shaped nanorods for complete CO oxidation, solely irradiated by third of standard solar light and outdoor sunlight. The results suggested that the photothermal CO oxidation can be driven by ambient solar irradiation in the presence of Fe 3 Si based photothermal system and Co 3 O 4 rhombus-shaped nanorods, facilitating for industrial applications.
研究领域:
催化
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材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2018
·Vol. 6
·期 28
·7661-7670
·
IF 5.976
Yongzhao Hou,Bo Xiao,Guowei Yang,Zhiyuan Sun,Wen Yang,Songsong Wu,Xiaoxiao Huang,Guangwu Wen
Tunable electromagnetic properties and excellent thermo-stability are important criteria while choosing absorbers. Here, carbon-coated Fe3Si nanoparticles in amorphous SiCO ceramics (SiCO/C/Fe3Si) were successfully obtained via polymer-derived ceramics (PDC) from ferric acetylacetonate modified-polysilylacetylene (PSA). By adjusting the magnetic components, the structure of the absorbers could be tuned and their bandwidth varied. The absorbers with a hybrid composition (4.35 wt% Fe) possessed a minimal reflection loss (RL) of −32 dB at 9.2 GHz with a thickness of 3.5 mm and an effective bandwidth (RL < −10 dB) of about 3.6 GHz. The absorbers (12.33 wt% Fe) were enhanced and the minimal RL value was close to −41 dB at 7.9 GHz with a thickness of 3.5 mm. Simultaneously, a broad bandwidth (RL < −5 dB) appeared and covered nearly the whole S-band (2–3.95 GHz) where the RL value reached −10 dB at 2 GHz. After the second thermal treatment under 1000 °C, the minimal RL value of the absorbers (12.33 wt% Fe) remained at −33 dB at 6.6 GHz with a thickness of 4 mm, while the effective bandwidth was 3.4 GHz with a thickness of 3 mm. In addition, the formation mechanism of carbon-coated Fe3Si, which possibly resulted from the mesophase SiCFe alloy was also discussed. The as-prepared SiCO/C/Fe3Si hybrid exhibits outstanding wave absorption ability and present a huge potential for the application at high temperatures.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Ali Reza Kamali,Haoyu Zhao
Natural graphite mineral (NGM) is an abundant and low-cost carbon source with the potential of being employed as the precursor for producing high-quality carbon nanostructures for energy storage applications. In this article, one-pot electrochemical conversion of NGM into graphitic carbon nanostructures incorporated with Fe 3 Si nanocrystals with enhanced bulk electrical conductivity and Li-ion storage performance is reported. To this end, electrodes made of NGM are negatively polarized in molten LiCl-NaCl at 740 °C under various cathode current densities. At 1 A cm −2 , the high-yield conversion of the mineral into carbon nanotubes (CNTs), nanofibers and onion-like carbon nanoparticles is realized. The product exhibits a specific electrical conductivity of 9.83 S m 2 g −1 , and the Li + transfer resistance of 24 Ω. The Li-ion storage capacity of the material is evaluated to be high at 382 mAh g −1 after 220 Li-ion insertion and extraction cycles under the current density of 200 mA g −1 , making the material an attractive low-cost candidate for the anode of lithium ion batteries . The ferromagnetic behavior of the nanostructured Fe 3 Si incorporated carbon is characterized by the saturation magnetization of 11.1 emu g −1 , potentially promoting the recyclability of spent anode material . This article reports on the green and low-cost conversion of NGMs into nanostructured carbon materials with enhanced Li-ion storage performance.
研究领域:
材料科学
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能源科学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Yurun Feng,Xue Guo,Junbin Lu,Jie Liu,Guantong Wang,Hongyu Gong
The SiCN(Fe) fibers with excellent one-dimensional microstructure and electromagnetic wave (EMW) absorption performance were synthesized by combining polymer-derived ceramics (PDCs) method and electrospinning. The in-situ generation of Fe 3 Si and CNTs by adding ferric acetylacetonate (FA) into the raw materials effectively improved the dielectric properties , magnetic properties and the impedance matching performance of the SiCN(Fe) fibers. The EMW absorption performance of SiCN(Fe) fibers were mainly based on dipole polarization loss, interface polarization loss and eddy current loss. The RL min value of SiCN(Fe) fibers reached −47.64 dB at 1.38 mm and the effective absorption band (EAB, RL ≤ −10 dB) reached 4.28 GHz (13.72–18 GHz, 1.35 mm).
研究领域:
材料科学
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电磁材料
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Yongzhao Hou,Bo Xiao,Zhiyuan Sun,Wen Yang,Songsong Wu,Shuai Qi,Guangwu Wen,Xiaoxiao Huang
With the rapid development of high power electromagnetic (EM) equipment and high-speed aircraft, the powerful and high oxidation-resistance absorbers are fundamentally desirable for the EM field. Herein, a novel high temperature anti-oxidative SiC/Fe 3 Si/CNTs composite is synthesized by a facile polymer derived ceramic (PDC) route from a Fe-containing polysilyacetylene (PSA). The microstructure of as-prepared SiC/Fe 3 Si/CNTs composite absorber is featured by micro-sized SiC ceramic grains with spherical Fe 3 Si nanoparticles and carbon nanotubes (CNTs) attached to. The vector network analyzer tests show a tunable wave-absorbing performance by adjusting the thickness of layer, and the effective bandwidth (the reflection loss < −10 dB) is 3.3–16.8 GHz for the sample S-1400 (heat treatment at 1400 °C in nitrogen flow). The minimal RL value is −41.2 dB at 10.5 GHz at a thickness of 2 mm and an effective bandwidth is nearly 4 GHz (12.9–16.9 GHz) at the thickness of only 1.5 mm. Moreover, after the oxidation treatment at 800 °C in the air, this absorber maintains the main structure and shows a good high temperature oxidation resistance . This absorber still remains excellent wave absorption property, in view of a minimal RL value of −40 dB at the thickness of 3 mm and a bandwidth of 4.8 GHz (10.4–15.2 GHz) at the thickness of 2.5 mm. The mechanism of high EM wave absorption performance is studied and attributed to the impendence matching, polarization, and the magnetic properties . Thus, the SiC/Fe 3 Si/CNTs composite is a promising EM absorber for high-temperature EM wave-absorbing applications.
研究领域:
材料科学
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电磁工程
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复合材料
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陶瓷
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2019
·Vol. 102
·期 12
·7098-7107
·
IF 3.094
Chong Gu,Changqing Guo,Xichao Dong,Zhiming Hu,Pengfei Wu,Zhiming Su,Yingxi Lu,Binbin Xu,Zhaoju Yu,Anhua Liu
In this work, novel core-shell structured Fe 3 Si@C/SiC/Fe 3 O 4 /SiO 2 nanoparticles were fabricated via a polymer-derived ceramic approach, starting from sol-like polycarbosilane-encapsulated polynuclear carbonyl iron nanoparticles and with pitch as an isolator to avoid aggregation during polymer-to-ceramic transformation. Elemental analysis, X-ray photoelectron spectroscopy, X-ray diffraction, transmission electron microscope, vibrating sample magnetometer and vector network analyzer were employed to investigate the composition, nano/microstructure, morphology, and dielectric/magnetic properties. The results show that the size of obtained Fe 3 Si@C/SiC/Fe 3 O 4 /SiO 2 nanoparticles is in the range of 2-200 nm. And the unique core-shell structure with the hetero-interface combined with simultaneous dielectric and magnetic loss endow Fe 3 Si@C/SiC/Fe 3 O 4 /SiO 2 nanoparticles outstanding electromagnetic (EM) wave absorbing performance. With a sample thickness of 4.5 mm, the minimum reflection coefficient (RC) of the composites Fe 3 Si@C/SiC/Fe 3 O 4 /SiO 2 mixed with paraffin wax reaches −44.7 dB, indicating that more than 99.99% EM waves can be attenuated by the composites. By adjusting the sample thicknesses, the effective bandwidth (the bandwidth of RC values lower than −10 dB) amounts 9.5 GHz (from 2.5 to 12.0 GHz), covering the whole C and X bands.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2022
·Vol. 10
·期 16
·6252-6262
·
IF 8.067
Zhaoju Yu,Qikun Zhu,Fen Li,Ting Chen,Hanzi Du
In the present work, novel single-source-precursors for CNTs/Fe3Si/Fe/SiOCN ceramic nanocomposites were synthesized by the reaction of poly(methylvinyl) silazane (HTT 1800) with ferric acetylacetonate [Fe(acac)3] and carboxylic functionalized carbon nanotubes (CNTs-COOH), which were characterized by means of Fourier transform infrared spectra. The microstructure, phase evolution, electromagnetic properties and electromagnetic microwave absorbing (EMA) performance of the as-prepared ceramics were investigated in detail. The results reveal that the introduced CNTs and the in situ formed nanocrystallites, including α-Fe, Fe3Si, α-Si3N4, β-Si3N4, Si2N2O, and SiC, are dispersed in an amorphous SiOCN matrix after annealing at 900–1500 °C. The obtained ceramic powders mixed with paraffin wax possess a very low minimum reflection coefficient of −65.3 dB and a broad effective absorption bandwidth of 6 GHz (12–18 GHz) with a thickness of 1.6 mm, indicating outstanding EMA performance. This is due to (i) the increase in interfacial polarization caused by the formation of multiple hetero-interfaces and (ii) the synergistic effect of magnetic and dielectric losses. Therefore, the multicomponent CNTs/Fe3Si/Fe/SiOCN ceramic nanocomposites have promising potential for thin and high-performance EMA materials applied in a harsh environment.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Jun Li,Liying Pan,Qiu Zhang,Xueyue Lyu,Xinrui Wang,Jiawei Qi,Guangdong Zhao
SiOC ceramics are recognized for their exceptional chemical stability and favorable dielectric loss properties, making them viable candidates for microwave-absorbing applications. Nonetheless, the reliance on a singular loss mechanism limits their effectiveness in achieving efficient wave absorption. In this study, we introduce the SiFeBOC ceramic, which integrates Fe 3Si spheres and SiO 2 nanowires through a straightforward sol-gel method combined with a polymer-derived ceramic technique to incorporate magnetic particles into SiOC ceramics. The resulting material exhibits multiple loss mechanisms, including interfacial polarization, dipolar polarization, conduction loss, natural resonance, and eddy current loss, which collectively enhance its wave-absorbing capabilities. At a thickness of only 1.9 mm, the SiFeBOC ceramics achieve a minimum reflection loss (RL min ) of -47.96 dB and an effective absorption bandwidth (EAB) of 3.25 GHz. Additionally, a broader bandwidth of 4.39 GHz is achieved at a reduced thickness of 1.6 mm, with an RL value of -44.54 dB and an EAB of 4.05 GHz at 1.5 mm. The reflection loss per unit thickness (RL/t) reaches a minimum value of -29.69 dB/mm, while the effective absorption bandwidth per unit thickness (EAB/t) achieves a minimum of 2.74 GHz/mm. Furthermore, radar scattering cross-section (RCS) measurements reveal enhanced radar stealth capabilities compared to a perfect electrical conductor (PEC), with an RCS reduction of 7.72 dB·m 2 at 0° and an RCS min of -53.27 dB·m 2 at 146°. This study demonstrates that SiFeBOC ceramics possess significant potential for use in high-efficiency microwave absorption applications. Furthermore, it offers insights for the advancement of a new generation of microwave-absorbing materials characterized by low profile, broad bandwidth, and thin dimensions.
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产品关联
DOI
高影响因子
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