Nanomaterials
·
2019
·Vol. 9
·期 2
·141
·
IF 4.034
Guangzhen Cui,Yanli Lu,Wei Zhou,Xuliang Lv,Jiangnan Hu,Guoyu Zhang,Guangxin Gu
Magnetic nanoparticles, such as Fe3O4and Co3O4, play a vital role in the research on advanced microwave absorbing materials, even if problems such as high density and narrow band impedance matching are still unsolved. Herein, the study of lightweight hollow Fe3O4@reduced graphite oxide (RGO) nanocomposites synthesized via the solvothermal method is presented. The microstructure and crystal morphology of the materials were characterized by X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses. Single crystalline hollow Fe3O4spheres were grown onto RGO flakes, leading to the formation of heterojunction, which further influenced the microwave absorption properties. The latter were evaluated by standard microwave characterization in the frequency range of 2–18 GHz. It was found that, for a specific Fe3O4@0.125 g RGO composite, the minimum reflection loss can reach −41.89 dB at 6.7 GHz, while the reflection loss was less than −10 dB from 3.4 GHz to 13.6 GHz for a nanocomposite sample thickness in the range of 1–4 mm. The combination of these two materials thus proved to give remarkable microwave absorption properties, owing to enhanced magnetic losses and favorable impedance matching conditions.Keywords:microwave absorption;solvothermal;heterojunction;hollow Fe3O4
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Mengxin Liu,Haoran Zhang,Xinmeng Huang,Ziyi Zhang,Kunlai Zhang,Zhenwu Chen,Jintang Zhou,Lei Pan
It is crucial to develop electromagnetic interference (EMI) shielding materials with high shielding efficiency (SE) and reduced reflection to mitigate the secondary pollution caused by electromagnetic waves (EMWs). Herein, a novel multilayer assembly strategy inspired by the structure of “Turkish dessert—Baklava” is proposed to introduce magnetic hollow Fe 3 O 4 nanospheres (HFO) and conductive MXene nanosheets into a bacterial cellulose (BC) network. Through a layer-by-layer vacuum filtration approach, a composite BC/MXene/HFO film with a controllable electric-magnetic dual-gradient structure is achieved. The construction of electric-magnetic dual gradients alleviates the impedance mismatch at the air-film interface, resulting in reduced reflectivity toward EMWs, while the unique hollow structure of HFO facilitates the “absorption–reflection–reabsorption” process of EMWs. Consequently, the as-prepared composite film (0.35 mm thickness) exhibits an extraordinary EMI SE of 67.6 dB and a reflection SE as low as 5.1 dB. Furthermore, it also demonstrates exceptional mechanical properties, efficient thermal management, and Joule heating capabilities, as well as remarkable passive and active infrared camouflage performances. This study offers an innovative approach to achieve less reflection and more absorption of EMWs, and expands the application scope of EMI shielding materials in precision electronics, aerospace, and military equipment fields.
研究领域:
材料科学
·
电子工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Yanhua Wang,Jianying Tong,Kefeng Xie
Among various electrochemical energy storage systems, Li-S batteries are one of the most promising candidates. However, the application of Li-S batteries is mainly hindered by the shuttle effect of soluble polysulfide. To inhibit this shuttle effect, hollow Fe 3 O 4 spheres (HFS) are prepared and used as host materials for sublimed sulfur. Due to the strong absorption between Fe 3 O 4 spheres and polysulfide, the as-prepared S@HFS composites exhibit excellent cycle stability. As a result, the S@HFS composites show a high initial specific capacity of 1310 mAh g -1 at 0.1 C.
研究领域:
材料科学
·
能源存储与转换
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2018
·Vol. 29
·期 9
·7539-7550
·
IF 2.324
Sui Mingxu,Sun Xiaodong,Lou Hongfei,Li Xiaopeng,Lv Xuliang,Li Ling,Gu Guangxin
Hollow Fe 3 O 4 particles with variable crystal sizes were synthesized by one-step solvothermal method for lightweight and efficient microwave absorber applications. The reactant concentration, reaction temperature and reaction time are three key factors for morphology control of the products and can further influence the microwave absorption properties. The diameters of as-prepared hollow magnetite particles ranged from 200 to 1000 nm, while the shell thickness differed from 35 to 280 nm. It is found that the microwave absorption properties are improved along with the increasing of the hollow structure size which depend on the reaction conditions. The sample prepared at 200 °C for 36 h exhibited an optimal reflection loss of − 55.14 dB at 11.76 GHz with the thickness of 2.07 mm, while possessing the broadest effective bandwidth reaching 4.72 GHz (5.6–10.32 GHz) at 2.49 mm. The excellent microwave absorbing properties of such materials can be attributed to the high magnetic loss and favorable impedance matching property.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2019
·
IF 6.309
Haoming Fang,Haichang Guo,Yiran Hu,Yanjuan Ren,Po-Chun Hsu,Shu-Lin Bai
With the increasing packaging density and multi-functionality, thermal management and electromagnetic pollution in electronic devices are crucial. In this work, we propose a novel method to in-situ grow hollow Fe 3 O 4 sphere (h-Fe 3 O 4 , inner and outer diameter of 870 nm and 975 nm, respectively) onto three-dimensional graphene foam (GF) surface and then filled it with polydimethylsiloxane (PDMS) to fabricate nanocomposites with high electromagnetic interference shielding effectiveness (70.37 dB from 8.2 to 12.4 GHz) and thermal conductivity (28.12 ± 1.212 W m −1 K −1 ) at room temperature. Moreover, conductive networks inside composites show super-flexible performance with high electrical conductivity (84.02 ± 8.385 S cm −1 ). The effect of in-situ growth hollow Fe 3 O 4 spheres in the enhancement of EMI SE has been demonstrated via comparing with different contents, morphologies and preparation processing. Besides, the mechanism of thermal conductivity has been investigated by FEM simulation and theoretical modeling. Finally, the usage of GF/h-Fe 3 O 4 /PDMS composites as thermal interface materials (TIMs) for chip cooling is proved to be successful, and the corresponding temperature under usage power density is accurately predicted. These comprehensive properties of GF/h-Fe 3 O 4 /PDMS composite open a potential application for next-generation TIMs in chip packaging.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Liu-Yang Sun,Lie Yang,Jing Li,R. Lakshmi Narayan,Xiao-Hui Ning
Iron oxide , a promising anode material for lithium ion batteries, has a high theoretical specific capacity but exhibits poor cycling performance and rate capability. To resolve these issues, 150 nm sized carbon coated, hollow Fe 3 O 4 nanoellipsoids are designed in this study. Owing to the relatively high utilization ratio of Fe 3 O 4 and the buffer provided by the carbon layer, this composite has enhanced lithium ion storage properties and long cycle life. From half-cell measurements, the capacity is found to be in excess of 400 mAh g −1 even after 1000 cycles at 5 A g −1 . And then, a facile and practical strategy is used to gain a relatively high compressed density (∼1.87 g cm −3 ), so the volumetric capacity of the Fe 3 O 4 @C electrode can be further enhanced by subjecting it to compression. In the full cell test, the Fe 3 O 4 @C electrode has a specific capacity of 400 mAh g −1 and volumetric capacity of 749 mAh cm −3 after 100 cycles. The improvement in cycling stability can be attributed to minimal volume expansion and the stability of the solid-electrolyte interphase (SEI) layer, over the nanoparticles . Finally, the evolution of solid-electrolyte interphase layer is indirectly monitored and the progressive loss of active lithium is quantitatively measured.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
MICROCHIMICA ACTA
·
2017
·
IF 4.58
Song Han,Xue Guipeng,Zhang Junjie,Wang Gang,Ye Bang-Ce,Sun Shiguo,Tian Liping,Li Yingchun
The authors describe an electrochemical sensor for simultaneous determination of dopamine (DA) and uric acid (UA). The sensor is based on the use of composite materials of carbon-encapsulated hollow magnetite (Fe 3 O 4 ) nanoparticles and graphene oxide nanosheets, which were homogeneously deposited on a glassy carbon electrode. The morphology of the materials was characterized by transmission electron microscopy and scanning electron microscopy, and the properties of differently decorated electrodes were investigated via cyclic voltammetry and differential pulse voltammetry (DPV). Simultaneous detection of DA and UA was carried out via DPV, and the potentials of electrooxidation peaks are 0.14 V and 0.27 V (vs. SCE) for DA and UA, respectively. The calibration plot is linear from 0.1 to 150 μM for DA, and from 1.0 to 100 μM for UA, with detection limits of 0.053 μM and 0.41 μM at an S/N ratio of 3. The method was applied to the quantification of DA and UA in brain tissue, urine and whole blood.
Schematic of an electrochemical sensor for simultaneous voltammetric determination of dopamine (DA) and uric acid (UA) using 3D carbon-encapsulated hollow Fe 3 O 4 nanoparticles (H-Fe 3 O 4 @C) anchored on graphene nanosheet (GNS) modified glassy carbon electrode (GCE).
研究领域:
电化学
·
纳米材料
·
分析化学
·
生物传感器
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）