RSC Advances
·
2016
·Vol. 6
·期 77
·73020-73027
·
IF 3.289
D. Li,Y. Feng,D. S. Pan,L. W. Jiang,Z. M. Dai,S. J. Li,Y. Wang,J. He,W. Liu,Z. D. Zhang
Cactus-shaped core double-shelled FeCo/C/Fe2.5Cr0.5Se4 nanostructures with a spiky surface were prepared by combining an arc-discharge process with a high-temperature solution chemical method, in which FeCo nanoparticles serve as the, while carbon and ferrimagnetic Fe2.5Cr0.5Se4 (FCS) are the inside and the outside shells, respectively. The magnetic properties, electromagnetic response, and microwave absorption properties of the (x)FeCo/C/FCS nanocomposites in the 1–18 GHz frequency range were investigated by changing the mass ratio x between FeCo/C and FCS. The frequency dependences of μ′′ (imaginary parts of complex permeability) and ε′′ (imaginary parts of complex permittivity) of the (0 ≤ x ≤ 0.15)FeCo/C/FCS nanocomposites show distinct inverse trends of change in the high frequency ranges. Negative minimum values of μ′′ are found to be coupled with positive maxima of ε′′ due to a phase lag. The bare FCS–paraffin composite starts with a minimum μ′′ of about −0.07, which shifts to −0.44 and −0.05 when the mass ratio x is increased to 0.1 and 0.15, respectively. As x increases to 0.2, all the μ′′ values of the nanocomposites become positive. The best absorption property with a reflection loss (RL) peak of −54.5 dB at 10 GHz is obtained in the (x = 0.1)FeCo/C/FCS–paraffin composite and RL exceeding −20 dB can be achieved within the 3–18 GHz frequency range by choosing an appropriate layer thickness between 1.4 and 6 mm. The contribution of the negative μ′′ response to the microwave absorption is discussed.
研究领域:
材料科学
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电磁学
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DOI
高影响因子
FIBERS AND POLYMERS
·
2024
·Vol. 25
·期 10
·3661-3671
·
IF 2.2
Molla Aniruddha,Lee Jeongui,Park Eunji,Youk Ji Ho
The catalytic activity of FeCo alloy nanoparticles (NPs) supported on nitrogen-doped mesoporous carbon spheres (FeCo/NMCS) was evaluated for hydrogen evolution and reduction of various organic dyes. The NMCS was spherical, with an average diameter of 488.1 nm, while the FeCo alloy NPs were evenly distributed across the NMCS, with an average diameter of 8.2 nm. The nitrogen content in FeCo/NMCS was found to be 3.91 wt%. The FeCo/NMCS displayed remarkable efficiency in hydrogen evolution through the hydrolysis of ammonia borane (AB), characterized by an activation energy of 23.49 kJ/mol. The FeCo/NMCS also demonstrated superior catalytic activity in reducing 4-nitrophenol (4-NP), with a reduction rate constant of 0.468 min⁻ 1 using 5 mg of FeCo/NMCS and 20 mg of AB. This rate places the FeCo/NMCS among the highest-performing catalysts for 4-NP reduction. Further, the catalyst efficiently reduced crystal violet, methylene blue, and rhodamine B under the same conditions. Azo dyes, including tartrazine, methyl orange, Red 195, and Yellow 145, underwent faster reduction than other tested dyes. The FeCo/NMCS maintained its integrity and activity even after four hydrogen generation cycles. These results highlight FeCo/NMCS’s potential as a multifunctional, magnetically separable, and reusable catalyst for efficient hydrogen production and environmental remediation applications.
研究领域:
材料科学
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催化化学
·
环境科学
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DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Zhe Wang,Jiaming Ang,Bowei Zhang,Youfang Zhang,Xiu Yun Daphne Ma,Tao Yan,Jian Liu,Boyang Che,Yizhong Huang,Xuehong Lu
The rational design and exploration of highly efficient, low-cost, and robust electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is critical for development of rechargeable metal-air batteries. Herein, we report a novel approach for the synthesis of bifunctional electrocatalysts, where Fe 0.5 Co 0.5 and Fe 0.5 Co 0.4 Ni 0.1 alloys are encapsulated in the nitrogen-doped carbon nanotubes-grafted porous polyhedron-derived hybrid fibers (FeCo/FeCoNi@NCNTs-HF). Benefiting from its hierarchically porous structure and strong synergetic coupling among FeCo, FeCoNi alloys, and N-doped carbon species. The obtained electrocatalyst exhibits a positive half-wave potential of 0.850 V for ORR and a low potential of 1.608 V to achieve a current density of 10 mA cm −2 for OER, as well as superior stability in alkaline media. As a demonstration, FeCo/FeCoNi@NCNTs-HF is employed as the electrocatalysts in the air cathode of a Zn-air battery, which shows superior discharge and charge performance, large power density, high specific capacity, and outstanding cycling stability of 240 h (360 cycles). More impressively, excellent cyclabilitiy with a lifetime of 670 h (1005 cycles) is also achieved by the Zn-air battery with FeCo/FeCoNi@NCNTs-HF as the self-supported air electrode. This work will open a novel avenue to develop advanced bifunctional electrocatalysts for the next generation of metal-air batteries.
研究领域:
材料科学
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电化学
·
能源存储与转换
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Yulong Luo,Kerun Li,Wei Liu
The Advanced Oxidation Process (AOPs) has garnered significant attention as an efficient and promising technology for wastewater treatment in the field of environmental remediation. Currently, the exploration of highly effective catalysts for peroxymonosulfate (PMS) activation remains a focal point of scientific research, with increasing emphasis placed on the reuse of waste materials. In line with this objective, this study reports the synthesis of a Fe Co bimetallic metal-organic framework (MOF)-sponge composite (FCS) via an in-situ growth method using discarded natural sponge as a support material. Subsequently, the carbonized derivative (FCSC), obtained through high-temperature carbonization, was employed as a catalyst for PMS activation. The resulting catalyst demonstrated remarkable efficiency in removing 4-nitrophenol (4-NP) from aqueous solutions. Utilizing waste natural sponge as a support not only facilitates resource recovery but also enables the uniform distribution of MOF particles within its inherent three-dimensional porous structure. This feature enhances the contact between the catalyst and pollutants, thereby improving catalytic performance. Moreover, diatomic active sites exhibit significantly higher degradation efficiency toward 4-NP compared to the monometallic configurations. This enhanced performance can be attributed to the more rapid generation of free radicals by diatomic structures during PMS activation, which accelerates electron transfer between metal centers and adjacent oxygen atoms. This work offers novel insights into the development of efficient strategies for the removal of organic contaminants.
研究领域:
环境科学
·
材料科学
·
化学工程
·
纳米技术
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产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2016
·
IF 3.782
Nannan Qin,Ya Zhang,Hongjian Zhou,Zhigang Geng,Gang Liu,Yunxia Zhang,Huijun Zhao,Guozhong Wang
The reactivity of zero valent iron (Fe 0 ) for removing Cr(VI) is self-inhibiting under neutral and alkaline conditions, due to the precipitation of ferrous hydroxide on the surface of Fe 0 . To overcome this difficulty, we incorporated a second metal (Co) into Fe 0 to form FeCo bimetallic nanoparticles (FeCo BNPs), which can achieve higher activity and significant improvement in the reaction kinetics for the removal of Cr(VI) compared with Fe 0 . The FeCo BNPs were synthesized by a hydrothermal reduction method without using any templates. The characterization analysis indicated that the products were highly uniform in large scale with 120–140 nm size in diameter. The obtained FeCo BNPs exhibited a remarkable removal ability for Cr(VI) in the pH range of 5.3–10.0. Especially, FeCo BNPs were able to reduce trace Cr(VI) (1.0 mg L −1 , pH = 7.5) down to about 0.025 mg L −1 within 1 h. XPS analysis confirmed that Cr(VI) was reduced to Cr(III) by FeCo BNPs, while Fe and Co was oxidized, implying a chemical reduction process. The enhanced removal of trace Cr(VI) could be originated from the introduction of Co, which not only served as a protecting agent against surface corrosion by galvanic cell effect, but also enhanced the efficient flow of electron transfer between iron and Cr(VI). All the results primarily imply that FeCo BNPs can be employed as high efficient material for wastewater treatment.
研究领域:
环境科学
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纳米技术
·
水处理
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产品关联
DOI
PubMed
高影响因子
Materials Today Nano
·
2025
·
IF 8.2
Ziqi Zhang,Beibei Zhan,Yuhao Yang,Xiaosi Qi,Junfei Ding,Xiu Gong,Yunpeng Qu,Lei Wang
Metal organic frameworks are broadly used as promising precursors or templates for the fabrication of carbon-based derivatives owing to their exceptional porosities, structural diversities, and large specific surface areas. In this study, a facile method was reported to construct yolk-shell FeCo@air@C nanocomposites via annealing FeCo-prussian blue analogues (PBA)@phenolic resin (PR) precursor at different temperatures under Ar atmosphere. The introduction of PR effectively reinforced the stability of FeCo-PBA microstructure during carbonization process and played a confining role in preventing the serious agglomeration of FeCo nanoparticles. By adjusting the pyrolysis temperature, different categories of yolk-shell FeCo@air@C nanocomposites had been selectively established. Amongst, the FeCo@air@C obtained at 600 °C exhibited the superior electromagnetic wave absorption performances with a minimum reflection loss of -68.3 dB at the thickness of 2.44 mm and an ultrabroad effective absorption bandwidth of 8.2 GHz at 3.20 mm. Interestingly, its corresponding radar cross section value exhibited excellent radar stealth property in the practical applications. Therefore, the results elucidate that the combination of space confinement engineering and temperature optimization strategy is an indeed advanced method to regulate the electromagnetic wave absorption performances of magnetic carbon-based materials derived from FeCo-PBA.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Ruiyang Tan,Jintang Zhou,Zhengjun Yao,Bo Wei,Jiaqi Zu,Haiyan Lin,Zhong Li
Magnetic-dielectric composites are widely used in microwave absorption applications and have been continuously concerned by researchers. The synthesis of high-performance microwave absorbers with specific structures is a hot research topic. However, the question on how to reasonably combine the magnetic and dielectric components for achieving excellent microwave absorption performance still remains unanswered. In this study, FeCo/C microspheres were synthesized by a two-step hydrothermal method . FeCo nanoparticles were embedded in carbon spheres and formed the graphite layers, which is similar to Ferrero Rocher® chocolates. The electromagnetic parameters can be effectively adjusted by controlling the hydrothermal reaction time and excellent microwave absorption properties can be achieved at a low filling ratio. The FeCo/C microspheres exhibit the maximum reflection loss of – 20.61 dB and – 51.36 dB at the thickness of 1.6 mm and 2.6 mm, respectively. The effective absorption bandwidth of these microspheres is about 4.3 GHz. The specific Ferrero Rocher® chocolates-like multi-level structure increases to a large extent the material’s conduction loss and polarization relaxation loss. At the same time, the reasonable ratio of the magnetic and dielectric components significantly improves the impedance matching. Therefore, this study is aimed at providing insights into understanding of the absorption mechanism and reliable references to the design of magnetic-dielectric composed microwave absorbers.
研究领域:
材料科学
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电磁学
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微波工程
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纳米技术
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2021
·
IF 6.901
Wei Chen,Guangfu Qian,Qinglian Xu,Miaojing Pan,Lin Luo,Shibin Yin
The exploitation of catalysts with low-cost and superior oxygen evolution reaction (OER) and urea oxidation reaction (UOR) performance is important to expand the application of water splitting. Herein, the FeCo/CoFe 2 O 4 nanoflowers are successfully embedded in N-doped graphitic carbon (NGC) by hydrothermal method and subsequently annealing process (FeCo/CoFe 2 O 4 @NGC). It only needs 1.47 V and 1.32 V for OER and UOR to produce a current density of 10 mA cm −2 . Besides, it can work continuously for 100 h at different current densities (10; ∼ 1000 mA cm −2 ), displays outstanding stability, which is mainly ascribed to the N-doped carbon encapsulated FeCo modified CoFe 2 O 4 heterostructure and porous structure. This study thus provides a simple synthesis method to design and manufacture low-cost and high-performance catalytic materials for OER and UOR, and promotes the industrial application of water splitting.
研究领域:
材料科学
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电化学
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纳米技术
·
能源材料
✓ 已验证
DOI
高影响因子
MOLECULES
·
2025
·Vol. 30
·期 9
·1869
·
IF 4.6
Lili Chen,Shuya Xue,Xin Li,Linbo Deng,Jiapeng Li,Jing Zhou,Yansha Gao,Xuemin Duan,Limin Lu
The development of sensitive and selective methods for detecting pesticide residues has become paramount for ensuring food safety. In this work, a high-performance molecularly imprinted electrochemical sensor based on the composite of Cu-BTC- and FeCo-ZIF-derived N-doped carbon (FeCo@NC), synthesized by pyrolysis and electrodeposition, was developed for Benomyl (BN) detection. The materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). In this sensing system, the Cu-BTC/FeCo@NC composite used as the electrode substrate displayed a large specific surface area, high electronic conductivity, and rich active catalytic sites, demonstrating excellent electrocatalytic ability toward BN oxidation. Meanwhile, Cu-BTC, with its abundant surface functional groups, facilitated strong hydrogen bonding interactions with the imprinted template molecule of 3,4-ethylenedioxythiophene (EDOT), promoting the formation of a uniform molecularly imprinted membrane on the substrate material surface. The introduced MIP-PEDOT could enhance the selective recognition and enrichment of the target BN, leading to an amplified detection signal. Thanks to the synergistic effects between Cu-BTC/FeCo@NC and MIP-PEDOT, the proposed sensor achieved a low detection limit of 1.67 nM. Furthermore, the fabricated sensor exhibited high selectivity, reproducibility, and interference resistance in detecting BN. The method has been successfully applied to the determination of BN in vegetable and fruit samples, indicating its potential for use in practical applications.
研究领域:
食品科学
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分析化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2025
·Vol. 36
·期 23
·1-16
·
IF 2.8
Lin Jiayang,Liu Han,Ding Jiangtao,Xu Lelin,Cheng Zhenzhi,Gao Fei,Luo Guangsheng,Zhou Weiping
The integration of magnetic materials with dielectric carbon architectures is promising for enhancing microwave absorption properties due to their inherent resonance properties. In this paper, magnetic composites constituted by high-entropy spinel oxides/conductive heterogeneous FeCo phase were obtained through solid-phase sintering and hydrogen reduction process, which show excellent wave-absorbing properties by modulating the elemental Cr content. Further coating with carbon nanotubes via chemical surface modification dramatically improves the composite’s microwave absorption capability across multiple frequency bands, achieving a reflection loss of − 43.10 dB at 3.1 mm thickness in the C-band and an exceptional minimum reflection loss of − 44.20 dB at 1.5 mm thickness in the Ku-band. This tri-phase composite demonstrates a wide effective absorption bandwidth of 4.77 GHz at a remarkably thin matched thickness of just 1.3 mm. The obtained superior microwave-absorbing properties were ascribed to excellent impedance matching and attenuation properties contributed by natural resonance, interfacial polarization, conductive loss, multiple reflections, and scattering in the multi-component system with abundant heterogeneous interfaces. This unique absorption behavior highlights its potential for next-generation compact microwave absorption applications.
研究领域:
材料科学
·
电磁吸收
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纳米复合材料
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微波工程
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产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2021
·
IF 4.464
Shanhua Chen,Yanqing Huang,Ming Li,Panpan Sun,Xiaowei Lv,Bing Li,Liang Fang,Xiaohua Sun
Currently, development of OER/ORR bifunctional electric catalysts with low cost, high catalytic activity and stability is the key step to promote the practical application of zinc-air batteries. Herein, composite catalyst with manganese oxide on N and O co-doped carbon nanotubes encapsulated with FeCo alloy (CoFe@CNT/MnO) was prepared in situ on CFP by hydrothermal and CVD pyrolysis methods. Owing to rich C O functional group on in situ growing carbon nanotubes with 3D open structure, alloying effect of CoFe core metal embedded in carbon nanotube and the contribution of MnO supported on carbon nanotubes to ORR performance and stability, the CoFe@CNT/MnO catalyst exhibits low overpotential of 193 mV at the current density of 10 mA/cm 2 for OER, larger diffusion-limited current density of 5.75 mA/cm 2 and half-wave potential (E 1/2 = 0.85 V) for ORR, high specific capacity (810 mAh/g Zn ) and peak power density (164 mW/cm 2 ) with the Zn-air battery and superior stability. Moreover, the peak power density of the single CoFe@CNT/MnO-based quasi-solid state ZAB could reach 142 mW/cm 2 , and two quasi-solid state ZABs connected in series can power a mini fan.
研究领域:
材料科学
·
电化学
·
能源存储与转换
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Chunmei Xu,Mengran Lou,Rui Liu,Taotao Lv,Yang Wang,Ruiying Wang,Hongtao Liu,Xia Kong
Metal-nitrogen-carbon (M–N–C) catalysts are promising alternatives to precious metal-based bifunctional catalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in Zn-air batteries (ZABs). Herein, FeCo@nitrogen doped carbon nanotube/nitrogen doped reduced graphene oxide (FeCo@NCNT/N-rGO) catalyst with unique 3D heterostructure was synthesized through one-step pyrolysis of FeCo-ZIF-8 precursor anchored on graphene oxide (FeCo-ZIF-8/GO). Benefiting from the coupling of FeCo dual-metal sites with nitrogen-doped carbon substrates, the FeCo@NCNT/N-rGO catalyst achieved extraordinary bifunctional oxygen electrocatalytic activity, exhibiting a high ORR half-wave potential (E 1/2 ) of 0.881 V (vs. RHE), which was superior to the Pt/C catalyst (0.838 V), and OER overpotential of 343 mV at 10 mA cm −2 , merely inferior to RuO 2 by 33 mV. The resulting ΔE (defined as E j=10 − E 1/2 ) reaches an impressively low value of 0.69 V, highlighting its superior reversible oxygen electrocatalytic performance. Meanwhile, achieving a high-power density of 240 mW cm −2 and open circuit voltage (OCV) of 1.488 V in ZAB applications, superior to that of Pt/C + RuO 2 in ZAB (1.447 V; 143 mW cm −2 ). Flexible solid-state ZAB with FeCo@NCNT/N-rGO achieves 1.416 V OCV and 47.4 mW cm −2 power density, remaining stable even when bent 180°. This study guides design of dual-site non-precious metal bifunctional oxygen catalysts.
研究领域:
电化学
·
材料科学
·
能源存储与转换
·
纳米技术
✓ 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）