Journal of Materials Chemistry C
·
2021
·Vol. 10
·期 1
·126-134
·
IF 7.393
Yan Guo,Dedong Wang,Yu Tian,Jingwen Wang,Tiantian Bai,Hu Liu,Zhanhu Guo,Chuntai Liu,Changyu Shen
Recently, low-cost biomass based carbon aerogels have turned out to be promising efficient electromagnetic wave (EMW) absorption materials, but the bad impedance matching and single loss mechanism often result in poor EMW absorption properties. In this study, magnetic FeCo alloy nanoparticle decorated cellulose-based carbon aerogel (FeCo@CCA) was prepared by calcining the cellulose aerogel with homogeneously dispersed CoFe2O4 particles (CoFe2O4@CA), which was the freeze-dried product of hydrothermal treated Fe2+/Co2+ metal ion absorbed cellulose hydrogel. Here, the hydrothermal synthesis method can effectively ensure the even dispersion of the calcination product of magnetic FeCo alloy nanoparticles, which is conducive to good impedance matching, additional magnetic loss, and improved dielectric loss. Besides, the porous structure of the aerogel can also result in multi-reflection/scattering to attenuate more the incident EMW. As a result, the EMW absorption properties of the prepared FeCo@CCA can be effectively tuned by changing the metal ion concentration, and the product arising from a metal ion concentration of 100 mmol L−1 (FeCo@CCA-100) displays the strongest EWM absorption capacity with a minimum reflection loss (RLmin) of −49.5 dB at a thickness of 4.05 mm at 9.84 GHz and a maximum effective absorption bandwidth (EABmax, RL < −10 dB) of 10.88 GHz (6.96–17.84 GHz), covering the whole Ku and X band and almost half of the C band. This study provides a guideline for developing efficient cellulose-based carbon aerogel based EMW absorbers.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Chong Cai,Lin Hao,Danhua Sun,Zitong Chen,Hongyuan Yan,Yufan Zhang
To improve the efficiency of the oxygen evolution reaction (OER) while minimizing energy consumption and costs, we propose a novel design strategy. Oatmeal, an abundant and inexpensive feedstock rich in carbon (C), nitrogen (N), and oxygen (O), serves as an ideal precursor for biochar synthesis. By utilizing N -doped carbon spheres (NCS) as carriers, we achieved uniform growth of ZIF-67 on their surface through polyvinyl pyrrolidone (PVP) activation. The FeCo layered double hydroxide (FeCo-LDH) was subsequently formed via the etching action of [Fe(C 2 O 4 ) 3 ] 3− . The incorporation of NCS not only prevents the agglomeration of FeCo-LDH but also enhances the electrical conductivity of the complexes, thereby improving catalytic performance. The overpotential was measured at a modest 317 mV in 1 M KOH at 10 mA cm −2 , with a Tafel slope as low as 44.6 mV dec −1 . This study significantly enhances the catalytic performance of the OER and highlights the potential of biomass-derived carbon in improving OER efficiency.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Yang Sun,Kai Wang,Dongyun Chen,Qingfeng Xu,Najun Li,Hua Li,Jianmei Lu
Design of high-performance, environmentally friendly catalysts for remediation of contaminated soil is critical. Nano-zero-valent iron is widely used for this purpose and has high catalytic activity, but it readily agglomerates, which limits its use. To design efficient, environmentally friendly, and inexpensive soil remediation materials, we developed a Fe/Co-and nitrogen-doped carbon catalyst (FeCo/NC). The Fe and Co on the support were highly dispersed, many active sites were exposed, and the two metals exhibited synergistic catalytic effects. The ability to degrade anthracene in soil was evaluated through activating peroxodisulfate (PDS). The catalytic performance of the dual-doped catalyst was up to 24% more than that of catalysts doped with only Fe or Co. The FeCo/NC@PDS system efficiently removed 98.87% of anthracene from soil after 6 h. Moreover, the catalyst maintained excellent stability in both acidic and alkaline environments. The reaction mechanism was explored using radical quenching experiments combined with ESR spectra. In addition to a radical pathway involving OH, SO 4 − , and O 2 − , there was a non-radical pathway involving 1 O 2 . The optimum conditions for use of the catalyst were determined, and possible degradation pathways for anthracene were proposed. This study provides data for the development of in-situ soil remediation catalysts.
研究领域:
环境科学
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Yubo Wang,Long Zhang,Xiaofei Ren,Junying Song,Dengzheng Gao,Qingbin Guo,Li Wang,Xiaolong Hu
In this study, the FeCo layered double hydroxide/Sepiolite composite was successfully synthesized by a water bath approach which exhibited outstanding norfloxacin (NOR) degradation performance in presence of peroxymonosulfate (PMS). The reaction rate constant in the FeCo-LDH/Sepiolite/PMS system was 0.1644 min −1 , which was around 1.78 times greater than that in the FeCo-LDH/PMS system. The introduction of the sepiolite carrier, which led to an increase in specific surface area and pore volume , was principally responsible for the considerable improvement in PMS activation efficiency. Moreover, the composite presented good stability and reusability. According to the results of the electron paramagnetic resonance (EPR) and quenching tests, the predominant reactive species in the FeCo-LDH/Sepiolite/PMS/NOR system were SO 4 •- and 1 O 2 . Furthermore, possible NOR degradation pathways and catalytic mechanism were proposed. In summary, our research provised new ideas in the synthesis of promising mineral based PMS catalyst for wastewater treatment .
研究领域:
环境科学
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Dengke Zhao,Ligui Li,Lihong Xie,Ni Zhou,Shaowei Chen
Sulfur- and nitrogen-codoped peapod-like carbon nanotubes are facilely prepared via pyrolyzing Fe- and Co-containing Prussian blue analogues supported on trithiocyanuric acid. Combined studies with X-ray diffraction, X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy measurements reveal the encapsulation of metallic FeCo alloy in such carbon nanotubes with a wall thickness of ca. 2.60 nm. Electrochemical measurements show that sulfur codoping with nitrogen dramatically enhances the catalytic activity towards oxygen reduction reaction compared with that of FeCo alloy encapsulated in N-doped only carbon nanotubes, and the sample prepared at a pyrolysis temperature of 800 °C is the best one among the series, exhibiting a more positive half-wave potential of +0.838 V, nearly 100% enhancement in kinetic current, a higher operation stability and stronger immunity to the negative impacts of fuel crossover than commercial Pt/C catalysts. The remarkable improvement of catalytic activity is ascribed to the intensified charge transfer from encapsulated FeCo alloy nanoparticles to thin walls of CNTs upon the additional sulfur doping besides nitrogen. The present results highlight the importance of deliberate doping and structuring in the development of more efficient catalysts based on metal nanoparticles encapsulated in CNTs for high-performance electrochemical energy devices.
研究领域:
材料化学
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电化学
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纳米催化
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能源材料
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表面科学
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金属有机框架衍生材料
✓ 已验证
DOI
高影响因子
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
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2023
·
IF 8.8
Zilong Zhao,Shuyu Qi,Jianli Zhou,Yatao Ren,Kaiyun Zheng,Jin Zhang,Wenyi Dong,Hongjie Wang
To enhance the polarization distribution of electron cloud density on the catalyst surface, we have introduced a novel bimetallic-substituted dual-reaction center (DRC) catalyst (FeCo-γ-Al 2 O 3 ) comprising iron (Fe) and cobalt (Co) for the decomplexation and mineralization of heavy metal complex Ni-EDTA in this study. Compared to the catalysts doped solely with Fe or Co, the bimetal-doped catalyst offered several advantages, including enhanced electron cloud polarization distribution, additional electron transfer pathway, and improved capacity of free radical generation. Through DFT calculations and EPR tests, we have elucidated the influences of the catalyst's adsorption toward Ni-EDTA and its decomplexation products on the electron transfer between the pollutant and the catalyst. The competition between the pollutants and H 2 O 2 affects the generation of free radicals in both electron-rich Fe and Co centers as well as electron-deficient Al center. Building on these findings, we have proposed a plausible removal mechanism of Ni-EDTA using the heterogeneous Fenton-like catalyst FeCo-γ-Al 2 O 3 . This study sheds light on the potential of FeCo-γ-Al 2 O 3 as a DRC catalyst and emphasizes the significance of pollutant characteristics in determining the catalyst's performance.
研究领域:
环境科学
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材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Yusheng Li,Yun Feng,Li Li,Keyan Wu,Xiangjie Bo,Jianbo Jia,Liande Zhu
Due to the obstacle of sluggish kinetics on cathode of fuel cells and metal–air batteries, developing low-cost and durable electrocatalysts to replace the platinum-based catalysts still remains a grand challenge. Here, we describe a simple self-template approach to synthesize N-doped mesoporous carbon nanocages (FeCo@NC) embedded with FeCo alloy nanoparticles as oxygen reduction reaction (ORR) electrocatalyst. The resulting heterostructure is derived from corresponding PBA@PPy composites, which are pre-prepared by polymerization of polypyrrole (PPy) layer on Prussian blue analogue (PBA) nanocubes. The FeCo alloy nanoparticles with an average particle size of ∼10 nm are well dispersed and confined within the shell of carbon nanocages. Benefiting from the mesoporous structure and the synergetic interaction of binary metals, the optimized FeCo@NC-3-800 electrocatalyst exhibits comparable ORR performances (0.83 V for half-wave potential (E 1/2 ), 5.323 mA cm −2 for limiting current density (J k )), superior durability and excellent methanol tolerance to the commercial Pt/C (20 wt%). This work provides an appropriate strategy for general, efficient and practical synthesis of more promising non-precious metal electrocatalyst with high ORR activity.
研究领域:
材料科学
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电化学
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2021
·Vol. 168
·期 9
·090514
·
IF 4.316
Xiaochao Liu,Siyuan Peng,Xiaoxiao Li,Chao Liu,Jinming Zeng,Xiaopeng Qi,Tongxiang Liang
The development of low-cost, high catalytic activity oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) electrocatalysts is the key to promoting the development of zinc-air batteries. In this paper, a simple one-step pyrolysis method was used to successfully synthesize a binary FeCo–Co/NC catalyst with FeCo and Co nanoparticles encapsulated in N-doped carbon nanotubes. This structure exhibits great characteristics: it has a variety of active species (FeCo, Co, NC), and there is close combination between these active species (FeCo, Co, NC). Electrochemical studies have shown that the initial potential of FeCo–Co/NC during ORR process is 0.93 V, the half-wave potential is 0.808 V, and the limiting current density is 4.94 mA cm−2. In the OER process, at an anode current density of 10 mA cm−2, an overpotential of only 353 mV is shown; a lower Tafel slope and good durability are also observed. Moreover, the zinc-air battery in preparation can be cycled for as long as 2000 times. This provides a new method for the preparation of high-efficiency dual-function electrocatalysts for OER and ORR.
研究领域:
材料科学
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电化学
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能源存储与转换
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Lianghao Song,Jing Zhang,Samrat Sarkar,Chenfei Zhao,Zhenwei Wang,Chengyu Huang,Liuming Yan,Yufeng Zhao
High performance zinc-air batteries (ZABs) demand highly active bifunctional catalysts for both oxygen reduction reaction (ORR) and oxygen evolution reactions (OER). Herein, we report a FeCo-Co bifunctional catalyst with well-engineered interfaces between FeCo nanoalloy and metallic Co, via an alloying-degree control strategy. The FeCo-Co architecture can be obtained by manipulating the alloying degree through proper introduction of Fe, while the stacked carbon nanosheet morphology inherited from the precursor can fully expose the active sites facilitating the ion transfer. FeCo-Co interface structure enables FeCo@Co/N-C-8 catalyst to exhibit an excellent half-wave potential (0.870 V) superior to Pt/C (0.846 V) for ORR and suppressed overpotential (312 mV) than IrO 2 (321 mV) for OER. The as prepared rechargeable ZAB based on FeCo@Co/N-C-8 catalyst displays an excellent peak power density of 148 mW cm −2 and an ultrahigh open circuit voltage of 1.52 V. This research provides an innovative technique in construction of bifunctional catalysts for ZABs through alloying degree control strategies.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
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
·
催化化学
·
环境科学
✓ 已验证
产品关联
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
·
电化学
·
能源存储与转换
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）