MATERIALS CHEMISTRY AND PHYSICS
·
2020
·
IF 3.408
Jintang Zhou,Ruiyang Tan,Zhengjun Yao,Haiyan Lin,Zhong Li
In the synthesis of colloidal carbon spheres (CCSs) from glucose by hydrothermal carbonization, agglomeration and cross-linking often occur, affecting their functions as templates. In this study, the effects of various surfactants on the dispersion and particle size of CCS were investigated. The CCS synthesized with dodecyltrimethylammonium bromide was much larger than those of other groups, and the average diameter exceeded 6.4 μm. CCS with complete spherical shape and good dispersion were obtained using sodium polyacrylate, with a diameter of approximately 450 nm CoFe 2 O 4 hollow spheres were prepared by a simple adsorption–calcination method using CCS as the templates, and the effects of different dispersions and particle sizes on the electromagnetic parameters and microwave absorption properties of hollow spheres were studied. The results show that the absorption bandwidth corresponding to reflection loss less than −7 dB widened from 2.64 GHz to 3.44 GHz with improving dispersion of hollow sphere structure. When the size of the hollow sphere increased to the micron level, the thickness required to reach the maximum bandwidth reduced by 0.5 mm. Compared to the unoptimized hollow spheres, the microwave absorption performance of the as-prepared CCCs improved effectively. The effect of surfactants on the dispersion of CCS and the effect of the dispersion and size of CoFe 2 O 4 hollow spheres on their electromagnetic properties are discussed in detail.
研究领域:
材料科学
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纳米技术
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电磁工程
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Liying Wu,Yongbo Yu,Qian Zhang,Junming Hong,Ji Wang,Yuecheng She
Through direct and indirect radical mechanism of peroxymonosulfate (PMS) activation, novel CoFe 2 O 4−x catalysts were successfully developed via hydrogen calcination to overcome popular disadvantages of the dependence on pH. Bisphenol A (BPA) was selected as the model pollutant to decipher the mechanism of catalysts for peroxymonosulfate (PMS) activation. Possible degradation pathways of Bisphenol A were proposed via analysis of liquid chromatograph mass spectrometer (LC-MS). The findings indicated that catalytic activation of CoFe 2 O 4−x was not dependent upon the initial pH, as the direct and indirect radicals seemed to be generated in parallel. FTIR analysis confirmed that surface hydroxyl groups were actively involved in the activation of PMS under alkaline conditions. During the reaction, the oxygen defects promoted electron transfer and participated in the redox cycle from Co 3+ /Fe 3+ to Co 2+ /Fe 2+ to generate 1 O 2 and O 2 − . Hydroxyl (OH ) and sulfate (SO 4 − ) radicals were generated on the surface of CoFe 2 O 4−x by the synergistic interactions among oxygen defects, transition metal, and surface hydroxyl groups. To the best of our knowledge, this combined mechanism of direct and indirect radical generation for advanced oxidation was a first-attempt study to be disclosed in public domain.
研究领域:
环境科学
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催化
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化学工程
·
水处理
✓ 已验证
产品关联
DOI
高影响因子
Advanced Composites and Hybrid Materials
·
2024
·Vol. 7
·期 2
·1-16
·
IF 23.2
Yuan Liying,Zhao Wenxin,Miao Yukun,Wang Chang,Cui Anguo,Tian Zhongning,Wang Ting,Meng Alan,Zhang Meng,Li Zhenjiang
The inadequate impedance matching and weak attenuation capability for incident electromagnetic waves exhibited by carbon fibers (CF) are critical factors limiting their application served as absorbing materials. Constructing a nanocomposite system that simultaneously exhibits both dielectric loss and magnetic loss characteristics is a feasible strategy to overcome these limitations. In the present study, a core-shell CF@PPy@CoFe 2 O 4 nanocomposite is fabricated through electrodeposition and subsequent hydrothermal methods to enhance the attenuation capacity and impedance matching of bare CF. Under the synergistic effects of diverse components and a peculiar network structure, the nanocomposite demonstrates optimized conductive loss and polarization loss, which results in a remarkable electromagnetic wave absorption performance with a minimum reflection loss (RL min ) of -55.33 dB and an effective absorption bandwidth (EAB) of 6.48 GHz (12 ~ 18 GHz) at optimal thicknesses of 2.11 and 2.42 mm, respectively, suggesting its promising application as a candidate absorber. More importantly, the exploration concerning the absorption mechanism provides significant insights into the attenuation modes of the dielectric-magnetic loss hetero-junction, which is beneficial for developing similar absorbing materials. Graphical abstract
CF@PPyCoFe 2 O 4 nanocomposite displays an efficient electromagnetic wave absorption capacity by virtue of its excellent conductive loss and polarization loss.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Fujin Sun,Jian He,Pan Wu,Qihui Zeng,Changjun Liu,Wei Jiang
A magnetic aggregation bed photocatalytic reactor (MABPR) was designed and constructed to achieve continuous photodegradation of methyl orange (MO) solution without subsequent photocatalyst separation. A magnetic photocatalyst, CoFe 2 O 4 -Ag 2 O, was scattered and immobilized on aggregated flower-like Fe 3 O 4 structures, which were anchored to the reactor with external magnets at the bottom. Under optimal operating conditions, MO is effectively photodegraded in the MABPR in 60 min with a fluid velocity of 0.01 m/s and a 100 mT magnetic field under natural illuminance (E v ). Magnetic aggregates in the MABPR support the magnetic photocatalyst, increasing their effective irradiation area and also increasing fluid disturbance to enhance mass transfer. Additional energy input for photodegradation and photocatalyst recovery were not required to operate the MABPR; the mass of photocatalyst did not decrease over the course of the experiment. The MABPR proposes a promising design for a usable, cost-effective, low-energy, continuous photoreactor using a magnetic photocatalyst.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Beili Pang,Shan Lin,Yongtang Shi,Yingying Wang,Yingjie Chen,Shuai Ma,Jianguang Feng,Chunkai Zhang,Liyan Yu,Lifeng Dong
A novel nanocomposite of CoFe 2 O 4 nanoparticles with graphene nanosheet (CoFe 2 O 4 /GN) is prepared as a counter electrode (CE) for dye-sensitized solar cells (DSSCs). The size of CoFe 2 O 4 nanoparticles is about 3 nm, and the influence of CoFe 2 O 4 on the electrochemical properties of graphene is studied. The CoFe 2 O 4 nanoparticles anchored on graphene nanosheets can serve as spacers to prevent graphene aggregations and thereby provide efficient diffusion pathways and more active surface area for electrolyte molecules. Also, the CoFe 2 O 4 nanoparticles with substantial catalytic activity accelerate the reduction of triiodide. Meanwhile the graphene improves charge transfer during the catalytic process. Compared with CoFe 2 O 4 , graphene, and Pt electrodes, the CoFe 2 O 4 /GN electrode displays higher catalytic activity because of its minimal charge transfer resistance. The DSSCs fabricated with CoFe 2 O 4 /GN demonstrate an improved photoelectric conversion efficiency of 9.04% in comparison to Pt electrodes (6.54%). This study suggests that CoFe 2 O 4 /GN can replace expensive Pt electrodes for large-scale fabrication of low cost and high efficiency DSSCs.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2013
·
IF 2.072
Jie Zhao,Yu Xie,Changlin Yu,Zhanggao Le,Rong Zhong,Yuancheng Qin,Jianfei Pan,Fuming Liu
A novel graphene–carbon nanotube (graphene–CNT)/CoFe 2 O 4 /polyaniline composite with reticular branch structures had been fabricated by in situ chemical polymerization method. The textured structures of the as-prepared composites were characterized by the fourier transform infrared (FTIR) and X-ray diffraction (XRD). The morphology was analyzed by the scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electromagnetic properties were tested by vibrating sample magnetometer and four-probe conductivity tester. The results showed that the graphene–CNT/CoFe 2 O 4 /polyaniline composite had the unique reticular branch structures. When the mass ratio of the graphene–CNT/CoFe 2 O 4 to aniline was 1:3, the magnetic saturation value of the composite achieved 39.6 emu g −1 , and the conductivity reached 1.957 S cm −1 . Based on the experimental results, a probable formation mechanism for the unique reticular branch structures was proposed.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
DIAMOND AND RELATED MATERIALS
·
2023
·
IF 4.1
Shixian Zhang,Xinshan Rong,Ting Sun,Ping Gao,Jun Liu,Xuchun Qiu,Xiangtong Zhou,Zhiren Wu
With the increasingly severe environmental problems the traditional high pollution and high energy consumption of nitrogen fixation industry is striving to develop new cleaner production technology. In this work, we designed and prepared the 3D porous g-C 3 N 4 with nitrogen vacancy (3DV N PCN) through a combination of alkali-assisted and supramolecular self-assembly methods. Subsequently, we synthesized, characterized and employed a Z -scheme 3DV N PCN/CoFe 2 O 4 photocatalyst with strong nitrogen adsorption and activation for nitrogen photofixation. The results show that the best photofixation nitrogen efficiency of the photocatalyst can reach 14.66 mmol/g/h within 120 min. This nitrogen fixation process carried out at room temperature, and only requires water and nitrogen as raw materials, which has the advantage of being energy efficient, environmental friendly and pollution-free.
研究领域:
材料科学
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环境科学
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化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2016
·Vol. 39
·期 18
·3647-3654
·
IF 2.741
Yan Xu,Jingjie Jin,Xianliang Li,Yide Han,Hao Meng,Junbiao Wu,Xia Zhang
Core–shell metal–organic framework materials have attracted considerable attention mainly due to their enhanced or new physicochemical properties compared with their single-component counterparts. In this work, a core–shell heterostructure of CoFe 2 O 4 -Zeolitic Imidazolate Framework-8 (ZIF-8@CoFe 2 O 4 ) is successfully fabricated and used as an solid-phase extraction adsorbent to efficiently extract Congo Red and Basic Red 2 dyes from contaminated aqueous solution. Vibrating sample magnetometry indicates that the saturated magnetization of ZIF-8@CoFe 2 O 4 is 3.3 emu/g, which is large enough for magnetic separation. The obtained hybrid magnetic metal-organic framework based material ZIF-8@CoFe 2 O 4 can remove the investigated dyes very fast within 1 min of the contact time. The adsorbent ZIF-8@CoFe 2 O 4 also shows a good reusability. After regeneration, the adsorbent can still exhibit high removal efficiency (∼97%) toward Congo Red for five cycles of desorption–adsorption. This work reveals the great potential of core–shell ZIF-8@CoFe 2 O 4 sorbents for the fast separation and preconcentration of organic pollutants in aqueous solution before high-performance liquid chromatography analysis.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Shuaijie Li,Jianzhi Wang,Jingyuan Wang,Chen Chen,Ziyi Guo,Ning Cai,Yanan Xue,Faquan Yu
Developing high-performance nonprecious-metal electrocatalysts for the oxygen evolution reaction (OER) is crucial for efficient water splitting. Therefore, the reasonable design principle of catalyst, leading to high activity catalytic center and improving the accessibility of active sites, is undoubtedly crucial. Here, we used a kind of Prussian blue analogue (CoFe-PBA) nanoparticles to anchor the nitrogen-carbon doped CoFe 2 O 4 (CoFe 2 O 4 @NC) species to reduced graphene oxide aerogels as OER catalysts. The strong interaction between nanosized CoFe 2 O 4 @NC and the graphitic carbon shell led to synergistic effects in the OER, and the protection of the carbon shell guaranteed stability of the catalyst. As a result, the aerogel electrocatalyst exhibits more excellent activity and stability than the most advanced RuO 2 catalyst in OER under the same mass load in alkaline medium. It shows smaller overpotential of 250 mV to afford a current density of 10 mA cm −2 in a continuous working time of more than 70 hours.
研究领域:
材料科学
·
电化学
·
能源转换与存储
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2025
·
IF 3.9
Wantao Li,Yunlan Xu,Dengjie Zhong,Danli Tang,Tanxia Xiang,Chunmiao Fan,Yuanfang Yang
In this study, CoFe2O4 anchored by MoS2 modified biochar (CoFe2O4@MoS2–BC) was synthesized using a hydrothermal approach and utilized to activate peroxymonosulfate (PMS) to degrade rhodamine B (RhB). The effects of pH value, catalyst and PMS dosage, RhB concentration, and coexisting compounds were systematically investigated. Within 7 min, CoFe2O4@MoS2–BC achieved a removal rate of 99.63% for 100 mg·L–1 RhB. The outstanding stability and environmental compatibility of CoFe2O4@MoS2–BC was verified by cycling and metal ion leaching experiments. The contribution of 1O2, SO4•–, •OH, and •O2– in the degradation procedure was revealed by quenching experiments, among which 1O2 was the predominant active species. Electrochemical characterization indicated that CoFe2O4@MoS2–BC exhibited enhanced current density, redox activity, and superior electron transfer capability. Comprehensive characterization analysis and experimental data revealed that the high efficiency of CoFe2O4@MoS2–BC was attributed to Co2+/Co3+, Fe2+/Fe3+, and Mo4+/Mo6+ redox cycling on the CoFe2O4@MoS2–BC surface. The cycles of Co2+/Co3+ and Fe2+/Fe3+ were enhanced by Mo, while unsaturated S increased the reactivity of Mo, thereby accelerating the redox of metal ions; oxygen vacancies (Ov) enhance the mobility of surrounding oxygen ions mobility and promoted the conversion from lattice oxygen (Olat) to reactive oxygen species (O*), thereby activating PMS effectively. This research is expected to provide innovative insights that will inform the design and development of excellent activity and stability of heterogeneous metal-based catalysts.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF LUMINESCENCE
·
2024
·
IF 3.3
Zhiqiang Wang,Zhi Wang,Jing Wu
Exploring advanced materials to enhance chemiluminescence (CL) emission is an original approach and sheds light on improving sensitivity of CL analysis. Fenton material and its relative reactions are scarcely utilized in CL systems although they are commonly applied in environmental monitoring, biological detection, chemical analysis and life science researches. In this study, one kind of Fenton material CoFe 2 O 4 ·MoS 2 nanosheets were successfully synthesized and applied in enhancing the CL intensity of the luminol-H 2 O 2 system. An acidic microenvironment was constructed on the surface of CoFe 2 O 4 ·MoS 2 nanosheets and ensured a stable circulation of iron ions which were beneficial for reactive oxygen species generation and then dramatically enhanced the CL emission of luminol-H 2 O 2 system even in alkaline conditions. This work introduces a new approach to enhance traditional CL process and explores new application fields of heterogeneous Fenton catalase-like catalysts.
研究领域:
分析化学
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
MINERALS ENGINEERING
·
2024
·
IF 4.9
Xiaoqi Wu,Zhaoyang Song,Qiongqiong He,Yifei Li,Pengxu Xiang,Yuan Xu,Ping Ma
Owing to the technological limitations associated with beneficiation technology, large amounts of flotation reagents remain in mineral processing wastewater, which is extremely detrimental to humans and the environment. In addition, direct reuse of mineral processing wastewater will adversely affect the entire mine water system. Efficient treatment of residual butyl xanthate from tailing wastewater has recently attracted increasing interest. In this study, we compared the degradation efficiencies of cobalt iron oxide (CoFe 2 O 4 ) nanoparticles assisted by sulfite-activated advanced processes and persulfate (PDS) and peroxymonosulfate (PMS) advanced oxidation processes on butyl xanthate (BX) for the first time and explored possible reaction mechanisms in various systems. We conducted comprehensive experiments on the acid/alkali washed catalysts using oxidizing agents, obtaining catalysts best adapted to three degradation systems. Results of batch experiments indicated that the BX degradation rate for all the three systems exceeded 95 % within 60 min under their respective optimal conditions and that the best total organic carbon content (TOC) removal rate for these systems was 85.79 %. The effects of key factors, such as catalyst dosage, oxidant dosage, solution pH, and coexisting ions, on BX degradation were investigated. Furthermore, the active free radicals that played a major role in each system were detected via electron paramagnetic resonance (EPR). EPR results indicated that SO 3 ·− and ·O 2 − were the main active species of the CoFe 2 O 4 /sodium sulfite system, ·OH and ·O 2 − participated in the degradation of BX in the CoFe 2 O 4 /PDS system, and ·O 2 − was present in the CoFe 2 O 4 /PMS system. Thus, this study promotes the application of CoFe 2 O 4 with magnetism as a catalyst in wastewater treatment and provides new insights into the effective treatment of organic pollutants in tailing wastewater.
研究领域:
环境科学
·
化学工程
·
材料科学
✓ 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）