JOURNAL OF ALLOYS AND COMPOUNDS
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2022
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IF 6.371
Keke Yang,Guilin Song,Yuanyuan Li,Qingda An,Shangru Zhai,Zuoyi Xiao
Nowadays there is much room for improvement in the designed synthesis of high-performance electromagnetic wave absorbers by combining metal-organic frameworks (MOFs) and biomass components. Herein, 3D N-doped porous carbon cobalt/cobalt oxide (NPC/Co/CoO) composites were successfully prepared by transforming in-situ grown ZIF-67 clusters on a chitosan matrix. Analysis results showed that the N-doped carbonaceous composites obtained had unique porosity, high specific surface area, and defect-enriched structure, which provided numerous paths for electron transfer , leading to big benefits to interfacial polarization and dipole polarization. Most importantly, the ferromagnetic resonance and magnetic coupling were enhanced by ZIF-67-derived Co/CoO nanoparticles . By adjusting the content of metallic cobalt salt, pyrolysis temperature, and sample filling content, the optimal impedance matching properties of the composites could be optimized. When the matching thickness is 2 mm, the RL min of NPC/Co/CoO-10/700–30 wt% achieved − 48.97 dB at 13.52 GHz, and the effective absorption bandwidth exceeds 5.36 GHz. The composites with excellent performance prepared by a controllable process using chitosan and ZIF-67 might be a promising alternative for the large-scale preparation of high-frequency electromagnetic wave absorbers.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2020
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IF 10.652
Xiaocong Gu,Zong Liu,Hui Liu,Chengang Pei,Ligang Feng
Efficient oxygen evolution nano-catalyst is significant for hydrogen generation in the water-splitting reaction. Herein, we demonstrate that fluorination of ZIF-67 Framework templated Prussian blue analogue hollow nano-box is highly efficient for the oxygen evolution reaction (OER). The structure and morphology observation shows the degree of structural transformation and morphology are influenced by the fluorination temperature, and the catalytic ability for OER is correspondingly correlated to these characters. The product obtained at the annealed temperature of 250 °C exhibits the highest catalytic performance for OER with an overpotential of 243 mV (No IR correction) to offer 10 mA cm −2 when loaded on the inert glass carbon electrode, which is much better than that of the commercial IrO 2 catalysts. High catalytic stability and kinetics are also found for the OER. Moreover, it has the highest intrinsic activity as demonstrated by the specific activity and turnover frequency indicating the intrinsic advantages of fluorination and hollow nano-box structure. This study enriches the application of Prussian blue analogue based hollow materials for OER by facile fluorination at low temperatures.
研究领域:
材料科学
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电化学
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纳米技术
✓ 已验证
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 17
·4059
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IF 4.2
Xin Yan,Yiyuan Yao,Chengming Xiao,Hao Zhang,Jia Xie,Shuai Zhang,Junwen Qi,Zhigao Zhu,Xiuyun Sun,Jiansheng Li
Catalytic performance decline is a general issue when shaping fine powder into macroscale catalysts (e.g., beads, fiber, pellets). To address this challenge, a phenolic resin-assisted strategy was proposed to prepare porous Co/N carbon beads (ZACBs) at millimeter scale via the phase inversion method followed by confined pyrolysis. Specially, p-aminophenol–formaldehyde (AF) resin-coated zeolitic imidazolate framework (ZIF-67) nanoparticles were introduced to polyacrylonitrile (PAN) solution before pyrolysis. The thermosetting of the coated AF improved the interface compatibility between the ZIF-67 and PAN matrix, inhibiting the shrinkage of ZIF-67 particles, thus significantly improving the void structure of ZIF-67 and the dispersion of active species. The obtained ZACBs exhibited a 99.9% removal rate of tetracycline (TC) within 120 min, with a rate constant of 0.069 min−1(2.3 times of ZIF-67/PAN carbon beads). The quenching experiments and electron paramagnetic resonance (EPR) tests showed that radicals dominated the reaction. This work provides new insight into the fabrication of high-performance MOF catalysts with outstanding recycling properties, which may promote the use of MOF powder in more practical applications.
研究领域:
环境科学
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材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2024
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IF 4.9
Danqiang Huang,Xiangyun Zhang,Jianfeng Dai,Zizhou Yuan
The rapid advancement of wireless communications, radar systems, and electronic devices has resulted in a substantial increase in electromagnetic interference (EMI), which poses a threat to electronic device performance and human health. This study addresses the urgent need for lightweight materials with strong absorption capacities, wide absorption bandwidths, and low thickness values. For this purpose, ZIF-67-derived C/Co nanofibers were synthesized via electrospinning, dipping, and high-temperature carbonization. Co 2+ ions were pre-anchored and encapsulated in polyacrylonitrile (PAN) fibers and are grown by immersion in an organic ligand. Utilizing 0.4 g of cobalt nitrate hexahydrate, the amount of encapsulated Co 2+ was optimized to provide the greatest electromagnetic wave absorption performance. Under these conditions, the reflection loss was −49.45 dB, and the maximum effective absorption bandwidth was 6.48 GHz, thereby covering the entire Ku band. The composite material demonstrated a significant improvement in impedance matching and electromagnetic wave dissipation, which was attributed to the uniform dispersion of Co particles and the formation of multi-component heterogeneous interfaces. This study presents a pragmatic method for creating high-performance materials that could potentially reduce electromagnetic interference (EMI) in the aerospace, telecommunications, and defense sectors.
研究领域:
材料科学
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电子工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2018
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IF 4.229
Meijia Liu,Xuezhang Xiao,Shuchun Zhao,Sina Saremi-Yarahmadi,Man Chen,Jiaguang Zheng,Shouquan Li,Lixin Chen
Transition-metal nanoparticles (NPs) can catalytically improve the hydrogen desorption/absorption kinetics of MgH 2 , yet this catalysis could be enhanced further by supporting NPs on carbon-based matrix materials . In this work, Co NPs with a uniform size of 10 nm loaded on carbon nanotubes (Co@CNTs) were synthesized in situ by carbonizing zeolitic imidazolate framework-67 (ZIF-67). The novel Co@CNTs nanocatalyst was subsequently doped into MgH 2 to remarkably improve its hydrogen storage properties. The MgH 2 -Co@CNTs starts to obviously release hydrogen at 267.8 °C, displaying complete release of hydrogen at the capacity of 6.89 wt% at 300 °C within 15 min. For absorption, the MgH 2 -Co@CNTs uptakes 6.15 wt% H 2 at 250 °C within 2 min. Moreover, both improved hydrogen capacity and enhanced reaction kinetics of MgH 2 -Co@CNTs can be well preserved during the 10 cycles, which confirms the excellent cycling hydrogen storage performances. Based on XRD , TEM and EDS results, the catalytic mechanism of MgH 2 -Co@CNTs can be ascribed to the synergetic effects of reversible phase transformation of Mg 2 Co to Mg 2 CoH 5 , and physical transformation of CNTs to carbon pieces. It is demonstrated that phase transformation of Mg 2 Co/Mg 2 CoH 5 can act as “hydrogen gateway” to catalytically accelerate the de/rehydrogenation kinetics of MgH 2 . Meanwhile, the carbon pieces coated on the surfaces of MgH 2 particles not only offer diffusion channels for hydrogen atoms but also prevent aggregation of MgH 2 NPs, resulting in the fast reaction rate and excellent cycling hydrogen storage properties of MgH 2 -Co@CNTs system.
研究领域:
材料科学
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Sciences
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2022
·
IF 6.796
Jiacheng Zhou,Hao Zhang,Tianying Xie,Ye Liu,Qicheng Shen,Jie Yang,Limei Cao,Ji Yang
The stronger coordination ability of mercury ions with organic ligands than the metal ions in metal organic framework (MOFs) provides an accessible way to separate mercury ions from solution using specific MOFs. In this study, a Co-based MOF (ZIF-67, Co(mIM) 2 ) was synthesized. It did not introduce specific functional groups, such as -SH and -NH 2 , into its structure through complicated steps. It separate Hg 2+ from wastewater with a new strategy, which utilized the stronger coordination ability of Hg 2+ with the nitrogen atom on the imidazole ring of the organic ligand than the Co 2+ ions. Hg 2+ replaced Co 2+ nodes from ZIF-67 and formed a more stable precipitate with mIM. The experimental results showed that this new strategy was efficient. ZIF-67 exhibited Hg 2+ adsorption capacity of 1740 mg/g, much higher than the known MOFs sorbents . mIMs is the reaction center and ZIF-67 can improve its utilization. The sample color faded from purple to white due to the loss of cobalt ion. It is a great feature of ZIF-67 that allows users to judge whether the sorbent is deactivated intuitively. ZIF-67 can be sustainable recycled by adding organic ligands to the solution after treatment due to its simple synthesis method at room temperature. It's a high-efficient and sustainable sorbent for Hg 2+ separation from wastewater.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
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2024
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IF 8.3
Deshuang Lu,Nikom Klomkliang,Francis Verpoort,Somboon Chaemchuen
Tailor-made unsaturated coordination of metal ions or organic linkers in zeolitic imidazole frameworks (ZIFs) has great potential in tuning the ZIFs’ properties and reactivity for their applications. Taking advantage of the solid-state thermal (SST) method as a facile and eco-friendly synthesis method, the rational coordination of metal ions with imidazole ligands in ZIF-67 through the SST method is investigated. The rational precursor ratio (metal-to-ligand source) under the solvent-free SST method emerges as a perfect strategy to tune the coordinately unsaturated sites within the ZIF-67 frameworks. Different analysis techniques, computational methods (DFT), and catalytic model reactions examine unsaturated coordination in ZIF-67 materials (defect structures). The unsaturated coordination provides unique characteristic properties on materials with excellent catalytic performance. However, the higher reactive properties are negotiated with weaker structural stability on materials. In addition, the post-SST approach is applied to enable rational coordination and modify the pristine ZIF-67 materials. The post-SST method rearranges and modifies coordination in the framework of materials. These findings are crucial to understanding the role of the uncoordinated degree to balance with structural stability based on ZIF-67, which is critical for effective heterogeneous catalysts.
研究领域:
材料科学
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催化化学
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计算化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
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2016
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IF 4.179
Shuaishuai Ding,Chunhua Zhang,Yefei Liu,Hong Jiang,Weihong Xing,Rizhi Chen
We reported a Pd@CN catalyst made of Pd nanoparticles supported on a N-doped carbon derived from ZIF-67. The CN materials with micro/mesoporous structures were well developed for the loading of Pd nanoparticles and improving the catalytic performances. With the increase of calcination temperature of ZIF-67, the BET surface of CN materials initially increased and then reduced. Moreover, the higher calcination temperature would lead to lower nitrogen content in CN materials, causing lower selectivity of phenol hydrogenation to cyclohexanone. Our Pd@CN 600 catalyst achieved a conversion of ca. 95% and a selectivity of ca. 95%, and exhibited excellent stability during recycling experiments.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2025
·
IF 5.3
Zhuo Chen,Ze Zhang,Rongxin Xia,Junhu Zhou,Jun Cheng
To improve the conversion rate of carbon dioxide (CO2) to methane (CH4) in a microbial electrochemical system (MES), the zeolitic imidazolate framework ZIF-67(Co) with electron storage properties was first grown in situ on MIL-100(Fe) with excellent CO2 adsorption properties by a hydrothermal method. The obtained binary core–shell MIL@ZIF material was then adsorbed by carbon felt on a cathode to grow biofilms composed of electroactive microorganisms for characterization and testing in an MES. This system exhibited a CH4 production rate of 0.42 mmol LR–1 d–1, along with an impressive faradaic efficiency of 96.4%. Three-dimensional excitation–emission matrix spectra of extracellular polymeric substances indicated that those containing higher contents of humic acid shifted electron pairs and converted redox states to facilitate electron transfer. MIL@ZIF enriched hydrogenotrophic methanogens and electrogenic bacteria in microbial communities with enhanced gene expression of electrically conductive pili and cytochrome C to strengthen interspecies electron transfer. MIL@ZIF enhanced CO2 adsorption and electron storage, reinforcing electron transfer chains and boosting CH4 yield by a factor of 10.7.
研究领域:
环境科学
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微生物学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2021
·
IF 4.464
Qing Wang,Zihan Zhang,Shaojie Shi,Fan Wu,Zhiguo Zhang,Guoneng Li,Yange Suo
In this work, highly active cobalt- and nitrogen-doped carbon (Co-N-C) materials were prepared for oxygen reduction reaction (ORR). The Co-N-C materials were synthesized through co-pyrolysis of ZIF-67 and melamine (ZIF-67@melamine). Detailed powder X-ray diffraction (XRD), fourier transform infrared (FTIR) spectroscopy and thermo-gravimentry (TG) analyses suggest melamine could accelerate the decomposition of the ZIF-67 framework. Compared with CoNC derived from pure ZIF-67, the CoNC- x C 3 H 6 N 6 materials derived from ZIF-67@melamine exhibit more carbon defects, larger BET specific surface area, higher content of pyridinic-N and graphitic-N, resulting in the enhanced activity of the CoNC- x C 3 H 6 N 6 samples. The onset potential of CoNC-0.5C 3 H 6 N 6 -700 catalyst towards ORR is 0.96 V (vs. RHE) and the half-wave potential is 0.87 V (vs. RHE), which are close to the state-of-the-art commercial Pt/C. Besides, the electrochemical stability of the CoNC-0.5C 3 H 6 N 6 -700 catalyst is much higher than that of commercial Pt/C.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2024
·
IF 9.4
Lulu Zheng,Siyu Gao,Shuaikang Yao,Yingjie Huang,Shangru Zhai,Jingai Hao,Xuemei Fu,Qingda An,Zuoyi Xiao
The development of novel materials for electrodes with high energy densities is essential to the advancement of energy storage technologies. In this study, N -doped layered porous carbon with ZIF-67-derived binary CoFe 2 O 4 -Fe particles was successfully fabricated by the pyrolysis of an Fe-based chitosan (CS) hydrogel mixed with ZIF-67 particles. Various characterization techniques were employed to assess the performance of the prepared porous CoFe 2 O 4 -Fe@NC composite. This composite exhibits excellent performance owing to the effective combination of multivalent CoFe 2 O 4 -Fe particles derived from ZIF-67 with N -doped porous carbon substances with a high surface area, which helps to accelerate ion and charge transfer. The specific capacitance of the CoFe 2 O 4 -Fe@NC composite carbonized at 700 °C reached 3960.9F/g at 1 A/g. When this composite is combined with activated carbon (AC) to construct an asymmetric supercapacitor (ASC), a density of energy of up to 84.9 W h kg −1 is attained at a power capacity of 291.6 W kg −1 . Moreover, this composite maintained a capacitance retention of up to 94.9 % after 10,000 cycles. This work offers new perspectives on high-performance supercapacitors and their applications.
研究领域:
材料科学
·
能源存储技术
✓ 已验证
DOI
高影响因子
Journal of Energy Storage
·
2024
·
IF 8.9
Guangjun Liu,Fei Zhou,Keling Yan,Changfu Zhuang,Ying Wang,Ce Wang,Di Tian
Recently, MOF derived metal sulfides have drawn much attentions in supercapacitor filed, but its electrochemical performance is limited by their dispersion and stability. Herein, an in situ growth process was designed to fabricate Co 3 S 4 /Ni 3 S 4 on electrospun carbon nanofibers modified by ZIF-67, which offered robust structural stability , high redox activities, and enhanced the electron/ion diffusion kinetics. These merits lead to the specific capacitance of 617.78 F g −1 (specific capacity of 278.00 C g −1 ) at 0.5 A g −1 , good rate performance, as well as long cycling durability for CNF@CoNi(1:4)S in three electrode system . Its charge storage mechanism involved in a combined process of surface and diffusion contribution. In addition, an asymmetric supercapacitor (CNF@CoNi(1:4)S//AC) was constructed with the maximum energy density of 40.54 Wh kg −1 (1 A g −1 ) and the maximum power density of 6788.00 W kg −1 . This device also showed an outstanding cyclic performance (its specific capacitance could maintain the initial 115.10 % after 5000 cycles), and provided enough energy for the emission of LED. This work opens an avenue for designing MOF based or metal sulfides based functional materials .
研究领域:
材料科学
·
电化学
✓ 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）