Chemistry Africa-A Journal of the Tunisian Chemical Society
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2021
·Vol. 5
·期 1
·79-87
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IF 0
Naz Farah,Ciprian Matteo,Luo Zhixiong,Yan Shilin,Iqbal Shahzad Zafar,Zhu Meifang,Chaemchuen Somboon,Verpoort Francis
The synthesis and use of MOF-derived Co/NCF (N-doped carbon framework) material as a heterogeneous catalyst for copolymers synthesis via ring-opening polymerization (ROP) are reported for the first time. The Co/NCF material is applied for the copolymerization of L -lactides (LA) and ε-caprolactone (ε-CL) as monomers via ROP in bulk without any solvent or co-catalyst. The as-prepared catalyst is characterized using XRD, TPD, XPS, SEM, and TEM analytical techniques. At the same time, 1 H and 13 C-NMR spectroscopy were used to analyze the microstructure of the copolymer confirming the random copolymer structure. The average r values calculated from the heterodiad analysis of the 1 H NMR, data were r LA = 0.96 and r CL = 0.93 and L value calculated from the triads analysis of 13 C NMR, data were L LA = 3.17 and L CL = 2.79, respectively. It has been observed that the melting temperature and glass transition temperature of the copolymer increases with higher LA content. The XRD and DSC analyses also confirmed that the as-synthesized copolymer possesses two phases corresponding to the polylactide and polycaprolactone, respectively. Additionally, the activity of Co/NCF is also compared with other Co-based heterogeneous catalysts to demonstrate its ability. Graphic Abstract
研究领域:
材料科学
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催化化学
✓ 已验证
DOI
CARBON
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2020
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IF 8.821
Jintao Zhang,Tong Zhang,Jing Ma,Zhi Wang,Junhao Liu,Xuzhong Gong
Two-step carbonization method was reported to synthesize Co–N doped coal tar pitch (CTP) carbon-based electrocatalysts with hierarchical pore structure , high local order degree and efficient Co-N x active structure simultaneously. The synergistic effect of the carbon substrate with highly ordered structure and the Co-N x active sites realized the “Point discharge effect”. The π-π interactions from the CTP aromatic ring sheets and Co-N x promoted the adsorption and dissociation of oxygen molecules, respectively. The increased diffusion coefficient ( D 0 ) indicated the mass transfer of oxygen molecules in the boundary layer was enhanced during the ORR process. Thanks to excellent structural characteristics, ACTP 5 @Co,N-800 exhibited better ORR performance than commercial Pt/C catalyst under alkaline conditions, and the OER activity was improved simultaneously. This work demonstrated a simple and practical strategy for the development of advanced carbon-based electrocatalysts, and also provided novel insights from kinetics perspectives for improving electrocatalytic efficiency.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
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2025
·
IF 5.4
Junjie Ma,Wei Li,Xiaoqi Lan,Zheng Liu,Fenghai Zhou,Mingjun Lu,Guo-Cheng Han
The Na 3 V 2 (PO 4 ) 2 F 3 /Co/N-PC composite was prepared based on nitrogen-doped porous carbon materials containing cobalt (Co/N-PC), which is obtained through high-temperature pyrolysis of bimetallic Co/Zn-MOF. The electrochemical test results showed that the discharge specific capacity of Na 3 V 2 (PO 4 ) 2 F 3 /Co/N-PC composite was 126.66 mAh/g at 0.1C, an increase of 15.6 % compared with Na 3 V 2 (PO 4 ) 2 F 3 /N-PC(109.56 mAh/g). The capacity retention rate was 91.84 % after 100 cycles and the R SEI of the Na 3 V 2 (PO 4 ) 2 F 3 /Co/N-PC composite (48.62 Ω) outperforms that of the Na 3 V 2 (PO 4 ) 2 F 3 /N-PC composite (81.55 Ω). This work applied the metal/carbon hybrid materials obtained through high temperature pyrolysis of bimetallic organic frameworks were employed in sodium-ion batteries, thereby offering enhanced potential for the advancement of sodium-rich phosphoric acid modified materials.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
CARBON
·
2022
·
IF 11.307
Zhiqian Yao,Feng Liu,Suqiong Xu,Xianke Zhang,Chuicai Rong,Zuzhou Xiong,Jujun Yuan,Yi Yu,Xiurong Zhu,Huajun Yu
Prussian blue, a member of the metal-organic frameworks (MOFs), has attracted great interest in electromagnetic wave absorption due to its unique properties, such as multiple morphologies and tunable structures. In this paper, La 2 O 3 /Co@N-doped carbon nanotubes (La 2 O 3 /Co@NCNTs) composites were synthesized by thermal annealing La[Co(CN) 6 ]·5H 2 O Prussian blue analogue (LaCo-PBA) precursors under an Argon (Ar) atmosphere. The studies of electromagnetic wave absorption show that La 2 O 3 /Co@NCNTs demonstrated the minimum reflection loss (RL) of −53.40 dB with the effective absorption bandwidth (EAB) of 4.34 GHz at the thickness of 2.45 mm. These excellent microwave absorption properties are attributed to multiple loss mechanisms, including conduction loss , polarization loss, magnetic resonance loss, and eddy current loss . This study offers a new possibility for the design of multifaceted lightweight carbon-based microwave absorbing materials.
研究领域:
材料科学
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电磁学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2025
·
IF 6.3
Xin Ling,Yihan Zhang,Yitong Zhou,Yu Wang,Yuqin Xiong,Yili Liu,Hui Pan,Wang Zhang,Di Zhang
The increasing demand for lightweight and efficient microwave absorbers has underscored the importance of simultaneously optimizing electromagnetic attenuation and impedance matching. Although MOF-derived carbon nanocomposites offer tunable conductivity and versatile microstructures, prior research has largely focused on single-structure modifications, overlooking the broader impact of microstructural configuration. In this study, we systematically engineered four distinct structural configurations, including solid, hollow, porous, and hollow-porous, within a unified ZIF-67-derived Co/N-doped carbon system. Comparative analysis reveals that hierarchical structure modulation plays a decisive role in balancing impedance matching and attenuation mechanisms. Specifically, the hollow-porous composite (HM-CoNC) achieves synergistic enhancement through multi-interface polarization, scattering, and conductive/magnetic losses, enabled by the integration of mesoporous, internal cavities, and uniformly dispersed Co nanoparticles. As a result, HM-CoNC exhibits a minimum reflection loss of -69.52 dB at 1.62 mm and an effective absorption bandwidth of 5.25 GHz at 1.69 mm, outperforming its structural counterparts. Radar cross-section simulations further validate its stealth potential with a 29.87 dB·m² reduction relative to the uncoated substrate. These findings provide valuable insight into the microstructure-performance relationship and highlight hierarchical engineering as an effective strategy for designing high-performance microwave absorbing materials.
研究领域:
材料科学
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纳米技术
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电磁学
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微波工程
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
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2024
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IF 5.5
Rui Wang,Yixin Yan,Lu Wang,Xiaoya Kang,Shengtao Niu,Youzhi Wu,Fen Ran
Metal-organic framework draws widespread interest on account of its large specific surface areas, which could be employed as sacrificial templates to synthesize Co/N-doped carbon nanocubes. Herein, Ni-Co 3 ZnC is used as an additive for improving the electrical conductivity as well as lithium-storage performance of Co/N-doped carbon because of the conductivity and catalytic activity of metal nanoparticles . Co/N-doped carbon nanocubes and Co/N-doped carbon-Ni-Co 3 ZnC anode materials are prepared through one-step precipitation and high-temperature calcination methods. The lithium-storage capabilities of Co/N-doped carbon and Co/N-doped carbon-Ni-Co 3 ZnC are investigated. Co/N-doped carbon-Ni-Co 3 ZnC manifests good electrochemical performance at 2.0 A g −1 compared to Co/N-doped carbon. The initial reversible capacities of Co/N-doped carbon and Co/N-doped carbon-Ni-Co 3 ZnC are 877.4/548.4 and 1, 170.5/557.3 mAh g −1 , and the reversible capacities could be maintained at 152.6/152.4 and 276.8/276.5 mAh g −1 after 2, 000 cycles. The electrode kinetic results evidence that Ni-Co 3 ZnC could enhance the conductivity of Co/N-doped carbon. The data provide a theoretical basis for improving the lithium-storage performance of prevalent anode materials.
研究领域:
材料科学
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电化学
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能源存储
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
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2019
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IF 3.683
Meiling Chen,Rui Xiong,Xin Cui,Qi Wang,Xiaowang Liu
The development of earth-abundant catalysts for efficient hydrolysis of ammonia borane is of great importance in the conversion and utilization of hydrogen energy. Here, we report the synthesis of SiO2-encompassed Co@N-doped porous carbon assemblies as a new type of recyclable catalyst for the purpose by calcination of zeolitic imidazolate framework-67@SiO2 microtubes at high temperatures under an N2 atmosphere. We find that the surface layer of SiO2 in the precursor microtubes is essential for the production of efficient catalysts by supplying an additional surface for Co nanoparticle dispersion in an effort to reduce their size. In addition, the SiO2 layer renders a highly ordered arrangement of Co@N-doped porous carbon within the catalysts, possibly allowing the ease of mass transfer of ammonia borane within the catalysts. The optimized catalysts obtained via calcination at 800 °C show a set of remarkable catalytic benefits, including a high hydrogen generation rate of 8.4 mol min–1 mol(Co)–1, a relatively low activation energy of 36.1 kJ mol–1, and a remarkable reusability (at least 10 times). Our results can provide new insight into the design and synthesis of highly ordered SiO2-supported catalysts for different reactions.
研究领域:
材料科学
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催化
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氢能
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBON
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2022
·
IF 11.307
Yuxin Bi,Mingliang Ma,Zhengguo Jiao,Yong Ma,Dongshuai Hou,Guoying Geng,Wenxuan Feng,Aijie Ma,Mingtao Qiao,Yanyan Liu
Electrospinning is one of the attractive technologies for fabrication carbon-based fibers due to its high efficiency, component controllability and functionalities. Here, a multi-step strategy was used for the efficient synthesis of one-dimensional (1D) MOF-derived C@Co/N-doped carbon@polypyrrole (C@Co/NC@PPy) composite fibers . The composite fibers synthesized by introducing the electrospinning method possessed unique structural anisotropy and multiple absorption mechanisms. The electromagnetic parameters , the absorption performance and the internal mechanisms of samples were thoroughly illustrated. By adjusting the filler loadings of samples, the electromagnetic wave (EMW) absorption could be optimized. The C@Co/NC@PPy with 35 wt% filler loading showed the optimal performance. Impressively, with a thickness of merely 1.65 mm, the C@Co/NC@PPy composite fibers delivered high performance with the minimum reflection loss (RL min ) of -72.14 dB. Correspondingly, the maximum effective absorption bandwidth (EAB max ) could reach 5.6 GHz with the thickness of 1.88 mm. Furthermore, the 35 wt% loading C@Co/NC@PPy composite fibers could reach 14.28 GHz (89.25% of 2–18 GHz) effective absorption, showing the ultrawide absorption. Those positive results forcefully verified that the 1D MOF-derived C@Co/NC@PPy composites showed great potential and superiority as EMW absorption material .
研究领域:
材料科学
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电磁工程
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CARBON
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2018
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IF 7.082
Guang Li,Qingfeng Yi,Xiaokun Yang,Yao Chen,Xiulin Zhou,Gang Xie
Ni-Co-N doped honeycomb carbon (HC) nano-composites Ni 3 Co 1 -N/HC (Ni 3 Co 1 -N/HC-20, Ni 3 Co 1 -N/HC-30 and Ni 3 Co 1 -N/HC-40 with respective metal mass percentage of 20%, 30% and 40%) with a regular hexagonal structure have been fabricated by using the simple polymethylmethacrylate (PMMA) emulsion template method . The side length of the carbon hexagon is ca. 100 nm for the honeycomb carbon (HC). For the Ni 3 Co 1 -N/HC catalysts, the NiCo nanoparticles and the nanocarbon tubes derived from dicyandiamide are uniformly dispersed on HCs. The as-synthesized Ni 3 Co 1 -N/HC catalysts exhibit efficient electroactivity for oxygen reduction reaction (ORR) in alkaline medium and possess excellent tolerance to the alcohols (ethanol, n -propanol and iso -propanol). Based on these results, a membrane-less direct alcohol fuel cell has been assembled with the Ni 3 Co 1 -N/HC as the cathodic catalyst, the ternary Pd 7 Ag 2 Sn 2 /CNT as the anodic catalyst and alcohol (ethanol, n -propanol or iso -propanol) as the fuel. The fuel cell with the Ni 3 Co 1 -N/HC-40 as the cathodic catalyst displays the open circuit voltage of 0.79 V and maximum power density of 42.2 mW cm −2 for the ethanol fuel , 0.60 V and 33.3 mW cm −2 for the n -propanol fuel, and 0.43 V and 14.4 mW cm −2 for the iso -propanol fuel. The membrane-less fuel cell also presents stable discharge performance at different discharging current densities.
研究领域:
材料科学
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电化学
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能源技术
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2024
·
IF 2.7
Kun Liu,Yujing Ling,Xianglong Guan,Ke Hu,Angli Zhang,Kaiqi Liu,Haoyi Li,Guangnian Xu,Xu-Cheng Fu
The commercialization of magnesia-air batteries (Mg-air) necessitates the development of highly efficient, cost-effective, and durable electrocatalysts for oxygen reduction reaction (ORR), replacing expensive and unstable precious metal electrocatalysts. A hard template-assisted synthesis of FeCo nanoparticles immobilized on N-doped porous carbon (Fe-Co-C-N) for the ORR is reported. The half-wave potential of Fe-Co-C-N for ORR (E1/2=0.88 V vs. RHE) is elevated by 40 mV compared to that of 20 wt% Pt/C (E1/2=0.84 vs. RHE). The catalyst exhibits exceptional catalytic performance and remarkable stability. The discharge voltage of the Mg-air battery, utilizing Fe-Co-C-N as the cathode catalyst (1.29 V), surpasses that of the battery employing 20 wt% Pt/C as the cathode catalyst (1.28 V). The Mg-air battery with Fe-Co-C-N as the cathode catalyst exhibited excellent discharge stability and maintained a stable discharge for over 200 hours. The present study offers valuable insights into the structural design and regulatory mechanisms governing the performance of M-N-C catalysts in Mg-air batteries.
研究领域:
材料科学
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电化学
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能源存储
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2025
·
IF 21.1
Sijia Liu,Jiangjie Zhan,Changqing Yang,Chaohai Wei,Yun Hu
The photocatalytic cooperative hydrogen evolution and alcohol oxidation process for producing of two valuable products is highly attractive strategy, but optimizing active sites and constructing dual-function photocatalysts with high activity and selectivity remains challenging. In this study, dual active sites photocatalysts of Co/N-doped graphitic carbon nanocages (CoNC)/ZnIn 2 S 4 nanosheets (ZIS) were successfully prepared, where the Co atom anchoring on N-doped carbon (Co-N structure) and Co nanoparticles (Co NPs) encapsulating in layered graphitic carbons, resulting in the simultaneous photocatalytic hydrogen production and selective oxidation of benzyl alcohol to benzaldehyde. After regulating the active sites ratio of Co NPs/Co-N, the CoNC/ZIS exhibited an excellent hydrogen production rate (2334 μmol g⁻¹h⁻¹) and benzaldehyde production yield (2825 μmol g⁻¹h⁻¹), which were 9.0 times and 17.5 times than that of pure ZIS, respectively. The characterization results indicated that the Co-N structure served as electron-rich sites and Co NPs served as sites for dehydrogenation, promoting directed electron-hole migration and providing sufficient the optimum reaction sites for hydrogen evolution and benzyl alcohol oxidation. Furthermore, the CoNC optimized structure and interface environment of ZIS, by reducing the potential of the valence band edge and enhancing the adsorption energy for benzaldehyde, thereby effectively improving the selectivity for benzaldehyde (increased from 47.9 % to 99.2 %). Based on DFT calculations, that the synergy of interfacial Co-N structure and Co NPs played a critical role in the coupled photocatalytic system and enhanced photogenerated carrier utilization. This study suggests new avenues to the design of a dual-function photocatalyst for significantly improve the utilization efficiency of solar energy.
研究领域:
催化
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材料科学
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纳米技术
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物理化学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2019
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IF 5.108
Huajing Zhou,Jun Luo,Yuancai Chen
Ethylenediaminetetraacetic acid (EDTA) could form stable complexes with toxic metals such as nickel due to its strong chelation. In this study, with the same doping level of Co and N, MoO 2 and ZIF-67 were used as precursors to prepare MoO 2 @Co/N and FeC@Co/N electrocatalysts for the modified graphite felt cathodes in heterogeneous-electro-Fenton-like reaction (HEFL) system. The X-ray diffraction and X-ray photoelectron spectroscopy results indicated that both of the catalysts are dominated with pyridinic N (2.42% and 2.82%) upon co-doping Co/N, and FeC@Co/N exhibited an obviously higher additional sp -hybridized nitrogen ( sp -N) peak. The co-doping of Co/N induced the lattice modifications to produce more lattice defects, where pyridinic N and sp -N, related with the active sites (C–N, Co-Nx), were formed at near-ring defects along sheet edges through the nitrogen replacement of C C groups. FeC@Co/N demonstrated superior oxygen reduction reaction catalytic activity in terms of Cyclic Voltammetry and Rotating Ring-disk Electrode, and exhibited the remarkably higher current density (30 mA) and lower onset potential (−0.208 V) in Linear Sweep Voltammetry analysis. In the FeC@Co/N/CF modified HEFL system, despite the generated H 2 O 2 concentrations (62.5 mg L −1 ) is not very high, the reducing reaction of ≡Fe(III)/Co(III)–OH could get the electron directly from the cathode, which would greatly reduce the consumption of H 2 O 2, high utilization efficiency of H 2 O 2 (η: 87.63%) could greatly improve the EDTA-Ni removal (97.5%) and TOC (92.6%). This work demonstrates the feasibility of utilizing FeC@Co/N/CF as a cathode for breaking metal-complex in HEFL process.
研究领域:
环境科学
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电化学
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材料科学
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催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）