Journal of Materials Chemistry A
·
2013
·Vol. 1
·期 47
·14943-14950
·
IF 0
Hai Fu,Zhong-jie Du,Wei Zou,Hang-quan Li,Chen Zhang
A carbon nanotube reinforced polypyrrole nanowire network was constructed by in situ polymerization of pyrrole in the presence of carbon nanotubes using cetyltrimethylammonium bromide micelles as a soft template. Carbon nanotubes as a reinforcer were embedded into a network of polypyrrole nanowires, thus retaining in the latter a complete network. The resulting network possessed a specific surface area of 112.1 m2 g−1 and a rough porous structure. The embedding of carbon nanotubes decreased the charge transfer resistance in the polypyrrole nanowires and allowed easy access and rapid diffusion of ions/electrons. When applied as a capacitive electrode, a specific capacitance of 183.2 F g−1 was observed at a current density of 8 A g−1. The specific capacitance retention was 85% after 1000 cycles at 1 A g−1. An asymmetric supercapacitor was fabricated using the network as a positive electrode and active carbon as a negative electrode, and when operated at a maximum voltage of 1.5 V, had a high energy density (15.1 W h kg−1 at 3000 W kg−1). A long-term cycling test of the asymmetric supercapacitor at a current density of 1 A g−1 displayed a capacitance retention of 72% even after 3000 cycles of charge and discharge.
研究领域:
材料科学
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纳米科技
·
电化学
·
能源存储
·
高分子科学
✓ 已验证
DOI
RSC Advances
·
2017
·Vol. 7
·期 64
·40650-40657
·
IF 3.108
Wei Chen,Qingyun Liu,Xixi Zhu,Min Fu
Strontium ferrites/graphene (SrFe12O19/G) composites were synthesized by a facile one-step surfactant assisted hydrothermal method. The structure, magnetic properties and electromagnetic parameters of the as-prepared composites were evaluated. Uniform SrFe12O19 nanoparticles with a diameter of 60–70 nm were well distributed on the graphene. The formation of SrFe12O19 nanoparticles and the reduction of graphene oxide were accomplished simultaneously. The re-stacking of graphene sheets and the aggregation of SrFe12O19 nanoparticles were inhibited. The as-obtained composites exhibited better absorbing properties than the pristine SrFe12O19 particles due to the synergistic effect of SrFe12O19 and graphene. The minimum reflection loss (RL) of SrFe12O19/G composites with the thickness of 3 mm reached −34.8 dB at 13.6 GHz, and the effective absorption bandwidth (RL < −10 dB) was 5.7 GHz. However, the minimum RL of the SrFe12O19 particles only reached −13.5 dB, and the effective absorption bandwidth was 4.6 GHz. A possible mechanism for the enhanced absorbing performance was proposed.
研究领域:
材料科学
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纳米材料
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电磁学
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功能材料
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复合材料
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2020
·
IF 7.216
Xiaojing Jiang,Jianian Chen,Fenglei Lyu,Chen Cheng,Qixuan Zhong,Xuchun Wang,Ayaz Mahsud,Liang Zhang,Qiao Zhang
Controllable fabrication of Fe-N-C based single-atom catalysts (SACs) for enhanced electrocatalytic performance is highly desirable but still challenging. Here, an in situ surface-confined strategy was demonstrated for the synthesis of single atomic Fe-N 4 on N-doped carbon nanoleaves (L-FeNC). The in situ generated Zn 3 [Fe(CN) 6 ] 2 could not only serve as a protection layer against collapse of nanoleaves but also provide abundant Fe source for the formation of Fe-N moieties during pyrolysis, leading to high surface area and high graphitization degree of L-FeNC simultaneously. Benefiting from abundant Fe-N 4 active sites, enhanced mass and charge transfer, the as-prepared L-FeNC manifested a half-wave potential of 0.89 V for oxygen reduction reaction (ORR) in 0.1 M KOH. A maximum power density of 140 mW cm −2 and stable discharge voltage even after operation for 50,000 s have been demonstrated when the L-FeNC was used as air cathode for Zn-air battery. This work not only provided a unique surface-confined strategy for the synthesis of two-dimensional nanocarbons, but also demonstrated the significant benefit from rational design and engineering of Fe-N-C SACs, thus offering great opportunities for fabrication of efficient energy conversion and storage devices.
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
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纳米科技
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催化化学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2021
·Vol. 42
·期 10
·1798-1807
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IF 8.271
Xiangyong Zhang,Tianying Liu,Ting Guo,Xueying Han,Zongyun Mu,Qiang Chen,Jiangmin Jiang,Jing Yan,Jiaren Yuan,Dezhi Wang,Zhuangzhi Wu,Zongkui Kou
Controllably mounting foreign atoms on the surfaces of earth-abundant electrocatalysts strongly improve their surface electronic properties for optimizing the catalytic performance of surficial sites to an unusual level, and provides a good platform to gain deep insights into catalytic reactions . The present work describes, employing ultrafine W 2 C nanoislands (average size: 2.3 nm) monodispersed on the N, P dual-doped carbon frameworks as a model system, how to regulate the atomic phosphorous-mounting effect on the surfaces of W 2 C to derive an active and stable P-mounting W 2 C (WCP) catalyst for both acidic and alkaline hydrogen evolution reaction (HER). Since in situ phosphorus substitution into carbon sites of preformed W 2 C nanoislands gradually proceeds from surfaces to solids, so that using a proper amount of phosphorus sources can readily control the surface mounting level to avoid the mass P-doping into the bulk. By this way, the activity per active site of WCP catalyst with robust stability can be optimized to 0.07 and 0.56 H 2 s −1 at –200 mV overpotential in acid and base, respectively, which reach up to the several-fold of pure-phase W 2 C (0.01 and 0.05 H 2 s −1 ). Theoretical investigations suggest that compared with solid P doping, the P mounting on W 2 C surface can more remarkably enhance its metallicity and decrease the hydrogen release barrier. This finding disclosed a key correlation between surface foreign atom-mounting and catalytic activity , and suggested a logical extension to other earth-abundant catalysts for various catalytic reactions .
研究领域:
材料化学
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电催化
·
纳米材料
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能源科学
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表面科学
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理论计算
✓ 已验证
DOI
高影响因子
FUEL
·
2017
·
IF 4.601
Junliang Wang,Shuyan Zhou,Ke Bei,I-Ming Chou,Chunmian Lin,Zhiyan Pan
This work developed a new method for measuring the volume expansion of a CO 2 + n -dodecane mixture, using a fused silica capillary cell (FSCC), combined with a heating-cooling stage and a confocal Raman spectrometer. The cell was constructed on the micron scale to reduce the temperature gradient and reagent consumption. The results confirmed the feasibility of this method that using Raman spectra to verify phase equilibrium, a digital camera to record images of the CO 2 + n -dodecane mixture and a micrometer to measure the volume, a section of water (water seal) between n -dodecane and gas phase to prevent n -dodecane from evaporating. It was shown that the volume expansion factor of the mixture increased with pressure going from 1.0 to 10.0 MPa, but decreased as the temperature was raised from 30 to 80 °C. In addition, a positive quadratic relationship ( R 2 > 0.99) was obtained between Raman peak intensity ratio and volume expansion factor, such that more volume expansion factors could be obtained according to the equations with measured Raman peak intensity ratio data. This experiment widens the ranges of temperature and pressure in the measurements of the volume expansion, and provides more volume expansion data for CO 2 -enhanced oil recovery.
研究领域:
物理化学
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能源科学
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油气开采
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光谱分析
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热力学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·Vol. 47
·期 15
·21459-21465
·
IF 4.527
Xianwei Su,Xiaojia Shang,Yusi Che,Shaolong Li,Jianxun Song,Jilin He
Homogenous ZrC x O y powders have been successfully synthesized by in-situ electro-reduction of solid ZrO 2 –C composite precursors in molten CaCl 2 . The effect of applied cell voltage and molar ratio of ZrO 2 to C on preparation of ZrC x O y were investigated. The reduction pathway of the composite electrode was studied based on the analysis of intermediate products using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that ZrO 2 is firstly converted to CaZrO 3 . The resulting CaZrO 3 is then reduced to ZrC x O y . The ZrC x O y formation is dramatically influenced by electrolysis voltage and molar ratio of ZrO 2 to C: a higher cell voltage and lower molar ratio of the ZrO 2 to C are more preferable for the formation of ZrC x O y powder. Homogenous ZrC x O y powders with particle size of ~100 nm are synthesized by ZrO 2 /C starting elemental powders in CaCl 2 molten salt at 1123 K for more than 3 h, when the cell voltage is 3.0 V and the molar ratio of the ZrO 2 to carbon starting materials is 1:1.0.
研究领域:
材料科学
·
无机非金属材料
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电化学合成
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粉末冶金
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固态化学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2022
·
IF 7.336
Yifan Zhang,Laifu Yang,Wenqiang Wang,Gengchao Wang
LiNbO 3 is an intercalation material with high theoretical specific capacity, which is promising for lithium-ion capacitor (LIC) anode. However, the poor charge transfer dynamics makes LiNbO 3 unable to match the capacitive cathode in rate performance and cycle stability, resulting in poor electrochemical performance of the device. Herein, through the integrated process of in-situ nitrogen-doping with polypyrrole as the nitrogen source and hydrothermal deposition, the coaxial heterostructure of ultrafine LiNbO 3 nanoparticles and nitrogen-doped carbon nanotubes (NCNT) was realized. The large lithium-ion accessible surface and the bonding with the conductive channel significantly enhance the pseudocapacitive behavior of LiNbO 3 (capacitance contribution of 78.5% at 1 mV s −1 ). After 1000 cycles at a current density of 2 A g −1 , NCNT@LiNbO 3 still has a specific capacity of 154.9 mAh g −1 (89.8%). Thus, the assembled NCNT@LiNbO 3 //AC devices can charge and discharge up to 10000 cycles at a current density of 2 A g −1 , and the capacity retention rate can still reach 90.3%, and can provide an energy density of 142 Wh kg −1 . This work provides ideas for the interface and structure design of nanocomposite electrode materials.
研究领域:
材料科学
·
电化学
·
纳米复合材料
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能源存储
·
界面工程
·
电极设计
✓ 已验证
DOI
高影响因子
Energy & Environmental Materials
·
2022
·Vol. 6
·期 3
·e12351
·
IF 13.443
Qiyu Wang,Xiangqun Xu,Bo Hong,Maohui Bai,Jie Li,Zhian Zhang,Yanqing Lai
Quasi-solid-state lithium metal battery is a promising candidate for next generation high energy density and high safety power supply. Despite intensive efforts on electrolytes, uncontrolled interfacial reactions on lithium with electrolyte and patchy interfacial contacts still hinder its practical process. Herein, we bring in rationally designed F contained groups into polymer skeleton via in-situ gelation for the first time to establish quasi-solid-state battery. This method achieves a capacity retention of 90% after 1000 cycles at 0.5C with LiFePO 4 cathodes. The interface constructed by polymer skeleton and reaction with –CF 3 lead to the predicted solid electrolyte interface species with high stability. Furthermore, we optimize molecular reactivity and interface stability with regulating F contained end groups in the polymer. Comparisons on different structures reveal that high performance solid stable lithium metal batteries rely on chemical modification as well as stable polymer skeleton, which is more critical to construct robust and steady SEI with uniform lithium deposition. New approach with functional groups regulation proposes a more stable cycling process with a capacity retention of 94.2% at 0.5C and 87.6% at 1C after 1000 cycles with LiFePO 4 cathodes, providing new insights for the practical development of quasi-solid-state lithium metal battery.
研究领域:
电化学
·
材料科学
·
能源存储
·
界面化学
·
高分子化学
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2016
·
IF 4.758
Yong Zhang,Tianyi Han,Ziying Wang,Chen Zhao,Jianning Li,Teng Fei,Sen Liu,Geyu Lu,Tong Zhang
Herein, a novel electrochemical hydrazine sensor has been successfully fabricated using N-doped carbon film-immobilized Au nanoparticles coated ZnO jungle on indium tin oxide (AuNPs@NC-ZnO/ITO) as working electrode. The AuNPs@NC-ZnO/ITO has been prepared by an in situ synthesis method through the following steps. Firstly, the ZnO jungle modified ITO was prepared by electrochemical deposition method. Then, zeolitic imidazolate framework-8 (ZIF-8) film was formed on the surface of ZnO jungle by wet-chemical method using ZnO jungle and 2-methylimidazole as Zn precursor and organic ligand, respectively. The loading AuNPs was performed by adsorption of Au 3+ into micropores of ZIF-8, followed by heat treatment under N 2 atmosphere, where the ZIF-8 converted into N-doped carbon and Au 3+ converted into AuNPs embedded in N-doped carbon film. Most importantly, such AuNPs@NC-ZnO/ITO exhibited good electrocatalytic activity for the oxidation of hydrazine. The hydrazine sensor based on AuNPs@NC-ZnO/ITO showed linear detection range from 0.05 to 10 μM and detection limit of 4.1 nM at a signal-to-noise ratio of 3.
研究领域:
分析化学
·
电化学传感
·
纳米材料
·
生物医学工程
·
环境监测
·
转化医学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2016
·Vol. 27
·期 7
·7265-7273
·
IF 1.798
Zhang Dongjiu,Cheng Haifeng,Zhang Zhaoyang,Kang Yue
This paper introduced a general method of etching suspended graphene by nonmetallic SiO x nanoparticles (SiO x NPs) in graphene synthesis. Effects of etching time, concentration of silica gel and type of graphene on the etching mode of graphene have been systematically considered with using as-grown graphene film on a silica gel coating copper as model system. Nonmetallic SiO x NPs acted as etchant plays important role in the in situ etching process during the fabrication of graphene. The etched multilayer graphene pattern can be modulated from large area films to a rectangle pattern by varying the Si concentration and etching time, while single layer graphene pattern alters little. The morphology and critical structure of SiO x etched graphene were characterized by Raman spectra, transmission electron microscopy, scanning electron microscope and X-ray photoelectron spectrum. The process and mechanism described here open the way for tailoring graphene via nanoparticles instead of metal, which show significant influence of the electrical properties of graphene.
研究领域:
纳米材料学
·
表面科学
·
凝聚态物理
·
材料化学
·
电子显微学
✓ 已验证
DOI
高影响因子
Sustainable Energy & Fuels
·
2023
·Vol. 8
·期 2
·358-368
·
IF 5.6
Hai Lu,Peichun Wang,Yitian Ma,Meng Liu,Linqing Chang,Rui Feng,Shuliang Luo,Zhiyun Zhang,Yi Wang,Yan Yuan
In this study, quasi-solid polymer electrolytes incorporating an ionic liquid (ILQSEs) fabricated in different organic solvents via a thermally-initiated polymerization strategy were investigated for flexible supercapacitors (SCs). It was found that low-viscous acetonitrile (AN) with a strongly-polar nitrile group was remained in the polymer matrix, which favored a higher ionic conductivity, wider electrochemical window, and better thermal stability of the ILQSE compared to its propylene carbonate (PC) counterpart. Moreover, the in situ polymerized quasi-solid electrolyte achieved close contact with the porous carbon electrode, accompanied by the favorable permeation of the IL into the electrode for enhancing the ion-transport kinetics and interface stability. Consequently, the as-assembled SC with the AN-based ILQSE delivered a high specific energy and specific power, excellent cycle stability, and reliable safety.
研究领域:
材料科学
·
电化学
·
高分子化学
·
能源存储
·
纳米科技
✓ 已验证
DOI
高影响因子
CATALYSIS TODAY
·
2012
·Vol. 194
·期 1
·38-43
·
IF 3.407
An-Hua Liu,Ran Ma,Meng Zhang,Liang-Nian He
Carbon dioxide, being one of the major greenhouse gases responsible for global warming, its atmospheric level grows ever faster since the beginning of industrial era. Great efforts have been devoted to developing versatile technologies/processes to adjust and manipulate the rapid growth of CO 2 emission. Besides CO 2 capture and storage/sequestration (CCS) to control its emission, chemical utilization of the captured CO 2 (CCU) emerges to be a rational technique for economical benefits as well as environmental concerns. As for the aim of CO 2 utilization, an environmentally benign CO 2 /water reversible acidic system was developed for the copper (II)-catalyzed selective oxybromination of electron-rich aromatics without the need of any conventional acid additive and organic solvent. Notably, up to 95% yields of the bromination products were attained with good regio-selectivity when cupric bromide was used as the catalyst and lithium bromide as a cheap and easy handling bromine source under supercritical CO 2 . The catalytic system worked well for electron-rich aromatics including ethers, sulfides and mesitylene. Carbonic acid in situ formed from CO 2 and water is supposed to act as the proton donator in the Brønsted acid-promoted reaction. Notably, CO 2 in this study serves as a reaction medium and a promoter in conjunction with water and also provides safe environment for aerobic reactions. Given with excellent reaction efficiency as well as no need of neutralization disposal, this process thus represents an environmentally friendly approach for aerobic bromination of aromatics with essential reduction of CO 2 emission as well as an economically beneficial way for application of captured CO 2 .
研究领域:
有机化学
·
绿色化学
·
催化化学
·
环境化学
·
化学工程
·
二氧化碳资源化
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）