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Hierarchical Carbon Microtube@Nanotube core-shell Structure for High-Performance Oxygen Electrocatalysis and Zn-Air Battery

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Nano-Micro Letters 2020年第8期12卷 46-59页

作者： Wenfu Xie Jianming Li Yuke Song Shijin Li Jianbo Li Mingfei Shao State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029People’s Republic of China Petroleum Geology Research and Laboratory Center Research Institute of Petroleum Exploration and Development(RIPED)PetroChinaBeijing 100083People’s Republic of China

Zinc-air batteries(ZABs)hold tremendous promise for clean and efficient energy storage with the merits of high theoretical energy density and environmental ***,the performance of practical ZABs is still unsatisfactory because of the inevitably decreased activity of electrocatalysts when assembly into a thick electrode with high mass ***,we report a hierarchical electrocatalyst based on carbon microtube@nanotube core-shell nanostructure(CMT@CNT),which demonstrates superior electrocatalytic activity for oxygen reduction reaction and oxygen evolution reaction with a small potential gap of 0.678 ***,when being employed as air-cathode in ZAB,the CMT@CNT presents an excellent performance with a high power density(160.6 mW cm^−2),specific capacity(781.7 mAhgZn^−1)as well as long cycle stability(117 h,351 cycles).Moreover,the ZAB performance of CMT@CNT is maintained well even under high mass loading(3 mg cm−2,three times as much as traditional usage),which could afford high power density and energy density for advanced electronic *** believe that this work is promising for the rational design of hierarchical structured electrocatalysts for advanced metal-air batteries.

关键词： Hierarchical structure Carbon microtube@nanotube core–shell Zinc–air battery

Stability of Ag@SiO2 core–shell particles in conditions of photocatalytic overall water-splitting

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Journal of Energy Chemistry 2017年第2期26卷 309-314页

作者： Sun-Young Park Kai Han Devin B.O’Neill Guido Mul Photo Catalytic Synthesis Group MESA+Institute for NanotechnologyUniversity of TwenteP.O.Box 2177500 AE EnschedeNetherlands

core–shell nanoparticles containing plasmonic metals（Ag or Au） have been frequently reported to enhance performance of photo-electrochemical（PEC） devices. However, the stability of these particles in water-splitting conditions is usually not addressed. In this study we demonstrate that Ag@SiOcore–shell particles are instable in the acidic conditions in which WO-based PEC cells typically operate, Ag in the core being prone to oxidation, even if the SiOshell has a thickness in the order of 10 nm. This is evident from in situ voltammetry studies of several anode composites. Similar to the results of the PEC experiments, the Ag@SiOcore–shell particles are instable in slurry-based, Pt/ZnO induced photocatalytic water-splitting. This was evidenced by in situ photodeposition of Ag nanoparticles on the Pt-loaded ZnO catalyst, observed in TEM micrographs obtained after reaction. We explain the instability of Ag@SiOby OH-radical induced oxidation of Ag, yielding dissolved Ag+. Our results imply that a decrease in shell permeability for OH-radicals is necessary to obtain stable, Ag-based plasmonic entities in photo-electrochemical and photocatalytic water splitting.

关键词： Photocatalysis Photoelectrochemistry Water-splitting Plasmon Stability Ag SiO2 core–shell WO3 ZnO Mechanism

Magnetic nanoparticle-modified hollow double-shell SiC@C@FeCo with excellent electromagnetic wave absorption

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Nano Research 2024年第4期17卷 3164-3174页

作者： Guiyu Peng Jintang Zhou Jiaqi Tao Weize Wang Jun Liu Junru Yao Yijie Liu Zhengjun Yao College of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211100China Key Laboratory of Material Preparation and Protection for Harsh Environment(Nanjing University of Aeronautics and Astronautics) Ministry of Industry and Information TechnologyNanjing 211100China

Integrated micro and nanostructures,heterogeneous components,defects,and interfaces is the way to develop high-performance microwave absorbing ***,there still needs to be more precise experimental routes and effective *** this work,by a continuous process of vacuum sintering,hydrothermal,and carbon thermal reduction,magnetic FeCo nanoparticles were successfully embedded on the hollow double-shell mesoporous SiC@C surface,thus solving the challenges of a single component loss *** hollow double-shell nanostructure introduces air to enhance impedance matching while significantly reducing the density of the *** extensive defects and heterogeneous grain boundaries effectively enhance the polarization loss *** magnetic loss mechanism introduced by the magnetic particles effectively improves the impedance matching properties of the *** synergy of these multiple advantages has enabled the SCFC_(2)-8(here SiC@C@FeCo is abbreviated to SCFC,2 represents the initial metal ion content,and 8 represents the hydrothermal time)sample to achieve an adequate absorption bandwidth of 6.09 GHz at 2.0 *** a minimum reflection loss of-60.56 dB,the absorption bandwidth can cover the entire C,X,and Ku bands by adjusting the matching thickness(1.3–4.0 mm).This work provides a valuable paradigm for the deeper exploitation of microwave absorption potential and guides the development of other high-performance materials.

关键词： SiC@C@FeCo(SCFC)composites core–shell hollow structure microwave absorption

Co-Co304@carbon core-shells derived from metal-organic framework nanocrystals as efficient hydrogenevolution catalysts

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Nano Research 2017年第9期10卷 3035-3048页

作者： Yanyan Liu Guosheng Han Xiaoyu Zhang Congcong Xing Chenxia Du Huaqiang Cao Baojun Li College of Chemistry and Molecular Engineering Zhengzhou University Zhengzhou 450001 China Department of Chemistry Tsinghua University Beijing 100084 China

Controllable pyrolysis of metal−organic frameworks (MOFs) in confined spaces is a promising strategy for the design and development of advanced functional materials. In this study, Co-Co3O4@carbon composites were synthesized via pyrolysis of a Co-MOFs@glucose polymer (Co-MOFs@GP) followed by partial oxidation of Co nanoparticles (NPs). The pyrolysis of Co-MOFs@GP generated a core–shell structure composed of carbon shells and Co NPs. The controlled partial oxidation of Co NPs formed Co-Co3O4 heterojunctions confined in carbon shells. Compared with Co-MOFs@GP and Co@carbon-n (Co@C-n), Co-Co3O4@carbon-n (Co-Co3O4@C-n) exhibited higher catalytic activity during NaBH4 hydrolysis. Co-Co3O4@C-II provided a maximum specific H2 generation rate of 5,360 mL·min−1·gCo −1 at room temperature due to synergistic interactions between Co and Co3O4 NPs. The Co NPs also endowed Co-Co3O4@C-n with the ferromagnetism needed to complete the magnetic momentum transfer process. This assembly-pyrolysis-oxidation strategy may be an efficient method of preparing novel nanocomposites.

关键词： Co-metal−organic frameworks (MOFs) core–shell NaBH 4 hydrolysis pyrolysis synergistic effect

Stepwise Fabrication of Co-Embedded Porous Multichannel Carbon Nanofibers for High-Efficiency Oxygen Reduction

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Nano-Micro Letters 2019年第2期11卷 206-216页

作者： Zeming Tang Yingxuan Zhao Qingxue Lai Jia Zhong Yanyu Liang Jiangsu Key Laboratory of Materials and Technology for Energy Conversion College of Materials Science and TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016People’s Republic of China Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites Nanjing 211816People’s Republic of China

A novel nonprecious metal material consisting of Coembedded porous interconnected multichannel carbon nanofibers(Co/IMCCNFs) was rationally designed for oxygen reduction reaction(ORR)*** the synthesis,ZnCo2O4 was employed to form interconnected mesoporous channels and provide highly active Co3O4/Co core–shell nanoparticle-based sites for the *** IMC structure with a large synergistic effect of the N and Co active sites provided fast ORR electrocatalysis *** Co/IMCCNFs exhibited a high half-wave potential of 0.82 V(*** hydrogen electrode) and excellent stability with a current retention up to 88% after 12,000 cycles in a current–time test,which is only 55% for 30 wt% Pt/C.

关键词： Nonprecious metal material Multichannel carbon nanofiber Oxygen reduction reaction core–shell nanoparticle Synergistic effect

Stable Au nanoparticles confined in boron nitride shells for optimizing oxidative desulfurization

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Nano Research 2023年第10期16卷 12076-12083页

作者： Linjie Lu Jing He Peiwen Wu Yang Sun Mingqing Hua Peng Cui Wenshuai Zhu Huaming Li Zhichang Liu Chunming Xu School of Chemistry and Chemical Engineering Jiangsu UniversityZhenjiang 212013China College of Chemical Engineering and Environment State Key Laboratory of Heavy Oil ProcessingChina University of Petroleum(Beijing)Beijing 102249China

Supported gold(Au)nanocatalysts have long played an important role in numerous heterogeneous ***,the dominant difficulty of poor thermodynamic stability hampers its practical ***,a core–shell structured Au nanocatalyst with Au nanoparticles(NPs)confined in boron nitride(BN)shells is proposed for enhanced thermodynamic *** two-dimensional porous structure of BN not only functions as a physical separator for the sintering resistance of Au NPs,but also provides a microchannel for catalytic reaction ***,owing to the confinement effect,a strengthened interaction between well-designed Au NPs and the BN can be expected,which further boosts the stability and catalytic *** experiments show that a proper BN shell thickness is important to maintain the balance between the sintering resistance and catalytic activity.A significantly boosted performance of 97.2%conversion in oxidative desulfurization(ODS)was obtained with a proper number of BN coating layers,outperforming the one with a thicker BN ***,the recyclability of the prepared catalyst was investigated with no obvious decrease in catalytic performance after 10 runs,greatly higher than that without a BN shell,suggesting excellent durability.

关键词： oxidative desulfurization core–shell boron nitride Au nanocatalyst confinement effect

Fabrication of C@MoxTi1-xO2-δ nanocrystalline with functionalized interface as efficient and robust PtRu catalyst support for methanol electrooxidation

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Journal of Energy Chemistry 2020年第1期29卷 7-14,I0001页

作者： Jialong Li Lei Zhao Xifei Li Sue Hao Zhenbo Wang MIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringHarbin Institute of TechnologyNo.92 West-Da Zhi StreetHarbin 150001HeilongjiangChina Institute of Advanced Electrochemical Energy&School of Materials Science and Engineering Xi'an University of TechnologyXi'an 710048ShaanxiChina

A core shell structured C@MoxTi1-xO2-δnanocrystal with a functionalized interface(C@MTNC-FI)was fabricated via the hydrothermal method with subsequent annealing derived from tetrabutyl *** formation of anatase TiO2 was inhibited by the simultaneous presence of the hydrothermal etching/regrowth process,infiltration of Mo dopants and carbon coating,which endows the C@MTNC-FI with an ultrafine crystalline architecture that has a Mo-functionalized interface and carbon-coated *** Ru nanoparticles(NPs)were supported on C@MTNC-FI by employing a microwave-assisted polyol process(MAPP).The obtained Pt Ru/C@MTNC-FI catalyst has 2.68 times higher mass activity towards methanol electrooxidation than that of the un-functionalized catalyst(Pt Ru/C@TNC)and 1.65 times higher mass activity than that of Pt Ru/C catalyst with over 25%increase in *** improved catalytic performance is due to several aspects including ultrafine crystals of TiO2 with abundant grain boundaries,Mofunctionalized interface with enhanced electron interactions,and core shell architecture with excellent electrical transport *** work suggests the potential application of an interface-functionalized crystalline material as a sustainable and clean energy solution.

关键词： Interface functionalization TiO2 Nanocrystalline Mo doping core–shell PtRu catalyst Methanol electrooxidation

Double-shelled L1_(2) Nano-structures in Quaternary Al–Er–Sc–Zr Alloys: Origin and Critical Significance

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Acta Metallurgica Sinica(English Letters) 2021年第9期34卷 1277-1284页

作者： Chao-Min Zhang Pan Xie Yong Jiang Sheng Zhan Wen-Quan Ming Jiang-Hua Chen Ke-Xing Song Hao Zhang School of Materials Science and Engineering Henan Key Laboratory of Non-Ferrous Materials Science&Processing TechnologyHenan University of Science and TechnologyLuoyang 471023China School of Materials Science and Engineering Central South UniversityChangsha 410083China College of Materials Science and Engineering Hunan UniversityChangsha 410082China Jiangsu Haoran Spray Forming Alloy Co. LtdZhenjiang 212132China

The formation of highly coherent double-shelled L1_(2) nano-precipitates in dilute Al–Er–Sc–Zr alloys was investigated with the combined use of Cs-corrected transmission electron microscopy characterization and first-principles energetics calculations. The double-shelled nano-precipitates are primarily featured with an Er-rich core surrounded by a Sc-rich inner shell and a Zr-rich outer shell. First-principles energetics analyses based on the classic homogenous nucleation theory suggested that once forms, this double-shell structure can be thermally stable. The predominant formation of this double-shell structure has thus both profound kinetic and thermodynamic origins. Its formation and stability preference to all other possible L1_(2) nano-structures would become more pronounced as its size increases, no matter what the solute ratio and aging temperature of interest.

关键词： Al alloys core–shell L12 nano-phase First-principles

Synthesis of Pd@Pt/GNs composite and its superior electrocatalysis for methanol oxidation

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Synthesis of Pd@Pt/GNs composite and its superior electrocat...