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Electrocatalysts based on metal@carbon core@shell nanocomposites:An overview 被引量:4
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作者 Yi Peng Shaowei Chen 《Green Energy & Environment》 SCIE 2018年第4期335-351,共17页
Developing low-cost, high-performance catalysts is of fundamental significance for electrochemical energy conversion and storage. In recent years, metal@carbon core@shell nanocomposites have emerged as a unique class ... Developing low-cost, high-performance catalysts is of fundamental significance for electrochemical energy conversion and storage. In recent years, metal@carbon core@shell nanocomposites have emerged as a unique class of functional nanomaterials that show apparent electrocatalytic activity towards a range of reactions, such as hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, and CO2 reduction reaction, that are important in water splitting, fuel cells and metal-air batteries. The activity is primarily attributed to interfacial charge transfer from the metal core to the carbon shell that manipulate the electronic interactions between the catalyst surface and reaction intermediates, and varies with the structures and morphologies of the metal core(elemental composition, core size, etc.) and carbon shell(doping,layer thickness, etc.). Further manipulation can be achieved by the incorporation of a third structural component. A perspective is also included highlighting the current gap between theoretical modeling and experimental results, and technical challenges for future research. 展开更多
关键词 Metal@carbon core@shell nanocomposite Electrocatalysis Hydrogen evolution REACTION OXYGEN evolution REACTION OXYGEN reduction REACTION
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Core@shell sulfur@polypyrrole nanoparticles sandwiched in graphene sheets as cathode for lithium–sulfur batteries 被引量:3
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作者 Xiangyang Zhou Feng Chen Juan Yang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2015年第4期448-455,共8页
A nano sulfur-based composite cathode material featured by uniform core@shell-structured sulfur@polypyrrole nanoparticles sandwiched in three-dimensional graphene sheets conductive network(S@PPy/GS) is fabricated vi... A nano sulfur-based composite cathode material featured by uniform core@shell-structured sulfur@polypyrrole nanoparticles sandwiched in three-dimensional graphene sheets conductive network(S@PPy/GS) is fabricated via a facile solution-based method. The S@PPy nanoparticles are synthesized by in situ chemical oxidative polymerization of pyrrole on the surface of sulfur particles,and then graphene sheets are covered outside the S@PPy nanoparticles,forming a three-dimensional conductive network. When evaluating the electrochemical performance of S@PPy/GS in a lithium–sulfur battery,it delivers large discharge capacity,excellent cycle stability,and good rate capability. The initial discharge capacity is up to 1040 m Ah/g at 0.1 C,the capacity can remain 537.8 m Ah/g at 0.2 C after 200 cycles,even at a higher rate of 1 C,the specific capacity still reaches 566.5 m Ah/g. The good electrochemical performance is attributed to the unique structure of S@PPy/GS,which can not only provide an excellent transport of lithium and electron ions within the electrodes,but also retard the shuttle effect of soluble lithium polysulfides effectively,thus plays a positive role in building better lithium-sulfur batteries. 展开更多
关键词 Nano sulfur Conductive polymer core@shell structure Graphene coating Lithium–sulfur battery
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S1-supported Pd@CeO_(2) quasi-core@shell materials as advanced catalysts for selective hydrogenation of furfural
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作者 Xiang Chu Lingling Zhang +4 位作者 Ke Wang Rui Zhang Xiao Wang Shuyan Song Hongjie Zhang 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第3期493-496,共4页
Bare Pd metal nanoparticles invariably suffer from poor selectivity in furfural hydrogenation by forming flat configurations,with the aromatic ring of the substrate molecules parallel to the metal surface.Herein,we pu... Bare Pd metal nanoparticles invariably suffer from poor selectivity in furfural hydrogenation by forming flat configurations,with the aromatic ring of the substrate molecules parallel to the metal surface.Herein,we put forward a promising solution by using CeO_(2)as promoters to modify Pd nanoparticles for modulating the adsorption behaviors of furfural molecules.To achieve the highly-desired ultra-small Pd@CeO_(2)core@shell nanostructure,a“constrained auto-redox”synthesis is developed,in which silicalite-1 supports play the key role of providing their surface as the landing place of PdO_(x)precursors for inhibiting the overgrowth and the deformation.To the best of our knowledge,this is one of the smallest core@shell materials obtained from aqueous synthesis.When evaluated as catalysts,Pd@CeO_(2)/S-1 gives 98.9%conversion of furfural with 94.3%selectivity for furfural alcohol in 15 h,which is much better than that of Pd/S-1(88.6%conversion with 44.3%selectively).The DFT simulation reveals a strong interaction between the defects of CeO_(2)and the oxygen atom of the–CHO group in furfural molecules,which benefits the selective hydrogenation occurred in the–CHO group rather than the furan ring. 展开更多
关键词 core@shell PALLADIUM CERIA Auto-redox synthesis HYDROGENATION
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Interface engineering and impedance matching strategy to develop core@shell urchin-like NiO/Ni@carbon nanotubes nanocomposites for microwave absorption
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作者 Tianming Jia Yanling Hao +5 位作者 Xiaosi Qi Yongchao Rao Lei Wang Junfei Ding Yunpeng Qu Wei Zhong 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2024年第9期1-12,共12页
It is well recognized that interfacial effect and/or impedance matching play a great impact on microwave absorption.Herein,we proposed a facile strategy to take full advantage of interface engineering and impedance ma... It is well recognized that interfacial effect and/or impedance matching play a great impact on microwave absorption.Herein,we proposed a facile strategy to take full advantage of interface engineering and impedance matching for boosting microwave absorption performance(MAPs).Three-dimensional(3D)hierarchical urchin-like core@shell structured NiO/Ni@CNTs multicomponent nanocomposites(MCNCs)were elaborately constructed and produced in high efficiency through a facile continuous chemical bath deposition,thermal treatment,and catalytic chemical vapor decomposition process.By controlling the pyrolysis time,the NiO/Ni@CNTs urchin-like MCNCs with different lengths and aggregation degrees of CNTs could be selectively synthesized.The obtained results revealed that the enhanced CNT contents provided abundant interfaces and effectively aggrandized their interfacial effects,which resulted in improved polarization loss,conductivity loss,and comprehensive MAPs.Impressively,the interfaces and impedance matching in the designed NiO/Ni@CNTs urchin-like MCNCs could be optimized by regulating the pyrolysis temperature,which further improved the comprehensive MAPs.And the designed NiO/Ni@CNTs urchin-like MCNCs could simultaneously display strong absorption capabilities,broad absorption bandwidths,and thin matching thicknesses.Therefore,our findings not only provided a simple and universal approach to produce core@shell structured magnetic carbon-based urchin-like MCNCs but also presented an interface engineering and impedance matching strategy to develop the tunable,strong absorption,broadband,lightweight high-efficiency microwave absorbers. 展开更多
关键词 Urchin-like geometrical morphology NiO/Ni@CNTs multicomponent NANOCOMPOSITES core@shell structure Interface engineering Microwave absorption
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Tunable and improved microwave absorption of flower-like core@shell MFe_(2)O_(4)@MoS_(2)(M=Mn,Ni and Zn)nanocomposites by defect and interface engineering 被引量:6
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作者 Junxiong Xiao Xiaosi Qi +4 位作者 Xiu Gong Qiong Peng Yanli Chen Ren Xie Wei Zhong 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2023年第8期137-146,共10页
Previous results revealed that the defect and/or interface had a great impact on the electromagnetic pa-rameters of materials.In order to understand the main physical mechanisms and effectively utilize these strategie... Previous results revealed that the defect and/or interface had a great impact on the electromagnetic pa-rameters of materials.In order to understand the main physical mechanisms and effectively utilize these strategies,in this study,M Fe_(2)O_(4)and flower-like core@shell M Fe_(2)O_(4)@MoS_(2)(M=Mn,Ni,and Zn)sam-ples with different categories were elaborately designed and selectively produced in large scale through a simple two-step hydrothermal reaction.We conducted the systematical investigation on their microstruc-tures,electromagnetic parameters and microwave absorption performances(MAPs).The obtained results revealed that the large radius of M^(2+)cation could effectively boost the concentration of oxygen vacancy in the M Fe_(2)O_(4)and M Fe_(2)O_(4)@MoS_(2)samples,which resulted in the improvement of dielectric loss capabil-ities and MAPs.Furthermore,the introduction of MoS_(2)nanosheets greatly improved the interfacial effect and enhanced the polarization loss capabilities,which also boosted the MAPs.By taking full advantage of the defect and interface,the designed M Fe_(2)O_(4)@MoS_(2)samples displayed tunable and excellent com-prehensive MAPs including strong absorption capability,wide absorption bandwidth and thin matching thicknesses.Therefore,the clear understanding of defect and interface engineering made these strategies well elaborately designed and applicable to improving MAPs. 展开更多
关键词 core@shell structure M Fe_(2)O_(4)@MoS_(2)(M=Mn Ni and Zn) Defect and interface engineering Improved microwave absorption properties
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Anion regulating endows core@shell structured hollow carbon spheres@MoSxSe_(2−x)with tunable and boosted microwave absorption performance 被引量:2
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作者 Junxiong Xiao Xiaosi Qi +7 位作者 Lei Wang Tao Jing Jing-Liang Yang Xiu Gong Yanli Chen Yunpeng Qu Qiong Peng Wei Zhong 《Nano Research》 SCIE EI CSCD 2023年第4期5756-5766,共11页
Due to the good manipulation of electronic structure and defect,anion regulating should be a promising strategy to regulate the electromagnetic(EM)parameters and optimize the EM wave absorption performances(EMWAPs).In... Due to the good manipulation of electronic structure and defect,anion regulating should be a promising strategy to regulate the electromagnetic(EM)parameters and optimize the EM wave absorption performances(EMWAPs).In this work,we proposed a facile route for the large-scale production of core@shell structured hollow carbon spheres@MoSxSe_(2−x)(x=0.2,0.6,and 1.0)multicomponent nanocomposites(MCNCs)through a mild template method followed by hydrothermal process.The obtained results revealed that the designed hollow carbon spheres@MoSxSe_(2−x)MCNCs presented the improved sulfur vacancy concentration by regulating the x value from 0.2 to 1.0.The obtained hollow carbon spheres@MoSxSe_(2−x)MCNCs displayed the extraordinary comprehensive EMWAPs because of the introduced abundant defects and excellent interfacial effects.Furthermore,the as-prepared hollow carbon spheres@MoSxSe_(2−x)MCNCs presented the progressively improved comprehensive EMWAPs with the x value increasing from 0.2 to 1.0,which could be explained by their boosted polarization loss abilities and impedance matching characteristics originating from the enhanced sulfur vacancy concentration.Therefore,our findings not only demonstrated that the anion regulating was a promising method to optimize EM parameters and EMWAPs,but also provided a facile route to design the transition metal dichalcogenides-based MCNCs as the much more attractive candidates for highperformance microwave absorbers. 展开更多
关键词 anion regulating core@shell structure hollow carbon spheres@MoSxSe_(2−x) interface and defect engineering microwave absorption
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Core@shell structured Au@Sn O2 nanoparticles with improved N2 adsorption/activation and electrical conductivity for efficient N2 fixation 被引量:4
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作者 Pengtang Wang Yujin Ji +2 位作者 Qi Shao Youyong Li Xiaoqing Huang 《Science Bulletin》 SCIE EI CAS CSCD 2020年第5期350-358,共9页
The design of electrocatalysts with enhanced adsorption and activation of nitrogen(N2)is critical for boosting the electrochemical N2reduction(ENR).Herein,we developed an efficient strategy to facilitate N2 adsorption... The design of electrocatalysts with enhanced adsorption and activation of nitrogen(N2)is critical for boosting the electrochemical N2reduction(ENR).Herein,we developed an efficient strategy to facilitate N2 adsorption and activation for N2 electroreduction into ammonia(NH3)by vacancy engineering of core@shell structured Au@Sn O2 nanoparticles(NPs).We found that the ultrathin amorphous SnO2 shell with enriched oxygen vacancies was conducive to adsorb N2as well as promoted the N2 activation,meanwhile the metallic Au core ensured the good electrical conductivity for accelerating electrons transport during the electrochemical N2 reduction reaction,synergistically boosting the N2 electroreduction catalysis.As confirmed by the15N-labeling and controlled experiments,the core@shell Au@amorphous SnO2 NPs with abundant oxygen vacancies show the best performance for N2 electroreduction with the NH3 yield rate of 21.9 lg h-1mg-1catand faradaic efficiency of 15.2%at-10.2 VRHE,which surpass the Au@crystalline SnO2 NPs,individual Au NPs and all reported Au-based catalysts for ENR. 展开更多
关键词 core@shell ELECTROREDUCTION Nitrogen FIXATION VACANCY engineering AMORPHOUS
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Construction of trace silver modified core@shell structured Pt-Ni nanoframe@CeO2 for semihydrogenation of phenylacetylene 被引量:4
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作者 Yan Long Jian Li +5 位作者 Lanlan Wu Qishun Wang Yu Liu Xiao Wang Shuyan Song Hongjie Zhang 《Nano Research》 SCIE EI CAS CSCD 2019年第4期869-875,共7页
The Pt-Ni nanoframe catalysts have attracted great interest owing to their unique electronic structure and excellent catalytic performance. However, the stability of the tenu ous edges of nano frame-structures is diss... The Pt-Ni nanoframe catalysts have attracted great interest owing to their unique electronic structure and excellent catalytic performance. However, the stability of the tenu ous edges of nano frame-structures is dissatisfactory and their un iversal applicati ons in catalytic market beyond electrocatalytic reactions are yet to be tapped and explored. Herein, we developed a new core@ shell structured Pt-Ni nanoframe@CeO2 (Pt-Ni NF@CeO2) composite via etching the Ni from inhomogeneous Pt-Ni rhombic dodecahedra (Pt-Ni RD) by cerium(lll) acetate hydrate (Ce(OAc)3). In this path, Pt-Ni RD was used as self-sacrificial 怕mplate, while the Ce(OAc)3 serves as the provider of the Ce3* source and OH' for the formation of CeO2 shell, etchant of Pt-Ni RD, and the surface modification agent. By this way, the etching of Pt-Ni RD and the formation of the CeO2 shell are simultaneously proceeded to form the final Pt-Ni NF@CeO2 in one step. The obtained Pt-Ni NF@CeO2 exhibits strong in terfacial charge tran sfer interactio n betwee n Pt-Ni NF core and CeO2 shell eve n without reductio n treatment, leading to enhan ced catalytic activity in the hydrogenation of phenylacetylene. After introduction of trace silver, the Pt-Ni-Ag4.9 NF@CeO2 achieves remarkable catalytic performa nee for the selective con versi on of phe ny lacetyle ne to styrene: high con version (100%), styre ne selectivity (86.5%), and good stability. It reveals that enc apsulatio n n oble metal nano frames into metal oxide to form core @ shell structured hybrids will in deed enhance their stability and catalytic properties. Particularly, this work expends the application of noble metal nanoframes materials to hydrogenation reacti ons. 展开更多
关键词 CEO2 Pt-Ni nanoframes core@shell sturcuture silver modification HYDROGENATION of PHENYLACETYLENE
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Defect and interface engineering in core@shell structure hollow carbon@MoS_(2)nanocomposites for boosted microwave absorption performance 被引量:6
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作者 Junxiong Xiao Xiaosi Qi +4 位作者 Xiu Gong Qiong Peng Yanli Chen Ren Xie Wei Zhong 《Nano Research》 SCIE EI CSCD 2022年第9期7778-7787,共10页
Defect and interface engineering are efficient approaches to adjust the physical and chemical properties of nanomaterials.In order to effectively utilize these strategies for the improvement of microwave absorption pr... Defect and interface engineering are efficient approaches to adjust the physical and chemical properties of nanomaterials.In order to effectively utilize these strategies for the improvement of microwave absorption properties(MAPs),in this study,we reported the synthesis of hollow carbon shells and hollow carbon@MoS_(2)nanocomposites by the template-etching and templateetching-hydrothermal methods,respectively.The obtained results indicated that the degree of defect for hollow carbon shells and hollow carbon@MoS_(2)could be modulated by the thickness of hollow carbon shell,which effectively fulfilled the optimization of electromagnetic parameters and improvement of MAPs.Furthermore,the microstructure investigations revealed that the precursor of hollow carbon shells was encapsulated by the sheet-like MoS_(2)in high efficiency.And the introduction of MoS_(2)nanosheets acting as the shell effectively improved the interfacial effects and boosted the polarization loss capabilities,which resulted in the improvement of comprehensive MAPs.The elaborately designed hollow carbon@MoS_(2)samples displayed very outstanding MAPs including strong absorption capabilities,broad absorption bandwidth,and thin matching thicknesses.Therefore,this work provided a viable strategy to improve the MAPs of microwave absorbers by taking full advantage of their defect and interface engineering. 展开更多
关键词 core@shell structure hollow carbon shells hollow carbon@MoS_(2) defect and interface engineering improved microwave absorption properties
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Microstructure optimization of core@shell structured MSe_(2)/FeSe_(2)@MoSe_(2)(M=Co,Ni)flower-like multicomponent nanocomposites towards high-efficiency microwave absorption 被引量:6
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作者 Jingjing Zhang Xiaosi Qi +4 位作者 Xiu Gong Qiong Peng Yanli Chen Ren Xie Wei Zhong 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2022年第33期59-70,共12页
In this work,we put forward a scheme to exquisitely design and selectively synthesize the core@shell structured MSe_(2)/FeSe_(2)@MoSe_(2)(M=Co,Ni)flower-like multicomponent nanocomposites(MCNCs)through a simple two-st... In this work,we put forward a scheme to exquisitely design and selectively synthesize the core@shell structured MSe_(2)/FeSe_(2)@MoSe_(2)(M=Co,Ni)flower-like multicomponent nanocomposites(MCNCs)through a simple two-step hydrothermal reaction on the surfaces of MFe_(2)O_4 nanospheres with the certain amounts of Mo and Se sources.With increasing the amounts of Mo and Se sources,the obtained core@shell structured MSe_(2)/FeSe_(2)@MoSe_(2)(M=Co,Ni)MCNCs with the enhanced content of MoSe_(2)and improved flower-like geometry morphology could be produced on a large scale.The obtained results revealed that the as-prepared samples displayed improved comprehensive microwave absorption properties(CMAPs)with the increased amounts of Mo and Se sources.The as-prepared CoSe_(2)/FeSe_(2)@MoSe_(2)and NiSe_(2)/FeSe_(2)@MoSe_(2)MCNCs with the well-defined flower-like morphology could simultaneously present the outstanding CMAPs in terms of strong absorption capability,wide absorption bandwidth,and thin matching thicknesses,which mainly originated from the conduction loss and flower-like geometry morphology.Therefore,the findings not only develop the very desirable candidates for high-performance microwave absorption materials but also pave a new way for optimizing the CMAPs through tailoring morphology engineering. 展开更多
关键词 core@shell structure MSe_(2)/FeSe_(2)@MoSe_(2)(M=Co.Ni) multicomponent nanocomposites Flower-like geometry morphology Broad frequency bandwidth Microwave absorption
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Mass production of Co3O4@CeO2 core@shell nanowires for catalytic CO oxidation 被引量:4
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作者 Jiangman Zhen Xiao Wang +5 位作者 Dapeng Liu Zhuo Wang Junqi Li Fan Wang Yinghui Wang Hongjie Zhang 《Nano Research》 SCIE EI CAS CSCD 2015年第6期1944-1955,共12页
In this study, Co3O4@CeO2 core@shell nanowires were successfully prepared via thermal decomposition of Co(CO3)0.5(OH).0.11H2O@CeO2 core@shell nanowire precursors. As a CO oxidation catalyst, Co3O4@CeO2 shows remar... In this study, Co3O4@CeO2 core@shell nanowires were successfully prepared via thermal decomposition of Co(CO3)0.5(OH).0.11H2O@CeO2 core@shell nanowire precursors. As a CO oxidation catalyst, Co3O4@CeO2 shows remarkably enhanced catalytic performance compared to Co3O4 nanowires and CeO2 nanoparticles (NPs), indicating obvious synergistic effects between the two components. It also suggests that the CeO2 shell coating can effectively prevent Co3O4 nanowires from agglomerating, hence effecting a substantial improvement in the structural stability of the Co3O4 catalyst. Furthermore, the fabrication of the welbdisperse4 core@shell structure results in a maximized interface area between Co3O4 and CeO2, as well as a reduced Co3O4 size, which may be responsible for the enhanced catalytic activity of Co3O4@CeO2. Further examination revealed that CO oxidation may occur at the interface of Co3O4 and CeO2. The influence of calcination temperatures and the component ratio between Co3O4 and CeO2 were then investigated in detail to determine the catalytic performance of Co3O4@CeO2 core@shell nanowires, the best of which was obtained by calcination at 250 ℃ for 3 h with a Ce molar concentration of about 38.5%. This sample achieved 100% CO conversion at a reduced temperature of 160 ℃. More importantly, more than 2.5 g of the Co3O4@CeO2 core@shell nanowires were produced in one pot by this simple process, which may be beneficial for practical applications as automobile-exhaust gas-treatment catalysts. 展开更多
关键词 Co3O4@CeO2 core@shell NANOWIRES CO oxidation synergistic effects
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Interfacial engineering of 3D hollow CoSe_(2)@ultrathin MoSe_(2)core@shell heterostructure for efficient pH-universal hydrogen evolution reaction 被引量:2
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作者 Lili Zhang Yuanting Lei +7 位作者 Danni Zhou Chengli Xiong Zhuoli Jiang Xinyuan Li Huishan Shang Yafei Zhao Wenxing Chen Bing Zhang 《Nano Research》 SCIE EI CSCD 2022年第4期2895-2904,共10页
Rational design and construction of low-cost and highly efficient electrocatalysts for hydrogen evolution reaction(HER)is meaningful but challenging.Herein,a robust three dimensional(3D)hollow CoSe_(2)@ultrathin MoSe_... Rational design and construction of low-cost and highly efficient electrocatalysts for hydrogen evolution reaction(HER)is meaningful but challenging.Herein,a robust three dimensional(3D)hollow CoSe_(2)@ultrathin MoSe_(2)core@shell heterostructure(CoSe_(2)@MoSe_(2))is proposed as an efficient HER electrocatalyst through interfacial engineering.Benefitting from the abundant heterogeneous interfaces on CoSe_(2)@MoSe_(2),the exposed edge active sites are maximized and the charge transfer at the hetero-interfaces is accelerated,thus facilitating the HER kinetics.It exhibits remarkable performance in pH-universal conditions.Notably,it only needs an overpotential(η10)of 108 mV to reach a current density of 10 mA·cm^(-2)in 1.0 M KOH,outperforming most of the reported transition metal selenides electrocatalysts.Density functional theory(DFT)calculations unveil that the heterointerfaces synergistically optimize the Gibbs free energies of H2O and H^(*)during alkaline HER,accelerating the reaction kinetics.The present work may provide new construction guidance for rational design of high-efficient electrocatalysts. 展开更多
关键词 transition metal selenides hydrogen evolution reaction core@shell heterostructure pH-universal
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Magnetic Fe_(2)P Nanowires and Fe_(2)P@C Core@Shell Nanocables
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作者 Junli Wang Qing Yang +4 位作者 Jun Zhou Kewen Sun Zude Zhang Xiaoming Feng Tanwei Li 《Nano Research》 SCIE EI CSCD 2010年第3期211-221,共11页
We report the synthesis of one-dimensional(1-D)magnetic Fe_(2)P nanowires and Fe_(2)P@C core@shell nanocables by the reactions of triphenylphosphine(PPh_(3))with Fe powder(particles)and ferrocene(Fe(C_(5)H_(5))_(2)),r... We report the synthesis of one-dimensional(1-D)magnetic Fe_(2)P nanowires and Fe_(2)P@C core@shell nanocables by the reactions of triphenylphosphine(PPh_(3))with Fe powder(particles)and ferrocene(Fe(C_(5)H_(5))_(2)),respectively,in vacuum-sealed ampoules at 380-400℃.The synthesis is based on chemical conversion of micrometer or nanometer sized Fe particles into Fe_(2)P via the extraction of phosphorus from liquid PPh_(3) at elevated temperatures.In order to control product diameters,a convenient sudden-temperature-rise strategy is employed,by means of which diameter-uniform Fe_(2)P@C nanocables are prepared from the molecular precursor Fe(C_(5)H_(5))2.In contrast,this strategy gives no obvious control over the diameters of the Fe_(2)P nanowires obtained using elemental Fe as iron precursor.The formation of 1-D Fe_(2)P nanostructures is ascribed to the cooperative effects of the kinetically induced anisotropic growth and the intrinsically anisotropic nature of hexagonal Fe_(2)P crystals.The resulting Fe_(2)P nanowires and Fe_(2)P@C nanocables display interesting ferromagnetic-paramagnetic transition behaviors with blocking temperatures of 230 and 268 K,respectively,significantly higher than the ferromagnetic transition temperature of bulk Fe_(2)P(TC=217 K). 展开更多
关键词 Metal phosphide NANOWIRES core@shell nanocables magnetic nanostructures chemical synthesis
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ZnO/TiO_(2)核-壳纳米结构的低温制备及其光电性能研究 被引量:1
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作者 李丽华 王贺 +1 位作者 王航 黄金亮 《功能材料》 CAS CSCD 北大核心 2024年第1期1217-1222,共6页
ZnO因其自身的高电荷复合、化学性质活泼,导致其应用受到限制,通过表面修饰进行复合可实现电子-空穴的分离并提高其化学稳定性。以二水合醋酸锌、六水合硝酸锌、六氟钛酸铵为原料,采用溶胶-凝胶、水热和液相沉积相结合的方法,在低温条... ZnO因其自身的高电荷复合、化学性质活泼,导致其应用受到限制,通过表面修饰进行复合可实现电子-空穴的分离并提高其化学稳定性。以二水合醋酸锌、六水合硝酸锌、六氟钛酸铵为原料,采用溶胶-凝胶、水热和液相沉积相结合的方法,在低温条件下制备出ZnO/TiO_(2)单异质结。采用XRD、SEM、EDS、TEM、PL等对样品进行表征并对其光电性能进行测试。结果表明,在沉积时间为20 min时,ZnO/TiO_(2)核-壳结构形貌最规整,其中ZnO直径约115 nm,TiO_(2)薄膜厚度约7.6 nm;TiO_(2)的负载,降低了电极中光生电荷的复合,提高了ZnO对光子的收集能力,光电流密度提升大约10倍,达到0.21μA/cm^(2),表现出优异的光电化学性能。 展开更多
关键词 ZnO/TiO_(2) 核-壳结构 异质结 光电极材料 液相沉积
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核壳结构C-TiO_(2)纳米复合材料用于高效光催化降解有机染料 被引量:1
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作者 王文静 汤晶 +2 位作者 刘维刚 程晓丽 徐英明 《黑龙江大学工程学报(中英俄文)》 2024年第1期1-11,F0002,共12页
化工、纺织印染与农药化肥等产业的蓬勃发展推动着人类社会的进步,但同时也给环境治理带来了巨大难题。目前,光催化降解局限于在特定波长下针对单一有机污染物进行降解,然而现实中的情况往往更复杂。因此,开发一种多功能光催化材料用于... 化工、纺织印染与农药化肥等产业的蓬勃发展推动着人类社会的进步,但同时也给环境治理带来了巨大难题。目前,光催化降解局限于在特定波长下针对单一有机污染物进行降解,然而现实中的情况往往更复杂。因此,开发一种多功能光催化材料用于光催化降解不同有机污染物显得尤为重要。采用一步无模板溶剂热法合成了核壳结构的C-TiO_(2)复合材料前驱体,并在氩气气氛下煅烧得到高结晶度的C-TiO_(2)复合光催化材料。运用SEM、TEM、XRD和TG等表征手段对材料进行表征,结论如下:550℃煅烧时的样品为包含少量碳的高结晶度的锐钛矿相TiO 2,且550℃煅烧时的样品依然保持了完整的核壳结构。此外,C-TiO_(2)复合材料的比表面积高达85.69 m 2·g^(-1),平均孔径为16.4 nm以及孔体积为0.423 m 3·g^(-1)。在UV-Vis光照射下,C-TiO_(2)复合材料分别对罗丹明B(RhB)、亚甲基蓝(MB)和刚果红(CR)3种染料显示出增强的光催化降解活性。 展开更多
关键词 光催化 C-TiO_(2) 溶剂热 核壳结构
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锂离子电池三元正极核-壳结构的电化学-力学模拟
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作者 苟蕾 杨哲祺 +3 位作者 余金花 樊小勇 李东林 李辉 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 2024年第9期112-121,共10页
利用有限元模拟技术构建了电化学-力学耦合的三维多物理场锂离子电池模型,进而获得了核-壳正极在放电过程中Li+浓度、应变和应力的分布与演变情况,并研究了放电结束时不同放电倍率、壳厚度和核粒径对应变和应力的影响.结果表明,颗粒中... 利用有限元模拟技术构建了电化学-力学耦合的三维多物理场锂离子电池模型,进而获得了核-壳正极在放电过程中Li+浓度、应变和应力的分布与演变情况,并研究了放电结束时不同放电倍率、壳厚度和核粒径对应变和应力的影响.结果表明,颗粒中心及核-壳界面处的应力在放电初期迅速达到最大值,然后随着Li+扩散过程的进行,应力逐渐减小.另外,黏结剂和相邻颗粒对电极应力分布有显著影响.减小放电速率和核粒径以及增加壳厚度能够降低电极中的应力.研究结果可为核-壳正极结构的设计与优化以及锂离子电池放电策略提供参考. 展开更多
关键词 锂离子电池 核-壳结构 有限元 电化学 扩散应力
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含氟高分子材料包覆铝核壳材料研究进展
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作者 郭学永 周近强 +5 位作者 李洪亮 吴成成 方华 邓鹏 朱艳丽 刘睿 《兵工学报》 EI CAS CSCD 北大核心 2024年第5期1534-1546,共13页
金属铝(Al)具有高燃烧热值、高密度、低耗氧量等优异性能,是固体复合推进剂领域最受青睐的金属添加剂。为了提高固体复合推进剂的性能,有必要采取措施对Al进行包覆改性。近年来含氟高分子包覆Al因其优异的综合性能而受到广泛关注。介绍... 金属铝(Al)具有高燃烧热值、高密度、低耗氧量等优异性能,是固体复合推进剂领域最受青睐的金属添加剂。为了提高固体复合推进剂的性能,有必要采取措施对Al进行包覆改性。近年来含氟高分子包覆Al因其优异的综合性能而受到广泛关注。介绍了不同种类的含氟高分子包覆金属Al核壳材料、不同包覆方法、Al核壳材料的性能以及含氟高分子与Al的作用机理,总结发现通过Al核壳结构设计、含氟高分子引入和Al颗粒表面的自活化策略等途径,含氟高分子与氧化铝层之间的表面发生剧烈的氧化过程,增强Al核壳材料点火和燃烧性能,显著改善推进剂的燃烧团聚和燃烧效率。但目前含氟高分子包覆Al核壳材料研究过程仍存在许多不足,如缺乏新型多元含氟高分子包覆Al的能量性能的研究;缺乏Al颗粒与包覆层在高升温速率下作用机理的认识;包覆效率和批量制备能力低,阻碍了其实际应用等。未来可从进一步增强朝着研发新型含氟聚合物、研究对反应历程中产物的实时捕捉和开发工业化生产制造技术等方向发展。 展开更多
关键词 含氟高分子 铝核壳材料 包覆 复合固体推进剂
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Cu-TiO_(2)@CeO_(2)催化剂催化氧化NH_(3)/Hg^(0)
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作者 陈传敏 彭钦磊 +5 位作者 曹悦 吴佳艺 陈韵伊 刘妍 刘松涛 贾文波 《化学工程》 CAS CSCD 北大核心 2024年第10期19-24,38,共7页
为了减少SCR系统逃逸氨和气态单质汞的排放,采用模板法制备一系列具有氨氧化和汞氧化活性的Cu-TiO_(2)@CeO_(2)催化剂,在150—400℃下测试其氨氧化和汞氧化性能,并对其进行了XRD(X射线衍射)、BET(比表面积测试)和XPS(X射线光电子能谱)... 为了减少SCR系统逃逸氨和气态单质汞的排放,采用模板法制备一系列具有氨氧化和汞氧化活性的Cu-TiO_(2)@CeO_(2)催化剂,在150—400℃下测试其氨氧化和汞氧化性能,并对其进行了XRD(X射线衍射)、BET(比表面积测试)和XPS(X射线光电子能谱)表征。结果表明:高温可以促进NH_(3)的氧化,但不利于保持高N 2选择性和Hg^(0)氧化效果。随着铜、铈质量分数的增加,催化剂的氨氧化和汞氧化活性均逐渐增加,而N_(2)选择性有所下降。其中Cu、Ce质量分数为5%的Cu-TiO_(2)@CeO_(2)-5催化剂可以达到较为理想的NH_(3)和Hg^(0)去除效果,350℃下对NH_(3)和Hg^(0)的氧化效率均高于90%,N_(2)选择性在95%以上,副产物N 2 O生成量低于5×10^(-6)。表征结果显示Cu-TiO_(2)@CeO_(2)催化剂中形成了Cu^(+)+Ce^(4+)←→Cu^(2+)+Ce^(3+)氧化还原双电对,Cu与Ce的氧化物在NH_(3)和Hg^(0)氧化反应中起协同作用,大量的Oβ作为活性氧参与到反应中,有效促进了NH_(3)和Hg^(0)的催化脱除。 展开更多
关键词 氨氧化 双功能催化剂 核壳结构
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纳米TiO_(2)微球的制备及光催化降解气相苯特性
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作者 杜晶晶 赵军伟 +1 位作者 施飞 程晓民 《功能材料》 CAS CSCD 北大核心 2024年第7期7231-7236,共6页
以四氯化钛和尿素为原料,通过溶剂热法制备了纳米TiO_(2)微球。利用XRD、FE-SEM、TEM、UV-Vis、BET测试手段对样品的组成、结构、形貌、光学性能、比表面特性进行分析,以气相苯为目标降解物,研究不同溶剂热时间所制备的微球对光催化活... 以四氯化钛和尿素为原料,通过溶剂热法制备了纳米TiO_(2)微球。利用XRD、FE-SEM、TEM、UV-Vis、BET测试手段对样品的组成、结构、形貌、光学性能、比表面特性进行分析,以气相苯为目标降解物,研究不同溶剂热时间所制备的微球对光催化活性的影响。结果表明,随溶剂热时间的延长,TiO_(2)微球结构经历了实心-核壳-空心的演变过程,但均由20 nm以下的颗粒组成。此类微球的光吸收带边出现明显“蓝移”现象,且光吸收性能较P25 TiO_(2)要高,比表面积是其3~5倍。其中溶剂热时间为6 h所制备的核壳结构微球光催化活性最佳,降解气相苯的矿化率高达93%,高于P25 TiO_(2)近3倍,分析表明,该优异性能得益于核壳结构对光的充分反射吸收和高比表面积导致的吸附协同光催化特性。 展开更多
关键词 纳米TiO_(2)微球 溶剂热法 中空核壳结构 光催化 气相苯
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BT@PANI核壳粒子的绿色制备及PVDF基复合材料的介电性能
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作者 王海燕 咸龙帝 +3 位作者 尚天蓉 姚佳岐 燕小斌 李澜 《材料导报》 EI CAS CSCD 北大核心 2024年第13期241-246,共6页
聚合物薄膜介电电容器在新能源汽车、太阳能和风力并网发电与储能等领域具有广泛应用和广阔的发展前景。钛酸钡/聚合物复合材料具有介电损耗低、击穿场强高的特点,是电容器中核心部分高介电有机薄膜材料极具潜力的选择之一。目前,迫切... 聚合物薄膜介电电容器在新能源汽车、太阳能和风力并网发电与储能等领域具有广泛应用和广阔的发展前景。钛酸钡/聚合物复合材料具有介电损耗低、击穿场强高的特点,是电容器中核心部分高介电有机薄膜材料极具潜力的选择之一。目前,迫切需要解决高极化特性与低损耗难以协同改善的问题。本工作提出以苹果酸同时作为钛酸钡(BT)表面修饰剂和聚苯胺(PANI)掺杂剂,采用原位聚合法制备了BT@PANI核壳粒子,并以此为填料制备了聚偏氟乙烯(PVDF)基复合材料。结果显示,通过苹果酸与盐酸的两步表面改性法,可获得钛酸钡-苯胺阳离子(BT-An^(+))粒子,为此不同苯胺(An)与BT-An^(+)质量比条件下填料产物的核壳结构特征明显。当An与BT-An^(+)的质量比为0.5∶1时产物平均粒径最小,约为450 nm,粒径分布最窄,且电导率为1.46×10^(-3)S/cm。以此为填料,30%(质量分数)填充量的PVDF基复合材料在10^(3)~10^(6)Hz范围内介电常数保持在高值水平,由31仅下降到15,介电损耗在宽的频率范围内低于0.3,不仅表现出优良的频率稳定性,而且在获得较高的介电常数情况下,实现了介电损耗的有效抑制。此外,这项工作极大地降低了无机氧化性酸与有机试剂的使用率,为实现高性能介电复合材料的绿色制备提供了实验指导。 展开更多
关键词 复合电介质 聚合物基体 介电性能 核壳结构 绿色制备
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