采用阳离子表面活性剂协助的自模板法合成了中空介孔Si O_2微球(HMSS),然后向含HMSS的悬浮液中加入醋酸钴溶液和氨水,让两种溶液经HMSS表面介孔进入空腔中反应生成Co_3O_4内核,合成了多核yolk-shell型Co_3O_4@m Si O_2(介孔Si O_2)纳米...采用阳离子表面活性剂协助的自模板法合成了中空介孔Si O_2微球(HMSS),然后向含HMSS的悬浮液中加入醋酸钴溶液和氨水,让两种溶液经HMSS表面介孔进入空腔中反应生成Co_3O_4内核,合成了多核yolk-shell型Co_3O_4@m Si O_2(介孔Si O_2)纳米反应器.结合XRD、XPS、SEM、STEM、BET等手段,分析了纳米反应器的形貌、结构、元素形态和比表面积.结果显示纳米反应器均匀分散,粒径约为300nm,表面布满介孔,内部分布大量Co_3O_4纳米粒子,拥有极大的比表面积161m^2/g,远大于Co_3O_4纳米粒子的比表面积35m^2/g,能有效吸附双酚A(BPA),1h吸附容量达12.7mg/g.多核yolk-shell型Co_3O_4@m Si O_2纳米反应器能高效催化过一硫酸氢盐(PMS)降解BPA,2h降解率达81.8%,远高于Co_3O_4纳米粒子的降解率51.3%,同时能节省PMS的投加量,避免水中盐度过高.此外,合成的纳米反应器具有很好的再利用性,在p H值3~9范围内表现出稳定而高效的催化性能.展开更多
Conversion-type reaction anode materials with high specific capacity are attractive candidates to improve lithium ion batteries(LIBs), yet the rapid capacity fading and poor rate capability caused by drastic volume ch...Conversion-type reaction anode materials with high specific capacity are attractive candidates to improve lithium ion batteries(LIBs), yet the rapid capacity fading and poor rate capability caused by drastic volume change and low electronic conductivity greatly hinder their practical applications. To circumvent these issues, the successful design of yolk@shell Fe2 O3@C hybrid composed of a columnar-like Fe2O3 core within a hollow cavity completely surrounded by a thin, self-supported carbon(C) shell is presented as an anode for high-performance LIBs. This yolk@shell structure allows each Fe2O3 core to swell upon lithiation without deforming the carbon shell. This preserves the structural and electrical integrity against pulverization, as revealed by in situ transmission electron microscopy(TEM) measurement. Benefiting from these structural advantages, the resulting electrode exhibits a high reversible capacity(1013 m Ah g-1 after80 cycles at 0.2 A g-1), outstanding rate capability(710 m Ah g-1 at 8 A g-1) and superior cycling stability(800 m Ah g-1 after 300 cycles at 4 A g-1). A Li-ion full cell using prelithiated yolk@shell Fe2 O3@C hybrid as the anode and commercial Li CoO2(LCO) as the cathode demonstrates impressive cycling stability with a capacity retention of 84.5% after 100 cycles at 1 C rate, holding great promise for future practical applications.展开更多
Non-spherical Cu@Cu S yolk–shell structures are successfully obtained using Cu_2 O cube templates in a process combining rapid surface sulfidation followed by disproportionation of the Cu_2 O core upon treatment with...Non-spherical Cu@Cu S yolk–shell structures are successfully obtained using Cu_2 O cube templates in a process combining rapid surface sulfidation followed by disproportionation of the Cu_2 O core upon treatment with a hydrochloric acid solution. By employing the above method,Cu@Cu S yolk–shell structures with different morphologies,including octahedral, truncated octahedral, and cuboctahedral shapes, can be synthesized. The void space within the hollow structures provides a unique confined space, where the metallic copper present in the core of a shell can be protected from agglomeration and oxidation. Furthermore,the presence of metal copper in these hollow structurescontributes to improvement in the photocatalytic properties of these materials. The application of these Cu@Cu S structures indeed shows clearly improved photocatalytic performance.展开更多
The conceptual design of yolk-shell structured Si/C composites is considered to be an effective way to improve the recyclability and conductivity of Si-based anode materials. Herein, a new type of yolk-shell structure...The conceptual design of yolk-shell structured Si/C composites is considered to be an effective way to improve the recyclability and conductivity of Si-based anode materials. Herein, a new type of yolk-shell structured Si/C composite (denoted as TSC-PDA-B) has been intelligently designed by rational engineering and precise control. In the novel structure, the multiple Si nanoparticles with small size are successfully encapsulated into the porous carbon shells with double layers benefiting from the strong etching effect of HF. The TSC-PDA-B product prepared is evaluated as anode materials for lithium-ion batteries (LIBs). The TSC-PDA-B product exhibits an excellent lithium storage performance with a high initial capacity of 2108 mAh g^-1 at a current density of 100 mA g^-1 and superior cycling performance of 1113 mAh g^-1 over 200 cycles. The enhancement of lithium storage performance may be attributed to the construction of hybrid structure including small Si nanoparticles, high surface area, and double carbon shells, which can not only increase electrical conductiv让y and intimate electrical contact with Si nanoparticles, but also provide built-in buffer voids for Si nanoparticles to expand freely without damaging the carbon layer. The present findings can provide some scientific insights into the design and the application of advanced Si-based anode materials in energy storage fields.展开更多
Lithium sulfur(Li-S)batteries hold great promising for high-energy-density batteries,but appear rapid capacity fading due to the lack of overall and elaborated design of both sulfur host and interlayer.Herein,we devel...Lithium sulfur(Li-S)batteries hold great promising for high-energy-density batteries,but appear rapid capacity fading due to the lack of overall and elaborated design of both sulfur host and interlayer.Herein,we developed a novel two-dimensional(2D)hierarchical yolk-shell heterostructure,constructed by a graphene yolk,2D void and outer shell of vertically aligned carbon-mediated MoS2 nanosheets(G@void@MoS2/C),as advanced host-interlayer integrated electrode for Li-S batteries.Notably,the 2D void,with a typical thickness of^80 nm,provided suitable space for loading and confining nano sulfur,and vertically aligned ultrathin MoS2 nanosheets guaranteed enriched catalytically active sites to effectively promote the transition of soluble polysulfides.The conductive graphene yolk and carbon mediated shell sufficiently accelerated electron transport.Therefore,the integrated electrode of G@void@MoS2/C not only exceptionally confined the sulfur/polysulfides in 2D yolk-shell heterostructures,but also achieved catalytic transition of the residual polysulfides dissolved in electrolyte to solid Li2S2/Li2S,both of which synergistically achieved an extremely low capacity fading rate of 0.05%per cycle over 1000 times at 2C,outperforming most reported Mo based cathodes and interlayers for Li-S batteries.2D hierarchical yolkshell heterostructures developed here may shed new insight on elaborated design of integrated electrodes for Li-S batteries.展开更多
A facile strategy to fabricate gold nanorod@polyacrylic acid/calcium phosphate(Au NR@-PAA/Ca P) yolk–shell nanoparticles(NPs) composed with a PAA/Ca P shell and an Au NR yolk is reported. The asobtained Au NR@PAA/Ca ...A facile strategy to fabricate gold nanorod@polyacrylic acid/calcium phosphate(Au NR@-PAA/Ca P) yolk–shell nanoparticles(NPs) composed with a PAA/Ca P shell and an Au NR yolk is reported. The asobtained Au NR@PAA/Ca P yolk–shell NPs possess ultrahigh doxorubicin(DOX) loading capability(1 mg DOX/mg NPs), superior photothermal conversion property(26%)and p H/near-infrared(NIR) dual-responsive drug delivery performance. The released DOX continuously increased due to the damage of the Ca P shell at low p H values. When the DOX-loaded Au NR@PAA/Ca P yolk–shell NPs wereexposed to NIR irradiation, a burst-like drug release occurs owing to the heat produced by the Au NRs. Furthermore,Au NR@PAA/Ca P yolk–shell NPs are successfully employed for synergic dual-mode X-ray computed tomography/photoacoustic imaging and chemo-photothermal cancer therapy. Therefore, this work brings new insights for the synthesis of multifunctional nanomaterials and extends theranostic applications.展开更多
Lithium-ion batteries(LIBs) and sodium-ion batteries(SIBs) have received much attention in energy storage system. In particular, among the great efforts on enhancing the performance of LIBs and SIBs, yolk–shell(YS) s...Lithium-ion batteries(LIBs) and sodium-ion batteries(SIBs) have received much attention in energy storage system. In particular, among the great efforts on enhancing the performance of LIBs and SIBs, yolk–shell(YS) structured materials have emerged as a promising strategy toward improving lithium and sodium storage. YS structures possess unique interior void space, large surface area and short diffusion distance, which can solve the problems of volume expansion and aggregation of anode materials, thus enhancing the performance of LIBs and SIBs. In this review, we present a brief overview of recent advances in the novel YS structures of spheres, polyhedrons and rods with controllable morphology and compositions. Enhanced electrochemical performance of LIBs and SIBs based on these novel YS structured anode materials was discussed in detail.展开更多
Transition metal oxides have been actively exploited for application in lithium ion batteries due to their facile synthesis,high specific capacity,and environmental-friendly.In this paper,Fe3O4@TiO2@C yolk-shell(Y-S)s...Transition metal oxides have been actively exploited for application in lithium ion batteries due to their facile synthesis,high specific capacity,and environmental-friendly.In this paper,Fe3O4@TiO2@C yolk-shell(Y-S)spheres,used as anode material for lithium ion batteries,were successfully fabricated by Stober method.XRD patterns reveal that Fe3O4@TiO2@C Y-S spheres possess a good crystallinity.But the diffraction peaks’intensity of Fe3O4 crystals in the composites is much weaker than that of bare Fe3O4 spheres,indicating that the outer anatase TiO2@C layer can cover up the diffraction peaks of inner Fe3O4 spheres.The yolk-shell structure of Fe3O4@TiO2@C spheres is further characterized by TEM,HAADFSTEM,and EDS mapping.The yolk-shell structure is good for improving the cycling stability of the inner Fe3O4 spheres during lithium ions insertion-extraction processes.When tested at 200 mA/g,the Fe3O4@TiO2@C Y-S spheres can provide a stable discharge capacity of 450 mAh/g over 100 cycles,which is much better than that of bare Fe3O4 spheres and TiO2@C spheres.Furthermore,cyclic voltammetry curves show that the composites have a good cycling stability compared to bare Fe3O4 spheres.展开更多
Yolk‐shell structured nanoparticles are of immense scientific and technological interests because of their unique architecture and myriad of applications.This review summarizes recent progresses in the use of yolk‐s...Yolk‐shell structured nanoparticles are of immense scientific and technological interests because of their unique architecture and myriad of applications.This review summarizes recent progresses in the use of yolk‐shell structured nanoparticles as nanoreactors for various chemical reactions.A very brief overview of synthetic strategies is provided with emphasis on recent research progress in the last five years.Catalytic applications of these yolk‐shell structured nanoreactors are then discussed by covering photocatalysis,methane reforming and electrochemical conversion.The state of the art research and perspective in future development are also highlighted.展开更多
Transitional metal phosphides(TMPs)anode materials usually have large volume change and weak diffusion kinetics,leading to poor cycle stability.Combining TMPs with conductive carbon matrix has been widely used to boos...Transitional metal phosphides(TMPs)anode materials usually have large volume change and weak diffusion kinetics,leading to poor cycle stability.Combining TMPs with conductive carbon matrix has been widely used to boost sodium storage.However,it still needs to make efforts in the rational and facile design of nano/micro-structural TMPs/carbon hybrid anode material.Herein,a MOFs-derived strategy is developed to synthesize porous yolk–shell Mo P/Cu_(3)P@carbon microcages(Mo P/Cu_(3)P@C)through in situ and confined phosphidation reaction as a high-performance sodium-ion batteries anode.This yolk–shell structure can offer adequate internal space to buffer the large volume expansion,shorten diffusion distance,and create more active sites of Na+.Especially,the Cu nanoparticles generated from Cu_(3)P have remarkable electronic conductivity of 5.73107S m-1(the second most conductive metal)to benefit transporting electrons.And the introduction of Mo(Mo P has high theoretical capacity of 633 mA h g^(-1))can enhance the reversible capacity of the whole anode material.Therefore,these porous yolk–shell Mo P/Cu_(3)P@carbon microcages possess excellent reversible capacity of 307.8 mA h g^(-1)at 1.0 A g^(-1)and extraordinary cycle stability of 132.1 m A h g^(-1)at 5.0 A g^(-1)even after 6000 cycles.展开更多
Though water electrolysis is effective in generating high-quality hydrogen gas,it requires effective electrocatalysts for hydrogen evolution reaction(HER).CoS_2 have been considered as a promising HER electrocatalyst ...Though water electrolysis is effective in generating high-quality hydrogen gas,it requires effective electrocatalysts for hydrogen evolution reaction(HER).CoS_2 have been considered as a promising HER electrocatalyst because of its high ctalytic activity.However,the key limitation for CoS_2 nanomaterial as HER electrocatalyst is its poor stability,which may be due to the structural breakdown of CoS_2 nanostructure or the evolution of S during H_2 evolution in acid media.Coating porous carbon thin layer for protection from structural breakdown and evolution of S is a good way to improve catalytic stability.In addition,coating carbon layer can change electronic structure of CoS_2 for the moderated hydrogen adsorption energy,leading to enhanced catalytic activity.Here,CoS_2 yolk-shell spheres coated with carbon thin layers exhibit superior catalytic performance for HER with low overpotential,small Tafel slope,and excellent stability.展开更多
文摘采用阳离子表面活性剂协助的自模板法合成了中空介孔Si O_2微球(HMSS),然后向含HMSS的悬浮液中加入醋酸钴溶液和氨水,让两种溶液经HMSS表面介孔进入空腔中反应生成Co_3O_4内核,合成了多核yolk-shell型Co_3O_4@m Si O_2(介孔Si O_2)纳米反应器.结合XRD、XPS、SEM、STEM、BET等手段,分析了纳米反应器的形貌、结构、元素形态和比表面积.结果显示纳米反应器均匀分散,粒径约为300nm,表面布满介孔,内部分布大量Co_3O_4纳米粒子,拥有极大的比表面积161m^2/g,远大于Co_3O_4纳米粒子的比表面积35m^2/g,能有效吸附双酚A(BPA),1h吸附容量达12.7mg/g.多核yolk-shell型Co_3O_4@m Si O_2纳米反应器能高效催化过一硫酸氢盐(PMS)降解BPA,2h降解率达81.8%,远高于Co_3O_4纳米粒子的降解率51.3%,同时能节省PMS的投加量,避免水中盐度过高.此外,合成的纳米反应器具有很好的再利用性,在p H值3~9范围内表现出稳定而高效的催化性能.
基金supported by the National Natural Science Foundation of China(Grants No.21703185)the leading Project Foundation of Science Department of Fujian Province(Grants No.2018H0034)+1 种基金Fundamental Research Funds for the Central Universities(Xiamen University:20720170042)the“Double-First Class”Foundation of Materials and Intelligent Manufacturing Discipline of Xiamen University。
文摘Conversion-type reaction anode materials with high specific capacity are attractive candidates to improve lithium ion batteries(LIBs), yet the rapid capacity fading and poor rate capability caused by drastic volume change and low electronic conductivity greatly hinder their practical applications. To circumvent these issues, the successful design of yolk@shell Fe2 O3@C hybrid composed of a columnar-like Fe2O3 core within a hollow cavity completely surrounded by a thin, self-supported carbon(C) shell is presented as an anode for high-performance LIBs. This yolk@shell structure allows each Fe2O3 core to swell upon lithiation without deforming the carbon shell. This preserves the structural and electrical integrity against pulverization, as revealed by in situ transmission electron microscopy(TEM) measurement. Benefiting from these structural advantages, the resulting electrode exhibits a high reversible capacity(1013 m Ah g-1 after80 cycles at 0.2 A g-1), outstanding rate capability(710 m Ah g-1 at 8 A g-1) and superior cycling stability(800 m Ah g-1 after 300 cycles at 4 A g-1). A Li-ion full cell using prelithiated yolk@shell Fe2 O3@C hybrid as the anode and commercial Li CoO2(LCO) as the cathode demonstrates impressive cycling stability with a capacity retention of 84.5% after 100 cycles at 1 C rate, holding great promise for future practical applications.
基金supported by the National Natural Science Foundation of China (Grant Nos. 21671085, 21473081, 21201088)the Natural Science Foundation of Jiangsu Province (BK20161160)the Qing Lan Project and the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Non-spherical Cu@Cu S yolk–shell structures are successfully obtained using Cu_2 O cube templates in a process combining rapid surface sulfidation followed by disproportionation of the Cu_2 O core upon treatment with a hydrochloric acid solution. By employing the above method,Cu@Cu S yolk–shell structures with different morphologies,including octahedral, truncated octahedral, and cuboctahedral shapes, can be synthesized. The void space within the hollow structures provides a unique confined space, where the metallic copper present in the core of a shell can be protected from agglomeration and oxidation. Furthermore,the presence of metal copper in these hollow structurescontributes to improvement in the photocatalytic properties of these materials. The application of these Cu@Cu S structures indeed shows clearly improved photocatalytic performance.
基金financially supported by the National Natural Science Foundation of China(21471096)Shanghai Pujiang Program(17PJD015)
文摘The conceptual design of yolk-shell structured Si/C composites is considered to be an effective way to improve the recyclability and conductivity of Si-based anode materials. Herein, a new type of yolk-shell structured Si/C composite (denoted as TSC-PDA-B) has been intelligently designed by rational engineering and precise control. In the novel structure, the multiple Si nanoparticles with small size are successfully encapsulated into the porous carbon shells with double layers benefiting from the strong etching effect of HF. The TSC-PDA-B product prepared is evaluated as anode materials for lithium-ion batteries (LIBs). The TSC-PDA-B product exhibits an excellent lithium storage performance with a high initial capacity of 2108 mAh g^-1 at a current density of 100 mA g^-1 and superior cycling performance of 1113 mAh g^-1 over 200 cycles. The enhancement of lithium storage performance may be attributed to the construction of hybrid structure including small Si nanoparticles, high surface area, and double carbon shells, which can not only increase electrical conductiv让y and intimate electrical contact with Si nanoparticles, but also provide built-in buffer voids for Si nanoparticles to expand freely without damaging the carbon layer. The present findings can provide some scientific insights into the design and the application of advanced Si-based anode materials in energy storage fields.
基金financially supported by the National Key R@D Program of China (Grants 2016YBF0100100 and 2016YFA0200200)the National Natural Science Foundation of China (Grants 51572259 and 51872283)+5 种基金LiaoNing Revitalization Talents Program (Grant XLYC1807153)the Natural Science Foundation of Liaoning Province (Grant 20180510038)DICP (DICP ZZBS201708, DICP ZZBS201802)DICP&QIBEBT (Grant DICP&QIBEBT UN201702)Dalian National Laboratory For Clean Energy (DNL), CAS, DNL Cooperation Fund, CAS (DNL180310, DNL180308)the Fundamental Research Funds for the Central Universities of China (Grant N180503012 and N172410002-16)
文摘Lithium sulfur(Li-S)batteries hold great promising for high-energy-density batteries,but appear rapid capacity fading due to the lack of overall and elaborated design of both sulfur host and interlayer.Herein,we developed a novel two-dimensional(2D)hierarchical yolk-shell heterostructure,constructed by a graphene yolk,2D void and outer shell of vertically aligned carbon-mediated MoS2 nanosheets(G@void@MoS2/C),as advanced host-interlayer integrated electrode for Li-S batteries.Notably,the 2D void,with a typical thickness of^80 nm,provided suitable space for loading and confining nano sulfur,and vertically aligned ultrathin MoS2 nanosheets guaranteed enriched catalytically active sites to effectively promote the transition of soluble polysulfides.The conductive graphene yolk and carbon mediated shell sufficiently accelerated electron transport.Therefore,the integrated electrode of G@void@MoS2/C not only exceptionally confined the sulfur/polysulfides in 2D yolk-shell heterostructures,but also achieved catalytic transition of the residual polysulfides dissolved in electrolyte to solid Li2S2/Li2S,both of which synergistically achieved an extremely low capacity fading rate of 0.05%per cycle over 1000 times at 2C,outperforming most reported Mo based cathodes and interlayers for Li-S batteries.2D hierarchical yolkshell heterostructures developed here may shed new insight on elaborated design of integrated electrodes for Li-S batteries.
基金the National Natural Science Foundation of China(Grant Nos.21573040 and 21603029)the Natural Science Foundation and Science and Technology Development Planning of Jilin Province(20150204086GX and20170520148JH)+3 种基金the Fundamental Research Funds for the Central Universities(2412016KJ007 and 2412016KJ020)the China Postdoctoral Science Foundation(2016M600224)the Jilin Provincial Research Foundation for Basic Research(20160519012JH)Jilin Provincial Key Laboratory of Advanced Energy Materials(Northeast Normal University)
文摘A facile strategy to fabricate gold nanorod@polyacrylic acid/calcium phosphate(Au NR@-PAA/Ca P) yolk–shell nanoparticles(NPs) composed with a PAA/Ca P shell and an Au NR yolk is reported. The asobtained Au NR@PAA/Ca P yolk–shell NPs possess ultrahigh doxorubicin(DOX) loading capability(1 mg DOX/mg NPs), superior photothermal conversion property(26%)and p H/near-infrared(NIR) dual-responsive drug delivery performance. The released DOX continuously increased due to the damage of the Ca P shell at low p H values. When the DOX-loaded Au NR@PAA/Ca P yolk–shell NPs wereexposed to NIR irradiation, a burst-like drug release occurs owing to the heat produced by the Au NRs. Furthermore,Au NR@PAA/Ca P yolk–shell NPs are successfully employed for synergic dual-mode X-ray computed tomography/photoacoustic imaging and chemo-photothermal cancer therapy. Therefore, this work brings new insights for the synthesis of multifunctional nanomaterials and extends theranostic applications.
基金supported by National Program on Key Basic Research Project (973 Program) No. 2013CB933301National Natural Science Foundation of China No. 51272038 and 61474015
文摘Lithium-ion batteries(LIBs) and sodium-ion batteries(SIBs) have received much attention in energy storage system. In particular, among the great efforts on enhancing the performance of LIBs and SIBs, yolk–shell(YS) structured materials have emerged as a promising strategy toward improving lithium and sodium storage. YS structures possess unique interior void space, large surface area and short diffusion distance, which can solve the problems of volume expansion and aggregation of anode materials, thus enhancing the performance of LIBs and SIBs. In this review, we present a brief overview of recent advances in the novel YS structures of spheres, polyhedrons and rods with controllable morphology and compositions. Enhanced electrochemical performance of LIBs and SIBs based on these novel YS structured anode materials was discussed in detail.
基金supported by the Tianjin Committee of Science and Technology (No.14JCZDJC32400)Tianjin Science and Technology Innovation Platform Program (No.14TXGCCX00017)
文摘Transition metal oxides have been actively exploited for application in lithium ion batteries due to their facile synthesis,high specific capacity,and environmental-friendly.In this paper,Fe3O4@TiO2@C yolk-shell(Y-S)spheres,used as anode material for lithium ion batteries,were successfully fabricated by Stober method.XRD patterns reveal that Fe3O4@TiO2@C Y-S spheres possess a good crystallinity.But the diffraction peaks’intensity of Fe3O4 crystals in the composites is much weaker than that of bare Fe3O4 spheres,indicating that the outer anatase TiO2@C layer can cover up the diffraction peaks of inner Fe3O4 spheres.The yolk-shell structure of Fe3O4@TiO2@C spheres is further characterized by TEM,HAADFSTEM,and EDS mapping.The yolk-shell structure is good for improving the cycling stability of the inner Fe3O4 spheres during lithium ions insertion-extraction processes.When tested at 200 mA/g,the Fe3O4@TiO2@C Y-S spheres can provide a stable discharge capacity of 450 mAh/g over 100 cycles,which is much better than that of bare Fe3O4 spheres and TiO2@C spheres.Furthermore,cyclic voltammetry curves show that the composites have a good cycling stability compared to bare Fe3O4 spheres.
文摘Yolk‐shell structured nanoparticles are of immense scientific and technological interests because of their unique architecture and myriad of applications.This review summarizes recent progresses in the use of yolk‐shell structured nanoparticles as nanoreactors for various chemical reactions.A very brief overview of synthetic strategies is provided with emphasis on recent research progress in the last five years.Catalytic applications of these yolk‐shell structured nanoreactors are then discussed by covering photocatalysis,methane reforming and electrochemical conversion.The state of the art research and perspective in future development are also highlighted.
基金supported by the National Natural Science Foundation of China(no.21646012)China Postdoctoral Science Foundation(no.2016M600253,2017T100246)+1 种基金the State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(no.2019DX13)the Fundamental Research Funds for the Central Universities(Grant No.HIT.NSRIF.201836)
文摘Transitional metal phosphides(TMPs)anode materials usually have large volume change and weak diffusion kinetics,leading to poor cycle stability.Combining TMPs with conductive carbon matrix has been widely used to boost sodium storage.However,it still needs to make efforts in the rational and facile design of nano/micro-structural TMPs/carbon hybrid anode material.Herein,a MOFs-derived strategy is developed to synthesize porous yolk–shell Mo P/Cu_(3)P@carbon microcages(Mo P/Cu_(3)P@C)through in situ and confined phosphidation reaction as a high-performance sodium-ion batteries anode.This yolk–shell structure can offer adequate internal space to buffer the large volume expansion,shorten diffusion distance,and create more active sites of Na+.Especially,the Cu nanoparticles generated from Cu_(3)P have remarkable electronic conductivity of 5.73107S m-1(the second most conductive metal)to benefit transporting electrons.And the introduction of Mo(Mo P has high theoretical capacity of 633 mA h g^(-1))can enhance the reversible capacity of the whole anode material.Therefore,these porous yolk–shell Mo P/Cu_(3)P@carbon microcages possess excellent reversible capacity of 307.8 mA h g^(-1)at 1.0 A g^(-1)and extraordinary cycle stability of 132.1 m A h g^(-1)at 5.0 A g^(-1)even after 6000 cycles.
基金supported by the National Basic Research Program of China(Nos.2015CB932304,2016YFA0202603)the Natural Science Foundation of China (No.91645104)+1 种基金the Natural Science Foundation of Guangdong Province(Nos.S2013020012833,2016A010104004)the Fundamental Research Fund for the Central Universities(No.16lgjc67)
文摘Though water electrolysis is effective in generating high-quality hydrogen gas,it requires effective electrocatalysts for hydrogen evolution reaction(HER).CoS_2 have been considered as a promising HER electrocatalyst because of its high ctalytic activity.However,the key limitation for CoS_2 nanomaterial as HER electrocatalyst is its poor stability,which may be due to the structural breakdown of CoS_2 nanostructure or the evolution of S during H_2 evolution in acid media.Coating porous carbon thin layer for protection from structural breakdown and evolution of S is a good way to improve catalytic stability.In addition,coating carbon layer can change electronic structure of CoS_2 for the moderated hydrogen adsorption energy,leading to enhanced catalytic activity.Here,CoS_2 yolk-shell spheres coated with carbon thin layers exhibit superior catalytic performance for HER with low overpotential,small Tafel slope,and excellent stability.
