The scalable preparation of multi-functional three-dimensional (3D) carbon nanotubes and graphene (CNTs-G) hybrids via a well-controlled route is urgently required and challenging. Herein, an easily operated, oxal...The scalable preparation of multi-functional three-dimensional (3D) carbon nanotubes and graphene (CNTs-G) hybrids via a well-controlled route is urgently required and challenging. Herein, an easily operated, oxalic acid-assisted method was developed for the in situ fabrication of a 3D lasagna-like Fe-N-doped CNTs-G framework (LMFC) from a precursor designed at the molecular level. The well-organized architecture of LMFC was constructed by multi-dimensionally interconnected graphene and CNTs which derived from porous graphene sheets, to form a fundamentally robust and hierarchical porous structure, as well as favorable conductive networks. The impressive oxygen reduction reaction (ORR) performances in both alkaline and acidic conditions helped confirm the significance of this technically favorable morphological structure. This product was also the subject of research for the exploration of decisive effects on the performance of ORR catalysts with reasonable control variables. The present work further advances the construction of novel 3D carbon architectures via practical and economic routes.展开更多
Iron-based nanostructures represent an emerging class of catalysts with high electroactivity for oxygen reduction reaction(ORR)in energy storage and conversion technologies.However,current practical applications have ...Iron-based nanostructures represent an emerging class of catalysts with high electroactivity for oxygen reduction reaction(ORR)in energy storage and conversion technologies.However,current practical applications have been limited by insufficient durability in both alkaline and acidic environments.In particular,limited attention has been paid to stabilizing iron-based catalysts by introducing additional metal by the alloying effect.Herein,we report bimetallic Fe_(2)Mo nanoparticles on N-doped carbon(Fe_(2)Mo/NC)as an efficient and ultra-stable ORR electrocatalyst for the first time.The Fe_(2)Mo/NC catalyst shows high selectivity for a four-electron pathway of ORR and remarkable electrocatalytic activity with high kinetics current density and half-wave potential as well as low Tafel slope in both acidic and alkaline medias.It demonstrates excellent long-term durability with no activity loss even after 10,000 potential cycles.Density functional theory(DFT)calculations have confirmed the modulated electronic structure of formed Fe_(2)Mo,which supports the electron-rich structure for the ORR process.Meanwhile,the mutual protection between Fe and Mo sites guarantees efficient electron transfer and long-term stability,especially under the alkaline environment.This work has supplied an effective strategy to solve the dilemma between high electroactivity and long-term durability for the Fe-based electrocatalysts,which opens a new direction of developing novel electrocatalyst systems for future research.展开更多
基金Acknowledgements Financial supports from the National Natural Science Foundation of China (Nos. 21622308, 91534114, and 21376208), the the China Ministry of Science and Technology (No. 2016YFA0202900), the Fundamental Research Funds for the Central Universities (No. 2016FZA3006), and the Partner Group Program of the Zhejiang University and the Max-Planck Society are appreciated greatly.
文摘The scalable preparation of multi-functional three-dimensional (3D) carbon nanotubes and graphene (CNTs-G) hybrids via a well-controlled route is urgently required and challenging. Herein, an easily operated, oxalic acid-assisted method was developed for the in situ fabrication of a 3D lasagna-like Fe-N-doped CNTs-G framework (LMFC) from a precursor designed at the molecular level. The well-organized architecture of LMFC was constructed by multi-dimensionally interconnected graphene and CNTs which derived from porous graphene sheets, to form a fundamentally robust and hierarchical porous structure, as well as favorable conductive networks. The impressive oxygen reduction reaction (ORR) performances in both alkaline and acidic conditions helped confirm the significance of this technically favorable morphological structure. This product was also the subject of research for the exploration of decisive effects on the performance of ORR catalysts with reasonable control variables. The present work further advances the construction of novel 3D carbon architectures via practical and economic routes.
基金supported by the National Key R&D Program of China(No.2021YFA1501101)the National Nature Science Foundation of China(Nos.21862011,21771156,and 51864024)+4 种基金Yunnan province(No.2019FI003)the Shenzhen Knowledge Innovation Program(Basic Research,No.JCYJ20190808181205752)the Research Grants Council(RGC)of the Hong Kong Special Administrative Region,China(Project No.CityU 11206520)the National Natural Science Foundation of China/RGC Joint Research Scheme(No.N_PolyU502/21)the funding for Projects of Strategic Importance of The Hong Kong Polytechnic University(Project Code:1-ZE2V).
文摘Iron-based nanostructures represent an emerging class of catalysts with high electroactivity for oxygen reduction reaction(ORR)in energy storage and conversion technologies.However,current practical applications have been limited by insufficient durability in both alkaline and acidic environments.In particular,limited attention has been paid to stabilizing iron-based catalysts by introducing additional metal by the alloying effect.Herein,we report bimetallic Fe_(2)Mo nanoparticles on N-doped carbon(Fe_(2)Mo/NC)as an efficient and ultra-stable ORR electrocatalyst for the first time.The Fe_(2)Mo/NC catalyst shows high selectivity for a four-electron pathway of ORR and remarkable electrocatalytic activity with high kinetics current density and half-wave potential as well as low Tafel slope in both acidic and alkaline medias.It demonstrates excellent long-term durability with no activity loss even after 10,000 potential cycles.Density functional theory(DFT)calculations have confirmed the modulated electronic structure of formed Fe_(2)Mo,which supports the electron-rich structure for the ORR process.Meanwhile,the mutual protection between Fe and Mo sites guarantees efficient electron transfer and long-term stability,especially under the alkaline environment.This work has supplied an effective strategy to solve the dilemma between high electroactivity and long-term durability for the Fe-based electrocatalysts,which opens a new direction of developing novel electrocatalyst systems for future research.