Surface area,pore properties,synergistic behavior,homogenous dispersion,and interactions between carbon matrix and metal-nanostructures are the key factors for achieving the better performance of carbon-metal based(el...Surface area,pore properties,synergistic behavior,homogenous dispersion,and interactions between carbon matrix and metal-nanostructures are the key factors for achieving the better performance of carbon-metal based(electro)catalysts.However,the traditional hydro-or solvothermal preparation of(electro)catalysts,particularly,bi-or tri-metallic nanostructures anchored graphene(G)or carbon nanotubes(CNTs),often pose to poor metal–support interaction,low synergism,and patchy dispersion.At first,bimetallic flower-like-CuFeS_(2)/NG and cube-like-NiFeS_(2)/NCNTs nanocomposites were prepared by solvothermal method.The resultant bimetallic nanocomposites were employed to derive the 2D-nano-sandwiched Fe_(2)CuNiS_(4)/NGCNTs-SW(electro)catalyst by a very simple and green urea-mediated“mix-heat”method.The desired physicochemical properties of Fe_(2)CuNiS_(4)/NGCNTs-SW such as multiple active sites,strong metal-support interaction,homogenous dispersion and enhanced surface area were confirmed by various microscopic and spectroscopic techniques.To the best of our knowledge,this is the first urea-mediated“mix-heat”method for preparing 2D-nano-sandwiched carbon-metal-based(electro)catalysts.The Fe_(2)CuNiS_(4)/NGCNTs-SW was found to be highly effective for alkaline-mediated oxygen evolution reaction at low onset potential of 284.24 mV,and the stable current density of 10 mA cm^(−2) in 1.0 m KOH for 10 h.Further,the Fe_(2)CuNiS_(4)/NGCNTs-SW demonstrated excellent catalytic activity in the reduction of 4-nitrophenol with good kapp value of 87.71×10^(−2)s^(-1)and excellent reusability over five cycles.Overall,the developed urea-mediated“mix-heat”method is highly efficient for the preparation of metal-nanoarchitectures anchored 2D-nano-sandwiched(electro)catalysts with high synergism,uniform dispersion and excellent metal-support interaction.展开更多
Electrocatalytic CO_(2) reduction to CH_(4) remains challenging due to multi-electron transfer and intermediates adsorption.Herein,we synthesized electrocatalysts by growing Ni-Cu alloy structure on nitrogen-doped car...Electrocatalytic CO_(2) reduction to CH_(4) remains challenging due to multi-electron transfer and intermediates adsorption.Herein,we synthesized electrocatalysts by growing Ni-Cu alloy structure on nitrogen-doped carbon nanotubes(NixCuy-NCNT)for electrocatalytic CO_(2) reduction reaction(CO_(2)RR)via hydrothermal method followed by pyrolysis.The optimized Ni_(1)Cu_(1)-NCNT demonstrated a superior CO_(2)RR performance,achieving 99.7%FECH_(4)(FE=Faradaic efficiency)and 11.54 mA·cm^(−2) current density at−1.2 V vs.reversible hydrogen electrode(RHE),which outperformed single metal counterparts.Its outstanding performance was due to the electrons transferred from Cu to Ni and Ni-Cu alloy shifted the d-band center toward the Fermi level,which was more conducive to the intermediate formation.In situ electrochemical attenuated total reflection(EC-ATR)and density functional theory(DFT)calculations revealed the appearance of *CHO intermediate and the pathway during the CO_(2)RR process.The design of the bimetallic electrocatalyst in this study provides a new perspective for the highly selective reduction of CO_(2).展开更多
The high-N-content, the cup-stacking and the macroscopic nitrogen doped carbon nanotubes（NCNT）were synthesized via an easily manufactured catalytic chemical vapor deposition（CCVD） method. Nitrogen physisorption, t...The high-N-content, the cup-stacking and the macroscopic nitrogen doped carbon nanotubes（NCNT）were synthesized via an easily manufactured catalytic chemical vapor deposition（CCVD） method. Nitrogen physisorption, transmission electron microscopy（TEM）, thermogravimetric analysis（TGA）, X-ray diffraction（XRD） and X-ray photoelectron spectroscopy（XPS） were used to characterize the as-obtained NCNTs. High reaction temperatures were found to be the key point to the formation of inner-cup-stacking NCNTs. However, the synthesis of the outer-cup-stacking NCNT needs special demands not only to the reaction temperature but also to the catalyst and the carrier gas. The possibility of CO oxidation by NCNT was proved to be very small, and the outer-cup-stacking NCNT showed obvious advantage in the oxidative dehydrogenation（ODH） of butene to butadiene compared to a bamboo-like NCNT with an even higher N content.展开更多
In this work,the framework of Co nanoparticles and nitrogen-doped carbon nanotubes(Co/NCNTs)derived from metal-organic frameworks(MOFs)through solid pyrolysis was successfully synthesized in the atmosphere of H2 and A...In this work,the framework of Co nanoparticles and nitrogen-doped carbon nanotubes(Co/NCNTs)derived from metal-organic frameworks(MOFs)through solid pyrolysis was successfully synthesized in the atmosphere of H2 and Ar gases.The Co/NCNTs composites exhibited superior electrocatalytic performance for tert-butyl hydroquinone(TBHQ)oxidation due to the synergistic effect between chemical composition and the specific structure of Co nanoparticles and nitrogen-doped carbon nanotubes.It was found that the reaction underwent a quasi-reversible redox reaction with 37-fold higher anodic current for TBHQ at Co/NCNT-modified electrode when compared to bare glassy carbon electrode(GCE).In optimal condition,Co/NCNTs/GCE exhibited a linear range of0.05-80.00μmol·L^(-1) for detecting TBHQ,and the limit of detection(LOD)was estimated to be as low as10 nmol·L^(-1)(signal/noise of S/N=3).Moreover,the asobtained modified electrode was successfully used to assay the content of TBHQ in edible oil samples.展开更多
Developing enzyme-free sensors with high sensitivity and selectivity for H2O2 and glucose is highly desirable for biological science.Especially,it is attractive to exploit noble-metal-free nanomaterials with large sur...Developing enzyme-free sensors with high sensitivity and selectivity for H2O2 and glucose is highly desirable for biological science.Especially,it is attractive to exploit noble-metal-free nanomaterials with large surface area and good conductivity as highly active and selective catalysts for molecular detection in enzyme-free sensors.Herein,we successfully fabricate hollow frameworks of Co3O4/N-doped carbon nanotubes(Co3O4/NCNTs)hybrids by the pyrolysis of metal-organic frameworks followed by calcination in the air.The as-prepared novel hollow Co3O4/NCNTs hybrids exhibit excellent electrochemical performance for H2O2 reduction in neutral solutions and glucose oxidation in alkaline solutions.As sensor electrode,the Co3O4/NCNTs show excellent non-enzymatic sensing ability towards H2O2 response with a sensitivity of 87.40μA(mmol/L)^-1 cm^-2,a linear range of 5.00μmol/L-11.00 mmol/L,and a detection limitation of 1μmol/L in H2O2 detection,and a good glucose detection performance with 5μmol/L.These excellent electrochemical performances endow the hollow Co3O4/NCNTs as promising alternative to enzymes in the biological applications.展开更多
The outstanding mechanical properties of nanocarbon materials, especially carbon nanotube（CNT）, make them one of the most promising reinforcing nanofillers for the high-performance lightweight structural material. H...The outstanding mechanical properties of nanocarbon materials, especially carbon nanotube（CNT）, make them one of the most promising reinforcing nanofillers for the high-performance lightweight structural material. However, the complicated but not eco-friendly surface functionalization processes（e.g. HNO3 oxidation） are generally necessary to help disperse nanocarbon materials into epoxy or build chemical bonds between them. Herein, nitrogen doped carbon nanotube（NCNT） was used to replace CNT to reinforce the epoxy resin, and the mechanical properties of the NCNT/epoxy nanocomposite showed significant superiorities over the CNT/epoxy nanocomposites. The fabrication process was simple and environmentally friendly, and avoided complicated, polluting and energy intensive surface functionalization processes. Moreover, the NCNT/epoxy suspension exhibited a relative low viscosity, which was favorable for the subsequent application. The reinforcing mechanism of NCNT was also proposed. The present work gives out an easy solution to the preparation of a high-performance nanocomposite as a potential lightweight structure material.展开更多
基金supported by JSPS KAKENHI(Grant number 24K15389)S.C.Kim greatly acknowledges the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education of the Republic of Korea(2020R1I1A3052258)for financial support.
文摘Surface area,pore properties,synergistic behavior,homogenous dispersion,and interactions between carbon matrix and metal-nanostructures are the key factors for achieving the better performance of carbon-metal based(electro)catalysts.However,the traditional hydro-or solvothermal preparation of(electro)catalysts,particularly,bi-or tri-metallic nanostructures anchored graphene(G)or carbon nanotubes(CNTs),often pose to poor metal–support interaction,low synergism,and patchy dispersion.At first,bimetallic flower-like-CuFeS_(2)/NG and cube-like-NiFeS_(2)/NCNTs nanocomposites were prepared by solvothermal method.The resultant bimetallic nanocomposites were employed to derive the 2D-nano-sandwiched Fe_(2)CuNiS_(4)/NGCNTs-SW(electro)catalyst by a very simple and green urea-mediated“mix-heat”method.The desired physicochemical properties of Fe_(2)CuNiS_(4)/NGCNTs-SW such as multiple active sites,strong metal-support interaction,homogenous dispersion and enhanced surface area were confirmed by various microscopic and spectroscopic techniques.To the best of our knowledge,this is the first urea-mediated“mix-heat”method for preparing 2D-nano-sandwiched carbon-metal-based(electro)catalysts.The Fe_(2)CuNiS_(4)/NGCNTs-SW was found to be highly effective for alkaline-mediated oxygen evolution reaction at low onset potential of 284.24 mV,and the stable current density of 10 mA cm^(−2) in 1.0 m KOH for 10 h.Further,the Fe_(2)CuNiS_(4)/NGCNTs-SW demonstrated excellent catalytic activity in the reduction of 4-nitrophenol with good kapp value of 87.71×10^(−2)s^(-1)and excellent reusability over five cycles.Overall,the developed urea-mediated“mix-heat”method is highly efficient for the preparation of metal-nanoarchitectures anchored 2D-nano-sandwiched(electro)catalysts with high synergism,uniform dispersion and excellent metal-support interaction.
基金supported by the National Natural Science Foundation of China(No.52170065).
文摘Electrocatalytic CO_(2) reduction to CH_(4) remains challenging due to multi-electron transfer and intermediates adsorption.Herein,we synthesized electrocatalysts by growing Ni-Cu alloy structure on nitrogen-doped carbon nanotubes(NixCuy-NCNT)for electrocatalytic CO_(2) reduction reaction(CO_(2)RR)via hydrothermal method followed by pyrolysis.The optimized Ni_(1)Cu_(1)-NCNT demonstrated a superior CO_(2)RR performance,achieving 99.7%FECH_(4)(FE=Faradaic efficiency)and 11.54 mA·cm^(−2) current density at−1.2 V vs.reversible hydrogen electrode(RHE),which outperformed single metal counterparts.Its outstanding performance was due to the electrons transferred from Cu to Ni and Ni-Cu alloy shifted the d-band center toward the Fermi level,which was more conducive to the intermediate formation.In situ electrochemical attenuated total reflection(EC-ATR)and density functional theory(DFT)calculations revealed the appearance of *CHO intermediate and the pathway during the CO_(2)RR process.The design of the bimetallic electrocatalyst in this study provides a new perspective for the highly selective reduction of CO_(2).
基金financial support from the National Natural Science Foundation of China(Nos.21133010,21473223,51221264,21261160487,21411130120,21503241,91545119 and 91545110)the“Strategic Priority Research Program”of the Chinese Academy of Sciences(Grant No.XDA09030103)the CAS/SAFEA International Partnership Program for Creative Research Teams
文摘The high-N-content, the cup-stacking and the macroscopic nitrogen doped carbon nanotubes（NCNT）were synthesized via an easily manufactured catalytic chemical vapor deposition（CCVD） method. Nitrogen physisorption, transmission electron microscopy（TEM）, thermogravimetric analysis（TGA）, X-ray diffraction（XRD） and X-ray photoelectron spectroscopy（XPS） were used to characterize the as-obtained NCNTs. High reaction temperatures were found to be the key point to the formation of inner-cup-stacking NCNTs. However, the synthesis of the outer-cup-stacking NCNT needs special demands not only to the reaction temperature but also to the catalyst and the carrier gas. The possibility of CO oxidation by NCNT was proved to be very small, and the outer-cup-stacking NCNT showed obvious advantage in the oxidative dehydrogenation（ODH） of butene to butadiene compared to a bamboo-like NCNT with an even higher N content.
基金the National Natural Science Foundation of China(No.21904004)the Domestic Visiting Scholar Program for Outstanding Young Talents of Anhui Province(Nos.gxgnfx2019019 and gxgnfx2019020)+1 种基金the Natural Foundation of Anhui Province(No.1808085MB31)the Stable Talent Program and the Outstanding Talent Program of Anhui Science and Technology University。
文摘In this work,the framework of Co nanoparticles and nitrogen-doped carbon nanotubes(Co/NCNTs)derived from metal-organic frameworks(MOFs)through solid pyrolysis was successfully synthesized in the atmosphere of H2 and Ar gases.The Co/NCNTs composites exhibited superior electrocatalytic performance for tert-butyl hydroquinone(TBHQ)oxidation due to the synergistic effect between chemical composition and the specific structure of Co nanoparticles and nitrogen-doped carbon nanotubes.It was found that the reaction underwent a quasi-reversible redox reaction with 37-fold higher anodic current for TBHQ at Co/NCNT-modified electrode when compared to bare glassy carbon electrode(GCE).In optimal condition,Co/NCNTs/GCE exhibited a linear range of0.05-80.00μmol·L^(-1) for detecting TBHQ,and the limit of detection(LOD)was estimated to be as low as10 nmol·L^(-1)(signal/noise of S/N=3).Moreover,the asobtained modified electrode was successfully used to assay the content of TBHQ in edible oil samples.
基金financially supported by the National Natural Science Foundation of China(NSFC)(Nos.51671003,21802003,21571112)Natural Science Foundation of Shandong Province(ZR2018BB031)+3 种基金the Shandong Taishan Scholar Program(H.W.)the China Postdoctoral Science Foundation(No.2017M610022)the start-up supports from Peking UniversityYoung Thousand Talented Program。
文摘Developing enzyme-free sensors with high sensitivity and selectivity for H2O2 and glucose is highly desirable for biological science.Especially,it is attractive to exploit noble-metal-free nanomaterials with large surface area and good conductivity as highly active and selective catalysts for molecular detection in enzyme-free sensors.Herein,we successfully fabricate hollow frameworks of Co3O4/N-doped carbon nanotubes(Co3O4/NCNTs)hybrids by the pyrolysis of metal-organic frameworks followed by calcination in the air.The as-prepared novel hollow Co3O4/NCNTs hybrids exhibit excellent electrochemical performance for H2O2 reduction in neutral solutions and glucose oxidation in alkaline solutions.As sensor electrode,the Co3O4/NCNTs show excellent non-enzymatic sensing ability towards H2O2 response with a sensitivity of 87.40μA(mmol/L)^-1 cm^-2,a linear range of 5.00μmol/L-11.00 mmol/L,and a detection limitation of 1μmol/L in H2O2 detection,and a good glucose detection performance with 5μmol/L.These excellent electrochemical performances endow the hollow Co3O4/NCNTs as promising alternative to enzymes in the biological applications.
基金supported by the National Natural Science Foundation of China (Nos. 21503241, 21473223, 51221264, 21261160487, 91545119 and 91545110)the "Strategic Priority Research Program" of the Chinese Academy of Sciences (XDA09030103)+1 种基金the CAS/SAFEA International Partnership Program for Creative Research TeamsChina Scholarship Council (CSC No. 201706340114)
文摘The outstanding mechanical properties of nanocarbon materials, especially carbon nanotube（CNT）, make them one of the most promising reinforcing nanofillers for the high-performance lightweight structural material. However, the complicated but not eco-friendly surface functionalization processes（e.g. HNO3 oxidation） are generally necessary to help disperse nanocarbon materials into epoxy or build chemical bonds between them. Herein, nitrogen doped carbon nanotube（NCNT） was used to replace CNT to reinforce the epoxy resin, and the mechanical properties of the NCNT/epoxy nanocomposite showed significant superiorities over the CNT/epoxy nanocomposites. The fabrication process was simple and environmentally friendly, and avoided complicated, polluting and energy intensive surface functionalization processes. Moreover, the NCNT/epoxy suspension exhibited a relative low viscosity, which was favorable for the subsequent application. The reinforcing mechanism of NCNT was also proposed. The present work gives out an easy solution to the preparation of a high-performance nanocomposite as a potential lightweight structure material.
