Metal selenides as anode materials for sodium-ion batteries have attracted considerable attention owing to their high theoretical specific capacities and variable composition and structures.However,the achievement of ...Metal selenides as anode materials for sodium-ion batteries have attracted considerable attention owing to their high theoretical specific capacities and variable composition and structures.However,the achievement of long cycle life and superior rate performance is challenging for these selenide materials due to the volume variation upon cycling.Herein,a composite composed of a new binary-metal selenide[Cu2SnSe3(CSS)]and carbon nanotubes(CNTs)was constructed via a hydrothermal process followed by calcination at 600℃.Benefited from the unique structure of binary-metal selenide and the conductive network of CNTs,the Cu2SnSe3/carbon nanotubes(CSS/CNT)composite exhibits excellent electrochemical performance when used as an anode material for sodium-ion batteries.A reversible specific capacity of 399 mA·h/g can be maintained at a current density of 100 mA/g even after 100 cycles.This work provides a promising strategy for rational design of binary-metal selenides upon delicate crystal phase control as electrode materials.展开更多
The carbon composite materials have been a research hotspot in the fields of catalysis,energy conversion and so on,because of their features of large structure and morphology variety,good chemical and electrochemical ...The carbon composite materials have been a research hotspot in the fields of catalysis,energy conversion and so on,because of their features of large structure and morphology variety,good chemical and electrochemical stability,and high electronic conductivity,large specific surface area and rich active sites.This paper summarizes some research progress of carbon composite materials,including assembly methodologies,their structure regulation,properties,and related applications.Moreover,the current challenges and the prospects of these materials are also discussed.展开更多
A series of Eu3+ -incorporated ETS-10 samples were successfully prepared based on the traditional ion exchange method. The relationship between photogenerated charge behaviors and luminescent properties has been inves...A series of Eu3+ -incorporated ETS-10 samples were successfully prepared based on the traditional ion exchange method. The relationship between photogenerated charge behaviors and luminescent properties has been investigated in detail. It has been demonstrated that as a result of the charge transfer from the titanate quantum wires to Eu3+ crystal field states, the host matrix ETS-10 functions as the sensitizer of Eu3+ to enhance the red luminescence, while Eu3+ cations contribute to the recombination of photogenerated charges. The behavior of photogenerated charges has significant impact on the luminescent properties of Eu3+ -incorporated ETS-10 materials.展开更多
Lithium-sulfur(Li-S)batteries with high energy densities have received increasing attention.However,the electrochemical performance of Li-S batteries is still far from the satisfactory of the practical application,whi...Lithium-sulfur(Li-S)batteries with high energy densities have received increasing attention.However,the electrochemical performance of Li-S batteries is still far from the satisfactory of the practical application,which can be mainly attributed to the shuttling of polysulfides and the slow reaction kinetics of polysulfide conversion.To address this issue,a 3D porous carbon structure constructed by 2D N-doped graphene and 1D carbon nanotubes with embedded Fe3C/Fe nanoparticles(NG@Fe3C/Fe)was designed and prepared by a simple programmed calcination method for the modification of polypropylene(PP)separator.The Fe3C/Fe nanoparticles demonstrate an excellent catalytic conversion and strong chemisorption towards polysulfides,while the unique architecture of N-doped graphene promotes the Li+/electron transfer and the physical adsorption of polysulfides.The electrochemical performance of the Li-S batteries with the NG@Fe3C/Fe-modified separator is significantly improved.A large discharge capacity of 1481 mA∙h∙g-1 is achieved at 0.2 C(1 C=1675 mA/g),and a high capacity of 601 mA∙h∙g-1 is maintained after discharged/charged for 500 cycles at a current rate of 1 C.This work provides a new approach for the development of high-performance Li-S batteries through the modification of the PP separator by rationally designed composites with large adsorption capability to polysulfides,good wettability to the electrolyte and high catalytic property.展开更多
In this study,we have provided a facile solution to synthesize well-aligned titanium dioxide nanorods by using hydrothermal reaction.By calcining the materials under different atmospheres and temperatures,a batch of t...In this study,we have provided a facile solution to synthesize well-aligned titanium dioxide nanorods by using hydrothermal reaction.By calcining the materials under different atmospheres and temperatures,a batch of titanium dioxides with excellent oxygen evolution reaction(OER)catalytic efficiency were obtained.This new structured TiO_(2) photoanode material yields a high photocurrent density of 5.69 mA/cm^(2) at 1.23 V vs.reversible hydrogen electrode(RHE)under simulated solar light(100 mW/cm^(2)).Surface photovoltage techniques and other measurements were carried out to confirm that the enhanced photoelectrochemical performances were attributed to the synergistic effect of the phase junction and a certain content of surface states,which accelerate the separation and transmission of the photogenerated charges.This material with phase junction and surface states promises a potential application in the field of photoelectric catalysis under solar light.展开更多
Heterogeneous catalysts have been developed for C-C coupling reactions,but stand low activity and always proceed under harsh conditions.Photocatalytic Stille cross-coupling reaction as a green catalytic method for C-C...Heterogeneous catalysts have been developed for C-C coupling reactions,but stand low activity and always proceed under harsh conditions.Photocatalytic Stille cross-coupling reaction as a green catalytic method for C-C bond formation is of great interest for a wide range of scientists but still lacks stable and highly efficient catalysts.Herein,we have designed an Au nanoparticle-graphitic carbon nitride heterojunction as an outstanding photocatalyst for artificial photosynthesis in Stille cross-coupling reaction.The interface effect between metal and semi.conductor makes electron rectify and prevents the recombination of electron-hole pairs.Moreover,the efficiency of Au nanoparticle catalysts could be adjusted by gold contents.Thus the turnover frequency(TOF)value reached the highest level of 788 h l over the optimal heterojunction catalyst.Most importantly,the C-C bond formation reaction has been proved to be carried out well under visible light irradiation,indicating the low-cost organic synthesis pro cess.Further analysis confirmed the stability and general application of our heterogeneous Au nano-heterojunctior catalyst.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.21871177,21671134,21720102002 and 21761132004).
文摘Metal selenides as anode materials for sodium-ion batteries have attracted considerable attention owing to their high theoretical specific capacities and variable composition and structures.However,the achievement of long cycle life and superior rate performance is challenging for these selenide materials due to the volume variation upon cycling.Herein,a composite composed of a new binary-metal selenide[Cu2SnSe3(CSS)]and carbon nanotubes(CNTs)was constructed via a hydrothermal process followed by calcination at 600℃.Benefited from the unique structure of binary-metal selenide and the conductive network of CNTs,the Cu2SnSe3/carbon nanotubes(CSS/CNT)composite exhibits excellent electrochemical performance when used as an anode material for sodium-ion batteries.A reversible specific capacity of 399 mA·h/g can be maintained at a current density of 100 mA/g even after 100 cycles.This work provides a promising strategy for rational design of binary-metal selenides upon delicate crystal phase control as electrode materials.
基金This work was supported by the National Natural Science Foundation of China(Nos.21931005,21720102002,21871177,22071146)the Project of the Shanghai Science and Technology Committee,China(No.19JC1412600).
文摘The carbon composite materials have been a research hotspot in the fields of catalysis,energy conversion and so on,because of their features of large structure and morphology variety,good chemical and electrochemical stability,and high electronic conductivity,large specific surface area and rich active sites.This paper summarizes some research progress of carbon composite materials,including assembly methodologies,their structure regulation,properties,and related applications.Moreover,the current challenges and the prospects of these materials are also discussed.
基金supported by the National Natural Science Foundation of China (21201121, 21271128)the National Basic Research Program of China (2011CB808703)
文摘A series of Eu3+ -incorporated ETS-10 samples were successfully prepared based on the traditional ion exchange method. The relationship between photogenerated charge behaviors and luminescent properties has been investigated in detail. It has been demonstrated that as a result of the charge transfer from the titanate quantum wires to Eu3+ crystal field states, the host matrix ETS-10 functions as the sensitizer of Eu3+ to enhance the red luminescence, while Eu3+ cations contribute to the recombination of photogenerated charges. The behavior of photogenerated charges has significant impact on the luminescent properties of Eu3+ -incorporated ETS-10 materials.
基金This work was supported by the National Natural Science Foundation of China (Nos.21931005,21871177,20172012002)the Natural Science Foundation of Shanghai,China(No.20ZR1427600)the Project of the Shanghai Science and Technology Committee,China(No.19JC1412600).
文摘Lithium-sulfur(Li-S)batteries with high energy densities have received increasing attention.However,the electrochemical performance of Li-S batteries is still far from the satisfactory of the practical application,which can be mainly attributed to the shuttling of polysulfides and the slow reaction kinetics of polysulfide conversion.To address this issue,a 3D porous carbon structure constructed by 2D N-doped graphene and 1D carbon nanotubes with embedded Fe3C/Fe nanoparticles(NG@Fe3C/Fe)was designed and prepared by a simple programmed calcination method for the modification of polypropylene(PP)separator.The Fe3C/Fe nanoparticles demonstrate an excellent catalytic conversion and strong chemisorption towards polysulfides,while the unique architecture of N-doped graphene promotes the Li+/electron transfer and the physical adsorption of polysulfides.The electrochemical performance of the Li-S batteries with the NG@Fe3C/Fe-modified separator is significantly improved.A large discharge capacity of 1481 mA∙h∙g-1 is achieved at 0.2 C(1 C=1675 mA/g),and a high capacity of 601 mA∙h∙g-1 is maintained after discharged/charged for 500 cycles at a current rate of 1 C.This work provides a new approach for the development of high-performance Li-S batteries through the modification of the PP separator by rationally designed composites with large adsorption capability to polysulfides,good wettability to the electrolyte and high catalytic property.
基金National Natural Science Foundation of China(Nos.21931005,21720102002)Project of the Shanghai Science and Technology Committee,China(Nos.20520741400,19JC1412600)Project of the Center of Hydrogen Science,Shanghai Jiao Tong University,China.
文摘In this study,we have provided a facile solution to synthesize well-aligned titanium dioxide nanorods by using hydrothermal reaction.By calcining the materials under different atmospheres and temperatures,a batch of titanium dioxides with excellent oxygen evolution reaction(OER)catalytic efficiency were obtained.This new structured TiO_(2) photoanode material yields a high photocurrent density of 5.69 mA/cm^(2) at 1.23 V vs.reversible hydrogen electrode(RHE)under simulated solar light(100 mW/cm^(2)).Surface photovoltage techniques and other measurements were carried out to confirm that the enhanced photoelectrochemical performances were attributed to the synergistic effect of the phase junction and a certain content of surface states,which accelerate the separation and transmission of the photogenerated charges.This material with phase junction and surface states promises a potential application in the field of photoelectric catalysis under solar light.
基金Supported by the National Natural Science Foundation of China(Nos.21722103,21931005,21720102002,and 21673140)the Projiect of the Shanghai Science and Technology Committee,China(No.19JC1412600)the Fund of the SJTU-MPI Partner Group.
文摘Heterogeneous catalysts have been developed for C-C coupling reactions,but stand low activity and always proceed under harsh conditions.Photocatalytic Stille cross-coupling reaction as a green catalytic method for C-C bond formation is of great interest for a wide range of scientists but still lacks stable and highly efficient catalysts.Herein,we have designed an Au nanoparticle-graphitic carbon nitride heterojunction as an outstanding photocatalyst for artificial photosynthesis in Stille cross-coupling reaction.The interface effect between metal and semi.conductor makes electron rectify and prevents the recombination of electron-hole pairs.Moreover,the efficiency of Au nanoparticle catalysts could be adjusted by gold contents.Thus the turnover frequency(TOF)value reached the highest level of 788 h l over the optimal heterojunction catalyst.Most importantly,the C-C bond formation reaction has been proved to be carried out well under visible light irradiation,indicating the low-cost organic synthesis pro cess.Further analysis confirmed the stability and general application of our heterogeneous Au nano-heterojunctior catalyst.
