剥离的石墨烯纳米片状粒子(x Gn Ps)是一种新型含有石墨烯片层的3D碳类层状纳米填料。通过研究4种市售碳类填料,即x Gn Ps(xg C750、xg M5、UF1 C98)和N339炭黑(CB)与丁腈橡胶(NBR 3945)的混炼胶。采用熔融混炼方法制备纳米复合材料。...剥离的石墨烯纳米片状粒子(x Gn Ps)是一种新型含有石墨烯片层的3D碳类层状纳米填料。通过研究4种市售碳类填料,即x Gn Ps(xg C750、xg M5、UF1 C98)和N339炭黑(CB)与丁腈橡胶(NBR 3945)的混炼胶。采用熔融混炼方法制备纳米复合材料。研究了含石墨烯纳米材料橡胶的特性,如填料分散指数、硬度、每个片状粒子中石墨烯的层数、流变曲线、拉伸强度、多次滞后应力-应变、动态力学性能、介电行为和阻隔性能。展开更多
Electrochemically exfoliated graphene(EEG)is a kind of high-quality graphene with few oxygen-containing functional groups and defects on the surface,and thereby is more suitable as catalyst support than other carbon m...Electrochemically exfoliated graphene(EEG)is a kind of high-quality graphene with few oxygen-containing functional groups and defects on the surface,and thereby is more suitable as catalyst support than other carbon materials such as extensively used reduced graphene oxide(rGO).However,it is difficult to grow functional materials on EEG due to its inert surface.In this work,ultra-small Pt nanocrystals(~2.6 nm)are successfully formed on EEG and show better electrocatalytic activity towards methanol oxidation than Pt catalysts on r GO.The outstanding catalytic properties of Pt catalysts on EEG can be attributed to the fast electron transfer through EEG and high quality of Pt catalysts such as small grain size,high dispersibility and low oxidation ratio.In addition,SnO2 nanocrystals are controllably generated around Pt catalysts on EEG to raise the poison tolerance of Pt catalysts through using glycine as a linker.Owing to its outstanding properties such as high electrical conductivity and mechanical strength,EEG is expected to be widely used as a novel support for catalysts.展开更多
Chemically exfoliated nanosheets have exhibited great potential for applications in various electronic devices.Solution-based processing strategies such as inkjet printing provide a low-cost,environmentally friendly,a...Chemically exfoliated nanosheets have exhibited great potential for applications in various electronic devices.Solution-based processing strategies such as inkjet printing provide a low-cost,environmentally friendly,and scalable route for the fabrication of flexible devices based on functional inks of twodimensional nanosheets.In this study,chemically exfoliated high-k perovskite nanosheets(i.e.,Ca_(2)Nb_(3)O_(10)and Ca_(2)NaNb_(4)O_(13))are well dispersed in appropriate solvents to prepare printable inks,and then,a series of microcapacitors with Ag and graphene electrodes are printed.The resulting microcapacitors,Ag/Ca_(2)Nb_(3)O_(10)/Ag,graphene/Ca_(2)Nb_(3)O_(10)/graphene,and graphene/Ca_(2)NaNb_(4)O_(13)/graphene,demonstrate high capacitance densities of 20,80,and 150 nF/cm^(2) and high dielectric constants of 26,110.and 200,respectively.Such dielectric enhancement in the microcapacitors with graphene electrodes is possibly attributed to the dielectric/graphene interface.In addition,these microcapacitors also exhibit good insulating performance with a moderate electrical breakdown strength of approximately 1 MV/cm,excellent flexibility,and thermal stability up to 200℃.This work demonstrates the potential of high-k perovskite nanosheets for additive manufacturing of flexible high-performance dielectric capacitors.展开更多
文摘剥离的石墨烯纳米片状粒子(x Gn Ps)是一种新型含有石墨烯片层的3D碳类层状纳米填料。通过研究4种市售碳类填料,即x Gn Ps(xg C750、xg M5、UF1 C98)和N339炭黑(CB)与丁腈橡胶(NBR 3945)的混炼胶。采用熔融混炼方法制备纳米复合材料。研究了含石墨烯纳米材料橡胶的特性,如填料分散指数、硬度、每个片状粒子中石墨烯的层数、流变曲线、拉伸强度、多次滞后应力-应变、动态力学性能、介电行为和阻隔性能。
基金Projects(21573023,21975030)supported by the National Natural Science Foundation of China。
文摘Electrochemically exfoliated graphene(EEG)is a kind of high-quality graphene with few oxygen-containing functional groups and defects on the surface,and thereby is more suitable as catalyst support than other carbon materials such as extensively used reduced graphene oxide(rGO).However,it is difficult to grow functional materials on EEG due to its inert surface.In this work,ultra-small Pt nanocrystals(~2.6 nm)are successfully formed on EEG and show better electrocatalytic activity towards methanol oxidation than Pt catalysts on r GO.The outstanding catalytic properties of Pt catalysts on EEG can be attributed to the fast electron transfer through EEG and high quality of Pt catalysts such as small grain size,high dispersibility and low oxidation ratio.In addition,SnO2 nanocrystals are controllably generated around Pt catalysts on EEG to raise the poison tolerance of Pt catalysts through using glycine as a linker.Owing to its outstanding properties such as high electrical conductivity and mechanical strength,EEG is expected to be widely used as a novel support for catalysts.
基金supported by the Basic Science Center Program of National Natural Science Foundation of China(51788104)the National Natural Science Foundation of China(52172124 and51872214)the Fundamental Research Funds for the Central Universities(WUT:2021III019JC,2018III041GX)。
文摘Chemically exfoliated nanosheets have exhibited great potential for applications in various electronic devices.Solution-based processing strategies such as inkjet printing provide a low-cost,environmentally friendly,and scalable route for the fabrication of flexible devices based on functional inks of twodimensional nanosheets.In this study,chemically exfoliated high-k perovskite nanosheets(i.e.,Ca_(2)Nb_(3)O_(10)and Ca_(2)NaNb_(4)O_(13))are well dispersed in appropriate solvents to prepare printable inks,and then,a series of microcapacitors with Ag and graphene electrodes are printed.The resulting microcapacitors,Ag/Ca_(2)Nb_(3)O_(10)/Ag,graphene/Ca_(2)Nb_(3)O_(10)/graphene,and graphene/Ca_(2)NaNb_(4)O_(13)/graphene,demonstrate high capacitance densities of 20,80,and 150 nF/cm^(2) and high dielectric constants of 26,110.and 200,respectively.Such dielectric enhancement in the microcapacitors with graphene electrodes is possibly attributed to the dielectric/graphene interface.In addition,these microcapacitors also exhibit good insulating performance with a moderate electrical breakdown strength of approximately 1 MV/cm,excellent flexibility,and thermal stability up to 200℃.This work demonstrates the potential of high-k perovskite nanosheets for additive manufacturing of flexible high-performance dielectric capacitors.
