The development of microwave absorption materials(MAMs) is a considerable important topic because our living space is crowed with electromagnetic wave which threatens human’s health.And MAMs are also used in radar st...The development of microwave absorption materials(MAMs) is a considerable important topic because our living space is crowed with electromagnetic wave which threatens human’s health.And MAMs are also used in radar stealth for protecting the weapons from being detected.Many nanomaterials were studied as MAMs,but not all of them have the satisfactory performance.Recently,metal-organic frameworks(MOFs) have attracted tremendous attention owing to their tunable chemical structures,diverse properties,large specific surface area and uniform pore distribution.MOF can transform to porous carbon(PC) which is decorated with metal species at appropriate pyrolysis temperature.However,the loss mechanism of pure MOF-derived PC is often relatively simple.In order to further improve the MA performance,the MOFs coupled with other loss materials are a widely studied method.In this review,we summarize the theories of MA,the progress of different MOF-derived PC-based MAMs,tunable chemical structures incorporated with dielectric loss or magnetic loss materials.The different MA performance and mechanisms are discussed in detail.Finally,the shortcomings,challenges and perspectives of MOF-derived PC-based MAMs are also presented.We hope this review could provide a new insight to design and fabricate MOF-derived PC-based MAMs with better fundamental understanding and practical application.展开更多
Exploring advanced electromagnetic wave(EMW)absorbers is one of the most feasible ways to solve the increasing electromagnetic pollution in both military and civil fields.In this work,γ-graphyne(γ-GY)is synthesized ...Exploring advanced electromagnetic wave(EMW)absorbers is one of the most feasible ways to solve the increasing electromagnetic pollution in both military and civil fields.In this work,γ-graphyne(γ-GY)is synthesized by a mechanochemical route using CaC2 and hexabromobenzene(PhBr6).Then three-dimensional(3D)reduced graphene oxide/γ-GY(RGO/GY)heterostructures are prepared through facile solvothermal self-assembly and subsequent thermal reduction.The influences of calcination temperature and the content ofγ-GY of the composite on EMW absorption performance are fully investigated.The minimum reflection loss(RL)value of the RGO/GY composite foam is−71.73 dB at 10.48 GHz with the matching thickness of 3.54 mm,and the effective absorption bandwidth(EAB)less than−10 dB is 7.36 GHz.Moreover,excellent terahertz(THz)absorption property is also obtained at 0.2–1.6 THz.The RL of 84.08 dB is acquired,and the EAB covers 100%of the entire measured bandwidth.In addition,the composite is also a promising anticorrosive EMW absorber.This work provides encouraging findings,which are also instructive for the potential advantages of graphyne-based materials as highly efficient EMW absorbers in both gigahertz and terahertz band ranges.展开更多
The wearable demand of modern electronic devices makes flexible and stretchable energy storage device urgently needed.Stretchable and flexible supercapacitors(SCs)are energy storage devices that provide ultrahigh powe...The wearable demand of modern electronic devices makes flexible and stretchable energy storage device urgently needed.Stretchable and flexible supercapacitors(SCs)are energy storage devices that provide ultrahigh power density while having long-term durability,high security,and electrochemical stability.Among different SCs electrode materials,CNTs and graphene-based materials exhibit great potential in terms of stretchable SCs due to its ultrahigh electrical conductivity,large specific surface area and good mechanical properties.In this review,the state-of-the-art process and achievements in the field of stretchable SCs enabled by CNTs and graphene are presented,which include the novel design strategy,mechanical and electrochemical properties.The final section highlights current challenges and future perspectives on research in this thriving field.展开更多
Electromagnetic interference(EMI)shielding at Terahertz(THz)frequency range attracts increasing attention due to the rapid development of THz science and technologies.EMI shielding materials with small thickness,high ...Electromagnetic interference(EMI)shielding at Terahertz(THz)frequency range attracts increasing attention due to the rapid development of THz science and technologies.EMI shielding materials with small thickness,high shielding effectiveness(SE),good flexibility and stability are highly desirable.Herein,an ultrathin flexible copper/graphene(Cu/Gr)nanolayered composite are prepared,which can reach the average EMI SE of 60.95 dB at 0.1–1.0 THz with a thickness of only 160 nm,indicating that more than 99.9999%of the THz wave power can be shielded.Furthermore,the Cu/Gr nanolayered composite also exhibits excellent oxidation resistance,with a 93.09%maintenance rate for EMI SE value after heating at 120℃for 3 h in air,far higher than that of the bare Cu film(62.15%).Besides,the Cu/Gr nanolayered composite exhibits good mechanical flexibility and flexural fatigue resistance.The EMI SE value of the Cu/Gr nanolayered composite shows a maintenance rate of 98.87%even after 1500 times bending cycles,obviously higher than that of multilayer Cu film(93.07%).These results demonstrate that the ultrathin flexible Cu/Gr nanolayered composites with excellent shielding performance and good stability have a broad application prospect in THz shielding for wearable devices and next generation mobile communication equipment.展开更多
Highly sensitive broadband photodetection is of critical importance for many applications.However,it is a great challenge to realize broadband photodetection by using a single device.Here we report photodetectors(PDs)...Highly sensitive broadband photodetection is of critical importance for many applications.However,it is a great challenge to realize broadband photodetection by using a single device.Here we report photodetectors(PDs)based on three-dimensional(3 D)graphene foam(GF)photodiodes with asymmetric electrodes,which show an ultra-broadband photoresponse from ultraviolet to microwave for wavelengths ranging from 10~2 to 10~6 nm.Moreover,the devices exhibit a high photoresponsivity of 10~3 A·W^-1,short response time of 43 ms,and3 d B bandwidth of 80 Hz.The high performance of the devices can be attributed to the photothermoelectric(PTE,also known as the Seebeck)effect in 3 D GF photodiodes.The excellent optical,thermal,and electrical properties of 3 D GFs offer a superior basis for the fabrication of PTE-based PDs.This work paves the way to realize ultra-broadband and high-sensitivity PDs operated at room temperature.展开更多
基金financial support from Ministry of Science and Technology of China(MoST,2016YFA0200200)the National Natural Science Foundation of China(NSFC,21875114,51373078,and 51422304)NSF of Tianjin City(15JCYBJC17700)。
文摘The development of microwave absorption materials(MAMs) is a considerable important topic because our living space is crowed with electromagnetic wave which threatens human’s health.And MAMs are also used in radar stealth for protecting the weapons from being detected.Many nanomaterials were studied as MAMs,but not all of them have the satisfactory performance.Recently,metal-organic frameworks(MOFs) have attracted tremendous attention owing to their tunable chemical structures,diverse properties,large specific surface area and uniform pore distribution.MOF can transform to porous carbon(PC) which is decorated with metal species at appropriate pyrolysis temperature.However,the loss mechanism of pure MOF-derived PC is often relatively simple.In order to further improve the MA performance,the MOFs coupled with other loss materials are a widely studied method.In this review,we summarize the theories of MA,the progress of different MOF-derived PC-based MAMs,tunable chemical structures incorporated with dielectric loss or magnetic loss materials.The different MA performance and mechanisms are discussed in detail.Finally,the shortcomings,challenges and perspectives of MOF-derived PC-based MAMs are also presented.We hope this review could provide a new insight to design and fabricate MOF-derived PC-based MAMs with better fundamental understanding and practical application.
基金We acknowledge the National Key R&D Program of China(No.2020YFA0711500)the National Natural Science Foundation of China(Nos.21875114,51373078,and 51422304)the 111 project(No.B18030).
文摘Exploring advanced electromagnetic wave(EMW)absorbers is one of the most feasible ways to solve the increasing electromagnetic pollution in both military and civil fields.In this work,γ-graphyne(γ-GY)is synthesized by a mechanochemical route using CaC2 and hexabromobenzene(PhBr6).Then three-dimensional(3D)reduced graphene oxide/γ-GY(RGO/GY)heterostructures are prepared through facile solvothermal self-assembly and subsequent thermal reduction.The influences of calcination temperature and the content ofγ-GY of the composite on EMW absorption performance are fully investigated.The minimum reflection loss(RL)value of the RGO/GY composite foam is−71.73 dB at 10.48 GHz with the matching thickness of 3.54 mm,and the effective absorption bandwidth(EAB)less than−10 dB is 7.36 GHz.Moreover,excellent terahertz(THz)absorption property is also obtained at 0.2–1.6 THz.The RL of 84.08 dB is acquired,and the EAB covers 100%of the entire measured bandwidth.In addition,the composite is also a promising anticorrosive EMW absorber.This work provides encouraging findings,which are also instructive for the potential advantages of graphyne-based materials as highly efficient EMW absorbers in both gigahertz and terahertz band ranges.
基金supported by Ministry of Science and Technology of China(No.2016YFA0200200)the National Natural Science Foundation of China(Nos.21875114,51373078,and 51422304)+1 种基金Natural Science Foundation of Tianjin City(No.15JCYBJC17700)111 Project(No.B18030).
文摘The wearable demand of modern electronic devices makes flexible and stretchable energy storage device urgently needed.Stretchable and flexible supercapacitors(SCs)are energy storage devices that provide ultrahigh power density while having long-term durability,high security,and electrochemical stability.Among different SCs electrode materials,CNTs and graphene-based materials exhibit great potential in terms of stretchable SCs due to its ultrahigh electrical conductivity,large specific surface area and good mechanical properties.In this review,the state-of-the-art process and achievements in the field of stretchable SCs enabled by CNTs and graphene are presented,which include the novel design strategy,mechanical and electrochemical properties.The final section highlights current challenges and future perspectives on research in this thriving field.
基金supported financially by the Foundation of Ministry of Science and Technology of China(No.2016YFA0200200)the National Natural Science Foundation of China(Nos.21875114,51373078 and 51422304)111 Project(No.B18030)。
文摘Electromagnetic interference(EMI)shielding at Terahertz(THz)frequency range attracts increasing attention due to the rapid development of THz science and technologies.EMI shielding materials with small thickness,high shielding effectiveness(SE),good flexibility and stability are highly desirable.Herein,an ultrathin flexible copper/graphene(Cu/Gr)nanolayered composite are prepared,which can reach the average EMI SE of 60.95 dB at 0.1–1.0 THz with a thickness of only 160 nm,indicating that more than 99.9999%of the THz wave power can be shielded.Furthermore,the Cu/Gr nanolayered composite also exhibits excellent oxidation resistance,with a 93.09%maintenance rate for EMI SE value after heating at 120℃for 3 h in air,far higher than that of the bare Cu film(62.15%).Besides,the Cu/Gr nanolayered composite exhibits good mechanical flexibility and flexural fatigue resistance.The EMI SE value of the Cu/Gr nanolayered composite shows a maintenance rate of 98.87%even after 1500 times bending cycles,obviously higher than that of multilayer Cu film(93.07%).These results demonstrate that the ultrathin flexible Cu/Gr nanolayered composites with excellent shielding performance and good stability have a broad application prospect in THz shielding for wearable devices and next generation mobile communication equipment.
基金National Natural Science Foundation of China(61675147,61605141,61735010,91838301)National Key Research and Development Program of China(2017YFA0700202)+2 种基金Basic Research Program of Shenzhen(JCYJ20170412154447469)Beiyang Yong Junior Faculties of Tianjin University(2019XRG-0056)Wenzhou City Governmental Public Industrial Technology Project(G20160014)。
文摘Highly sensitive broadband photodetection is of critical importance for many applications.However,it is a great challenge to realize broadband photodetection by using a single device.Here we report photodetectors(PDs)based on three-dimensional(3 D)graphene foam(GF)photodiodes with asymmetric electrodes,which show an ultra-broadband photoresponse from ultraviolet to microwave for wavelengths ranging from 10~2 to 10~6 nm.Moreover,the devices exhibit a high photoresponsivity of 10~3 A·W^-1,short response time of 43 ms,and3 d B bandwidth of 80 Hz.The high performance of the devices can be attributed to the photothermoelectric(PTE,also known as the Seebeck)effect in 3 D GF photodiodes.The excellent optical,thermal,and electrical properties of 3 D GFs offer a superior basis for the fabrication of PTE-based PDs.This work paves the way to realize ultra-broadband and high-sensitivity PDs operated at room temperature.