As an emerging member of the two-dimensional(2D)material family,V_(2)CT_(X)MXene shows great potential in the application of lithium-ion capacitors(LICs)due to its unique structure and excellent electrical conductivit...As an emerging member of the two-dimensional(2D)material family,V_(2)CT_(X)MXene shows great potential in the application of lithium-ion capacitors(LICs)due to its unique structure and excellent electrical conductivity.However,severe nanosheets stacking and intra-layer transport barriers have limited the further development of V_(2)CT_(X)MXene-based materials.Herein,we prepared Kions and–O functional group co-modified V_(2)CT_(X)MXene(VCT-K)and further incorporated it with single-walled carbon nanotube(SWCNT),obtaining freestanding V_(2)CT_(X)composite films(VCT-K@C)with the 3D conductive network.Significantly,K+ions were introduced into V_(2)CT_(X)MXene to stabilize the interlayer structure and prevent the aggregation of nanosheets,the terminal group of–O was controllably modified on the surface of MXene to improve the Li+ions storage reversible capacities and the SWCNT acted as the bridge between MXene nanosheets to opens up the channels for ion/electron transportation in the longitudinal direction.Benefited from the synergistic effect of VCT-K and SWCNT,the VCT-K@C exhibits superior reversible specific capacities of 671.8 mA h g^(-1)at 0.1 A g^(-1)and 318 mA h g^(-1)at 1.0 A g^(-1).Furthermore,the assembled LICs with VCT-K@C anode coupling activated carbon(AC)cathode deliver an outstanding power density of 19.0 kW kg^(-1)at 67.4 Wh kg^(-1),a high energy density of 140.5 Wh kg^(-1)at 94.8 W kg^(-1)and a stable capacitance retention of 86%after 6000 cycles at 10 A g^(-1).Such unique structures and excellent electrochemical properties are expected to pave the way for the large-scale application in LICs of MXene-based materials.展开更多
Two-dimensional(2D) semiconductors have captured broad interest as light emitters, due to their unique excitonic effects. These layer-blocks can be integrated through van der Waals assembly, i.e., fabricating homo-or ...Two-dimensional(2D) semiconductors have captured broad interest as light emitters, due to their unique excitonic effects. These layer-blocks can be integrated through van der Waals assembly, i.e., fabricating homo-or heterojunctions, which show novel emission properties caused by interface engineering. In this review, we will first give an overview of the basic strategies that have been employed in interface engineering, including changing components, adjusting interlayer gap, and tuning twist angle. By modifying the interfacial factors, novel emission properties of emerging excitons are unveiled and discussed. Generally, well-tailored interfacial energy transfer and charge transfer within a 2D heterostructure cause static modulation of the brightness of intralayer excitons. As a special case, dynamically correlated dual-color emission in weakly-coupled bilayers will be introduced, which originates from intermittent interlayer charge transfer. For homobilayers and type Ⅱ heterobilayers, interlayer excitons with electrons and holes residing in neighboring layers are another important topic in this review. Moreover, the overlap of two crystal lattices forms moiré patterns with a relatively large period, taking effect on intralayer and interlayer excitons. Particularly, theoretical and experimental progresses on spatially modulated moiré excitons with ultra-sharp linewidth and quantum emission properties will be highlighted. Moiré quantum emitter provides uniform and integratable arrays of single photon emitters that are previously inaccessible, which is essential in quantum many-body simulation and quantum information processing. Benefiting from the optically addressable spin and valley indices, 2D heterostructures have become an indispensable platform for investigating exciton physics, designing and integrating novel concept emitters.展开更多
To understand the deformation mechanism of molecular crystals under mechanical forces will accelerate the molecular design and preparation of deformable crystals.Herein,the relationship between structural halogenation...To understand the deformation mechanism of molecular crystals under mechanical forces will accelerate the molecular design and preparation of deformable crystals.Herein,the relationship between structural halogenation and molecular-level stacking,micro/nanoscale surface morphology,and macroscopic mechanical properties are investigated.Elastic crystals of halo-pyrimidinyl carbazoles(CzM-Cl,CzM-Br and CzM-I)with lamellar structure and brittle crystal(CzM-F)were quantitatively analyzed by crystal energy framework(CEF)providing the inter/intralayer interaction energy(Inter/Intra-IE).It is revealed that the elastic crystals bend under external force as a result from stronger Intra-IE to prevent cleavage and weaker Inter-IE for the short-range movement of molecules on the slip plane.This research will provide an insight for the molecular design of flexible crystals and facilitate the development of next-generation smart crystal materials.展开更多
基金funded by the National Natural Science Foundation of China(Grant Nos.22005167 and 21905152)the Shandong Provincial Natural Science Foundation of China(Grant Nos.ZR2020QB125 and ZR2020MB045)+1 种基金the China Postdoctoral Science Foundation(Grant Nos.2021M693256,2021T140687 and 2022M713249)the Qingdao Postdoctoral Applied Research Project and the Youth Innovation Team Project for Talent Introduction and Cultivation in Universities of Shandong Province。
文摘As an emerging member of the two-dimensional(2D)material family,V_(2)CT_(X)MXene shows great potential in the application of lithium-ion capacitors(LICs)due to its unique structure and excellent electrical conductivity.However,severe nanosheets stacking and intra-layer transport barriers have limited the further development of V_(2)CT_(X)MXene-based materials.Herein,we prepared Kions and–O functional group co-modified V_(2)CT_(X)MXene(VCT-K)and further incorporated it with single-walled carbon nanotube(SWCNT),obtaining freestanding V_(2)CT_(X)composite films(VCT-K@C)with the 3D conductive network.Significantly,K+ions were introduced into V_(2)CT_(X)MXene to stabilize the interlayer structure and prevent the aggregation of nanosheets,the terminal group of–O was controllably modified on the surface of MXene to improve the Li+ions storage reversible capacities and the SWCNT acted as the bridge between MXene nanosheets to opens up the channels for ion/electron transportation in the longitudinal direction.Benefited from the synergistic effect of VCT-K and SWCNT,the VCT-K@C exhibits superior reversible specific capacities of 671.8 mA h g^(-1)at 0.1 A g^(-1)and 318 mA h g^(-1)at 1.0 A g^(-1).Furthermore,the assembled LICs with VCT-K@C anode coupling activated carbon(AC)cathode deliver an outstanding power density of 19.0 kW kg^(-1)at 67.4 Wh kg^(-1),a high energy density of 140.5 Wh kg^(-1)at 94.8 W kg^(-1)and a stable capacitance retention of 86%after 6000 cycles at 10 A g^(-1).Such unique structures and excellent electrochemical properties are expected to pave the way for the large-scale application in LICs of MXene-based materials.
基金supported by the Natural Science Foundation of China(22203042,21873048 and 22173044)。
文摘Two-dimensional(2D) semiconductors have captured broad interest as light emitters, due to their unique excitonic effects. These layer-blocks can be integrated through van der Waals assembly, i.e., fabricating homo-or heterojunctions, which show novel emission properties caused by interface engineering. In this review, we will first give an overview of the basic strategies that have been employed in interface engineering, including changing components, adjusting interlayer gap, and tuning twist angle. By modifying the interfacial factors, novel emission properties of emerging excitons are unveiled and discussed. Generally, well-tailored interfacial energy transfer and charge transfer within a 2D heterostructure cause static modulation of the brightness of intralayer excitons. As a special case, dynamically correlated dual-color emission in weakly-coupled bilayers will be introduced, which originates from intermittent interlayer charge transfer. For homobilayers and type Ⅱ heterobilayers, interlayer excitons with electrons and holes residing in neighboring layers are another important topic in this review. Moreover, the overlap of two crystal lattices forms moiré patterns with a relatively large period, taking effect on intralayer and interlayer excitons. Particularly, theoretical and experimental progresses on spatially modulated moiré excitons with ultra-sharp linewidth and quantum emission properties will be highlighted. Moiré quantum emitter provides uniform and integratable arrays of single photon emitters that are previously inaccessible, which is essential in quantum many-body simulation and quantum information processing. Benefiting from the optically addressable spin and valley indices, 2D heterostructures have become an indispensable platform for investigating exciton physics, designing and integrating novel concept emitters.
基金the primary financial support by the National Natural Science Foundation of China (No. 21975126)the open research fund from Anhui Province Key Laboratory of Optoelectronic Materials Science and Technology+1 种基金the Technology and Research Innovation in University of Jiangsu Province (No.KYCX21_0772)the Ministry of Education and Synergetic Innovation Center for Organic Electronics and Information Displays
文摘To understand the deformation mechanism of molecular crystals under mechanical forces will accelerate the molecular design and preparation of deformable crystals.Herein,the relationship between structural halogenation and molecular-level stacking,micro/nanoscale surface morphology,and macroscopic mechanical properties are investigated.Elastic crystals of halo-pyrimidinyl carbazoles(CzM-Cl,CzM-Br and CzM-I)with lamellar structure and brittle crystal(CzM-F)were quantitatively analyzed by crystal energy framework(CEF)providing the inter/intralayer interaction energy(Inter/Intra-IE).It is revealed that the elastic crystals bend under external force as a result from stronger Intra-IE to prevent cleavage and weaker Inter-IE for the short-range movement of molecules on the slip plane.This research will provide an insight for the molecular design of flexible crystals and facilitate the development of next-generation smart crystal materials.