Hydrogenated two-dimensional(2D)materials have gained significant attention due to their tunable properties,which can be engineered through various functionalization techniques.This review discusses hydrogenated Xenes...Hydrogenated two-dimensional(2D)materials have gained significant attention due to their tunable properties,which can be engineered through various functionalization techniques.This review discusses hydrogenated Xenes,a new class of fully hydrogenated mono-elemental 2D materials,including graphane,germanane,silicane,and stanane.Hydrogenation enhances the properties of Xenes,making them transparent,mechanically strong,electrically conductive,and rare.These materials off er a unique combination of characteristics that make them highly desirable for a variety of advanced applications in energy storage,organic electronics,and optoelectronics.Xenes such as silicane and germanane are semiconductors with tunable bandgaps,making them ideal for use in transistors,logic circuits,and sensors.Their electronic and optical properties can be finely adjusted,allowing them to be used in high-performance devices like LEDs,solar cells,and photodetectors.Furthermore,hydrogenated Xenes show potential in applications like batteries,supercapacitors,hydrogen storage,piezoelectricity,and biosensing,owing to their high surface area and versatility.This review also explores the impact of various hydrogenation techniques,including plasma treatment,wet chemical methods,and electrochemical hydrogenation,on the electronic,mechanical,thermal,optical,and magnetic properties of these materials.Advanced characterization techniques,such as X-ray absorption spectroscopy(XANES),have provided valuable insights into the electronic structure and bonding environments of these materials.Finally,the paper highlights the challenges and limitations of hydrogenation,including structural instability and environmental concerns,while discussing the future prospects and advancements needed to harness the full potential of hydrogenated 2D materials.This review serves as a comprehensive resource for researchers aiming to explore the applications of hydrogenated Xenes in next-generation technologies.展开更多
Outdoor jackets are engineered to protect against extreme weather while ensuring comfort and safety. Key to this protection is the thermal properties, achieved through insulation materials like down feathers and synth...Outdoor jackets are engineered to protect against extreme weather while ensuring comfort and safety. Key to this protection is the thermal properties, achieved through insulation materials like down feathers and synthetic fibers, which trap heat and minimize heat loss. Resistance to wind, rain, and snow is provided by waterproof and windproof fabrics, while breathability allows moisture to escape, maintaining a comfortable microclimate. Air permeability and water resistance are essential for achieving this balance. This study examines two outdoor jacket prototypes with six material layers each. The outer layer (Layer 1) consists of 100% polyester coated with polyurethane for waterproofing. Inner layers (Layers 2, 3, and 6) use wool/cotton and wool/polyamide blends, offering insulation and moisture-wicking properties. Down feathers are used as the filling material, providing excellent warmth. Advanced materials like graphene and silver honeycomb fabrics were included to enhance thermal conductivity and regulate heat transfer. Performance testing focused on thermal conductivity, comfort (water and air permeability), and mechanical properties like tensile strength and tear resistance. Tests also assessed spray application and fastness to evaluate durability under environmental exposure. Results showed that jackets with silver-infused honeycomb fabrics had superior thermal conductivity, enabling better heat regulation and comfort in harsh conditions. The findings highlight the advantages of integrating silver honeycomb fabrics into outdoor jackets. These materials enhance insulation, thermal regulation, and overall comfort, making them ideal for high-performance designs. Incorporating such fabrics ensures functionality, durability, and user protection in extreme environments.展开更多
The present analytical review is devoted to the current problem of thermodynamic stability and related thermodynamic characteristics of the following graphene layers systems: 1) double-side hydrogenated graphene of co...The present analytical review is devoted to the current problem of thermodynamic stability and related thermodynamic characteristics of the following graphene layers systems: 1) double-side hydrogenated graphene of composition CH (theoretical graphane) (Sofo et al. 2007) and experimental graphane (Elias et al. 2009);2) theoretical single-side hydrogenated graphene of composition CH;3) theoretical single-side hydrogenated graphene of composition C2H (graphone);4) experimental hydrogenated epitaxial graphene, bilayer graphene and a few layers of graphene on SiO2 or other substrates;5) experimental and theoretical single-external side hydrogenated single-walled carbon nanotubes, and experimental hydrofullerene C60H36;6) experimental single-internal side hydrogenated (up to C2H or CH composition) graphene nanoblisters with intercalated high pressure H2 gas inside them, formed on a surface of highly oriented pyrolytic graphite or epitaxial graphene under the atomic hydrogen treatment;and 7) experimental hydrogenated graphite nanofibers-multigraphene with intercalated solid H2 nano-regions of high density inside them, relevant to solving the problem of hydrogen on-board storage (Nechaev 2011-2012).展开更多
Nearly free electron （NFE） state has been widely studied in low dimensional systems. Based on first-principles calculations, we identify two types of NFE states in graphane nanoribbon superlattice, similar to those ...Nearly free electron （NFE） state has been widely studied in low dimensional systems. Based on first-principles calculations, we identify two types of NFE states in graphane nanoribbon superlattice, similar to those of graphene nanoribbons and boron nitride nanoribbons. Effect of electron doping on the NFE states in graphane nanoribbon superlattice has been studied, and it is possible to open a vacuum transport channel via electron doping.展开更多
Chemical modification and vertical stacking of two-dimensional materials are promising techniques for new nanoelectronic devices. We present Density Functional Tight Binding(DFTB) calculations of a field-effect device...Chemical modification and vertical stacking of two-dimensional materials are promising techniques for new nanoelectronic devices. We present Density Functional Tight Binding(DFTB) calculations of a field-effect device,based on lateral and vertical heterostructures of 2D materials. The device consists of a phosphorene channel protected by graphene sheets, which work as contacts and are divided into the source and drain by local hydrogenation of graphene, which gives insulating graphane. In this device composed of only 3 layers, single sheets of graphene-graphane can work as both leads and oxide gate, while also acting as protective layers for a phosphorene channel. We show how for perfect vd W heterostructures of graphane/phosphorene/graphane and graphene/phosphorene/graphene the Schottky barrier is deeply influenced by normal electric fields, and we characterize electronic transport of such a device. Finally, we characterize phosphorene channel doping and defects, which, at very high densities in the transport direction, enables transport inside the phosphorene bandgap.展开更多
We perform first-principles total energy calculations to investigate the stabilities and the electronic structures of graphane-like structures of carbon-halogen compounds, where the hydrogen atoms in the graphane are ...We perform first-principles total energy calculations to investigate the stabilities and the electronic structures of graphane-like structures of carbon-halogen compounds, where the hydrogen atoms in the graphane are substituted by halogen atoms. Three halogen elements, fluorine （F）, chlorine （C1） and bromine （Br）, are considered, and the graphane-like structures are named as CF, CC1 and CBr, respectively. It is found that for the single-atom adsorption, only the F adatom can be chemically adsorbed on the graphene. However, the stable graphane-like structures of CF, CC1 and CBr can form due to the interaction between the halogen atoms. The carbon atoms in the stable CF, CC1 and CBr compounds are in the sp3 hybridization, forming a hexagonal network similar to the graphane. The electronic band calculations show that CF and CC1 are semiconductors with band gaps of 3.28 eV and 1.66 eV, respectively, while CBr is a metal. Moreover, the molecular dynamics simulation is employed to clarify the stabilities of CF and CC1. Those two compounds are stable at room temperature. A high temperature （：〉 1200 K） is needed to damage CF, while CC1 is destroyed at 700 K. Furthermore, the effects of a vacancy on the structure and the electronic property of CF are discussed.展开更多
Inspired by the successful synthesis of h Hv-graphane[Nano Lett.15903(2015)],a new two-dimensional(2D)Janus material Cu-graphane is proposed based on the first-principles calculations.Without the spin-orbit coupling(S...Inspired by the successful synthesis of h Hv-graphane[Nano Lett.15903(2015)],a new two-dimensional(2D)Janus material Cu-graphane is proposed based on the first-principles calculations.Without the spin-orbit coupling(SOC)effect,Cu-graphane is a Dirac semimetal with a highly anisotropic Dirac cone,whose Fermi velocity ranges from 0.12×10^(5)m/s to2.9×10^(5)m/s.The Dirac cone near the Fermi level can be well described with an extended 2D Dirac model Hamiltonian.In the presence of the SOC effect,band splitting is observed around the Fermi level,and a large intrinsic spin Hall conductivity(ISHC)with a maximum value of 346(h/e)S/cm is predicted.Moreover,the spin Hall transport can be regulated by slightly adjusting the Fermi energy,e.g.,grid voltage or chemical doping.Our work not only proposes a new 2D Janus material with a highly anisotropic Dirac cone and a large ISHC,but also reveals that a large ISHC may exist in some Dirac systems.展开更多
With support from the National Natural Science Foundation of China and the Top 1000-Talents Awards,the research team led by Dr.Zheng HaiYan(郑海燕)and Dr.Li Kuo(李阔)from the Center for High Pressure Science and Techn...With support from the National Natural Science Foundation of China and the Top 1000-Talents Awards,the research team led by Dr.Zheng HaiYan(郑海燕)and Dr.Li Kuo(李阔)from the Center for High Pressure Science and Technology Advanced Research in Beijing recently synthesized H-F-substituted graphane(H,F-graphane)with a layered structure by compressing 1:1 C6H6-C6F6 co-crystal(abbreviated as CHCF).展开更多
基金partially supported by the financial supports from Aaivalayam-DIRAC,Indiathe Science and Technology Development Fund(Nos.007/2017/A1 and 132/2017/A3),Macao Special Administration Region(SAR),China+2 种基金National Natural Science Fund(Nos.61875138,61435010,and 6181101252)Science and Technology Innovation Commission of the Shenzhen(Nos.KQTD2015032416270,JCYJ20150625103619275,and JCYJ20170811093453105)research funding from the Ministry of Science and Higher Education of the Russian Federation(Ural Federal University project within the Priority 2030 Program)。
文摘Hydrogenated two-dimensional(2D)materials have gained significant attention due to their tunable properties,which can be engineered through various functionalization techniques.This review discusses hydrogenated Xenes,a new class of fully hydrogenated mono-elemental 2D materials,including graphane,germanane,silicane,and stanane.Hydrogenation enhances the properties of Xenes,making them transparent,mechanically strong,electrically conductive,and rare.These materials off er a unique combination of characteristics that make them highly desirable for a variety of advanced applications in energy storage,organic electronics,and optoelectronics.Xenes such as silicane and germanane are semiconductors with tunable bandgaps,making them ideal for use in transistors,logic circuits,and sensors.Their electronic and optical properties can be finely adjusted,allowing them to be used in high-performance devices like LEDs,solar cells,and photodetectors.Furthermore,hydrogenated Xenes show potential in applications like batteries,supercapacitors,hydrogen storage,piezoelectricity,and biosensing,owing to their high surface area and versatility.This review also explores the impact of various hydrogenation techniques,including plasma treatment,wet chemical methods,and electrochemical hydrogenation,on the electronic,mechanical,thermal,optical,and magnetic properties of these materials.Advanced characterization techniques,such as X-ray absorption spectroscopy(XANES),have provided valuable insights into the electronic structure and bonding environments of these materials.Finally,the paper highlights the challenges and limitations of hydrogenation,including structural instability and environmental concerns,while discussing the future prospects and advancements needed to harness the full potential of hydrogenated 2D materials.This review serves as a comprehensive resource for researchers aiming to explore the applications of hydrogenated Xenes in next-generation technologies.
文摘Outdoor jackets are engineered to protect against extreme weather while ensuring comfort and safety. Key to this protection is the thermal properties, achieved through insulation materials like down feathers and synthetic fibers, which trap heat and minimize heat loss. Resistance to wind, rain, and snow is provided by waterproof and windproof fabrics, while breathability allows moisture to escape, maintaining a comfortable microclimate. Air permeability and water resistance are essential for achieving this balance. This study examines two outdoor jacket prototypes with six material layers each. The outer layer (Layer 1) consists of 100% polyester coated with polyurethane for waterproofing. Inner layers (Layers 2, 3, and 6) use wool/cotton and wool/polyamide blends, offering insulation and moisture-wicking properties. Down feathers are used as the filling material, providing excellent warmth. Advanced materials like graphene and silver honeycomb fabrics were included to enhance thermal conductivity and regulate heat transfer. Performance testing focused on thermal conductivity, comfort (water and air permeability), and mechanical properties like tensile strength and tear resistance. Tests also assessed spray application and fastness to evaluate durability under environmental exposure. Results showed that jackets with silver-infused honeycomb fabrics had superior thermal conductivity, enabling better heat regulation and comfort in harsh conditions. The findings highlight the advantages of integrating silver honeycomb fabrics into outdoor jackets. These materials enhance insulation, thermal regulation, and overall comfort, making them ideal for high-performance designs. Incorporating such fabrics ensures functionality, durability, and user protection in extreme environments.
文摘The present analytical review is devoted to the current problem of thermodynamic stability and related thermodynamic characteristics of the following graphene layers systems: 1) double-side hydrogenated graphene of composition CH (theoretical graphane) (Sofo et al. 2007) and experimental graphane (Elias et al. 2009);2) theoretical single-side hydrogenated graphene of composition CH;3) theoretical single-side hydrogenated graphene of composition C2H (graphone);4) experimental hydrogenated epitaxial graphene, bilayer graphene and a few layers of graphene on SiO2 or other substrates;5) experimental and theoretical single-external side hydrogenated single-walled carbon nanotubes, and experimental hydrofullerene C60H36;6) experimental single-internal side hydrogenated (up to C2H or CH composition) graphene nanoblisters with intercalated high pressure H2 gas inside them, formed on a surface of highly oriented pyrolytic graphite or epitaxial graphene under the atomic hydrogen treatment;and 7) experimental hydrogenated graphite nanofibers-multigraphene with intercalated solid H2 nano-regions of high density inside them, relevant to solving the problem of hydrogen on-board storage (Nechaev 2011-2012).
基金This work was supported by the National Natural Science Foundation of China （No.20933006, No.20803071, and No.50721091）, the Ministry of Science and Technology （No.2011CB921404）, and Super Computer Center of University of Science and Technology of China, Supercomputing Center of Chinese Academy of Science, and Shanghai Supercomputer Center.
文摘Nearly free electron （NFE） state has been widely studied in low dimensional systems. Based on first-principles calculations, we identify two types of NFE states in graphane nanoribbon superlattice, similar to those of graphene nanoribbons and boron nitride nanoribbons. Effect of electron doping on the NFE states in graphane nanoribbon superlattice has been studied, and it is possible to open a vacuum transport channel via electron doping.
基金supported through the German Research Foundation within the project “Straintronics of imperfect quasi-two-dimensional materials: coplanar vs lamellar heterostructures” (CU 44/43).
文摘Chemical modification and vertical stacking of two-dimensional materials are promising techniques for new nanoelectronic devices. We present Density Functional Tight Binding(DFTB) calculations of a field-effect device,based on lateral and vertical heterostructures of 2D materials. The device consists of a phosphorene channel protected by graphene sheets, which work as contacts and are divided into the source and drain by local hydrogenation of graphene, which gives insulating graphane. In this device composed of only 3 layers, single sheets of graphene-graphane can work as both leads and oxide gate, while also acting as protective layers for a phosphorene channel. We show how for perfect vd W heterostructures of graphane/phosphorene/graphane and graphene/phosphorene/graphene the Schottky barrier is deeply influenced by normal electric fields, and we characterize electronic transport of such a device. Finally, we characterize phosphorene channel doping and defects, which, at very high densities in the transport direction, enables transport inside the phosphorene bandgap.
基金supported by the National Natural Science Foundation of China(Grant No.10874089)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK2008398)the Foundation of Jiangsu Innovation Program for Graduate Education, China(Grant No.CX08B-005Z)
文摘We perform first-principles total energy calculations to investigate the stabilities and the electronic structures of graphane-like structures of carbon-halogen compounds, where the hydrogen atoms in the graphane are substituted by halogen atoms. Three halogen elements, fluorine （F）, chlorine （C1） and bromine （Br）, are considered, and the graphane-like structures are named as CF, CC1 and CBr, respectively. It is found that for the single-atom adsorption, only the F adatom can be chemically adsorbed on the graphene. However, the stable graphane-like structures of CF, CC1 and CBr can form due to the interaction between the halogen atoms. The carbon atoms in the stable CF, CC1 and CBr compounds are in the sp3 hybridization, forming a hexagonal network similar to the graphane. The electronic band calculations show that CF and CC1 are semiconductors with band gaps of 3.28 eV and 1.66 eV, respectively, while CBr is a metal. Moreover, the molecular dynamics simulation is employed to clarify the stabilities of CF and CC1. Those two compounds are stable at room temperature. A high temperature （：〉 1200 K） is needed to damage CF, while CC1 is destroyed at 700 K. Furthermore, the effects of a vacancy on the structure and the electronic property of CF are discussed.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12074150,12174157,12174158,and 11874314)the Innovation and Entrepreneurship Talent Project of Jiangsu Province of China+1 种基金the Scientific Research Startup of Jiangsu University(Grant No.5501710001)the College Students’Innovation Training Program of Jiangsu Province of China(Grant No.202110299123Y)。
文摘Inspired by the successful synthesis of h Hv-graphane[Nano Lett.15903(2015)],a new two-dimensional(2D)Janus material Cu-graphane is proposed based on the first-principles calculations.Without the spin-orbit coupling(SOC)effect,Cu-graphane is a Dirac semimetal with a highly anisotropic Dirac cone,whose Fermi velocity ranges from 0.12×10^(5)m/s to2.9×10^(5)m/s.The Dirac cone near the Fermi level can be well described with an extended 2D Dirac model Hamiltonian.In the presence of the SOC effect,band splitting is observed around the Fermi level,and a large intrinsic spin Hall conductivity(ISHC)with a maximum value of 346(h/e)S/cm is predicted.Moreover,the spin Hall transport can be regulated by slightly adjusting the Fermi energy,e.g.,grid voltage or chemical doping.Our work not only proposes a new 2D Janus material with a highly anisotropic Dirac cone and a large ISHC,but also reveals that a large ISHC may exist in some Dirac systems.
文摘With support from the National Natural Science Foundation of China and the Top 1000-Talents Awards,the research team led by Dr.Zheng HaiYan(郑海燕)and Dr.Li Kuo(李阔)from the Center for High Pressure Science and Technology Advanced Research in Beijing recently synthesized H-F-substituted graphane(H,F-graphane)with a layered structure by compressing 1:1 C6H6-C6F6 co-crystal(abbreviated as CHCF).
