检索结果-南通市图书馆

Six-membered-ring inorganic materials: definition and prospects

在线全文

学校读者我要写书评

暂无评论

National Science Review 2021年第1期8卷 175-197页

作者： Gang Liu Xing-Qiu Chen Bilu Liu Wencai Ren Hui-Ming Cheng Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences School of Materials Science and Engineering University of Science and Technology of China Shenzhen Geim Graphene Center Tsinghua-Berkeley Shenzhen Institute and Shenzhen International Graduate School Tsinghua University

The six-membered ring (SMR) is a common structure unit for numerous material systems. These materials include, but are not limited to, the typical two-dimensional materials such as graphene, h-BN, and transition metal dichalcogenides, as well as three-dimensional materials such as beryllium, magnesium, Mg B2 and Bi2Se3. Although many of these materials have already become ‘stars’ in materials science and condensed-matter physics, little attention has been paid to the roles of the SMR unit across a wide range of compositions and structures. In this article, we systematically analyze these materials with respect to their very basic SMR structural unit, which has been found to play a deterministic role in the occurrence of many intriguing properties and phenomena, such as Dirac electronic and phononic spectra, superconductivity and topology. As a result, we have defined this group of materials as SMR inorganic materials, opening up a new perspective on materials research and development. With their unique properties, SMR materials deserve wide attention and in-depth investigation from materials design, new physical discoveries to target-wizard applications. It is expected that SMR materials will find niche applications in next-generation information technology, renewable energy, space, etc.

关键词： six-membered-ring (SMR) materials SMR concept SMR physics SMR chemistry SMR mechanics SMR classifications

Two-dimensional superconducting MoSi2N4(MoN)4n homologous compounds

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2023年第4期10卷 142-149页

作者： Zhibo Liu Lei Wang Yi-Lun Hong Xing-Qiu Chen Hui-Ming Cheng Wencai Ren Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences School of Materials Science and Engineering University of Science and Technology of China Shenzhen Institute of Advanced Technology Chinese Academy of Sciences

The number and stacking order of layers are two important degrees of freedom that can modulate the properties of 2D van der Waals(vdW) materials. However, the layers’ structures are essentially limited to the known layered 3D vdW materials. Recently, a new 2D vdW material, MoSi2N4, without known 3D counterparts, was synthesized by passivating the surface dangling bonds of non-layered 2D molybdenum nitride with elemental silicon, whose monolayer can be viewed as a monolayer MoN(-N-Mo-N-)sandwiched between two Si-N layers. This unique sandwich structure endows the MoSi2N4monolayer with many fascinating properties and intriguing applications, and the surface-passivating growth method creates the possibility of tuning the layer’s structure of 2D vdW materials. Here we synthesized a series of MoSi2N4(MoN)4nstructures confined in the matrix of multilayer MoSi2N4. These super-thick monolayers are the homologous compounds of MoSi2N4, which can be viewed as multilayer MoN(Mo4n+1N4n+2)sandwiched between two Si-N layers. First-principles calculations show that MoSi2N4(MoN)4monolayers have much higher Young’s modulus than Mo N, which is atributed to the strong Si-N bonds on the surface.Importantly, different from the semiconducting nature of the Mo Si2N4monolayer, the MoSi2N4(MoN)4monolayer is identified as a superconductor with a transition temperature of 9.02 K. The discovery of MoSi2N4(MoN)4nstructures not only expands the family of 2D materials but also brings a new degree of freedom to tailor the structure of 2D vd W materials, which may lead to unexpected novel properties and applications.

关键词： MoSi2N4 2D layered materials homologous compounds iDPC-STEM superconduct

Controlling reduction degree of graphene oxide membranes for improved water permeance

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science Bulletin 2018年第12期63卷 788-794页

作者： Qing Zhang Xitang Qian Khalid Hussain Thebo Hui-Ming Cheng Wencai Ren Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of China.Shenyang 110016China University of Chinese Academy of Sciences Beijing 100049China Tsinghua-Berkeley Shenzhen Institute(TBSI) Tsinghua University.Shenzhen 518055.China

Tailoring the pore structure and surface chemistry of graphene-based laminates is essentially important for their applications as separation membranes.Usually,pure graphene oxide(GO) and completely reduced GO(r GO) membranes suffer from low water permeance because of the lack of pristine graphitic sp^2 domains and very small interlayer spacing,respectively.In this work,we studied the influence of reduction degree on the structure and separation performance of r GO membranes.It was found that weak reduction retains the good dispersion and hydrophilicity of GO nanosheets.More importantly,it increases the number of pristine graphitic sp^2 domains in rGO nanosheets while keeping the large interlayer spacing of the GO membranes in most regions at the same time.The resultant membranes show a high water permeance of 56.3 L m^(-2)h^(-1)bar^(-1),which is about 4 times and over 10~4 times larger than those of the GO and completely reduced r GO membranes,respectively,and high rejection over 95% for various dyes.Furthermore,they show better structure stability and more superior separation performance than GO membranes in acid and alkali environments.

关键词：氧化物膜水位线控制结构稳定性分离膜表面化学应用程序孔结构

Defects boost graphitization for highly conductive graphene films

在线全文

学校读者我要写书评

暂无评论

National Science Review 2023年第7期10卷 172-182页

作者： Qing Zhang Qinwei Wei Kun Huang Zhibo Liu Wei Ma Zehui Zhang Yanfeng Zhang Hui-Ming Cheng Wencai Ren Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences School of Materials Science and Engineering University of Science and Technology of China School of Materials Science and Engineering Peking University Shenzhen Institute of Advanced Technology Chinese Academy of Sciences

Fabricating highly crystalline macroscopic films with extraordinary electrical and thermal conductivities from graphene sheets is essential for applications in electronics,telecommunications and thermal management.High-temperature graphitization is the only method known to date for the crystallization of all types of carbon materials,where defects are gradually removed with increasing temperature.However,when using graphene materials as precursors,including graphene oxide,reduced graphene oxide and pristine graphene,even lengthy graphitization at 3000℃ can only produce graphene films with small grain sizes and abundant structural disorders,which limit their conductivities.Here,we show that high-temperature defects substantially accelerate the grain growth and ordering of graphene films during graphitization,enabling ideal AB stacking as well as a 100-fold,64-fold and 28-fold improvement in grain size,electrical conductivity and thermal conductivity,respectively,between 2000℃ and 3000℃.This process is realized by nitrogen doping,which retards the lattice restoration of defective graphene,retaining abundant defects such as vacancies,dislocations and grain boundaries in graphene films at a high temperature.With this approach,a highly ordered crystalline graphene film similar to highly oriented pyrolytic graphite is fabricated,with electrical and thermal conductivities(～2.0×104S cm-1;～1.7×103W m-1K-1) that are improved by about 6-and 2-fold,respectively,compared to those of the graphene films fabricated by graphene oxide.Such graphene film also exhibits a superhigh electromagnetic interference shielding effectiveness of ～90 dB at a thickness of 10 μm,outperforming all the synthetic materials of comparable thickness including MXene films.This work not only paves the way for the te chnological application of highly conductive graphene films but also provides a general strategy to efficiently improve the synthesis and properties of other carbon materials such as graphene fibers,carbon nanotube fibers,carbon fibers,polym

关键词： graphene film defects graphitization electrical and thermal conductivity thermal management and EMI shielding

Graphene： a promising 2D material for electrochemical energy storage

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science Bulletin 2017年第10期62卷 724-740页

作者： Yanfeng Dong Zhong-Shuai Wu Wencai Ren Hui-Ming Cheng Xinhe Bao Dalian National Laboratory for Clean Energy Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences. Shenyang 110016 China Tsinghua-Berkeley Shenzhen Institute (TBSI) Tsinghua University Shenzhen 518055 China State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China

Graphene, with unique two-dimensional form and numerous appealing properties, promises to remarkably increase the energy density and power density of electrochemical energy storage devices(EESDs),ranging from the popular lithium ion batteries and supercapacitors to next-generation high-energy batteries. Here, we review the recent advances of the state-of-the-art graphene-based materials for EESDs,including lithium ion batteries, supercapacitors, micro-supercapacitors, high-energy lithium-air and lithium-sulfur batteries, and discuss the importance of the pore, doping, assembly, hybridization and functionalization of different nano-architectures in improving electrochemical performance. The major roles of graphene are highlighted as(1) a superior active material,(2) ultrathin 2D flexible support,and(3) an inactive yet electrically conductive additive. Furthermore, we address the enormous potential of graphene for constructing new-concept emerging graphene-enabled EESDs with multiple functionalities of lightweight, ultra-flexibility, thinness, and novel cell configurations. Finally, future perspectives and challenges of graphene-based EESDs are briefly discussed.

关键词：储能材料电化学石墨

Defective graphene as a high-efficiency Raman enhancement substrate

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2019年第9期35卷 1996-2002页

作者： Tong Zhao Zhibo Liu Xing Xin Hui-Ming Cheng Wencai Ren Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Material Science and Engineering University of Science and Technology of ChinaShenyang 110016China University of Chinese Academy of Sciences Shenyang 110016China Shenzhen Geim Graphene Center Tsinghua-Berkeley Shenzhen Institute (TBSI)Tsinghua University1001 Xueyuan RoadShenzhen 518055China

Pristine graphene (PG) has been demonstrated to be an excellent substrate for Raman enhancement, which is called graphene-enhanced Raman scattering. However, the chemically inert and hydrophobic surface of PG hinders the adsorption of molecules especially in aqueous solutions, and consequently limits the Raman enhanced efficiency. Here, we synthesized defective graphene (DG) films by chemical vapor deposition on Au, which has a defect density of ~2.0 ×10^11 cm^-2. The DG shows a much better wettability than PG towards dye solution. Combining with the strong adsorption ability of defects to molecules, DG shows greatly enhanced efficiency than PG with perfect lattice. For example, the detection limit for rhodamine B can reach 2×10^9 M for DG while it is on the order of 10^-7 M for PG. In addition, DG has high enhancement uniformity and the Au substrate can be reused after electrochemical bubbling transfer. These advantages suggest the great potential of the DG grown on Au for practical applications in environmental monitoring.

关键词： Defective graphene Raman enhancement Chemical vapor deposition Bubbling transfer

Electrochemically derived nanographene oxide activates endothelial tip cells and promotes angiogenesis by binding endogenous lysophosphatidic acid

在线全文

学校读者我要写书评

暂无评论

Bioactive Materials 2022年第3期7卷 92-104页

作者： Wenjing Liu Haiyun Luo Qinwei Wei Jia Liu Junrong Wu Yanli Zhang Lili Chen Wencai Ren Longquan Shao Stomatological Hospital Southern Medical UniversityGuangzhou510280China Guangdong Provincial Key Laboratory of Construction and Detection in Tissue Engineering Guangzhou510515China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang110016China Stomatology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China

Graphene oxide(GO)exhibits good mechanical and physicochemical characteristics and has extensive application prospects in bone tissue engineering.However,its effect on angiogenesis is unclear,and its potential toxic effects are heavily disputed.Herein,we found that nanographene oxide(NGO)synthesized by one-step water electrolytic oxidation is smaller and shows superior biocompatibility.Moreover,NGO significantly enhanced angiogenesis in calvarial bone defect areas in vivo,providing a good microenvironment for bone regeneration.Endothelial tip cell differentiation is an important step in the initiation of angiogenesis.We verified that NGO activates endothelial tip cells by coupling with lysophosphatidic acid(LPA)in serum via strong hydrogen bonding interactions,which has not been reported.In addition,the mechanism by which NGO promotes angiogenesis was systematically studied.NGO-coupled LPA activates LPAR6 and facilitates the formation of migratory tip cells via Hippo/Yes-associated protein(YAP)independent of reactive oxygen species(ROS)stimulation or additional complex modifications.These results provide an effective strategy for the application of electrochemically derived NGO and more insight into NGO-mediated angiogenesis.

关键词： Nanographene oxide Lysophosphatidic acid Hydrogen bonding Endothelial tip cell Hippo signalling

Stably doped graphene transparent electrode with improved lightextraction for efficient flexible organic light-emitting diodes

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2023年第11期16卷 12788-12793页

作者： Lai-Peng Ma Zhongbin Wu Yukun Yan Dingdong Zhang Shichao Dong Jinhong Du Dongge Ma Hui-Ming Cheng Wencai Ren Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Frontiers Science Center for Flexible Electronics Institute of Flexible Electronics(IFE)Northwestern Polytechnical UniversityXi’an 710072China State Key Laboratory of Luminescent Materials&Devices South China University of TechnologyGuangzhou 510640China Shenzhen Institute of Advanced Technology Chinese Academy of SciencesShenzhen 518055China

Graphene-based flexible transparent electrodes(FTEs)are promising candidate materials for developing next-generation flexible organic light-emitting diodes(OLEDs).However,the quest for high-efficiency OLEDs is hindered by the low light-extraction and charge injection efficiencies of graphene electrode.Here,we combine the frustrated Lewis pair doping with nanostructure engineering to obtain high-performance graphene FTE.A p-type dopant aci-nitromethane-tris(pentafluorophenyl)borane(ANBCF)was synthesized and deposited on graphene FTE to form an aperiodic nanostructure,which not only improves the light-extraction but also stably p-dopes graphene to enhance its hole injection.The use of ANBCF-doped graphene as the anode enables high-efficiency flexible green OLEDs with external quantum efficiency(EQE)and power efficiency(PE)out-performing most flexible graphene OLEDs of comparable structure.This study provides a simple and effective pathway to fabricate high-performance graphene FTEs for efficient flexible OLEDs.

关键词： graphene transparent electrode flexible organic light-emitting diode(OLED) doping light-extraction

Synthesis and flexible device applications of 2D materials

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Synthesis and flexible device applications of 2D materials