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以天然鳞片石墨为原料,氧化插层制备可膨胀石墨,微波热解膨胀后,对膨胀石墨进行二次氧化插层并微波膨胀,采用超声剥离法制备出包含大量少层数碳原子的石墨烯纳米片。采用傅里叶红外光谱(FT-IR)、X射线衍射(XRD)、扫描电镜(SEM)、原子力显微镜(AFM)和拉曼光谱(Raman)对其结构和形貌进行分析。结果表明,氧化插层增大了石墨层间距,膨胀石墨更易于进一步氧化插层引入含氧基团;在微波作用下,石墨内部含氧基团热分解放出气体,进一步增大石墨层间距,甚至部分剥离;对二次膨胀处理的石墨薄片进行超声剥离可得到石墨烯纳米片,大部分石墨烯层数低于5层。 相似文献
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Large-scale exfoliation of inorganic layered compounds in aqueous surfactant solutions 总被引:1,自引:0,他引:1
Smith RJ King PJ Lotya M Wirtz C Khan U De S O'Neill A Duesberg GS Grunlan JC Moriarty G Chen J Wang J Minett AI Nicolosi V Coleman JN 《Advanced materials (Deerfield Beach, Fla.)》2011,23(34):3944-3948
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Xueyi Lu Mohang Cai Xuemin Wu Yongfei Zhang Shuai Li Shijun Liao Xia Lu 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(9):2206702
2D materials have captured much recent research interest in a broad range of areas, including electronics, biology, sensors, energy storage, and others. In particular, preparing 2D nanosheets with high quality and high yield is crucial for the important applications in energy storage and conversion. Compared with other prevailing synthetic strategies, the electrochemical exfoliation of layered starting materials is regarded as one of the most promising and convenient methods for the large-scale production of uniform 2D nanosheets. Here, recent developments in electrochemical delamination are reviewed, including protocols, categories, principles, and operating conditions. State-of-the-art methods for obtaining 2D materials with small numbers of layers—including graphene, black phosphorene, transition metal dichalcogenides and MXene—are also summarized and discussed in detail. The applications of electrochemically exfoliated 2D materials in energy storage and conversion are systematically reviewed. Drawing upon current progress, perspectives on emerging trends, existing challenges, and future research directions of electrochemical delamination are also offered. 相似文献
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Liyong Niu Jonathan N. Coleman Hua Zhang Hyeonsuk Shin Manish Chhowalla Zijian Zheng 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(3):272-293
Tremendous efforts have been devoted to the synthesis and application of two‐dimensional (2D) nanomaterials due to their extraordinary and unique properties in electronics, photonics, catalysis, etc., upon exfoliation from their bulk counterparts. One of the greatest challenges that scientists are confronted with is how to produce large quantities of 2D nanomaterials of high quality in a commercially viable way. This review summarizes the state‐of‐the‐art of the production of 2D nanomaterials using liquid‐based direct exfoliation (LBE), a very promising and highly scalable wet approach for synthesizing high quality 2D nanomaterials in mild conditions. LBE is a collection of methods that directly exfoliates bulk layered materials into thin flakes of 2D nanomaterials in liquid media without any, or with a minimum degree of, chemical reactions, so as to maintain the high crystallinity of 2D nanomaterials. Different synthetic methods are categorized in the following, in which material characteristics including dispersion concentration, flake thickness, flake size and some applications are discussed in detail. At the end, we provide an overview of the advantages and disadvantages of such synthetic methods of LBE and propose future perspectives. 相似文献
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Ti3AlC2/Al2O3 nanopowders were synthesized by the combination of mechanically-induce self-propagating reaction (MSR) of Ti, C, Al and TiO2 powder mixtures and subsequently heat treatment. Effects of high energy milling and heat treatment temperatures on the phase transformation were investigated in detail. X-ray diffraction (XRD) was used to characterize the powders of milled and annealed, respectively. The morphology and microstructure of as fabricated products were also studied by scanning electron microscopy (SEM) equipped with energy-dispersive spectroscopy (EDS). Results show that TiC, TixAly and Al2O3 transitional phases were formed when the initial powder mixtures were milled for 24 h. The desired Ti3AlC2/Al2O3 nanopowders with high purity were obtained when annealed the as-milled powders at 1100 °C. SEM image confirmed that the as fabricated Ti3AlC2/Al2O3 particles has nanocrystalline layered structural matrix of Ti3AlC2, and the second phase of nanosized Al2O3 disperses uniformly in the Ti3AlC2 matrix. 相似文献
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采用热压工艺以Ti、Al、Si元素粉和活性炭为原料,分别以2.0Ti/1.1Al/1.0C(摩尔比)及以0.1和0.2mol的Si取代Al,合成了Ti2AlC/Ti3AlC2块体材料.通过建立Ti2AlC、Ti3AlC2和掺Si的计算模型,计算了平均原子净电荷和平均共价键键级.结果表明:以元素粉2.0Ti/1.1Al/1.0C为原料在1450℃热压60min合成只含有非常少量Ti3AlC2的Ti2AlC材料;当Si取代Al达到0.2mol时,作用非常明显,表现为使同一温度下Ti3AlC2含量增加而Ti2AlC含量减少.另外,应用掺Si后对原子净电荷和共价键键级的影响解释了实验结果. 相似文献
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银基电触头在低压开关领域扮演重要角色。作为一种具有良好导电导热性能的新型二维碳化物材料,MXene家族典型代表材料(Ti3C2Tx)在多个领域显示出极大的应用潜力。Ti3C2Tx有望作为一种新型环保银基电触头增强相材料。本研究采用粉末冶金法制备了Ag/Ti3C2Tx复合材料,并对Ti3C2Tx和Ti3AlC2的物相和微观结构进行表征。同时研究了Ti3C2Tx增强Ag基复合材料的综合性能,包括电阻率、显微硬度、机械加工性能、抗拉强度和抗电弧侵蚀性能,并与Ti3AlC2增强Ag基复合材料进行了比较。Ag/Ti3C2Tx的电阻率(30×10 -3 μΩ·m)相对于Ag/Ti3AlC2(42×10 -3 μΩ·m)降低了29%。Ag/Ti3C2Tx硬度适中(64 HV),具有良好的可加工性,作为无毒电触头材料应用前景广阔。Ag/Ti3C2Tx复合材料导电性能的提高主要归因于Ti3C2Tx本身优异的金属性以及由Ti3C2Tx微观结构特征带来的可变形性。由于缺乏Al-Ag相互扩散,Ag/Ti3C2Tx复合材料的拉伸强度(32.77 MPa)明显低于Ag/Ti3AlC2复合材料(145.52 MPa)。正因为缺失Al层,Ag/Ti3C2Tx的抗电弧侵蚀性能也无法与Ag/Ti3AlC2相媲美。尽管Ag/Ti3C2Tx的抗电弧侵蚀性能有待进一步提高,但优异的导电性使其有望替代当下有毒的Ag/CdO电接触材料。该研究结果为开发新型环保电触头材料提供了新的探索方向。 相似文献
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The oxidation behavior of Ti3AlC2-20TiB2 composite was studied at 500?°C–900?°C in air. The composite showed a very low oxidation rate and followed a logarithmic oxidation law. The in-situ incorporation of TiB2 suppressed the anomalous rapid oxidation of the substrate Ti3AlC2 occurred near 600?°C by forming a protective B2O3 glass layer, and also improved the oxidation resistance of the MAX phase at intermediate-temperature. 相似文献
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Engineering 2D Nanofluidic Li‐Ion Transport Channels for Superior Electrochemical Energy Storage
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Chunshuang Yan Chade Lv Yue Zhu Gang Chen Jingxue Sun Guihua Yu 《Advanced materials (Deerfield Beach, Fla.)》2017,29(46)
Rational surface engineering of 2D nanoarchitectures‐based electrode materials is crucial as it may enable fast ion transport, abundant‐surface‐controlled energy storage, long‐term structural integrity, and high‐rate cycling performance. Here we developed the stacked ultrathin Co3O4 nanosheets with surface functionalization (SUCNs‐SF) converted from layered hydroxides with inheritance of included anion groups (OH?, NO3?, CO32?). Such stacked structure establishes 2D nanofluidic channels offering extra lithium storage sites, accelerated Li‐ion transport, and sufficient buffering space for volume change during electrochemical processes. Tested as an anode material, this unique nanoarchitecture delivers high specific capacity (1230 and 1011 mAh g?1 at 0.2 and 1 A g?1, respectively), excellent rate performance, and long cycle capability (1500 cycles at 5 A g?1). The demonstrated advantageous features by constructing 2D nanochannels in nonlayered materials may open up possibilities for designing high‐power lithium ion batteries. 相似文献
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Wei Tang Wenpei Fan Weizhong Zhang Zhen Yang Ling Li Zhantong Wang Ya‐Ling Chiang Yijing Liu Liming Deng Liangcan He Zheyu Shen Orit Jacobson Maria A. Aronova Albert Jin Jin Xie Xiaoyuan Chen 《Advanced materials (Deerfield Beach, Fla.)》2019,31(19)
2D nanomaterials have attracted broad interest in the field of biomedicine owing to their large surface area, high drug‐loading capacity, and excellent photothermal conversion. However, few studies report their “enzyme‐like” catalytic performance because it is difficult to prepare enzymatic nanosheets with small size and ultrathin thickness by current synthetic protocols. Herein, a novel one‐step wet‐chemical method is first proposed for protein‐directed synthesis of 2D MnO2 nanosheets (M‐NSs), in which the size and thickness can be easily adjusted by the protein dosage. Then, a unique sono‐chemical approach is introduced for surface functionalization of the M‐NSs with high dispersity/stability as well as metal‐cation‐chelating capacity, which can not only chelate 64Cu radionuclides for positron emission tomography (PET) imaging, but also capture the potentially released Mn2+ for enhanced biosafety. Interestingly, the resulting M‐NS exhibits excellent enzyme‐like activity to catalyze the oxidation of glucose, which represents an alternative paradigm of acute glucose oxidase for starving cancer cells and sensitizing them to thermal ablation. Featured with outstanding phototheranostic performance, the well‐designed M‐NS can achieve effective photoacoustic‐imaging‐guided synergistic starvation‐enhanced photothermal therapy. This study is expected to establish a new enzymatic phototheranostic paradigm based on small‐sized and ultrathin M‐NSs, which will broaden the application of 2D nanomaterials. 相似文献
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