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石墨烯作为一种结构、性能独特的二维碳材料在CO2还原转化过程中展现出良好的应用前景,寻找石墨烯丰富的碳质前驱体和可控制备方法是实现其大规模应用的基础。煤炭作为一种富碳矿物资源,含有丰富的官能团和高芳香度纳米石墨微晶结构。以煤炭及其衍生物为碳源制备高附加值石墨烯材料具有独特优势,是同时实现煤炭材料清洁化利用和石墨烯低成本实际应用的重要途径。针对不同变质程度煤种,从化学组成和煤质结构出发,通过适当的分子剪裁和化学结构组装,成功实现了系列多尺度、多形态煤基石墨烯材料的可控制备。常用的制备方式包括:机械力剪切、化学插层氧化、电化学剥离、气相沉积、阳极电弧放电及液相自组装等。如通过化学氧化或超声物理剪裁煤大分子结构制备零维石墨烯量子点;煤炭热解得到的含碳烃类小分子气体通过化学气相沉积制备二维石墨烯薄膜;煤炭高温石墨化后通过物理或化学剥离得到二维石墨烯纳米片;二维石墨烯经过结构自组装制备三维石墨烯气凝胶。由于煤基石墨烯的组成及其表界面结构具有易调控、可修饰等特性,其在CO2还原过程中展现出良好的催化活性。通过总结煤基石墨烯系列材料在CO2 相似文献
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锂硫电池因具有超高的理论比容量(1675 mA·h·g-1)而被认为是最具有应用前景的二次电池。但硫基正极面临着硫导电性差、利用率低、正极结构稳定性差等问题。采用KOH化学活化法将廉价易得的农业废弃物玉米苞叶制备为多孔碳材料后,与升华硫复合获得硫/碳复合材料。利用XRD、SEM、TEM和BET对该硫/碳复合材料的微观结构、形貌等进行表征发现,玉米苞叶制备的多孔碳材料具有类石墨烯片层结构,且表面具有大量的介孔结构,硫元素均匀分布在多孔碳材料中。采用恒流充放电和交流阻抗法对该复合材料正极电化学性能进行测试发现其具有较高的放电比容量和良好的循环性能,这是由于类石墨烯片层结构的多孔碳材料提高了硫正极的导电性,且其极大的比表面积大幅增加了电化学反应位点,提高了硫的利用率。 相似文献
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《化工学报》2017,(11)
锂硫电池因具有超高的理论比容量(1675 mA·h·g~(-1))而被认为是最具有应用前景的二次电池。但硫基正极面临着硫导电性差、利用率低、正极结构稳定性差等问题。采用KOH化学活化法将廉价易得的农业废弃物玉米苞叶制备为多孔碳材料后,与升华硫复合获得硫/碳复合材料。利用XRD、SEM、TEM和BET对该硫/碳复合材料的微观结构、形貌等进行表征发现,玉米苞叶制备的多孔碳材料具有类石墨烯片层结构,且表面具有大量的介孔结构,硫元素均匀分布在多孔碳材料中。采用恒流充放电和交流阻抗法对该复合材料正极电化学性能进行测试发现其具有较高的放电比容量和良好的循环性能,这是由于类石墨烯片层结构的多孔碳材料提高了硫正极的导电性,且其极大的比表面积大幅增加了电化学反应位点,提高了硫的利用率。 相似文献
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海上漏油的频繁发生以及采油废水、工业含油污水的大量排放造成水资源大片污染和生态系统平衡的严重破坏。目前,从水体中分离油品和有机污染物已受到越来越多的商业和学术的关注。石墨烯基气凝胶是由二维石墨烯片层组装成的三维宏观材料,因其孔隙率高、比表面积大、密度低、机械性能强等特点在油水分离领域具有广阔的应用前景,已成为当今的研究热点之一。本文结合最新研究进展系统地总结了石墨烯基气凝胶的结构设计、组装及干燥方法,归纳了近年来其在油水分离中的应用进展,并对石墨烯基气凝胶在油水分离领域的研究现状和未来研究方向做了简要评述,以期为该领域的深入探索提供新的视角。 相似文献
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Graphene, with its excellent physical, chemical, and mechanical properties, holds tremendous potential for a wide variety of biomedical applications. As research on graphene-based nanomaterials is still at a nascent stage due to the short time span since its initial report in 2004, a focused review on this topic is timely and necessary. In this feature review, we first summarize the results from toxicity studies of graphene and its derivatives. Although literature reports have mixed findings, we emphasize that the key question is not how toxic graphene itself is, but how to modify and functionalize it and its derivatives so that they do not exhibit acute/chronic toxicity, can be cleared from the body over time, and thereby can be best used for biomedical applications. We then discuss in detail the exploration of graphene-based nanomaterials for tissue engineering, molecular imaging, and drug/gene delivery applications. The future of graphene-based nanomaterials in biomedicine looks brighter than ever, and it is expected that they will find a wide range of biomedical applications with future research effort and interdisciplinary collaboration. 相似文献
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由于石墨烯优异的电子结构和电子传输性能,使得其在光催化领域的研究得到了广泛的关注。本文简要介绍了最新以石墨烯为基础的复合光催化剂的制备方法及其在催化水分解制氢方面的应用,重点评述了石墨烯及其氧化物、TiO2与石墨烯类复合物、CdS与石墨烯类复合物、含氧金属酸盐与石墨烯类复合物等的光催化性能,简要说明了光敏化、贵金属负载、非金属掺杂等对复合物光催化性能的影响。最后,指出对于石墨烯与纳米材料复合物的结构及光催化作用的机理都有待于进一步的研究,以便充分利用石墨烯的二维平面结构制得具有较高光催化水解制氢活性的催化剂。 相似文献
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Graphene has been attracting wide attention owing to its superb electronic, thermal and mechanical properties. These properties allow great applications in the next generation of optoelectronics, where flexibility and stretchability are essential. In this context, the recent development of graphene growth/transfer and its applications in field-effect transistors are involved. In particular, we provide a detailed review on the state-of-the-art of graphene-based flexible and stretchable thin film transistors. We address the principles of fabricating high-speed graphene analog transistors and the key issues of producing an array of graphene-based transistors on flexible and stretchable substrates. It provides a platform for future work to focus on understanding and realizing high-performance graphene-based transistors. 相似文献
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ABSTRACT: Graphene has received significant attention due to its excellent mechanical properties, which has resulted in the emergence of graphene-based nano-electro-mechanical system such as nanoresonators. The nonlinear vibration of a graphene resonator and its application to mass sensing (based on nonlinear oscillation) have been poorly studied, although a graphene resonator is able to easily reach the nonlinear vibration. In this work, we have studied the nonlinear vibration of a graphene resonator driven by a geometric nonlinear effect due to an edge-clamped boundary condition using a continuum elastic model such as a plate model. We have shown that an in-plane tension can play a role in modulating the nonlinearity of a resonance for a graphene. It has been found that the detection sensitivity of a graphene resonator can be improved by using nonlinear vibration induced by an actuation force-driven geometric nonlinear effect. It is also shown that an in-plane tension can control the detection sensitivity of a graphene resonator that operates both harmonic and nonlinear oscillation regimes. Our study suggests the design principles of a graphene resonator as a mass sensor for developing a novel detection scheme using graphene-based nonlinear oscillators. 相似文献
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石墨烯具有独特的二维结构、较大的理论比表面积、高载流子迁移率、高杨氏模量以及高热导率等特性,一直以来被视为新能源转换与存储领域的潜在应用材料。这些优势使其可以与一种或多种高活性的无机/有机材料通过共价键/非共价键进行复合,并通过协同效应来改善材料自身的缺陷,实现材料的性能最优化,进而拓展了其应用范围。因此,如何设计并合成具有一定功能作用的石墨烯基复合材料,构筑新型石墨烯结构,满足能源及其相关领域对于材料相关性质的要求,成为石墨烯材料领域的研究热点方向之一。本文综述了近年来石墨烯基复合材料的设计思路及该类材料在新能源转换与存储领域上的应用现状,并对其在各领域存在的关键问题进行了总结。最后,对石墨烯在各领域今后的研究和发展方向进行了展望。 相似文献
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节能高效的CO2分离技术的开发具有重要的现实及长远意义,膜法CO2分离在该领域备受关注,具有优异传质特性的新型分离膜材料对膜分离过程有决定性的影响。近年来,石墨烯及其衍生材料因独特的单原子层厚度、亚纳米级别的孔道结构以及优异的机械、化学和热稳定性,成为气体分离膜领域的研究热点,膜的加工难度、技术成本、大面积制备、工作稳定性等问题是限制其实际应用的关键因素。石墨烯基CO2分离膜主要有三种形式:纳米孔石墨烯膜、层状结构氧化石墨烯膜、基于石墨烯及其衍生材料的混合基质膜。本文综述了石墨烯基CO2分离膜领域的突破性研究进展,重点介绍了气体的跨膜传质机理和膜的构性关系,总结了膜性能的优化思路和原理,梳理了石墨烯基CO2分离膜发展面临的挑战,提出了潜在的研究方向。分析表明,进行系统的理论研究,采用先进的表征手段,以建立膜构性关系的理论模型,指导膜结构设计是未来研究的重点。此外,进一步降低膜加工成本,充分研究膜在实际工作环境中的稳定性也至关重要。 相似文献
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Mohammad Javad Kiani Fauzan Khairi Che Harun Mohammad Taghi Ahmadi Meisam Rahmani Mahdi Saeidmanesh Moslem Zare 《Nanoscale research letters》2014,9(1):371
Graphene is an attention-grabbing material in electronics, physics, chemistry, and even biology because of its unique properties such as high surface-area-to-volume ratio. Also, the ability of graphene-based materials to continuously tune charge carriers from holes to electrons makes them promising for biological applications, especially in lipid bilayer-based sensors. Furthermore, changes in charged lipid membrane properties can be electrically detected by a graphene-based electrolyte-gated graphene field effect transistor (GFET). In this paper, a monolayer graphene-based GFET with a focus on the conductance variation caused by membrane electric charges and thickness is studied. Monolayer graphene conductance as an electrical detection platform is suggested for neutral, negative, and positive electric-charged membrane. The electric charge and thickness of the lipid bilayer (QLP and LLP) as a function of carrier density are proposed, and the control parameters are defined. Finally, the proposed analytical model is compared with experimental data which indicates good overall agreement. 相似文献