石墨烯的功能化及其相关应用

石墨烯是2004年才被发现的一种新型二维平面纳米材料,其特殊的单原子层结构决定了它具有丰富而新奇的物理性质．过去几年中,石墨烯已经成为了备受瞩目的国际前沿和热点．在石墨烯的研究和应用中,为了充分发挥其优良性质,并改善其成型加工性（如分散性和溶解性等）,必须对石墨烯进行功能化,研究人员也在这方面开展了积极而有效的工作．但是,关于石墨烯的功能化方面的研究还处在探索阶段,对各种功能化的方法和效果还缺乏系统的认识．如何根据实际需求对石墨烯进行预期和可控的功能化是我们所面临的机遇和挑战．本文重点阐述了石墨烯的共价键和非共价键功能化领域的最新进展,并对功能化石墨烯的应用作了介绍,最后对相关领域的发展趋势作了展望．     

Assembly and application advancement of organic‐functionalized graphene‐based materials: A review

Owing to the remarkable physicochemical properties such as hydrophobicity, conductivity, elasticity, and light weight, graphene‐based materials have emerged as one of the most appealing carbon allotropes in materials science and chemical engineering. Unfortunately, pristine graphene materials lack functional groups for further modification, severely hindering their practical applications. To render graphene materials with special characters for different applications, graphene oxide or reduced graphene oxide has been functionalized with different organic agents and assembled together, via covalent binding and various noncovalent forces such as π–π interaction, electrostatic interaction, and hydrogen bonding. In this review, we briefly discuss the state‐of‐the‐art synthetic strategies and properties of organic‐functionalized graphene‐based materials, and then, present the prospective applications of organic‐functionalized graphene‐based materials in sample preparation.     

Graphene Oxide-Based Stimuli-Responsive Platforms for Biomedical Applications

Graphene is a two-dimensional sp² hybridized carbon material that has attracted tremendous attention for its stimuli-responsive applications, owing to its high surface area and excellent electrical, optical, thermal, and mechanical properties. The physicochemical properties of graphene can be tuned by surface functionalization. The biomedical field pays special attention to stimuli-responsive materials due to their responsive abilities under different conditions. Stimuli-responsive materials exhibit great potential in changing their behavior upon exposure to external or internal factors, such as pH, light, electric field, magnetic field, and temperature. Graphene-based materials, particularly graphene oxide (GO), have been widely used in stimuli-responsive applications due to their superior biocompatibility compared to other forms of graphene. GO has been commonly utilized in tissue engineering, bioimaging, biosensing, cancer therapy, and drug delivery. GO-based stimuli-responsive platforms for wound healing applications have not yet been fully explored. This review describes the effects of different stimuli-responsive factors, such as pH, light, temperature, and magnetic and electric fields on GO-based materials and their applications. The wound healing applications of GO-based materials is extensively discussed with cancer therapy and drug delivery.     

A Versatile Platform of 2‐(3,4‐Dihydroxyphenyl) Pyrrolidine Grafted Graphene for Preparation of Various Graphene‐derived Materials

Covalent functionalization has proven an effective solution for graphene to realize its revolutionary potential in real applications, whereas the platform strategy (a reactive graphene‐based material acting as the platform to undergo post‐reactions for generation of various graphene‐derived materials) is an attractive option to execute efficiently such a task. This contribution demonstrates that 2‐(3,4‐dihydroxyphenyl) pyrrolidine (DHPP) grafted graphene, G‐OH, is a competent platform. Four typical but not exclusive graphene‐derived materials have been prepared from G‐OH by using the chemical virtue of each DHPP unit having three categories totaling six reactive sites. The controlled feature of 1,3‐dipolar cycloaddition for the synthesis of G‐OH ensures that the electronic structure and properties of pristine graphene are succeeded largely by G‐OH and thus its derivatives. A promising alternative to graphene oxide, which has been widely used as a platform to prepare the graphene‐derived materials but suffers from some intrinsic disadvantages, is thus developed.     

Biological and chemical sensors based on graphene materials

Owing to their extraordinary electrical, chemical, optical, mechanical and structural properties, graphene and its derivatives have stimulated exploding interests in their sensor applications ever since the first isolation of free-standing graphene sheets in year 2004. This article critically and comprehensively reviews the emerging graphene-based electrochemical sensors, electronic sensors, optical sensors, and nanopore sensors for biological or chemical detection. We emphasize on the underlying detection (or signal transduction) mechanisms, the unique roles and advantages of the used graphene materials. Properties and preparations of different graphene materials, their functionalizations are also comparatively discussed in view of sensor development. Finally, the perspective and current challenges of graphene sensors are outlined (312 references).     

石墨烯化聚合物:一种兼具电子和离子传输通道的三维富碳高分子能源材料

近年来,用于电化学能源存储和转化的石墨烯材料,得到了研究者们越来越多的关注。但是,这些石墨烯材料不同于严格定义的单原子碳层结构,往往具有孔洞、杂原子和化学官能团等缺陷结构。由于制备方法的不同,缺陷结构各不相同,其电化学性能也表现各异。结构分析表明,这类材料是由类似石墨烯片段的单元与聚合物链共价连接而成,使其具有石墨烯和聚合物的双重特性,我们称之为石墨烯化聚合物。由小分子通过自下而上的方法制备的多孔聚合物,也可以通过进一步热交联等方法,使其形成包含石墨烯片段单元与聚合物链的化学结构。这些材料与石墨烯衍生材料一起组成了石墨烯化聚合物的整个谱系;这个谱系涵盖了由聚合物到石墨烯的过渡区。更重要的是,这类材料特殊的结构与性质,使其成为一种兼具电子和离子传输通道的三维富碳高分子材料,非常适合作为电极材料应用于电化学能源存储和转化,这为我们深入研究储能器件中电极材料的结构与性能的相关关系提供了很好的材料平台。     

Graphene and graphene-based nanomaterials: the promising materials for bright future of electroanalytical chemistry

Similar to its popular older cousins of fullerene and carbon nanotubes (CNTs), the latest form of nanocarbon, graphene, is inspiring intensive research efforts in its own right. As an atomically thin layer of sp(2)-hybridized carbon, graphene possesses spectacular electronic, optical, magnetic, thermal and mechanical properties, which make it an exciting material in a variety of important applications. In this review, we present the current advances in the field of graphene electroanalytical chemistry, including the modern methods of graphene production, and graphene functionalization. Electrochemical (bio) sensing developments using graphene and graphene-based materials are summarized in more detail, and we also speculate on their future and discuss potential progress for their applications in electroanalytical chemistry.     

Recent advances in the use of graphene-family nanoadsorbents for removal of toxic pollutants from wastewater

Adsorption technology is widely considered as the most promising and robust method of purifying water at low cost and with high-efficiency. Carbon-based materials have been extensively explored for adsorption applications because of their good chemical stability, structural diversity, low density, and suitability for large scale production. Graphene – a single atomic layer of graphite – is the newest member in the family of carbon allotropes and has emerged as the “celeb” material of the 21st century. Since its discovery in 2004 by Novoselov, Geim and co-workers, graphene has attracted increased attention in a wide range of applications due to its unprecedented electrical, mechanical, thermal, optical and transport properties. Graphene's infinitely high surface-to-volume ratio has resulted in a large number of investigations to study its application as a potential adsorbent for water purification. More recently, other graphene related materials such as graphene oxide, reduced graphene oxide, and few-layered graphene oxide sheets, as well as nanocomposites of graphene materials have also emerged as a promising group of adsorbent for the removal of various environmental pollutants from waste effluents. In this review article, we present a synthesis of the current knowledge available on this broad and versatile family of graphene nanomaterials for removal of dyes, potentially toxic elements, phenolic compounds and other organic chemicals from aquatic systems. The challenges involved in the development of these novel nanoadsorbents for decontamination of wastewaters have also been examined to help identify future directions for this emerging field to continue to grow.     

A Review on Graphene Oxide Two-dimensional Macromolecules: from Single Molecules to Macro-assembly

Graphene oxide(GO), which consists of two-dimensional(2 D) sp² carbon hexagonal networks and oxygen-contained functional groups, has laid the foundation of mass production and applications of graphene materials. Made by chemical oxidation of graphite, GO is highly dispersible or even solubilized in water and polar organic solvents, which resolves the hard problem of graphene processing and opens a door to wet-processing of graphene. Despite its defects, GO is easy to functionalize, dope, punch holes, cut into pieces, conduct chemical reduction, form lyotropic liquid crystal, and assemble into macroscopic materials with tunable structures and properties as a living building block. GO sheet has been viewed as a single molecule, a particle, as well as a soft polymer material. An overview on GO as a 2 D macromolecule is essential for studying its intrinsic properties and guiding the development of relevant subjects. This review mainly focuses on recent advances of GO sheets, from single macromolecular behavior to macro-assembled graphene material properties. The first part of this review offers a brief introduction to the synthesis of GO molecules. Then the chemical structure and physical properties of GO are presented, as well as its polarity in solvent and rheology behavior. Several key parameters governing the ultimate stability of GO colloidal behavior, including size, p H and the presence of cation in aqueous dispersions, are highlighted. Furthermore, the discovery of GO liquid crystal and functionalization of GO molecules have built solid new foundations of preparing highly ordered, architecture-tunable, macro-assembled graphene materials, including 1 D graphene fibers, 2 D graphene films, and 3 D graphene architectures. The GO-based composites are also viewed and the interactions between these target materials and GO are carefully discussed. Finally, an outlook is provided in this field, where GO is regarded as macromolecules, pointing out the challenges and opportunities that exist in the field. We hope that this review will be beneficial to the understanding of GO in terms of chemical structure,molecular properties, macro-assembly and potential applications, and encourage further development to extend its investigations from basic research to practical applications.     

《碳纳米材料电化学》专辑序言 ——方兴未艾的电化学能量转换和存储先进材料和技术

可以预见,在相当一段时期内,能源和环境将是全球发展的两大主题. 其实,人类对能源的获取方式将对地球的生态环境和人类未来的生存状态和生活方式产生重要影响. 正因为如此,世界各国正在大力发展可再生能源和清洁能源. 电化学能源是将化学能高效转变为电能的一种能量转换方式,它历史悠久,但不断被改进和创新,尤其是近年来得到了较快的发展. 目前,电化学能源转换和存储器件主要包括一次电池（如锌锰电池等）、二次电池（如铅酸电池、镍氢电池、锂离子电池等）、燃料电池、金属-空气电池以及超级电容器等. 电化学能源和其它可再生能源相互补充、交叉利用将是未来清洁能源的主要发展方向.     

Graphene-Based Antimicrobial Biomedical Surfaces

Biomedical application of graphene derivatives have been intensively studied in last decade. With the exceptional structural, thermal, electrical, and mechanical properties, these materials have attracted immense attention of biomedical scientists to utilize graphene derivatives in biomedical devices to improve their performance or to achieve desired functions. Surfaces of graphene derivatives including graphite, graphene, graphene oxide and reduce graphene oxide have been demonstrated to pave an excellent platform for antimicrobial behavior, enhanced biocompatibility, tissue engineering, biosensors and drug delivery. This review focuses on the recent advancement in the research of biomedical devices with the coatings or highly structured polymer nanocomposite surfaces of graphene derivatives for antimicrobial activity and sterile surfaces comprising an entirely new class of antibacterial materials. Overall, we aim to highlight on the potential of these materials, current understanding and knowledge gap in the antimicrobial behavior and biocompatibility to be utilized of their coatings to prevent the cross infections.     

Application of carbon-based nanomaterials in sample preparation: A review

In this paper, a broad overview on the applications of different carbon-based nanomaterials, including nanodiamonds, fullerenes, carbon nanotubes, graphene, carbon nanofibers, carbon nanocones-disks and nanohorns, as well as their functionalized forms, in sample preparation is provided. Particular attention has been paid to graphene because many papers regarding its application in this research field are becoming available. The distinctive properties, derivatization methods and application techniques of these materials were summarized and compared. According to their research status and perspective, these nanomaterials were classified in four groups (I: graphene and carbon nanotubes; II: carbon nanofibers; III: fullerenes; and IV: nanodiamonds, carbon nanocones/disks and carbon nanohorns) and characteristics and future trends of every group were discussed.     

Current trends in spinel based modified polymer composite materials for electromagnetic shielding

The present article deals with current trends in spinel based modified polymer composite materials for applications in the field of electromagnetic shielding. The interaction between the various spinel based materials and polymers is an emerging field of studies among various researchers. The thermal stability, electrical conductivity, the bonding between the metal ferrites and the polymer plays an important role in the interaction of electromagnetic radiation. These properties also effect the mechanism of the EM waves for the shielding applications. Considering these all properties, polyaniline appears to be an suitable polymer for electromagnetic shielding applications. Polyaniline composites not only reinforced the properties of spinel materials but also enhanced the dielectric properties of the composite material. When carbon based materials such as graphene, graphene oxide and CNT was added along with spinel material in polyaniline based composite, they accelerate the electrical properties and enhances the shielding applications. In this paper the various synthesis methods, fabrication methods of polyaniline, and the properties of polyaniline based composites have been discussed. In addition, the various salient features and futuristic challenges of polyaniline based composite materials for EMI shielding applications were attempted to make a well equipped material for radar absorption.     

Aligned Nanotubes

Since the discovery of carbon nanotubes by Iijima in 1991, various carbon nanotubes with either a single‐ or multilayered graphene cylinder(s) have been produced, along with their noncarbon counterparts (for example, inorganic and polymer nanotubes). These nanostructured materials often possess size‐dependent properties and show new phenomena related to the nanosize confinement of the charge carriers inside, which leads to the possibility of developing new materials with useful properties and advanced devices with desirable features for a wide range of applications. In particular, carbon nanotubes have been shown to exhibit superior properties attractive for various potential applications, ranging from their use as novel electron emitters in flat‐panel displays to electrodes in electrochemical sensors. For many of the applications, it is highly desirable to have aligned/patterned forms of carbon nanotubes so that their structure/property can be easily assessed and so that they can be effectively incorporated into devices. In this Review, we present an overview on the development of aligned and micropatterned nanotubes, with an emphasis on carbon nanotubes.     

Two-dimensional MOFs: Design & Synthesis and Applications

For the past few years, two-dimensional materials have attracted widespread attention owing to their special properties and potential applications. It is well-known that graphene, transition metal disulfide compounds (TMDC), carbon nitride, transition metal carbonitrides (Mxenes), silene and hexagonal boron nitride are typical two-dimensional materials. Compared with these traditional two-dimensional materials, two-dimensional MOF is favored by numerous researchers because of its unique structure. Based on the unique metal ion and organic ligand coordination of MOF and two-dimensional layered structure, the applications of two-dimensional MOF were getting serious, including catalysis, supercapacitor, gas adsorption/separation, sensors and so on. This review presents a relatively comprehensive summary of the design & synthesis and applications of two-dimensional MOF over the past few years. Furthermore, the opportunities and challenges have been discussed to supply a promising prospect to this field.     

功能化石墨烯材料：定义、分类及制备策略

自2004年被成功制备后,石墨烯因其独特迷人的性质在近十几年来备受关注,同时也引发了二维纳米材料的研究热潮。单原子层厚度的二维结构赋予石墨烯非同寻常的光学、电子学、磁学及力学等性质,使得石墨烯在生物学、医学、化学、物理学和环境科学等多个领域展现出极大的应用潜力。制得注意的是,石墨烯在应用时通常需要进行功能化,调节其组成、大小、形状和结构等,以便于加工处理或满足不同的应用需求。石墨烯功能化方法多样,功能化产物也是种类繁多。然而,到目前为止,石墨烯功能化产物并没有系统全面的分类和精确的定义。因此,本文在系统总结现有石墨烯功能化研究的基础上,给出了石墨烯功能化产物的系统分类、各类的精确定义和相应的制备策略,并通过典型示例进行了详细地阐述。石墨烯功能化的产物统称为“功能化石墨烯材料”,分为两类：“功能化石墨烯”和“功能化石墨烯复合材料”。功能化石墨烯材料的制备可由“自上而下”和“自下而上”两种策略实现。制备策略的选择取决于应用需求。系统分类、精确命名和制备策略的归纳必将有助于功能化石墨烯材料的进一步发展。     

Selective Removal of Hydroxyl Groups from Graphene Oxide

Graphene has a wide range of potential applications, thus tremendous efforts have been put into ensuring that the most direct and effective methods for its large‐scale production are developed. The formation of graphene materials from graphene oxide through a chemical reduction method is still one of the most preferred routes. Numerous methods starting from various reducing agents have been developed to obtain near‐pristine graphene sheets. However, most of the reducing agents are not mechanistically supported by classical organic chemistry knowledge and of those that are supported, they are only theoretically capable of, at most, reducing oxygen‐containing groups on graphene oxide to hydroxyl groups. Herein, we present a mechanistically proven method for the selective defunctionalisation of hydroxyl groups from graphene oxide that is based on ethanethiol–aluminium chloride complexes and provides a graphene material with improved properties. The structural, morphological and electrochemical properties of the graphene materials have been fully characterised based on high‐resolution X‐ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, electrochemical impedance spectroscopy and cyclic voltammetry techniques. Our analyses showed that the obtained graphene materials exhibited high heterogeneous electron‐transfer rates, low charge‐transfer resistance and high conductivity as compared to the parent graphene oxide. Moreover, the selective defunctionalisation of hydroxyl groups could potentially allow for the tailoring of graphene properties for various applications.     

基于3d元素掺杂的石墨二炔分子传感材料性能调控

二维碳材料因其独特的性质成为凝聚态物理、纳米电子学、生物医药等领域的前沿研究热点。石墨二炔具有天然的半导体特性及独特的大孔网状结构,在纳米电子器件和生物传感方面比石墨烯更具优势。本文使用第一性原理计算研究了单层石墨二炔的纳米带电子输运性质和及石墨二炔对小分子的吸附。我们考虑用掺杂3d金属原子的方法来增强对分子的吸附力。选择在石墨二炔表面吸附能较大的钪(Sc)、钛(Ti)原子,确定石墨二炔表面Sc、Ti单原子在室温下的稳定性,研究了Sc、Ti掺杂石墨二炔用于分子检测的潜在可能。从能带、载流子浓度等方面全面探讨了Sc、Ti掺杂石墨二炔对甲醛分子(HCHO)的响应。又进一步研究了石墨二炔与氨基酸分子间相互作用,发现色散力在相互作用中占主导地位。研究了吸附氨基酸对石墨二炔电子输运的影响,探讨石墨二炔在生物传感方面的潜在应用。     

The electrochemistry of CVD graphene: progress and prospects

The unique electronic properties of graphene, a one atom thick carbon layer, were reported by scientists in 2004. Since this time graphene has subsequently been found to display several more unique and fascinating electrical, optical and mechanical properties. One particular area in which graphene has reportedly made an impact is in the field of electrochemistry, such as in providing enhancements in energy storage/generation and electrochemical sensing applications. Since 2005, when graphene was shown to be fabricated by the so-called 'Scotch tape technique' where multiple layers of graphene are peeled from a slab of Highly Ordered Pyrolytic Graphite using adhesive tape and transferred onto an appropriate substrate, other fabrication methodologies of graphene have emerged. In the majority of cases, graphene is produced and supplied in solution, such that graphene has to be immobilised onto the desired surface. A fabrication process where graphene is grown upon a substrate and is ready for implementation is the Chemical Vapour Deposition (CVD) of graphene. In this perspective article we overview recent developments in the fabrication of CVD graphene and explore its utilisation in electrochemistry, considering its fundamental understanding through to applications in sensing and energy related devices.