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Among various 2D materials, graphene has received extensive research attention in the last 2-3 decades due to its fascinating properties. The discovery of graphene provided an immense boost up and new dimension to materials research and nanotechnology. The multidisciplinary characteristics of graphene havea wide range of applications from health to aerospace. Modern graphene research has been directed towards the exploration of new graphene derivatives and their utilisations for fabrication of products and devices. The enhancement of graphene properties by functionalization or surface modification is another innovative approach. However, like other 2D materials, graphene research also needs amendments and up-gradation in the light of recent scientific output. In this contribution, we have reassessed the recent research output on graphene and graphene-based materials for applications in different fields. For the reader's comfort and to maintain lucidity, first, some fundamental aspects of graphene are discussed and then recent overviews in graphene research are explored in a systematic manner. Overall, this review article provides an outline of graphene in terms of fundamental properties, cutting-edge research and applications. Keywords: Graphene, 2D materials, Graphene oxide, Engineering application of graphene

While noncovalent interactions between graphene derivatives and biosystems are extensively studied, less knowledge about their covalent multivalent interactions at biointerfaces is available. Due to the affinity of boronic acids towards cis-diol bearing biosystems, graphene sheets with this functionality were synthesized and their covalent interactions with the bacteria and nematode were investigated. As expected, graphene platforms with boronic acid functionality were able to wrap bacteria and destroy it in a short time. Surprisingly, body of nematodes was ruptured and their viability decreased to 30% after 24 h incubation with the functionalized graphene sheets. Because of their antibacterial and antiparasitic activities as well as their ability for wound dressing, graphene platforms with the boronic acid functionality were further investigated for diabetic wound healing. In vivo experiments showed that graphene platforms are more efficient than the commercially available drug, phenytoin, and restore both infected and non-infected diabetic wounds in ten days. Taking advantage of their straightforward synthesis, strong interactions with different biosystems as well as their ability to heal diabetic wounds, the boronic acid functionalized graphene sheets are promising candidates for a broad range of future biomedical applications.

Since the first discovery of graphene in 2004, the scientific and industrial community is still finding fields to bring the excellent mechanical performance of graphene into full play. Herein, this review summarizes the recent advances in graphene and graphene derivatives toughened polymer nanocomposites, which gives full play to the unique two-dimensional nanostructure, extra specific surface area and ultrahigh mechanical properties of graphene and graphene derivatives. Using graphene and graphene derivatives as toughening modifier of polymers can not only enhance the toughness of the polymer matrix but also endow the polymer nanocomposites with enhanced strength. The preparation, performance and mechanism of graphene and graphene derivatives toughened polymer nanocomposites are highlighted in this review. The factors influencing the efficiency of graphene and graphene derivatives toughening polymers are discussed in detail. Current challenge and future direction in graphene and graphene derivatives toughened polymer nanocomposites are proposed for promoting the application of graphene in toughening polymers. This review provides a guidance for fabricating high-performance polymer/graphene nanocomposites.

In search of alternate procedures and raw materials to manufacture graphene oxide and graphene derivatives that could be scaled up to be industrially implemented, we have developed a simple thermal treatment of petroleum asphalt that gives rise to graphite oxide-like materials in high yield. Subsequent treatment of the oxide at higher temperature gives rise to graphene-like products similar to those obtained by conventional top-down methods based on graphite. The method offers economy in manufacturing time and energy spent, allowing the valorization of a waste material.

Thanks to their remarkable mechanical, electrical, thermal, and barrier properties, graphene-based nanocomposites have been a hot area of research in the past decade. Because of their simple top-down synthesis, graphene oxide (GO) and reduced graphene oxide (rGO) have opened new possibilities for gas barrier, membrane separation, and stimuli-response characteristics in nanocomposites. Herein, we review the synthesis techniques most commonly used to produce these graphene derivatives, discuss how synthesis affects their key material properties, and highlight some examples of nanocomposites with unique and impressive properties. We specifically highlight their performances in separation applications, stimuli-responsive materials, anti-corrosion coatings, and energy storage. Finally, we discuss the outlook and remaining challenges in the field of practical industrial-scale production and use of graphene-derivative-based polymer nanocomposites. Keywords: Graphene oxide, Reduced graphene oxide, Graphene quantum dots polymer, Nanocomposites, Synthesis, Properties of graphene and graphene oxide, Applications

In the last decade, a great deal of research has been devoted to the design and development of graphene-based polymer nanocomposites characterized by a prescribed arrangement of the graphene-based nanosheets into spatially segregated 3D architectures. The formation of a continuous filler network obtained by confining the nanosheets into a constrained volume of the polymeric matrix is particularly attractive from a technological point of view. The preparation of segregated 3D graphene-based architectures facilitates the proper tailoring of the overall performance of the resulting polymer nanocomposites, providing significant improvements in terms of structural (i.e., mechanical properties) and functional (electrical properties, sensing ability, and adsorption/absorption capacity) features. This review focuses on polymer-based nanocomposites in two categories, namely bulk and porous (foam and aerogels) systems. These all share the common distinctive feature that relies on the peculiar arrangement of the graphene-based nanosheets in the form of a segregated yet continuous 3D assembly. For each class of materials, the main preparation strategies are presented and the resulting structure-property correlations are highlighted and discussed, together with the technological implications, and possible future directions.

Graphene derivatives are known to be suitable for biomedical applications, especially for stem cell-based therapies. Herein, we report the size effects of graphene oxide (GO) on differentiation of human adipose-derived mesenchymal stem cells (hADMSCs), using micro-sized (MGO) and nano-sized graphene oxide (NGO) sheets. The MGO and NGO sheets having lateral sizes of 1–10 μm and 100–300 nm, respectively, are coated on glass substrates by drop casting. The hADMSCs grown on the MGO-coated substrates show enhanced cell spreading and proliferation rate when compared with those of NGO counterpart, regardless of their densities. The GO size-dependency of hADMSCs becomes more prominent when it comes to their differentiation capabilities. After 4 weeks of differentiation under the same culture conditions, the osteogenesis of hADMSCs grown on the MGO-coated substrate is particularly higher than that on the NGO-coated substrate. The difference in osteogenic differentiation of hADMSCs is found to be most dominant after 21–28 days of differentiation according to the calcification level of osteoblasts. These finding signify the importance of graphene size in controlling the osteogenesis of hADMSCs, which may shed new insight into the use of graphene-based materials for stem cell research and therapy.

The interest of researchers towards graphene, is now becoming very significant and promising. Although graphene possesses brilliant mechanical and physical properties, the commercialization path of graphene remains a challenge for researchers. Graphene production has been immensely studied since its first discovery by Andre Geim and Konstantin Novoselov in 2010. Until now, there is a minimal indication for graphene to take over the nanomaterial market. Limited scale-up in producing a mass volume of high-quality pristine graphene or any graphene derivatives is a huge concern. The path of transforming graphene from laboratory scale to consumer-used products requires large-scale graphene production that is practical and competitive. This review aims to better understand graphene and its derivatives as a step to introduce this material into industrial-scale production. Various synthesis processes to fulfill the need of the market for graphene are reviewed. A detailed discussion of the sustainability of graphene and its derivatives using biomass is also mentioned.

Nanomaterial-enabled electrochemical sensors are designed as an economical, efficient, and user-friendly analytical tool for on-site and routine nitrate analysis over a wide range of environmental samples. The remarkable advances and tunable attributes of nanomaterials have greatly improved the analytical performance of electrochemical nitrate sensors. In this review, a comprehensive elucidation of the recent advances in nanomaterial-based electrochemical nitrate sensors is presented. The review firstly provides a general introduction, followed by typical electrochemical sensing methods. The next two sections detail various nanomaterials, including graphene derivatives, carbon nanotubes/fibers, metal/bimetal/metal oxide nanoparticles, and conducting polymers for modifying electrodes in enzymatic and non-enzymatic electrochemical nitrate sensors. Finally, the perspectives and current challenges in achieving real-world applications of nanomaterial-based electrochemical nitrate sensors are outlined.

The realization of unique scientific phenomena in two-dimensional nanomaterials (2DNMs) has led to their applications in several electronic fields; making it imperative to understand the conduction mechanism of charge carriers in such systems. Though several studies have been conducted on 2DNMs with pristine crystallinity, the inevitable presence of defects in the crystals requires careful consideration of their effect on 2DNMs’ electrical behavior. Here, we outline the effects of chemical, structural, substrate-induced defects and disorder on the conduction mechanism within 2DNMs, particularly graphene derivatives and MoS2. The conduction mechanisms discussed in this work are thermally activated conduction, nearest neighbor hopping, Efros-Shklovskii variable range hopping, and Mott variable range hopping. This review will be beneficial to the various material scientists studying the electronic properties of two-dimensional nanomaterials.

A novel strategy to precisely detect or monitor various biomaterials in living cells poses paramount importance in understanding cellular processes. Graphene, a newly emerged two-dimensional carbon material, has been widely utilized for biosensors owing to its multifarious characteristics including mechanical, electrical, and optical properties (e.g. stability, conductivity, fluorescence quenching and photoluminescence). In addition, graphene derivatives and their innate characteristics, such as biocompatibility low cytotoxicity and water solubility have facilitated the use of graphene-based materials for live cell biosensing, wherein graphene is utilized as a core material by itself or in combination with other functional nanomaterials to load target-specific probes, fluorescent dyes, and other signaling molecules. Such graphene-based hybrid nanomaterials have been employed to detect various cellular entities in living cells, including ions, biomolecules, genetic molecules, proteins, enzymes, and even whole cells. The following review will discuss a number of previous studies in which graphene-based hybrid constructs were used for live cell biosensing, and their potential applications in cancer research and stem cell therapy.

The three-dimensional (3D) macroscopic assembly of tailored porous architectures built of graphene derivatives or other two-dimensional (2D) materials has attracted great attention in both academia and industry. The reason being that such 3D assemblies with controlled morphology can provide ultra-large accessible surface areas and interconnected networks, as well as preventing the undesirable re-stacking phenomena of 2D materials. Herein, we review the synthetic routes and formation mechanism of bulk gel and interface mediated 3D architectures made of diverse 2D materials encompassing both graphene derivatives and non-graphene 2D materials. We also suggest universal strategies that can provide useful insight into application-oriented architecture design. The gelation mechanism is explained in detail; it involves controlled destabilization of the suspension involving a delicate balance between attractive and repulsive interactions. Further, interface mediated self-assembly processes between liquid-solid, liquid-liquid, liquid-gas, and ice-water phases are discussed with a view to tailoring 3D layered and interconnected morphologies. Finally, we highlight the demand for future applications of 2D material-based 3D macroporous architectures. Despite recent progress, more precise control strategies for tuning surface area, pore size distribution, orientation/interconnectivity of pores, density of architectures, and mechanical stability, remain as key scientific and technological barriers that must be addressed to enable practical applications. Further, an important frontier area for future research will involve multilateral hybridization, involving diverse combinations of materials, morphologies, and assembly methods This will provide researchers a multi-dimensional toolbox to access hitherto unavailable properties of 2D material-based 3D architectures for a whole host of applications.

Graphene and its derivatives are called graphene family nanomaterials (GFNs). Over the past few years, they have been heavily investigated in biomedical arena due to their extraordinary physiochemical properties and potential biomedical applications. However, the biocompatibility of GFNs is becoming important for biomedical applications such as drug and gene delivery, tissue engineering, biosensing and imaging. In this regard, it is crucial to understand the process of interaction of GFNs with immune system, which is also meaningful to manipulate their interaction for safe and efficient applications. Herein, different modalities of GFNs interaction with various components of immune system and the outcome of these interactions are described and evaluated. This review also summarizes different mechanisms involved in immunological effects of GFNs and techniques that are employed for GFNs, to escape the clutches of immune system. We elucidate the intricate balance between immune-stimulation and immune-suppression and expect that understanding of immunological effects of graphene derivatives would help evaluate and estimate the possible biomedical applications as far as immune system is concerned.

International audience; Graphene derivatives are promising nanomaterials for producing nanofluids due to their excellent intrinsic characteristics. Among thermophysical profile, and in addition to thermal properties, relevant property to evaluate the potential of graphene-based nanofluids as efficient and reliable heat transfer fluids is viscosity, and rheological behavior in a wider sense. Therefore, the aim of this review paper is to give a comprehensive overview of the current knowledge and results about the rheological properties of graphene-based nanofluids. After a brief description of the most common methods used for fabricating or extracting graphene derivatives, the main steps of graphene-based nanofluids preparation are introduced. Then, literature results on Newtonian/non-Newtonian behavior as well as variations in apparent dynamic viscosity of suspensions containing graphene derivatives are reviewed, analyzing the effects of shear rate, concentration, base fluids and temperature. Such an analysis is performed distinguishing the different types of graphene derivatives, namely graphene oxide, reduced graphene oxide, pristine graphene, graphene quantum dots, functionalized and doped graphene. Also, the impact of base fluid, temperature, concentration and surfactant on viscosity enhancement of graphene-based nanofluids is graphically and newly presented and discussed. In addition, the current models for viscosity prediction or correlation of those nanofluids are detailed. Finally, challenges and future works are summarized.

Graphene has obtained a great interest both in research and industries due to its potential and promising physical, electrical and mechanical properties. While it has been widely researched for advanced applications, its fundamental properties are still being explored and have to be well understood. The physical properties such as specific surface area (SSA), inter-sheet distance (d-spacing) and Raman spectroscopy data for graphene derivatives are closely related to each other, and this work focused on establishing the correlation between these critical factors with respect to their electrical conductivities. Different graphitic materials f(graphene oxide (GO), reduced graphene oxides (rGO), functionalised graphene oxide (frGO) and graphene nanoplatelets (GNP)) were taken in to account to elaborate the underlying mechanisms between extrinsic SSA and other physical parameters, such as intrinsic electrical conductivity. It has been analytically observed that SSA has a direct relationship with d-spacing and defect density of the graphene materials and thus their electrical conductivity highly depends on how large their SSA is the largest the SSA, the highest the electrical conductivity. Materials that poorly reduced were identified to be having low SSA and a higher level of discrepancies. Among different reducing agents used, hydroiodic reduced graphene oxide found to be having larger SSA as 670.98 m2 g−1 and higher electrical conductivity up to 103.3 S cm−1.

Graphene and graphene derivatives with the large surface area are receiving significant attention as good additives into anti-corrosion coatings due to their excellent hydrophobicity, chemical resistance, stability, high mechanical strength. The graphene oxide (GO), on the other hand, has shown high water dispersibility because of its hydrophilic nature, attributed to the presence of oxygen-containing functional groups. Moreover, the presence of functional groups on the surface of GO facilitates chemical functionalization, which enhances the dispersibility and corrosion inhibition performance. The GO-based aqueous corrosion inhibitors is a new area gaining attention from the corrosion scientists. The chapter features the major works on graphene and its derivatives as a new class of materials for corrosion control and covers the synthesis of modified GO and their salient features as corrosion-resistant coatings and inhibitors. The major objectives of this article are to explore the various covalent/ non-covalent approaches for the modification of graphene and GO. An outline of the different types of single and multi-layer graphene-based anticorrosion coatings is discussed. An overview of the literature on the chemically modified GO-based aqueous corrosion inhibitors is outlined with a focus on the different mechanisms underlying the corrosion protection behavior. Finally, the research prospects on some newly emerging 2D material-based corrosion protecting agents is also explored.

Enzymatic biofuel cells (EBFCs) have attracted increasing attention due to their potential to harvest energy from a wide range of fuels under mild conditions. Fabrication of effective bioelectrodes is essential for the practical application of EBFCs. Graphene possesses unique physiochemical properties making it an attractive material for the construction of EBFCs. Despite these promising properties, graphene has not been used for EBFCs as frequently as carbon nanotubes, another nanoscale carbon allotrope. This review focuses on current research progress in graphene-based electrodes, including electrodes modified with graphene derivatives and graphene composites, as well as free-standing graphene electrodes. Particular features of graphene-based electrodes such as high conductivity, mechanical flexibility and high porosity for bioelectrochemical applications are highlighted. Reports on graphene-based EBFCs from the last five years are summarized, and perspectives for graphene-based EBFCs are offered.

GOPY is a free and open-source Python tool specifically written to automate the generation of 2D graphene-based molecular models such as pristine graphene (PG) and several graphene derivatives i.e. graphene oxide (GO), reduced graphene oxide (rGO), aminated polyethylene glycol functionalised reduced graphene oxide (rGO-PEG-NH2), and N-doped graphene (NG) in the Protein Data Bank file format (PDB). These models are generally built manually, but the process can become lengthy and cumbersome. That is especially the case when investigating larger molecules such as those used in Molecular Dynamics (MD) simulations. Using GOPY significantly speeds up the process from hours to minutes, reducing potential bias that may come with the manual placement of functional groups on a graphene layer. Moreover, the building procedure becomes effortless for the researcher, granting the possibility of producing larger and more complex molecular models than one would be able to build manually. Of its more intensive tasks, the generation of a 4 x 4 nm2 rGO-PEG-NH2 layer takes about 9 min on a CodeOcean capsule. Each model is generated in the PDB format, which is easily convertible to a wide array of other molecular formats.

The rapid progresses in the reduction of nitro compounds represent a potent and extensively utilized transformation, which allows the introduction of amino compounds. From the standpoint of organic chemistry, amines have many applications in the synthesis of drugs, biologically active molecules, pharmaceutical products, dyes, polymers, etc. For this aim and owing to the environmental concerns about toxic nitro contaminants such as 4-nitrophenol (4-NP), up to know, much research has been carried out on the reduction/degradation of nitroarenes for the fabrication of amines using different heterogeneous (nano)catalysts. This review provides the current developments in the area of production, classification and applications of graphene-based catalysts in the reduction of nitro compounds to amines. The application of graphene derivatives in the synthesis of various catalysts is advantageous compared to other catalysts and thus increases the rate of reduction of nitro compounds. The use of these catalysts offers several benefits such as straightforward work-up, high catalytic prowess and recovery.

With the emergence of scientific interest in graphene oxide (GO) in recent times, researchers have endeavored to incorporate GO in thermoset polymeric matrix to develop composites with extraordinary set of properties. The current state of research in graphene/thermoset polymer composites is highlighted here with a focus on the role of interface in dictating the overall properties of the composites. Different strategies like covalent and non-covalent functionalization of GO have been discussed with respect to improvement in mechanical, electrical, thermal and rheological properties. In addition, future prospects have been outlined. By assessing the current state of research in graphene/thermoset composites, it is obvious that graphene derivatives are promising materials in enhancing the structural properties of the nanocomposites at extremely low levels of filler loading. This opens new avenues in designing lightweight composites for myriad applications and by tailoring the interfacial adhesion with the polymer, ordered structure can be achieved at macroscopic processing scales. (C) 2015 Elsevier Ltd. All rights reserved.

Carbon based nanomaterials have attracted significant attention over the past decades due to their unique physical properties, versatile functionalization chemistry, and biological compatibility. In this review, we will summarize the current state-of-the-art applications of carbon nanomaterials in cancer imaging and drug delivery/therapy. The carbon nanomaterials will be categorized into fullerenes, nanotubes, nanohorns, nanodiamonds, nanodots and graphene derivatives based on their morphologies. The chemical conjugation/functionalization strategies of each category will be introduced before focusing on their applications in cancer imaging (fluorescence/bioluminescence, magnetic resonance (MR), positron emission tomography (PET), single-photon emission computed tomography (SPECT), photoacoustic, Raman imaging, etc.) and cargo (chemo/gene/therapy) delivery. The advantages and limitations of each category and the potential clinical utilization of these carbon nanomaterials will be discussed. Multifunctional carbon nanoplatforms have the potential to serve as optimal candidates for image-guided delivery vectors for cancer.

Graphene, the recently discovered allotrope of carbon, is a single atom layered aromatic carbon material which is tightly packed into a two-dimensional hexagonal crystal lattice. It is the thinnest material known to man and has a huge application in various fields of science and technology. However, despite having excellent characteristics, the use of pure graphene sheets has limited application. Graphene-based composites offer a considerable potential in the field of environmental remediation for the efficient removal of biological contaminants. Therefore, a comprehensive review of the antibacterial property of the graphene-based nanocomposites and advancements in this field is of significant value for the scientific community. In the present review, firstly, a concise overview about graphene, its exceptional chemical and physical features, and different fabrication and characterization techniques employed for graphene-based nanocomposites are discussed. Then, a comprehensive discussion was performed on the disinfectant property of binary, ternary, and complex metal oxide-graphene and graphene derivatives-based composites, along with the mechanistic models of disinfection. Furthermore, the future prospects and the remaining challenges in utilizing graphene nanocomposites in energy and environmental disciplines is discussed by giving a precise conclusion and a prospective outlook.

Graphene derivatives generated by modifying the surface oxygen functional groups of graphene oxide have been widely investigated in recent years. Graphene derivatives possess excellent aqueous solubility and biocompatibility similar to graphene oxide, which are important in their biomedical application. Research progress on the use of graphene derivatives in biological imaging, drug carriers and photodynamic therapy of cancer is presented. Future efforts to improve their performance in cancer therapy are also proposed, such as lowering the toxic effects introduced by chemicals used in the preparation of the graphene derivatives, expanding the drug to include genes and proteins, and coupling photodynamic therapy with imaging.