Graphene Nanoparticle Composites Research Articles

Contemporary updates on bioremediation applications of graphene and its composites

Graphene, a 2D single-layered carbon sp2 hybrid substance set in a honeycomb network, is widespread in many carbon-based materials. Due to its extraordinary optical, electrical, thermal, mechanical, and magnetic competences as well as its significant specific surface area, it has attracted a lot of interest recently. Synthesizing graphene refers to any process for creating or extracting the material, depending on the desired purity, size, and efflorescence of the finished good. Numerous methods have been employed for graphene synthesis categorized as top-down procedures and bottom-up procedures. Graphene finds its implementations in various industries such as electronics, energy, chemical, transport, defence, and biomedical areas such as accurate biosensing. It has been widely used in water treatment as a binder for organic contaminants and heavy metals. Many researches have fixated on creating various modified graphene, graphene oxide composites, graphene nanoparticle composites and semiconductor hybrids of graphene for contaminant removal from water. In this review, we have tried to address various production methods for graphene and its composites along with their advantages and disadvantages. Furthermore, we have presented a summary on graphene's outstanding immobilization of a variety of contaminants like toxic heavy metals, organic dyes, inorganic pollutants and pharmaceutical wastes. Additionally, a development of graphene-based microbial fuel cell (MFC) has been evaluated in an effort to produce ecological wastewater treatment and bioelectricity.

Review on Graphene Nanoparticle Composites

In recent years, graphene has attracted atlcntion. Grapheneis a thick planar sheet of Sp2 bonded carbon atoms. Its lattice is honey comb structure. Graphene is one of the most rising material due to its various fascinatingl properties. From recent study it is proved that graphene based composites with different nanoparticle show extensive applielltion. In this review we focus on recent developement in the synthetic approach, properties and the facilities of use of graph nanoparticle comosites. The advantages of graphene-nanupartide composites are specifically observed in catalytic reactions, electrochemical sensing, detection by surface enhanced Raman spectroscopy, purification of waterusing adsurbent and other applications are discussed here.

Review on Graphene Nanoparticle Composites

Review on Graphene Nanoparticle Composites

纳米银石墨烯的制备及其疏水性能的研究

纳米银石墨烯的制备及其疏水性能的研究

Laser-induced noble metal nanoparticle-graphene composites enabled flexible biosensor for pathogen detection

Noble metal nanoparticle-3D graphene hybrid nanocomposites possess the advantage of nanoparticles and graphene, which have attracted extensive interest. Here we developed a one-step laser induction method to prepare various noble metal nanoparticle-3D graphene nanocomposites. The nanocomposites were converted from polyimide film coated with the corresponding metal precursor-chitosan hydrogel ink. These nanoparticles including gold nanoparticles (AuNPs), silver nanoparticles (AgNPs), and platinum nanoparticles (PtNPs), were evenly distributed on the surface of porous 3D graphene. Furthermore, we prepared an AuNPs-3D graphene interdigitated array electrode using the one-step laser induction method, which was used to fabricate a flexible impedimetric immunosensor for the detection of Escherichia coli O157:H7. The immunosensor shows excellent performance including low detection limit, high selectivity, and great flexibility.

Electrochemical sensor study of TiO2 nanoparticle–graphene composite produced by mechanical milling and sonication-assisted exfoliation

TiO2 nanoparticle-decorated graphene was produced by mechanical milling of TiO2 powder with graphite followed by sonication of the nanocomposite in the presence of sodium lauryl sulfate surfactant. Sonication led to the exfoliation of graphite to produce TiO2 nanoparticle–graphene composite. The as-prepared TiO2–graphite nanocomposite was characterized using X-ray diffraction and scanning electron microscopy and the exfoliated TiO2–graphene nanocomposite was analyzed using Raman spectroscopy, atomic force microscopy, and transmission electron microscopy. The results indicated the formation of faceted titanium dioxide particles with an average size of ~ 200 nm. Thickness of the few layered graphene sheets was found to be 2 + 0.8 nm. The glassy carbon electrode coated with the TiO2 nanoparticle–graphene composite was used to detect potassium ferricyanide (K3FeCN6) by cyclic voltammetric method. TiO2 nanoparticle–graphene-coated surface demonstrated improved response with enhanced current for K3FeCN6 detection.

One-Step Photochemical Synthesis of Transition Metal–Graphene Hybrid for Electrocatalysis

For widespread use of renewable energy such as water splitting, the development of electrocatalysts on a large-scale at a low-cost that remains safe and environmentally friendly is still a great challenge. Here, we report the use of α-aminoalkyl radicals in a one-step procedure that synthesizes transition metal nanoparticle–graphene composites via photoreduction. The organic photocatalyst 2-methyl-1-[4-(methylthio)phenyl]-2-(morpholinyl)phenyl]-1-butanone (I-907) undergoes Norrish Type I photocleavage to generate strongly reducing α-aminoalkyl radicals, when exposed to UVA. For the first time, we demonstrate its ability to reduce graphene oxide (GO) and successfully synthesize Co3O4 nanoparticles decorated on graphene (Co3O4NP-rGO). The α-aminoalkyl radicals simultaneously reduce GO and Co2+ salts, which nucleates on the negatively charged GO sheets and grows to form nanoparticles. The resulting Co3O4NP-rGO showed decent catalytic activity and stability for the oxygen evolution reaction. Our work introduc...

Graphene and Graphene-Based Nanomaterials for DNA Detection: A Review.

DNA detection with high sensitivity and specificity has tremendous potential as molecular diagnostic agents. Graphene and graphene-based nanomaterials, such as graphene nanopore, graphene nanoribbon, graphene oxide, and reduced graphene oxide, graphene-nanoparticle composites, were demonstrated to have unique properties, which have attracted increasing interest towards the application of DNA detection with improved performance. This article comprehensively reviews the most recent trends in DNA detection based on graphene and graphene-related nanomaterials. Based on the current understanding, this review attempts to identify the future directions in which the field is likely to thrive, and stimulate more significant research in this subject.

First Report on High Entropy Alloy Nanoparticle Decorated Graphene

This is the first report on synthesis of multimetal high entropy alloy (HEA) nanoparticle-few layer graphene composite. A two-step methodology for synthesizing multi-component HEA nanoparticle-graphene composite is provided. In the first step, high purity graphite powder was mechanically milled with metal powders (Ni, Cr, Co, Cu, Fe) to produce multimetal-graphite composite. This composite was then sonicated with sodium lauryl sulphate (SLS) for 2 hours to produce a dispersion of graphene decorated with multi-component nanoparticles with face centred cubic structure. Potentiodynamic polarization and electrochemical impedance spectroscopy methods revealed that the HEA nanoparticle graphene composite possess excellent corrosion resistance properties which was better than the corrosion resistance exhibited by milled and exfoliated graphene. The HEA nanoparticle-graphene composite can be used for corrosion resistant coating applications.

Synthesis of Graphene–Magnetite Nanoparticle Composite Using Mechanical Milling and Electrochemical Exfoliation

This work describes a two-step methodology for synthesizing a magnetite nanoparticle-graphene composite. In the first step, iron metal powder was ball milled with graphite to produce a mixture that was subsequently compacted to produce a pellet. In the second step, electrochemical exfoliation of this pellet was performed to produce graphene decorated with magnetite nanoparticles. Formation of graphene was established by methods such as x-ray diffraction, Raman spectroscopy, and x-ray photoelectron spectroscopy. The formation of magnetite nanoparticle-graphene composite was established by transmission-electron-microscopy-based imaging and electron diffraction methods. The magnetite nanoparticles on the graphene sheet had an average size of ~12 nm and were nonuniformly distributed.

Ag and Cu Monometallic and Ag/Cu Bimetallic Nanoparticle-Graphene Composites with Enhanced Antibacterial Performance.

Increased proliferation of antimicrobial resistance and new strains of bacterial pathogens severely impact current health, environmental, and technological developments, demanding design of novel, highly efficient antibacterial agents. Ag, Cu monometallic and Ag/Cu bimetallic nanoparticles (NPs) were in situ grown on the surface of graphene, which was produced by chemical vapor deposition using ferrocene as precursor and further functionalized to introduce oxygen-containing surface groups. The antibacterial performance of the resulting hybrids was evaluated against Escherichia coli cells and compared through a series of parametrization experiments of varying metal type and concentration. It was found that both Ag- and Cu-based monometallic graphene composites significantly suppress bacterial growth, yet the Ag-based ones exhibit higher activity compared to that of their Cu-based counterparts. Compared with well-dispersed colloidal Ag NPs of the same metal concentration, Ag- and Cu-based graphene hybrids display weaker antibacterial activity. However, the bimetallic Ag/CuNP-graphene hybrids exhibit superior performance compared to that of all other materials tested, i.e., both the monometallic graphene structures as well as the colloidal NPs, achieving complete bacterial growth inhibition at all metal concentrations tested. This striking performance is attributed to the synergistic action of the combination of the two different metals that coexist on the surface as well as the enhancing role of the graphene support.

Facile Synthesis of Cu/Cu2O Nanoparticles–Graphene Composites for Efficient Detection of NO2 at Room Temperature

Cu/Cu2O nanoparticles-reduced graphene oxide composites (CuGCs) have been successfully prepared by a facile solvothermal method. The combined characterizations indicate the successful formation of CuGCs. The [Formula: see text] 3 nm Cu/Cu2O nanoparticles homogeneously in situ grow on reduced graphene oxide sheets. CuGCs-based gas sensors were investigated for detection of NO2 at room temperature. The CuGCs exhibited fast response behavior, relatively high response and could achieve a detection limit as low as 5[Formula: see text]ppm. Furthermore, sensing mechanism and the reason for enhancing sensing performance have also been discussed.

One-step synthesis of Au nanoparticle–graphene composites using tyrosine: electrocatalytic and catalytic properties

The in situ synthesis of a reduced graphene oxide/Au nanoparticle composite for nonenzymatic H2O2 detection and nitrophenol reduction.

Electrophoretic separation and deposition of metal–graphene nanocomposites and their application as electrodes in solar cells

Synthesis of metal nanoparticle–graphene composites without the use of any stabilising ligands has enabled the nanoparticle surface to be available for electron transfer reactions in the development of new counter electrodes for solar cells.

In Situ synthesis of Three-Dimensional Self-Assembled SnO2 - Reduced Graphene Oxide Architecture for Lithium Ion Batteries

The structure of graphene, a single layer of carbon atoms patterned in a hexagonal lattice, results in an unusual combination of characteristics including outstanding electronic properties, high thermal conductivity, good optical properties, high mechanical strength, and a large surface area. As such, graphene has attracted considerable attention worldwide for potential applications in sensors, catalysis, energy-storage devices, and environmental fields. Although most of this previous research has focused on two-dimensional (2-D) specimens and devices,1 these 2-D graphene sheets must be integrated into macroscopic 3-D structures to take full advantage of their properties and associated benefits.2 Of the available techniques for integrating nanostructured building blocks into macroscopic materials, the fabrication of self-assembled, 3-D graphene structures has been recognized as one of the most effective, as it is capable of harnessing nanoscale properties to provide novel functionalities of hierarchically structured macroscopic devices. Furthermore, superstructures assembled in this way exhibit unique collective physiochemical properties different from those of the individual components and bulk material, which help enrich the variety of graphene-based materials and broaden their capacity for practical application.3A number of different interactions such as dipole interactions, electrostatic attraction or repulsion, hydrophilic/hydrophobic interactions, and hydrogen bonding have also been utilized in the self-assembly process itself. Studies pertaining to composites of graphene and nanoparticles have flourished in recent years, as such materials combine the advantages of both graphene and nanoparticles and therefore have potential for application in catalysis, sensors, and energy fields.4 More recently, the capture of pre-prepared metal oxide nanoparticles or metal salts in 3-D graphene networks has been reported as possible with the assistance of a suitable reducing agent (NaHSO3, Na2S, vitamin C, HI, and hydroquinone).5 In most previous studies, nanometer-sized 3-D structured metal oxide (MO)–graphene has been synthesized by physically mixing the MO with graphene oxide (GO), dispersing it in an aqueous solution, and then adding a reducing agent. In this process, MO particles are randomly captured and aggregated between the graphene sheets, which significantly inhibits their nanoscale effects.6 Consequently, most such materials are instead prepared from 2-D graphene nanosheets onto which nanoparticles have been deposited or adsorbed, and there are still very few reports on different routes for directly preparing 3-D graphene–nanoparticle composites.7 With this in mind, we herein report on a self-assembled, 3-D RGO architecture that is prepared with electrochemically active SnO2 interfacially anchored between highly conductive RGO structures. This was achieved with a simple one-pot synthesis in which a SnCl2 was used not only as a reducing agent to transform GO into highly conductive 3-D RGO but also as a precursor to form a 3-D SnO2 structure under carefully controlled reduction conditions. The 3D SnO2-RGO composite synthesized in this manner is electrochemically assessed for use as a binder-free anode in high-rate Li-ion batteries. More details on the synthetic procedure, electrochemical and structural properties will be presented at the meeting. <Reference> (1) Geim, A. K.; Novoselov, K. S. Nat. Mater. 2007, 6, 183. (2) Liu, F.; Seo, T. S. Adv. Funct. Mater. 2010, 20, 1930. (3) Tang, Z.; Shen, S.; Zhuang, J.; Wang, X.; Angew. Chem. Int. Ed. 2010, 19, 6306. (4) Wang, X.; Tang, Z. H.; Shen, S. L.; Zhuang, J. Angew. Chem. Int. Ed. 2010, 49, 4603. (5) Cong, H. P.; Ren, X. C.; Wang, P.; Yu, S. H. ACS Nano 2012, 2693. (6) Park, S. H.; Kim, H. K.; Ahn, D. J.; Lee, S. I.; Roh, K. C.; Kim, K. B. Electrochem. Comm. 2013, 34, 117. (7) Wen, Z.; Wang, Q.; Zhang, Q.; Li, J. Adv. Funct. Mater. 2007, 17, 2772.

Graphene‐based nanomaterials as molecular imaging agents

Molecular imaging (MI) is a noninvasive, real-time visualization of biochemical events at the cellular and molecular level within tissues, living cells, and/or intact objects that can be advantageously applied in the areas of diagnostics, therapeutics, drug discovery, and development in understanding the nanoscale reactions including enzymatic conversions and protein-protein interactions. Consequently, over the years, great advancement has been made in the development of a variety of MI agents such as peptides, aptamers, antibodies, and various nanomaterials (NMs) including single-walled carbon nanotubes. Recently, graphene, a material popularized by Geim & Novoselov, has ignited considerable research efforts to rationally design and execute a wide range of graphene-based NMs making them an attractive platform for developing highly sensitive MI agents. Owing to their exceptional physicochemical and biological properties combined with desirable surface engineering, graphene-based NMs offer stable and tunable visible emission, small hydrodynamic size, low toxicity, and high biocompatibility and thus have been explored for in vitro and in vivo imaging applications as a promising alternative of traditional imaging agents. This review begins by describing the intrinsic properties of graphene and the key MI modalities. After which, we provide an overview on the recent advances in the design and development as well as physicochemical properties of the different classes of graphene-based NMs (graphene-dye conjugates, graphene-antibody conjugates, graphene-nanoparticle composites, and graphene quantum dots) being used as MI agents for potential applications including theranostics. Finally, the major challenges and future directions in the field will be discussed.

Understanding the Enhanced Catalytic Performance of Ultrafine Transition Metal Nanoparticles–Graphene Composites

Catalysis, as the key to minimize the energy requirement and environmental impact of today's chemical industry, plays a vital role in many fields directly related to our daily life and economy, including energy generation, environment control, manufacture of chemicals, medicine synthesis, etc. Rational design and fabrication of highly efficient catalysts have become the ultimate goal of today's catalysis research. For the purpose of handling and product separation, heterogeneous catalysts are highly preferred for industrial applications and a large part of which are the composites of transition metal nanoparticles (TMNPs). With the fast development of nanoscience and nanotechnology and assisted with theoretical investigations, basic understanding on tailoring the electronic structure of these nanocomposites has been gained, mainly by precise control of the composition, morphology, interfacial structure and electronic states. With the rise of graphene, chemical routes to prepare graphene were developed and various graphene-based composites were fabricated. Transition metal nanoparticles-reduced graphene oxide (TMNPs–rGO) composites have attracted considerable attention, because of their intriguing catalytic performance which have been extensively explored for energy- and environment-related applications to date. This review summarizes our recent experimental and theoretical efforts on understanding the superior catalytic performance of subnanosized TMNPs–rGO composites.

Design, synthesis, and characterization of graphene-nanoparticle hybrid materials for bioapplications.

Graphene is composed of single-atom thick sheets of sp2 bonded carbon atoms that are arranged in a perfect two-dimensional (2D) honeycomb lattice. Because of this structure, graphene is characterized by a number of unique and exceptional structural, optical, and electronic properties.1 Specifically, these extraordinary properties include, but are not limited to, a high planar surface area that is calculated to be 2630 m2 g−1,2 superior mechanical strength with a Young’s modulus of 1100 GPa,3 unparalleled thermal conductivity (5000 W m−1 K−1),4 remarkable electronic properties (e.g., high carrier mobility [10 000 cm2 V−1 s−1] and capacity),5 and alluring optical characteristics (e.g., high opacity [~97.7%] and the ability to quench fluorescence).6 As such, it should come as no surprise that graphene is currently, without any doubt, the most intensively studied material for a wide range of applications that include electronic, energy, and sensing outlets.1c Moreover, because of these unique chemical and physical properties, graphene and graphene-based nanomaterials have attracted increasing interest, and, arguably, hold the greatest promise for implementation into a wide array of bioapplications.7 In the last several years, numerous studies have utilized graphene in bioapplications ranging from the delivery of chemotherapeutics for the treatment of cancer8 to biosensing applications for a host of medical conditions9 and even for the differentiation and imaging of stem cells.10 While promising and exciting, recent reports have demonstrated that the combination of graphene with nanomaterials such as nanoparticles, thereby forming graphene–nanoparticle hybrid structures, offers a number of additional unique physicochemical properties and functions that are both highly desirable and markedly advantageous for bioapplications when compared to the use of either material alone (Figure 1).11 These graphene–nanoparticle hybrid structures are especially alluring because not only do they display the individual properties of the nanoparticles, which can already possess beneficial optical, electronic, magnetic, and structural properties that are unavailable in bulk materials, and of graphene, but they also exhibit additional advantageous and often synergistic properties that greatly augment their potential for bioapplications. Open in a separate window Figure 1 Graphene nanoparticle hybrids exist in two forms, as graphene–nanoparticle composites and graphene-encapsulated nanoparticles, and can be used for various bioapplications including biosensors, photothermal therapies, stem cell/tissue engineering, drug/gene delivery, and bioimaging. Panel (A) reprinted with permission from ref 110. Copyright 2012 Wiley. Panel (B) reprinted with permission from ref 211. Copyright 2013 Elsevier. Panel (C) reprinted with permission from ref 244. Copyright 2013 Wiley.

Effect of size and oxidation state of platinum nanoparticles on the electrocatalytic performance of graphene-nanoparticle composites

Size and oxidation state of Pt nanoparticles significantly influence the electrocatalytic performance of Pt–graphene nanocomposites for methanol oxidation and 2.2 nm Pt with variable oxidation states offers the best catalytic activity and durability.

Graphene-Nanoparticle Composites and Their Applications in Energy, Environmental and Biomedical Science

Graphene-Nanoparticle Composites and Their Applications in Energy, Environmental and Biomedical Science