Nitrogen-doped twisted graphene grown on copper by atmospheric pressure CVD from a decane precursor

• Ivan V. Komissarov,
• Nikolai G. Kovalchuk,
• Vladimir A. Labunov,
• Ksenia V. Girel,
• Olga V. Korolik,
• Mikhail S. Tivanov,
• Algirdas Lazauskas,
• Mindaugas Andrulevičius,
• Tomas Tamulevičius,
• Viktoras Grigaliūnas,
• Šarunas Meškinis,
• Sigitas Tamulevičius and
• Serghej L. Prischepa

Beilstein J. Nanotechnol. 2017, 8, 145–158, doi:10.3762/bjnano.8.15

• consists of mechanical exfoliation, which imposes severe mechanical, uncontrolled defects in the sample. The most common and preferable is the wet-chemical etching of the catalyst (substrate). Usually a poly(methylmethacrylate) (PMMA) scaffold is applied to coat the graphene surface and support it during

Evolution of the graphite surface in phosphoric acid: an AFM and Raman study

• Rossella Yivlialin,
• Luigi Brambilla,
• Gianlorenzo Bussetti,
• Matteo Tommasini,
• Andrea Li Bassi,
• Carlo Spartaco Casari,
• Matteo Passoni,
• Franco Ciccacci,
• Lamberto Duò and
• Chiara Castiglioni

Beilstein J. Nanotechnol. 2016, 7, 1878–1884, doi:10.3762/bjnano.7.180

• electrochemical (EC) treatment, graphite is carefully ultrasonicated to ease the exfoliation process. After that single- or multi-layer graphene sheets with a size of about 1 μm can be retrieved from the electrochemical bath. The electronic and mechanical properties of the graphene sheets [1][2][3][4][5][6] and

• allows for successful graphite exfoliation, as reported quite recently [12][13]. However, a detailed analysis of the surface modification of a graphite crystal subjected to EC processes in phosphoric acid solution is still missing. In a recent work [7], we have shown that the EC characterization of the

• thinner modified surface layer. The C-region is compatible with incipient anion intercalation and/or exfoliation of small graphene sheets. However, a wider EC-AFM/Raman analysis on samples subjected to different CV treatments is required in order to definitely assess the ability of phosphoric acid to give

Role of RGO support and irradiation source on the photocatalytic activity of CdS–ZnO semiconductor nanostructures

• Suneel Kumar,
• Rahul Sharma,
• Vipul Sharma,
• Gurunarayanan Harith,
• Vaidyanathan Sivakumar and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2016, 7, 1684–1697, doi:10.3762/bjnano.7.161

• washed with 10% HCl and then with deionized water until pH value of the filtrate was neutral. Obtained graphite oxide was subjected to ultrasonication for its exfoliation followed by centrifugation at 4500 rpm for 15 min. The final product was obtained by drying with rotary evaporator at 40 °C followed

• of graphite and formation of GO with well-defined lamellar structure [42][43]. This interlayer distance weakens the van der Waal interactions between sheets and makes exfoliation possible [44]. Once GO is reduced to RGO during hydrothermal treatment, the (002) reflection peak of GO disappears. The

A composite structure based on reduced graphene oxide and metal oxide nanomaterials for chemical sensors

• Vardan Galstyan,
• Elisabetta Comini,
• Iskandar Kholmanov,
• Andrea Ponzoni,
• Veronica Sberveglieri,
• Nicola Poli,
• Guido Faglia and
• Giorgio Sberveglieri

Beilstein J. Nanotechnol. 2016, 7, 1421–1427, doi:10.3762/bjnano.7.133

• oxidation and ultrasonic exfoliation, the GO exhibits a broad and intense D band in its Raman spectrum [28]. The intensity ratio between D and G peaks (ID/IG = 0.94) also indicates the high defect concentration in GO platelets. High intensity peaks at about 520 cm−1 and 950 cm−1 in the Raman spectrum can be

Reasons and remedies for the agglomeration of multilayered graphene and carbon nanotubes in polymers

• Rasheed Atif and
• Fawad Inam

Beilstein J. Nanotechnol. 2016, 7, 1174–1196, doi:10.3762/bjnano.7.109

• the epoxy matrix due to strong covalent bonding [41]. The treatment with sulfuric acid and nitric acid also causes functionalization of MLG and CNTs. These oxygenated side groups exert electrostatic repulsive forces causing exfoliation. However, this acid treatment results in a shortening of the

Characterisation of thin films of graphene–surfactant composites produced through a novel semi-automated method

• Nik J. Walch,
• Alexei Nabok,
• Frank Davis and
• Séamus P. J. Higson

Beilstein J. Nanotechnol. 2016, 7, 209–219, doi:10.3762/bjnano.7.19

• Lane, Chichester, West Sussex, PO19 6PE, UK 10.3762/bjnano.7.19 Abstract In this paper we detail a novel semi-automated method for the production of graphene by sonochemical exfoliation of graphite in the presence of ionic surfactants, e.g., sodium dodecyl sulfate (SDS) and cetyltrimethylammonium

• sensor applications, for use in flexible electronics [2] and graphene-based printable inks for printed electrical circuits [3]. Graphene has reportedly been produced in a number of different ways. The method chosen for this research is sonochemical exfoliation in water in the presence of a surfactant, as

• subsequent reduction to graphene [5], and secondly it guarantees single-layer or few-layer graphene, rather than the potentially larger products or graphene sheets with an uneven size distribution that might be produced in other techniques such as mechanical exfoliation (the “scotch tape” method). The

Synthesis and applications of carbon nanomaterials for energy generation and storage

• Marco Notarianni,
• Jinzhang Liu,
• Kristy Vernon and
• Nunzio Motta

Beilstein J. Nanotechnol. 2016, 7, 149–196, doi:10.3762/bjnano.7.17

• industry in the development of this technology. There are more than ten processes available to synthesize graphene but only the following five can be reasonably considered in terms of quality and material scalability (Figure 14) [81]: Mechanical exfoliation Chemical exfoliation Chemical exfoliation via

• graphene oxide CVD Synthesis on SiC Each of these methods has its advantages and disadvantages in terms of quality, yield production and applications, as summarized in Table 1. In particular, mechanical exfoliation most likely produces the best samples in terms of charge carrier mobility but is probably

• based on the chemical exfoliation of graphite and thermal or chemical reduction of graphene oxide can produce graphene on an industrial scale but unfortunately with structural defects that can affect the electronic and electrical properties [84][85]. These are the main problems that impede the

Nanostructured surfaces by supramolecular self-assembly of linear oligosilsesquioxanes with biocompatible side groups

• Maria Nowacka,
• Anna Kowalewska and
• Tomasz Makowski

Beilstein J. Nanotechnol. 2015, 6, 2377–2387, doi:10.3762/bjnano.6.244

• the lamellar structure of mica. The mineral can be easily cleaved along the plane located in the K+ layer to expose a perfectly smooth surface [39] that can serve as a very good AFM imaging substrate for studies on biomaterials [40][41] and polymers [42][43]. Upon exfoliation, K+ becomes accessible to

Enhanced model for determining the number of graphene layers and their distribution from X-ray diffraction data

• Beti Andonovic,
• Abdulakim Ademi,
• Anita Grozdanov,
• Perica Paunović and
• Aleksandar T. Dimitrov

Beilstein J. Nanotechnol. 2015, 6, 2113–2122, doi:10.3762/bjnano.6.216

• attracted great interest in terms of fundamental studies as well as potential applications [2]. To date, several methods have been used to produce high-quality graphene sheets, such as mechanical exfoliation of graphite, chemical vapor deposition (CVD) of gases containing carbon atoms on the surface of

• molten salt, and 25 °C in aqueous solution. It should be underlined that, during the electrolysis, the cations reduced at the electrode intercalate at the graphite surface and generate a high mechanical stress that causes exfoliation of the cathode. This phenomenon enables the electrochemical synthesis

Metal hydrides: an innovative and challenging conversion reaction anode for lithium-ion batteries

• Luc Aymard,
• Yassine Oumellal and
• Jean-Pierre Bonnet

Beilstein J. Nanotechnol. 2015, 6, 1821–1839, doi:10.3762/bjnano.6.186

• d(002) drastically increases (step B). Firstly, The mechanical energy transferred to the carbon produces an exfoliation of the graphene layer. Then, the cumulated mechanical energy coming from the grinding is sufficient to promote fissure propagation within the graphene layer, resulting in the

Electroburning of few-layer graphene flakes, epitaxial graphene, and turbostratic graphene discs in air and under vacuum

• Andrea Candini,
• Nils Richter,
• Domenica Convertino,
• Camilla Coletti,
• Franck Balestro,
• Wolfgang Wernsdorfer,
• Mathias Kläui and
• Marco Affronte

Beilstein J. Nanotechnol. 2015, 6, 711–719, doi:10.3762/bjnano.6.72

• first consider the case of few-layer graphene flakes obtained by the mechanical exfoliation technique (see Experimental for more details). A typical flake is shown in the inset of Figure 1a. Several electrical contacts are fabricated on the same sample, leading to a certain number of nearly identical

• role to initiate the burning. Indeed, the presence of nonsaturated carbon bonds makes the edges the most reactive part of the device. Edges cleaved during the exfoliation (exfoliated graphene), edges created during the oxygen plasma (graphene on SiC and turbostratic discs after the patterning), and

• exfoliation method from natural graphite pieces on top of a p-doped silicon wafer coated with 300 nm of oxide. Flakes of suitable thickness (1 to approx. 20 layers) were located with an optical microscope on the basis of their contrast with the substrate. In some cases, the effective number of layers is also

Overview of nanoscale NEXAFS performed with soft X-ray microscopes

• Peter Guttmann and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2015, 6, 595–604, doi:10.3762/bjnano.6.61

• studied with the HZB-TXM. The electronic states of freestanding CNH aggregate in a dahlia-like shape were investigated and could be related to the presence of pentagonal rings and folding of the graphene sheet in the CNH [66]. Metal impurities due to the exfoliation process of graphite give rise to a pre

X-ray photoelectron spectroscopy of graphitic carbon nanomaterials doped with heteroatoms

• Toma Susi,
• Thomas Pichler and
• Paola Ayala

Beilstein J. Nanotechnol. 2015, 6, 177–192, doi:10.3762/bjnano.6.17

• chemical vapor deposition in a high-vacuum system and a triisopropyl borate precursor [182], and the important role of B adhesion to Fe catalyst particles was also highlighted. For boron-doped graphene, successful synthesis recipes range from the mechanical exfoliation of boron-doped graphite [183] to

Liquid-phase exfoliated graphene: functionalization, characterization, and applications

• Mildred Quintana,
• Jesús Iván Tapia and
• Maurizio Prato

Beilstein J. Nanotechnol. 2014, 5, 2328–2338, doi:10.3762/bjnano.5.242

• exfoliation of graphite in water and organic solvents. The challenges involve the production of a large quantity of graphene sheets with tailored distribution in thickness, size, and shape. In this review, we present some of the recent efforts towards the controlled production of graphene in dispersions. We

• ]. Among them, micromechanical exfoliation [2] and metal supported growth [3] produced the best layers in terms of electrical and structural quality. Unfortunately, these strategies are time consuming, expensive or produce low material yield. It is crucial to push these methodologies forward towards the

• graphene layers and the colloidal mechanisms that guide stabilization of graphene sheets possessing diverse physical and chemical features such as charge, size and shape. To date, the exfoliation of graphite in dispersions has been obtained by a number of mechanochemical methods. Each one of these

Nanobioarchitectures based on chlorophyll photopigment, artificial lipid bilayers and carbon nanotubes

• Marcela Elisabeta Barbinta-Patrascu,
• Stefan Marian Iordache,
• Ana Maria Iordache,
• Nicoleta Badea and
• Camelia Ungureanu

Beilstein J. Nanotechnol. 2014, 5, 2316–2325, doi:10.3762/bjnano.5.240

• exfoliation of CNT bundles in the case of free-cholesterol biohybrids (sample V3). On the contrary, the cholesterol-containing, carbon-based biohybrids (sample V4) proved to be more effective in CNT dispersion. In this case, the AFM analysis revealed a lipid coating around the carbon nanotubes that prevents

Two-dimensional and tubular structures of misfit compounds: Structural and electronic properties

• Tommy Lorenz,
• Jan-Ole Joswig and
• Gotthard Seifert

Beilstein J. Nanotechnol. 2014, 5, 2171–2178, doi:10.3762/bjnano.5.226

• )1.00MoSe2, and (SnSe)1.03MoSe2 [5][6][7][8], and misfit layer compounds consisting of other elements such as tellurium [9] or lanthanides [10] have been synthesized. Although some misfit compounds occur naturally [1][11], the recent developments in the synthesis, exfoliation, and handling of layered, two

• exfoliation is easily possible [24]. As a consequence of their structure, interaction between the M atoms of the MX layer and the X atoms of the TMX2 layer exists in all misfit compounds. In each unit cell this interaction occurs twice: at the top and the bottom sides of the layers. This can be seen in Figure

Donor–acceptor graphene-based hybrid materials facilitating photo-induced electron-transfer reactions

• Anastasios Stergiou,
• Georgia Pagona and
• Nikos Tagmatarchis

Beilstein J. Nanotechnol. 2014, 5, 1580–1589, doi:10.3762/bjnano.5.170

• surfaces [5][6], liquid exfoliation via sonication [7][8], dissolution in superacids such as chlorosulfonic acid [9] and ball milling [10]. However, a major drawback of graphene, likewise of carbon nanotubes, stems from its insolubility in all solvents, which impedes the chemical manipulation toward

• electronic properties of graphene are of primary importance. Alternatively, wet exfoliation of graphite followed by functionalization is a more efficient strategy. Although functionalization of exfoliated graphene can be achieved by either covalent anchoring of organic molecules onto the graphene lattice [13

• chemical reactions leading to the covalent modification of a graphene framework are displayed. Briefly, after the exfoliation of graphite, the following reactions can be performed to modify the graphene sheet (summarized in Scheme 1): [3 + 2] 1,3-Dipolar cycloaddition of in situ generated azomethine ylides

Highly NO₂ sensitive caesium doped graphene oxide conductometric sensors

• Carlo Piloto,
• Marco Notarianni,
• Mahnaz Shafiei,
• Elena Taran,
• Dilini Galpaya,
• Cheng Yan and
• Nunzio Motta

Beilstein J. Nanotechnol. 2014, 5, 1073–1081, doi:10.3762/bjnano.5.120

• processes to make pristine graphene sheets, like chemical vapour deposition, epitaxial growth or mechanical exfoliation [30][31][32][33]. By dispersion and sonication of graphite oxide in aqueous solution or organic solvent, a colloidal suspension of GO sheets is produced. The density of oxygen functional

Nanostructure sensitization of transition metal oxides for visible-light photocatalysis

• Hongjun Chen and
• Lianzhou Wang

Beilstein J. Nanotechnol. 2014, 5, 696–710, doi:10.3762/bjnano.5.82

• electron–hole pairs and further improve the photocatalytic ability [145]. The last feature is that an appreciable number of ion-exchangeable semiconductors can be exfoliated into single-layer two-dimensional (2D) nanosheets by the intercalation–exfoliation method, as shown in Figure 10. The thickness of

Fullerenes as adhesive layers for mechanical peeling of metallic, molecular and polymer thin films

• Maria B. Wieland,
• Anna G. Slater,
• Barry Mangham,
• Neil R. Champness and
• Peter H. Beton

Beilstein J. Nanotechnol. 2014, 5, 394–401, doi:10.3762/bjnano.5.46

• , the transfer and removal of monolayer films has been widely adopted by graphene researchers through exfoliation [10] and, for samples grown by chemical vapour deposition, by etching the underlying metal thin film or foil used as a growth substrate [11][12][13]. In a complementary strand of research

Routes to rupture and folding of graphene on rough 6H-SiC(0001) and their identification

• M. Temmen,
• O. Ochedowski,
• B. Kleine Bussmann,
• M. Schleberger,
• M. Reichling and
• T. R. J. Bollmann

Beilstein J. Nanotechnol. 2013, 4, 625–631, doi:10.3762/bjnano.4.69

• various ways. The growth of graphene on metals followed by transfer to another substrate as well as epitaxial growth on SiC, both have a potential for mass production if technological shortcomings can be overcome. However, exfoliation from graphite still results in graphene flakes of highest quality [1][2

• ]. Severe heating results in the opening at locations of existing rupture, creating type (iii) structures. For this type of modification, the interfacial layer residing between the substrate and the SLG flake due to its exfoliation in ambient, is anticipated to play a major role. Thin water films resulting

• from exfoliation in ambient have been recognized in literature as an important feature determining the sheet properties [33][34][35][36][37][38][39]. The structures of type (iii) might act as a pressure release for heated water confined at the interface. The dashed box in Figure 3a shows the same

Micro- and nanoscale electrical characterization of large-area graphene transferred to functional substrates

• Gabriele Fisichella,
• Salvatore Di Franco,
• Patrick Fiorenza,
• Raffaella Lo Nigro,
• Fabrizio Roccaforte,
• Cristina Tudisco,
• Guido G. Condorelli,
• Nicolò Piluso,
• Noemi Spartà,
• Stella Lo Verso,
• Corrado Accardi,
• Cristina Tringali,
• Sebastiano Ravesi and
• Filippo Giannazzo

Beilstein J. Nanotechnol. 2013, 4, 234–242, doi:10.3762/bjnano.4.24

• flexible organic solar cells [9][10]. Currently, the most used method of graphene production for basic studies is the mechanical exfoliation of graphite [1], which was the first method to obtain graphene under ambient laboratory conditions. This method yields graphene fragments of excellent crystalline

Pure hydrogen low-temperature plasma exposure of HOPG and graphene: Graphane formation?

• Baran Eren,
• Dorothée Hug,
• Laurent Marot,
• Rémy Pawlak,
• Marcin Kisiel,
• Roland Steiner,
• Dominik M. Zumbühl and
• Ernst Meyer

Beilstein J. Nanotechnol. 2012, 3, 852–859, doi:10.3762/bjnano.3.96

• spectroscopy measurements were prepared by exfoliation of HOPG using a PDMS stamp and transferring them on SiO2 [42]. The number of layers was determined from the 2D peak of the Raman spectra, which was acquired prior to plasma treatment. An intermittent contact-mode AFM experiment was performed by means of a

A facile approach to nanoarchitectured three-dimensional graphene-based Li–Mn–O composite as high-power cathodes for Li-ion batteries

• Wenyu Zhang,
• Yi Zeng,
• Chen Xu,
• Ni Xiao,
• Yiben Gao,
• Lain-Jong Li,
• Xiaodong Chen,
• Huey Hoon Hng and
• Qingyu Yan

Beilstein J. Nanotechnol. 2012, 3, 513–523, doi:10.3762/bjnano.3.59

• .3.59 Abstract We report a facile method to prepare a nanoarchitectured lithium manganate/graphene (LMO/G) hybrid as a positive electrode for Li-ion batteries. The Mn2O3/graphene hybrid is synthesized by exfoliation of graphene sheets and deposition of Mn2O3 in a one-step electrochemical process, which

• . There are also some reports on the preparation of LIB anodes using graphene prepared by chemical vapor deposition [33][34]. However, such application will be limited due to cost and scalability. Electrochemical exfoliation is a newly developed method that can be used to prepare highly conductive

• graphene-based electrode materials, especially for LIB cathodes. In this paper, we report a facile approach to synthesize lithium manganate/graphene (LMO/G) hybrids by combining the exfoliation of graphene sheets with the deposition of Mn2O3 nanowalls in a one-step electrochemical process, followed by

X-ray absorption spectroscopy by full-field X-ray microscopy of a thin graphite flake: Imaging and electronic structure via the carbon K-edge

• Carla Bittencourt,
• Adam P. Hitchock,
• Xiaoxing Ke,
• Gustaaf Van Tendeloo,
• Chris P. Ewels and
• Peter Guttmann

Beilstein J. Nanotechnol. 2012, 3, 345–350, doi:10.3762/bjnano.3.39

• combined with full-field transmission X-ray microscopy can be used to study the electronic structure of graphite flakes consisting of a few graphene layers. The flake was produced by exfoliation using sodium cholate and then isolated by means of density-gradient ultracentrifugation. An image sequence

• image and to study the electronic structure of a free-standing thin graphite flake produced by means of density-gradient ultracentrifugation (DGU) [20]. In the DGU process the bile salt sodium cholate (C24H39O5Na) is used to promote graphite exfoliation, resulting in graphene–surfactant complexes having

• the spectrum recorded on an amorphous carbon film with the sodium cholate, we suggest that this structure arises instead from metal impurities in the graphite used for exfoliation. A careful examination of the spectrum of the folded region (Figure 2) shows the presence of a shoulder at the same photon