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

• the photoemission response of all carbon nanomaterials. A further advantage specific to highly oriented pyrolytic graphite (HOPG) is that it is relatively straightforward to prepare large but extremely pure and uniform samples. As mentioned above, in a metallic system such as graphite, the line shape

Controlling the dispersion of supported polyoxometalate heterogeneous catalysts: impact of hybridization and the role of hydrophilicity–hydrophobicity balance and supramolecularity

• Gijo Raj,
• Colas Swalus,
• Eglantine Arendt,
• Pierre Eloy,
• Michel Devillers and
• Eric M. Gaigneaux

Beilstein J. Nanotechnol. 2014, 5, 1749–1759, doi:10.3762/bjnano.5.185

• ) phosphomolybdic [P2Mo18O62]6− anions deposited on mica (hydrophilic), and highly oriented pyrolytic graphite (HOPG) (hydrophobic) surfaces. Next, the supramolecular organization of the organic–inorganic hybrid materials formed from the association of POM anions and dimethyldioctadecylammonium bromide (DODA) is

• assemblies on the surfaces with the orientation of their long molecular axis (ca. 1.6 nm) depending on the hydrophilic or hydrophobic properties of the substrate. Namely, the long axis is parallel on mica, and perpendicular on HOPG. When hybridized with DODA, the organization of the hybrid material is

• dictated by the interaction of the alkyl side chains of DODA with the substrate surface. On HOPG, the DODA–POM hybrid forms small domains of epitaxially arranged straight nanorod structures with their orientation parallel to each other. Conversely, randomly distributed nanospheres are formed when the

Energy dissipation in multifrequency atomic force microscopy

• Valentina Pukhova,
• Francesco Banfi and
• Gabriele Ferrini

Beilstein J. Nanotechnol. 2014, 5, 494–500, doi:10.3762/bjnano.5.57

• pyrolytic graphite (HOPG) without any external excitation. The experiment is conducted in air, at room temperature (296 K) an a relative humidity of 55%. The temporal trace has been recorded with a digitizing oscilloscope with a vertical resolution of 8-bit, an analog bandwidth of 250 MHz, and a maximum

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

• different BLG stackings, we investigate the topography by non-contact atomic force microscopy (NC-AFM) combined with measuring the local contact potential differences (LCPD) using Kelvin probe force microscopy (KPFM). Experimental Graphene is exfoliated from a HOPG crystal (Momentive Performance Materials

Kelvin probe force microscopy of nanocrystalline TiO₂ photoelectrodes

• Alex Henning,
• Gino Günzburger,
• Res Jöhr,
• Yossi Rosenwaks,
• Biljana Bozic-Weber,
• Catherine E. Housecroft,
• Edwin C. Constable,
• Ernst Meyer and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2013, 4, 418–428, doi:10.3762/bjnano.4.49

• photodetector. To deduce the sample work function and monitor the integrity of the tip, a highly ordered pyrolytic graphite (HOPG) reference sample was measured before and after each measured specimen. The HOPG reference with a known work function of = 4.6 eV [65] was stored inside the glove box. Microscopic

Ni nanocrystals on HOPG(0001): A scanning tunnelling microscope study

• Michael Marz,
• Keisuke Sagisaka and
• Daisuke Fujita

Beilstein J. Nanotechnol. 2013, 4, 406–417, doi:10.3762/bjnano.4.48

• clusters evaporated in UHV on HOPG has been investigated by scanning tunnelling microscopy. The size, the size distribution, and the shape of the clusters have been evaluated for different evaporation conditions and annealing temperatures. The total coverage of the surface strongly depends on the

• weak interaction of the metal with the substrate is favourable [17]. Graphite, in particular highly ordered pyrolytic graphite (HOPG), serves as an excellent substrate due to its low reactivity and large atomically flat surface. Among the transition metals the most commonly used materials for catalytic

• important role for the aforementioned applications. Therefore, in this study we focus on the initial growing process of Ni clusters by evaporating Ni on the HOPG surface in ultrahigh vacuum (UHV). A quantitative characterization of the cluster properties, e.g., size, shape and distribution, for different

Influence of the solvent on the stability of bis(terpyridine) structures on graphite

• Daniela Künzel and
• Axel Groß

Beilstein J. Nanotechnol. 2013, 4, 269–277, doi:10.3762/bjnano.4.29

• hindered by barriers [6][11]. Recently it was shown by scanning tunneling microscopy (STM) experiments that 3,3′-BTP exhibits a variety of adlayer structures at the interface between highly oriented pyrolytic graphite (HOPG) and the liquid as a function of the concentration in solution [6]. The resulting

• the liquid/HOPG interface three closely related linear patterns and one hexagonal two-dimensional pattern were identified, at the gas/HOPG interface only one of the linear patterns and the hexagonal structure were found. The concentration dependence of the different surface structures was rationalized

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

• increasing behaviour with the back-gate bias values in the considered bias range. Compared to the typically ambipolar behaviour observed in back-gated FET devices fabricated in graphene exfoliated from HOPG onto SiO2 (which exhibit hole conduction for negative gate bias and electron conduction for positive

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

• graphite (HOPG) were exposed to a pure hydrogen low-temperature plasma (LTP). Characterizations include various experimental techniques such as photoelectron spectroscopy, Raman spectroscopy and scanning probe microscopy. Our photoemission measurement shows that hydrogen LTP exposed HOPG has a diamond-like

• peak to G peak ratio is over 4, associated with hydrogenation on both sides. A very low defect density was observed in the scanning probe microscopy measurements, which enables a reverse transformation to graphene. Hydrogen-LTP-exposed HOPG possesses a high thermal stability, and therefore, this

• transformation requires annealing at over 1000 °C. Keywords: graphane; HOPG; hydrogenation; plasma; Introduction Being an sp2-hybridized single layer of carbon atoms arranged in a densely packed honeycomb lattice with true atomic thickness (Figure 1a), graphene possesses unusual electronic and mechanical

Dimer/tetramer motifs determine amphiphilic hydrazine fibril structures on graphite

• Loji K. Thomas,
• Nadine Diek,
• Uwe Beginn and
• Michael Reichling

Beilstein J. Nanotechnol. 2012, 3, 658–666, doi:10.3762/bjnano.3.75

• directed to the centre; for example, six such wedge pieces may lead to a hexagonal columnar mesophase. Further stacking of discs in a face-to-face configuration leads to columns [6][12][13]. To evaluate the possibilities of self-assembly of 2CHd-10 and 1CHn-10 molecules on HOPG, we note that their amide

• functionalities can efficiently stabilize structures through intermolecular hydrogen bonds. On the other hand, the alkyl chains are expected to promote self-assembly into extended structures through interchain van der Waals interactions as well as adsorption on HOPG due to their epitaxial match with the C–C bonds

• not a head group but a central part, which is expected and found to have considerable influence on the self-assembly behaviour. We observe that the molecules self-assemble into one-dimensional structures at the solution/HOPG interface, which are distinctly different from those of the “disc-stacking

Probing three-dimensional surface force fields with atomic resolution: Measurement strategies, limitations, and artifact reduction

• Mehmet Z. Baykara,
• Omur E. Dagdeviren,
• Todd C. Schwendemann,
• Harry Mönig,
• Eric I. Altman and
• Udo D. Schwarz

Beilstein J. Nanotechnol. 2012, 3, 637–650, doi:10.3762/bjnano.3.73

• sample surface. Force fields have now been recorded on NiO(001) [10][12][13], MgO/Ag(001) [14], NaCl(001) [15][16], Si(111)-(7×7) [17][18][19], HOPG [20][21], KBr(001) [9][22][23], Cu(111) [24], and CaCO3() [25] surfaces, as well as single molecules of PTCDA [26][27], pentacene [28], CO [29], C60 [30

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

• (HOPG, 1.5 cm × 1.5 cm × 0.3 mm) and platinum wires (0.2 mm in diameter) were used as the working electrodes and counter electrodes, respectively. The electrolyte was prepared by mixing MnSO4, CH3COONa and Li2SO4 with deionized water. The concentrations of Mn2+ were selected to be 0.15, 0.3 and 0.6 M

Structural, electronic and photovoltaic characterization of multiwalled carbon nanotubes grown directly on stainless steel

• Luca Camilli,
• Manuela Scarselli,
• Silvano Del Gobbo,
• Paola Castrucci,
• Eric Gautron and
• Maurizio De Crescenzi

Beilstein J. Nanotechnol. 2012, 3, 360–367, doi:10.3762/bjnano.3.42

• highly oriented pyrolytic graphite (HOPG). Notably, a broadening of the π-plasmon peak in the case of MWCNTs is evident. In addition, a photocurrent was measured when MWCNTs were airbrushed onto a silicon substrate. External quantum efficiency (EQE) and photocurrent values were reported both in planar

• of graphite. In particular, a broadening of the π-plasmon of CNTs is found, which can be ascribed to the presence of several structures that are completely absent in HOPG and probably due to transitions among Van Hove singularities. Here we also show that MWCNTs exhibit an interesting photovoltaic

• degree of the synthesized nanostructures is evidenced in the inset of Figure 3b, in which the reported Fast Fourier Transform of the TEM image consists of two single points located at 0.35 nm from the centre. In Figure 4 we report the carbon core-valence-valence (CVV) Auger features for HOPG and a MWCNT

Drive-amplitude-modulation atomic force microscopy: From vacuum to liquids

• Miriam Jaafar,
• David Martínez-Martín,
• Mariano Cuenca,
• John Melcher,
• Arvind Raman and
• Julio Gómez-Herrero

Beilstein J. Nanotechnol. 2012, 3, 336–344, doi:10.3762/bjnano.3.38

• magnitudes grow monotonically with the tip–sample distance. Figure 7b shows this dependence again with the same tip but this time contaminated after scanning a highly oriented pyrolytic graphite (HOPG) substrate with viruses adsorbed on it. While the dissipation is still monotonic, the frequency shift is not

• . This type of frequency-shift dependence makes scanning the surface impractical with FM. However, this is not an issue for DAM. Figure 7c displays an in-liquid DAM topography in which a bacteriophage [31] adsorbed on a HOPG surface can be seen. Figure 7d shows a height profile along the green line

• . Frequency shift (black) and dissipation (light gray) for a clean tip (a) and after becoming contaminated (b). Note that the flat region of the frequency shift in (b) reflects the saturation of the PLL. (c) DAM topography showing a virus adsorbed on a HOPG substrate. (d) Height profile along the green line

Direct-write polymer nanolithography in ultra-high vacuum

• Woo-Kyung Lee,
• Minchul Yang,
• Arnaldo R. Laracuente,
• William P. King,
• Lloyd J. Whitman and
• Paul E. Sheehan

Beilstein J. Nanotechnol. 2012, 3, 52–56, doi:10.3762/bjnano.3.6

• , as illustrated in Figure 4a. Note that the thickness of our films lies intermediate to values reported previously for PDDT on other substrates. Scifo et al. used STM to measure the thickness in UHV of a PDDT film drop cast on highly oriented pyrolytic graphite (HOPG) and reported a film thickness of

STM study on the self-assembly of oligothiophene-based organic semiconductors

• Elena Mena-Osteritz,
• Marta Urdanpilleta,
• Erwaa El-Hosseiny,
• Berndt Koslowski,
• Paul Ziemann and
• Peter Bäuerle

Beilstein J. Nanotechnol. 2011, 2, 802–808, doi:10.3762/bjnano.2.88

• using scanning tunneling microscopy (STM) at the liquid–solid interface under ambient conditions. The characteristics of the 2-D crystals formed on the (0001) plane of highly ordered pyrolitic graphite (HOPG) strongly depend on the length of the π-conjugated oligomer backbone, on the functional groups

• weak intermolecular van der Waals forces and molecule–substrate interactions, as well as intermolecular hydrogen bonding in the case of functionalized oligothiophenes [15][16][17]. The typical flat metallic substrates (HOPG, Au(111), Ag(111), etc.) employed in STM differ from the ITO electrodes used in

• the devices, which are usually rendered flat by an organic hole-transporting layer. Despite the differences, a good approach to elucidate the bulk properties of the active molecules is to probe their intermolecular interactions on nonreactive substrates, such as HOPG, by means of STM. In this paper

STM visualisation of counterions and the effect of charges on self-assembled monolayers of macrocycles

• Tibor Kudernac,
• Natalia Shabelina,
• Wael Mamdouh,
• Sigurd Höger and
• Steven De Feyter

Beilstein J. Nanotechnol. 2011, 2, 674–680, doi:10.3762/bjnano.2.72

• attention so far, mostly because they could not be visualised by STM [11][12][13][14]. Here, we report on self-assembly of a neutral shape-persistent macrocycle 1 and its charged analogue 2 (Figure 1) at the interface between an organic solvent and highly oriented pyrolytic graphite (HOPG). We demonstrate

• freshly cleaved HOPG surface. Figure 2a shows three different domains of 1, separated by domain boundaries. Regularly spaced bright columns are tilted 30° away from the main crystallographic directions of the underlying graphite and comprise the aromatic parts of the molecule. High resolution images

• that one out of three chains is desorbed (dissolved in TCB). Figure 2c shows a tentative packing model for self-assembly of 1 at the TCB/HOPG interface. With respect to previously investigated shape-persistent macrocycles with similar shapes and sizes [15][16][17], domains formed by 1 show high

Septipyridines as conformationally controlled substitutes for inaccessible bis(terpyridine)-derived oligopyridines in two-dimensional self-assembly

• Daniel Caterbow,
• Daniela Künzel,
• Michael G. Mavros,
• Axel Groß,
• Katharina Landfester and
• Ulrich Ziener

Beilstein J. Nanotechnol. 2011, 2, 405–415, doi:10.3762/bjnano.2.46

• , Ackermannweg 10, D-55128 Mainz, Germany 10.3762/bjnano.2.46 Abstract The position of the peripheral nitrogen atoms in bis(terpyridine)-derived oligopyridines (BTPs) has a strong impact on their self-assembly behavior at the liquid/HOPG (highly oriented pyrolytic graphite) interface. The intermolecular

• (terpyridine)-derived oligopyridines (BTPs), are large polyaromatic molecules with C2v symmetry, are well established compounds, and are known to self-assemble [5] at the liquid/HOPG [6][7][8][9][10][11] and at the gas/solid interface [12][13][14]. Self-assembly also occurs under electrochemical conditions [15

• its self-assembly properties at the liquid/HOPG interface. Additionally, a new class of oligopyridines comprising seven pyridine units and one phenyl substituent, the so-called phenylseptipyridines (PhSpPy), is presented. The PhSpPys display the same symmetry, shape, and size as the BTPs and can be

Intermolecular vs molecule–substrate interactions: A combined STM and theoretical study of supramolecular phases on graphene/Ru(0001)

• Michael Roos,
• Benedikt Uhl,
• Daniela Künzel,
• Harry E. Hoster,
• Axel Groß and
• R. Jürgen Behm

Beilstein J. Nanotechnol. 2011, 2, 365–373, doi:10.3762/bjnano.2.42

• interaction; large organic molecules; substrate–adsorbate interaction; supramolecular structure; Introduction It is well known that the formation of highly ordered 2D supramolecular networks on smooth surfaces, such as metal substrates or highly oriented pyrolytic graphite (HOPG), is mainly governed by the

• interactions in the range of 130 meV [26]. In the following, we first present STM observations of the adlayer phases formed by these molecules on graphene/Ru(0001) and compare these with adlayers of the corresponding phases on HOPG as a model for a low corrugation substrate. Subsequently, we present results of

• 3,3'-BTP-molecules on HOPG led to networks with similar types of building blocks as formed on graphene/Ru(0001). At both the solid–liquid and the solid–gas interface we predominantly found a chiral 2D hexagonal network consisting of ring-like units of six molecules (Figure 3d) [24]. At the solid–gas

Recrystallization of tubules from natural lotus (Nelumbo nucifera) wax on a Au(111) surface

• Sujit Kumar Dora and
• Klaus Wandelt

Beilstein J. Nanotechnol. 2011, 2, 261–267, doi:10.3762/bjnano.2.30

• ) surface. A comparison of the tubule growth on Au(111) to that on HOPG is discussed. Although the tubule formation on both Au(111) and HOPG takes place on an intermediate wax film which should mask the substrate properties, the tubule orientations differ. In contrast to a vertical tubule orientation on

• HOPG, the tubules lie flat on Au(111). Taking into account the physical properties of HOPG and Au(111), we put forward a hypothesis which can explain the different tubule orientations on both substrates. Keywords: AFM; Au(111); lotus wax; Introduction Natural nonacosan-10-ol waxes derived from plant

• (XRD) and electron diffraction (ED) techniques [10][11]. Koch and co-workers applied tapping mode AFM to study the continuous growth of nonacosan-10-ol tubules on HOPG [8]. By applying a 10 µL droplet of natural wax molecules derived from nasturtium (Tropaeolum majus) and lotus (Nelumbo nucifera

Manipulation of gold colloidal nanoparticles with atomic force microscopy in dynamic mode: influence of particle–substrate chemistry and morphology, and of operating conditions

• Samer Darwich,
• Karine Mougin,
• Akshata Rao,
• Enrico Gnecco,
• Shrisudersan Jayaraman and
• Hamidou Haidara

Beilstein J. Nanotechnol. 2011, 2, 85–98, doi:10.3762/bjnano.2.10

• effect, as-synthesized Au NPs were also manipulated on different substrates such as nanopatterned silicon wafers presenting grooves, and steeped HOPG surfaces [40]. Manipulation experiments were repeated to check the influence of the deep grooves (either on Si wafers or on HOPG) on the trajectory of the

• islands on HOPG, scan size: 1.5 µm; (c) Au nanotriangles on silicon wafer. Middle triangles have been intentionally colored in to illustrate the trajectory of the Au nanoparticles during manipulation, scan size: 5 µm. (a) Average power dissipation accompanying the onset of motion of as-synthesized and

Switching adhesion forces by crossing the metal–insulator transition in Magnéli-type vanadium oxide crystals

• Bert Stegemann,
• Matthias Klemm,
• Siegfried Horn and
• Mathias Woydt

Beilstein J. Nanotechnol. 2011, 2, 59–65, doi:10.3762/bjnano.2.8

• materials revealed consistent results: Comparative adhesion force measurements of the (0001) basal planes and the (10−10) prism planes of highly oriented pyrolytic graphite (HOPG) and MoS2 also showed that the metallic state lowers the adhesion at the nanoscale [36]. Experimental Vanadium oxide crystal

Tip-sample interactions on graphite studied using the wavelet transform

• Giovanna Malegori and
• Gabriele Ferrini

Beilstein J. Nanotechnol. 2010, 1, 172–181, doi:10.3762/bjnano.1.21

• displaced at constant velocity of approximately 225 nm/s. The sampling time is 240 ns so that the signal string is composed by 4166 sampling points every ms of acquisition time. The CWT analysis is performed off-line. The sample consisted of a freshly cleaved highly oriented pyrolitic graphite (HOPG

• spectroscopy curves on the hard HOPG surface, assuming a negligible indentation and thus equal distances spanned by the cantilever tip and the piezotube. The obtained sensitivity is in the range of 50–200 nm/V, depending on the cantilever type, beam position, and laser light power level. The cantilever has a

A collisional model for AFM manipulation of rigid nanoparticles

• Enrico Gnecco

Beilstein J. Nanotechnol. 2010, 1, 158–162, doi:10.3762/bjnano.1.19

• benchmark would be the flower-shaped Sb islands first manipulated by Ritter et al. on HOPG and MoS2 [9]. Possible discrepancies between theory and experiment concerning the direction of motion and angular speed of the islands could be related to the friction forces between island and substrate and even used