Double layer effects in a model of proton discharge on charged electrodes

• Johannes Wiebe and
• Eckhard Spohr

Beilstein J. Nanotechnol. 2014, 5, 973–982, doi:10.3762/bjnano.5.111

• the most fundamental electrochemical reactions is proton discharge from an aqueous solution to a charged electrode, which is the first step of the hydrogen evolution reaction. This basic electrocatalytic reaction and its dependence on the nature and the surface structure of the electrode, on

Measuring air layer volumes retained by submerged floating-ferns Salvinia and biomimetic superhydrophobic surfaces

• Matthias J. Mayser,
• Holger F. Bohn,
• Meike Reker and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2014, 5, 812–821, doi:10.3762/bjnano.5.93

• be approximated. Table 1 displays the measured surface structure dimensions and parameters for the four investigated Salvinia species needed for this calculation. To estimate the volume occupied by the trichomes, we idealized them as assemblies of truncated cones for the emergence and the hairs. The

Shape-selected nanocrystals for in situ spectro-electrochemistry studies on structurally well defined surfaces under controlled electrolyte transport: A combined in situ ATR-FTIR/online DEMS investigation of CO electrooxidation on Pt

• Sylvain Brimaud,
• Zenonas Jusys and
• R. Jürgen Behm

Beilstein J. Nanotechnol. 2014, 5, 735–746, doi:10.3762/bjnano.5.86

• , IR spectro-electrochemistry [3] was successfully employed to investigate the relations between electrode surface structure and the binding modes of adsorbed species [4][5][6][7][8][9][10], to identify poisoning species and adsorbed intermediates formed during electrocatalytic reactions [2][11][12][13

• hydrogen sorption peaks are convincing indicators for both a well ordered Pt nanocrystal surface structure and the cleanness of the experimental setup and procedures. The hydrogen-region voltammograms obtained for such samples are approximated as weighted sum of the respective features of extended low

• investigated, independently of the Pt nanocrystal surface structure (see Table 2). This allows us to determine the Epztc [27][28][29] for each of the working electrodes prepared from one of the three different batches of nanocrystals (see section ‘Preparation and characterization of the Pt nanocrystals’). The

The role of surface corrugation and tip oscillation in single-molecule manipulation with a non-contact atomic force microscope

• Christian Wagner,
• Norman Fournier,
• F. Stefan Tautz and
• Ruslan Temirov

Beilstein J. Nanotechnol. 2014, 5, 202–209, doi:10.3762/bjnano.5.22

• corresponding to the Au(111) surface structure and a corrugation amplitude Vc(z) ≈ (2.6/z)7 that decays rapidly with increasing distance to the surface. Since here we aim at a qualitative description, the precise functional form of the corrugation potential is not relevant and we also can assume that the

Constant-distance mode SECM as a tool to visualize local electrocatalytic activity of oxygen reduction catalysts

• Michaela Nebel,
• Thomas Erichsen and
• Wolfgang Schuhmann

Beilstein J. Nanotechnol. 2014, 5, 141–151, doi:10.3762/bjnano.5.14

• retraction of the tip with simultaneous data acquisition at each pre-defined tip-to-sample separation is performed. Diffusion profiles exceed far the geometric dimensions of the investigated surface structure. The collection of electrochemical data in z-direction requires therefore comparable large distances

Design criteria for stable Pt/C fuel cell catalysts

• Josef C. Meier,
• Carolina Galeano,
• Ioannis Katsounaros,
• Jonathon Witte,
• Hans J. Bongard,
• Angel A. Topalov,
• Claudio Baldizzone,
• Stefano Mezzavilla,
• Ferdi Schüth and
• Karl J. J. Mayrhofer

Beilstein J. Nanotechnol. 2014, 5, 44–67, doi:10.3762/bjnano.5.5

Exploring the retention properties of CaF₂ nanoparticles as possible additives for dental care application with tapping-mode atomic force microscope in liquid

• Matthias Wasem,
• Joachim Köser,
• Sylvia Hess,
• Enrico Gnecco and
• Ernst Meyer

Beilstein J. Nanotechnol. 2014, 5, 36–43, doi:10.3762/bjnano.5.4

• and on tooth enamel in liquid. From the phase-lag of the forced cantilever oscillation the local energy dissipation at the detachment point of the nanoparticle was determined. This enabled us to compare different as-synthesized CaF2 nanoparticles that vary in shape, size and surface structure. CaF2

• spherical surface structure of these particles. Compared to the smaller particles (A) and (B), which have plane and smooth faceting, the high surface roughness leads to a smaller contact area on the substrate. The fact that the lowest energy dissipation was observed for specimen (C) is consistent with the

• . Remarkably, the energy dissipation for each of the particles is found to be much higher on enamel than on mica. For particles (C) the power dissipation is found to be up to 10-times higher on tooth enamel. The specimens (A) and (B), which are similar in size and surface structure show an increase in the

Surface assembly and nanofabrication of 1,1,1-tris(mercaptomethyl)heptadecane on Au(111) studied with time-lapse atomic force microscopy

• Tian Tian,
• Burapol Singhana,
• Lauren E. Englade-Franklin,
• Xianglin Zhai,
• T. Randall Lee and
• Jayne C. Garno

Beilstein J. Nanotechnol. 2014, 5, 26–35, doi:10.3762/bjnano.5.3

• liquid environment, studies of surface reactions can be accomplished using time-lapse atomic force microscopy (AFM). To understand more completely the surface structure and self-assembly process for multidentate thiols, we chose a tridentate molecule, 1,1,1-tris(mercaptomethyl)heptadecane (TMMH) for in

Some reflections on the understanding of the oxygen reduction reaction at Pt(111)

• Ana M. Gómez-Marín,
• Ruben Rizo and
• Juan M. Feliu

Beilstein J. Nanotechnol. 2013, 4, 956–967, doi:10.3762/bjnano.4.108

• step (RDS) on Pt, which would be an essential step toward an optimized design of new ORR electrocatalysts [15]. Results and Discussion Ideally, the surface structure and composition of a catalyst remain unchanged over the whole potential range in which a probe reaction is scrutinized. However, as can

• peak contribution at high potentials increases at higher Eup (Figure 8). As the upper potential limit is not too high, this observation is compatible with the preservation of the Pt(111) surface structure. It should be remarked that the product, PtO, could be formed through a chemical process that

• general points of agreement and disagreement highlighted. It has been shown that despite the ORR shows a dependence on the surface structure, experimental and theoretical results disagree in acidic media while they seem to agree in alkaline solutions. The reasons behind this fact are not clearly known

AFM as an analysis tool for high-capacity sulfur cathodes for Li–S batteries

• Renate Hiesgen,
• Seniz Sörgel,
• Rémi Costa,
• Linus Carlé,
• Ines Galm,
• Natalia Cañas,
• Brigitta Pascucci and
• K. Andreas Friedrich

Beilstein J. Nanotechnol. 2013, 4, 611–624, doi:10.3762/bjnano.4.68

• was found with the magnitude of current values measured by AFM. High current values correspond to highly conductive, most likely carbon-rich, areas that are not sufficient for a good battery. The surface structure changed differently for the studied samples, e.g., the sample with PVDF lost only the

Mapping of plasmonic resonances in nanotriangles

• Simon Dickreuter,
• Julia Gleixner,
• Andreas Kolloch,
• Johannes Boneberg,
• Elke Scheer and
• Paul Leiderer

Beilstein J. Nanotechnol. 2013, 4, 588–602, doi:10.3762/bjnano.4.66

• near-field enhancement have not been altered. Additionally, the surface texture of the triangles in the modified region has changed. While the unmodified regions have a roughness comparable to the deposited gold film, the surface structure in the regions, which show a change due to the laser radiation

Digging gold: keV He⁺ ion interaction with Au

• Vasilisa Veligura,
• Gregor Hlawacek,
• Robin P. Berkelaar,
• Raoul van Gastel,
• Harold J. W. Zandvliet and
• Bene Poelsema

Beilstein J. Nanotechnol. 2013, 4, 453–460, doi:10.3762/bjnano.4.53

• in the imaged area. This is a common problem in conventional non-UHV HIM and scanning electron microscopes (SEM) [15][17][19]. The absence of the carbon layer that is normally present, allows us to obtain detailed information on the surface structure and how it evolves during repeated imaging of the

Porous polymer coatings as substrates for the formation of high-fidelity micropatterns by quill-like pens

• Michael Hirtz,
• Marcus Lyon,
• Wenqian Feng,
• Andrea E. Holmes,
• Harald Fuchs and
• Pavel A. Levkin

Beilstein J. Nanotechnol. 2013, 4, 377–384, doi:10.3762/bjnano.4.44

• prevented the SPT from touching the surface in some places) and because of inhomogeneous wetting behaviour due to the fibrous structure of the paper, as seen by sometimes brighter and sometimes fainter features. Overall the rough surface structure prevents clear homogenous patterning of phloxine B, and

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

• adsorbed ordered surface structure in the presence of the solvent and another trajectory run for the BTP molecules in solution, as illustrated in Figure 2 using the same unit cell, were performed. Ideally, no interaction between a BTP molecule and the surface or another BTP molecule should occur in the

Catalytic activity of nanostructured Au: Scale effects versus bimetallic/bifunctional effects in low-temperature CO oxidation on nanoporous Au

• Lu-Cun Wang,
• Yi Zhong,
• Haijun Jin,
• Daniel Widmann,
• Jörg Weissmüller and
• R. Jürgen Behm

Beilstein J. Nanotechnol. 2013, 4, 111–128, doi:10.3762/bjnano.4.13

• characterized again. A representative SEM image taken from the NPG(Ag)-4 sample after reaction showed a distinct coarsening of the porous surface structure (see Figure 1b). This is confirmed also by the XRD patterns (see Figure 2a), where exposure to the reaction gas mixture caused a considerable sharpening of

Growth behaviour and mechanical properties of PLL/HA multilayer films studied by AFM

• Cagri Üzüm,
• Johannes Hellwig,
• Narayanan Madaboosi,
• Dmitry Volodkin and
• Regine von Klitzing

Beilstein J. Nanotechnol. 2012, 3, 778–788, doi:10.3762/bjnano.3.87

• the film bilayer number n. This result contradicts the results of Richert et al. [4], who reported a decrease in E from 90 kPa for n = 20 to 40 kPa for n = 60. The authors suggested a possibility of film softening due to greater hydration of the upper layers rather than due to a change in surface

• structure, heterogeneity or roughness. The film thickness range reported in the mentioned study [4] is nearly threefold larger than ours, which may result in significant structural differences. Despite some fluctuations, E in our study ranges between 10 and 40 kPa, being in the same order of magnitude with

Macromolecular shape and interactions in layer-by-layer assemblies within cylindrical nanopores

• Thomas D. Lazzara,
• K. H. Aaron Lau,
• Wolfgang Knoll,
• Andreas Janshoff and
• Claudia Steinem

Beilstein J. Nanotechnol. 2012, 3, 475–484, doi:10.3762/bjnano.3.54

• adsorbing components, to generate multilayered structures. Different functional materials can be stepwise incorporated by LbL, within a single surface structure by electrostatic self-assembly [3][4], molecular-recognition pairs [5][6][7], or covalent-bond formation [8]. Homogeneous and heterogeneous layered

Repulsive bimodal atomic force microscopy on polymers

• Alexander M. Gigler,
• Christian Dietz,
• Maximilian Baumann,
• Nicolás F. Martinez,
• Ricardo García and
• Robert W. Stark

Beilstein J. Nanotechnol. 2012, 3, 456–463, doi:10.3762/bjnano.3.52

• between both types of polymers, which differ considerably in stiffness. However, if the amplitude of the additional oscillation becomes too large, the bimodal technique may become destructive to the surface structure, counteracting a good phase contrast. Figure 5 shows an SB sample measured in the

The morphology of silver nanoparticles prepared by enzyme-induced reduction

• Henrik Schneidewind,
• Thomas Schüler,
• Katharina K. Strelau,
• Karina Weber,
• Dana Cialla,
• Marco Diegel,
• Roland Mattheis,
• Andreas Berger,
• Robert Möller and
• Jürgen Popp

Beilstein J. Nanotechnol. 2012, 3, 404–414, doi:10.3762/bjnano.3.47

• silver nanoparticles consist of single-crystalline plates of pure silver. The surface-enhanced Raman spectroscopic (SERS) activity of the EGNP structures is promising due to the exceptionally rough surface structure of the silver nanoparticles. SERS measurements of the vitamin riboflavin incubated on the

Modeling noncontact atomic force microscopy resolution on corrugated surfaces

• Kristen M. Burson,
• Mahito Yamamoto and
• William G. Cullen

Beilstein J. Nanotechnol. 2012, 3, 230–237, doi:10.3762/bjnano.3.26

• -supported graphene, due to apparent differences in surface structure between the carefully UHV-prepared quartz in that study and the SiO2 substrates used for graphene. As with the barium silicate measurements, for high-resolution measurements of SiO2, special conditions were necessary [18]. In order to

Noncontact atomic force microscopy study of the spinel MgAl₂O₄(111) surface

• Morten K. Rasmussen,
• Kristoffer Meinander,
• Flemming Besenbacher and
• Jeppe V. Lauritsen

Beilstein J. Nanotechnol. 2012, 3, 192–197, doi:10.3762/bjnano.3.21

• and in particular a direct atomic-scale characterization of the surface structure is largely missing for a range of important metal oxides. In recent years, the noncontact atomic force microscope (NC-AFM) has been established as a unique tool to provide atomic-resolution real-space images of all types

• atomic scale of this important group of materials. In this work, a new surface-structure model of the MgAl2O4(111) surface, based on experimental NC-AFM data obtained on this surface, prepared under well-controlled ultrahigh vacuum (UHV) conditions, is presented. MgAl2O4 is a prototypical material with

• available concerning the surface structure. According to a theoretical study by Harding et al., and other theoretical studies [15][16][17], the oxygen-terminated MgAl2O4(111) is evaluated to be in its lowest energy state with 42% of the oxygen atoms removed from the oxygen crystal plane to fulfill the

Quantitative multichannel NC-AFM data analysis of graphene growth on SiC(0001)

• Christian Held,
• Thomas Seyller and
• Roland Bennewitz

Beilstein J. Nanotechnol. 2012, 3, 179–185, doi:10.3762/bjnano.3.19

• , the surface structure remains the same upon oxide removal (Figure 2b). The width of the large terraces is slightly reduced and a number of smaller and larger pits and islands with lateral extensions of only a few nanometers up to hundreds of nanometers are found. Except for a few remaining rough spots

• change in contact potential (Figure 3b). The underlying surface structure is analyzed in Figure 3c and represented in an atomic ball-and-stick scheme in Figure 3d. The left step is a substrate step of three bilayers of SiC with a height of 0.75 nm, indicated by the three blue blocks representing the

• graphene spots are regularly observed to grow over a SiC bilayer substrate step. No change in contact potential is observed without a corresponding change in step height. The much simpler surface structure of samples prepared in an argon atmosphere is demonstrated in Figure 4b. The identification of

qPlus magnetic force microscopy in frequency-modulation mode with millihertz resolution

• Maximilian Schneiderbauer,
• Daniel Wastl and
• Franz J. Giessibl

Beilstein J. Nanotechnol. 2012, 3, 174–178, doi:10.3762/bjnano.3.18

• -polarized tip and the spin-dependent local density of states of the sample (Figure 1b). STM is unable to probe insulating surfaces but AFM can be used: The antiferromagnetic surface structure of NiO (001) was imaged by Magnetic Exchange Force Microscopy (MExFM) [5]. In MExFM the magnetic exchange force

• systems [19] and low-temperature systems [12][20][21]. For this sensor setup, see inset in Figure 3a, we found an amplitude of 25 nm in both paths and a lift height of 35 nm to be a good choice. The first-pass topography data set shows the expected surface structure (Figure 3a). The scan speed again had

Effect of the tip state during qPlus noncontact atomic force microscopy of Si(100) at 5 K: Probing the probe

• Adam Sweetman,
• Sam Jarvis,
• Rosanna Danza and
• Philip Moriarty

Beilstein J. Nanotechnol. 2012, 3, 25–32, doi:10.3762/bjnano.3.3

• -prepared tips and surfaces, however, a wide range of imaging interactions are often observed, resulting in varying apparent topographic structures [5][6][7]. In cases where there has been debate as to the surface structure (for example TiO2 [8] and Si(100) [9]) different imaging mechanisms can result in

Approaches to nanostructure control and functionalizations of polymer@silica hybrid nanograss generated by biomimetic silica mineralization on a self-assembled polyamine layer

• Jian-Jun Yuan and
• Ren-Hua Jin

Beilstein J. Nanotechnol. 2011, 2, 760–773, doi:10.3762/bjnano.2.84

• -driven self-assembly of preformed PSS-wrapped CNTs. In our case, the presence of IPA in the media was assumed to play an essential role in the formation of the pyramidlike structure since the use of neat water did not give this kind of surface structure. However, the detailed formation mechanism is still

• (Figure 2f). There was no aggregation of nanoribbon heads on the film surface. TEM images indicate that this nanograss is composed of well-defined nanoribbons with a typical width of about 50 nm and a very smooth surface structure (Figure 3c and d). Cross-sectional observation showed a nanograss thickness

• silica source. However, the TEM study illustrates the obvious difference in the surface structure of the ribbon film. The ribbons from TMOS source show a particulatelike and rough surface (Figure 3e and 3f), whereas the use of MS51 as the source led to ribbons with a very smooth surface (Figure 3d). This