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

Many-body effects in semiconducting single-wall silicon nanotubes

• Wei Wei and
• Timo Jacob

Beilstein J. Nanotechnol. 2014, 5, 19–25, doi:10.3762/bjnano.5.2

• correlation between excited electrons and holes in real space. Figure 5 shows the resulting three-dimensional electron probability distribution |ψ(re;rh)|2 of the bound excitons of selected SiNTs. As shown in Figure 5a, the bound exciton of (4,4) SiNT has a relatively small distribution radius featured by a

• empty bands and a Lorentzian broadening of 0.05 eV are used. Electron probability distribution |ψ(re;rh)|2 for finding the electrons re with the hole position rh (black dot) fixed slightly above a Si atom for the bound excitonic state of silicon nanotubes (4,4) (a); (6,6) (b) and (10,0) (c). One

• -dimensional electron probability distribution |Ψ(re;rh)|2 in real space of the first excitonic state (the first absorption peak) of silicon nanotubes (4,4) (a), (6,6) (b) and (10,0) (c). This one-dimensional distribution is plotted along the tube axis (z) with the hole position rh fixed at zero; the other

Preparation of NiS/ZnIn₂S₄ as a superior photocatalyst for hydrogen evolution under visible light irradiation

• Liang Wei,
• Yongjuan Chen,
• Jialin Zhao and
• Zhaohui Li

Beilstein J. Nanotechnol. 2013, 4, 949–955, doi:10.3762/bjnano.4.107

• reactions. Due to their negligible overpotential for hydrogen evolution and excellent kenetics for driving the hydrogen evolution reaction, noble metals like Pt [24][25][26], Rh [27], Au [28][29] and their oxides like RuO2 [30], RhxCr2−xO3 [31][32][33] are generally used as the co-catalysts for

Cyclic photochemical re-growth of gold nanoparticles: Overcoming the mask-erosion limit during reactive ion etching on the nanoscale

• Burcin Özdemir,
• Axel Seidenstücker,
• Alfred Plettl and
• Paul Ziemann

Beilstein J. Nanotechnol. 2013, 4, 886–894, doi:10.3762/bjnano.4.100

• performed in a glove box at very low humidity (<5% RH). The sealed desiccator (0.2 mbar) was placed in an oven at 110 °C for 4 h for the self-assembly of OTMS. Finally, the substrates were rinsed with acetone and dried with nitrogen. Photochemical deposition of gold: For the selective photochemical

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

• purposes are Ag, Pt, Pd, Cu, Rh and Ni [3]. Nickel clusters have recently received a lot of attention besides their catalytic properties [2][3][4] for the use as templates for the growth of small graphene islands [18]. The control of the size and the shape as well as the particle distribution play an

Selective surface modification of lithographic silicon oxide nanostructures by organofunctional silanes

• Thomas Baumgärtel,
• Christian von Borczyskowski and
• Harald Graaf

Beilstein J. Nanotechnol. 2013, 4, 218–226, doi:10.3762/bjnano.4.22

• electrically contacted to a voltage source by conductive ink. The oxide structures were generated in contact mode operation with a voltage in the range of −8 to −11 V applied between tip and substrate at a relative humidity (RH) of around 65% and a writing velocity of about 1 µm/s. To control the humidity of

Effect of normal load and roughness on the nanoscale friction coefficient in the elastic and plastic contact regime

• Aditya Kumar,
• Thorsten Staedler and
• Xin Jiang

Beilstein J. Nanotechnol. 2013, 4, 66–71, doi:10.3762/bjnano.4.7

• characterization: The mechanical and tribological sample characterization was carried out by a transducer-based scanning nanoindenter (TriboIndenter, Hysitron Inc.) in a laboratory environment (RT and 50% RH). The mechanical properties of the samples were evaluated with a Berkovich diamond tip following the

Characterization and properties of micro- and nanowires of controlled size, composition, and geometry fabricated by electrodeposition and ion-track technology

• Maria Eugenia Toimil-Molares

Beilstein J. Nanotechnol. 2012, 3, 860–883, doi:10.3762/bjnano.3.97

• electrode arrangement by using a Pt rod as anode was reported by Rauber et al. [55]. Contrary to copper and gold, the crystallinity of nanowires of metals with high melting temperatures, such as Pt and Rh, is difficult to control through the deposition parameters (i.e., to control nucleation and surface

Pinch-off mechanism in double-lateral-gate junctionless transistors fabricated by scanning probe microscope based lithography

• Farhad Larki,
• Arash Dehzangi,
• Alam Abedini,
• Ahmad Makarimi Abdullah,
• Elias Saion,
• Sabar D. Hutagalung,
• Mohd N. Hamidon and
• Jumiah Hassan

Beilstein J. Nanotechnol. 2012, 3, 817–823, doi:10.3762/bjnano.3.91

• contact mode employing a Cr/Pt coated tip with a force constant of 0.2 N m−1 and a resonance frequency of 13 kHz. The room humidity (RH) was controllable from 50% to 80% with an accuracy of 1%. At a constant RH and contact force, the AFM tip voltage and writing speed (exposing time) are important factors

• to determine the size of the oxide patterns. Figure 1a and Figure 1b show that oxide protrusions were produced on the hydrogen passivated silicon surface with various voltages from 6 to 9 V at a constant writing speed of 1 µm/s, at 65% RH, and in contact mode. The effect of different writing speeds

• at constant voltage of 9 V is shown in Figure 1c. The optimized oxidation parameters correspond to a voltage of 9 V on the tip, with a speed of 1 µm/s, with the RH in the range of 65–67%. After patterning of the oxide mask, the first step of wet chemical etching was carried out with a solution of 30

Effect of spherical Au nanoparticles on nanofriction and wear reduction in dry and liquid environments

• Dave Maharaj and
• Bharat Bhushan

Beilstein J. Nanotechnol. 2012, 3, 759–772, doi:10.3762/bjnano.3.85

• ) have also been manipulated in water and ethanol with an AFM operated in intermittent-contact mode [34]. In addition to the contact-area dependence of friction observed in these studies, the relative-humidity (RH) dependence of friction was investigated by Mougin et al. [32] and Palacio and Bhushan [31

• lower at lower RH (10%) compared to higher RH (40%) for both Au and SiO2 particles. Both studies were performed on silicon substrates. This would suggest that some adsorbed moisture between the nanoparticle and substrate is necessary for enhanced lubricity. Manipulation studies of nanoparticles

Friction and durability of virgin and damaged skin with and without skin cream treatment using atomic force microscopy

• Bharat Bhushan,
• Si Chen and
• Shirong Ge

Beilstein J. Nanotechnol. 2012, 3, 731–746, doi:10.3762/bjnano.3.83

• scraped off with scissors, and the hair was shaved carefully with a razor. Then, the skin was gently cleaned with a 10% (v/v) soap solution (liquid hand soap, Kroger Co., Cincinnati, OH), rinsed with tap water for 30 s, and leveled on the table to dry under ambient conditions (22 °C, RH 25–35%). After

The memory effect of nanoscale memristors investigated by conducting scanning probe microscopy methods

• César Moreno,
• Carmen Munuera,
• Xavier Obradors and
• Carmen Ocal

Beilstein J. Nanotechnol. 2012, 3, 722–730, doi:10.3762/bjnano.3.82

• force microscopy Scanning force microscopy (SFM) measurements were performed using a commercial head and software from Nanotec [14] under a N2 environment (RH < 5%) to diminish any possible humidity effects. For the conductivity measurements (C-SFM), we used either commercial conductive B-doped diamond

FTIR nanobiosensors for Escherichia coli detection

• Stefania Mura,
• Gianfranco Greppi,
• Maria Laura Marongiu,
• Pier Paolo Roggero,
• Sandeep P. Ravindranath,
• Lisa J. Mauer,
• Nicoletta Schibeci,
• Francesco Perria,
• Massimo Piccinini,
• Plinio Innocenzi and
• Joseph Irudayaraj

Beilstein J. Nanotechnol. 2012, 3, 485–492, doi:10.3762/bjnano.3.55

• ) oriented (one side polished and one side etched) were obtained from Jocam (Italy). Film preparation Titania (TiO2) thin films were prepared by dipping silicon wafers in a solution composed of TiCl4/Pluronic F127/H2O/EtOH (1:0.005:10:40) under controlled conditions of temperature and RH (relative humidity

• ). Films were deposited with a dip coater, aged at room temperature (RH 50% for 24 h) and, to increase the inorganic polycondensation and stabilize the mesophase, the films were submitted to different firing steps at 60, 120 and 200 °C for 24 h at each temperature in an oven at a heating rate of 10 °C·min

Conducting composite materials from the biopolymer kappa-carrageenan and carbon nanotubes

• Ali Aldalbahi,
• Jin Chu,
• Peter Feng and
• Marc in het Panhuis

Beilstein J. Nanotechnol. 2012, 3, 415–427, doi:10.3762/bjnano.3.48

• stable for a period of at least 10 days. In addition, these dispersions appeared to be stable after two months of storage under controlled conditions (21 °C, RH = 45%, Figure 4b). The flow curves of KC–CNT dispersions and sonicated KC solutions are shown in Figure 4b and Figure 4c. It is clear that the

• = 55 mm), which were then dried under controlled conditions (35 °C, relative humidity, RH = 45%) in a temperature–humidity chamber (Thermoline Scientific) for 24 h. The resulting films were peeled off the substrate to yield uniform free-standing films (Figure 9b). Preparation of films by vacuum

• conditions (21 °C, RH = 45%) for 24 h. The films were then peeled off from the filtration membrane (Figure 9c). Characterization UV–visible–NIR absorption spectra of KC solutions and KC–CNTs dispersions were obtained with a UV–vis–NIR spectrophotometer (Cary 500) by using a quartz cuvette (path length = 5 mm

Functionalised zinc oxide nanowire gas sensors: Enhanced NO₂ gas sensor response by chemical modification of nanowire surfaces

• Eric R. Waclawik,
• Jin Chang,
• Andrea Ponzoni,
• Isabella Concina,
• Dario Zappa,
• Elisabetta Comini,
• Nunzio Motta,
• Guido Faglia and
• Giorgio Sberveglieri

Beilstein J. Nanotechnol. 2012, 3, 368–377, doi:10.3762/bjnano.3.43

• V bias to the films and measuring the through current with a picoammeter. Gas-sensing measurements were carried out by the flow-through method, working at a constant flow of 300 sccm in a thermostatic sealed chamber at room pressure under constant-humidity conditions (RH = 30% @ 20 °C). Controlled

Parallel- and serial-contact electrochemical metallization of monolayer nanopatterns: A versatile synthetic tool en route to bottom-up assembly of electric nanocircuits

• Jonathan Berson,
• Assaf Zeira,
• Rivka Maoz and
• Jacob Sagiv

Beilstein J. Nanotechnol. 2012, 3, 134–143, doi:10.3762/bjnano.3.14

• specimens are pressed together with a force of about 100 N in a water-saturated atmosphere (RH 100%). Deposited silver dots were removed (Figure 2) by immersion in HNO3/H2O (20% v/v) for ~3 h followed by rinsing with pure water. All monolayer nanopatterning (CNL) and serial metallization (CET) operations

• were carried out in the contact mode (in a regime of minimal repulsive force), under controlled humidity at 55–65% RH. A SOLVER P47 SFM system (NT-MDT) was used in the fabrication of the OTSeo@OTS nanopatterns in Figure 2 and Figure 3. The patterns were written with doped-silicon contact probes (CSC-38

Octadecyltrichlorosilane (OTS)-coated ionic liquid drops: Micro-reactors for homogenous catalytic reactions at designated interfaces

• Xiaoning Zhang and
• Yuguang Cai

Beilstein J. Nanotechnol. 2012, 3, 33–39, doi:10.3762/bjnano.3.4

• . Next, the OTS-coated samples were rinsed in toluene and annealed in a sealed vial at 40 °C, 100% relative humidity (RH) for 12 h. Subsequently, the samples were incubated in a 5 mM OTS toluene solution again. The stabilization (rinsing-annealing-OTS solution incubating) process was repeated for three

• times in order to remove the pinholes inside the OTS film [17][19][20][21]. The final OTS film was an ultra-flat, pinhole-free, featureless film. The OTSpd patterns were fabricated by the scanning probe deep oxidation lithography. In a 100% RH environment (at 25 °C), a Pt–Ti coated conducting AFM tip

Size-dependent phase diagrams of metallic alloys: A Monte Carlo simulation study on order–disorder transitions in Pt–Rh nanoparticles

• Johan Pohl,
• Christian Stahl and
• Karsten Albe

Beilstein J. Nanotechnol. 2012, 3, 1–11, doi:10.3762/bjnano.3.1

• Johan Pohl Christian Stahl Karsten Albe Institut für Materialwissenschaft, Technische Universität Darmstadt, Petersenstr. 32, D-64287 Darmstadt, Germany 10.3762/bjnano.3.1 Abstract Nanoparticles of Pt–Rh were studied by means of lattice-based Monte Carlo simulations with respect to the stability

• simulation; nanoparticles; nanothermodynamics; phase diagram; Pt-Rh; thermodynamics; Introduction Pt–Rh is an important alloy due to its catalytic activity in different reactions. In the past it was assumed that Pt–Rh is immiscible at low temperatures [1][2], but theoretical studies revealed that Pt–Rh

• were studied by means of lattice Monte Carlo simulations [25]. However, as far as we know, a complete size-dependent phase diagram of an ordering nanoalloy has not yet been studied. It is our intention to examine such a size-dependent phase diagram by using the model system of Pt–Rh particles and

Influence of water on the properties of an Au/Mpy/Pd metal/molecule/metal junction

• Jan Kučera and
• Axel Groß

Beilstein J. Nanotechnol. 2011, 2, 384–393, doi:10.3762/bjnano.2.44

• -dicyanobenzene [4] molecules covered by monolayers of Pd [1], Pt [5], or Rh [6], respectively. In addition, further progress extended the limits of the method towards the preparation of a prototypical Au/Mpy/Pd/Mpy/Pt double decker junction [7]. These achievements can eventually open the way towards the rational

Characterization of protein adsorption onto FePt nanoparticles using dual-focus fluorescence correlation spectroscopy

• Pauline Maffre,
• Karin Nienhaus,
• Faheem Amin,
• Wolfgang J. Parak and
• G. Ulrich Nienhaus

Beilstein J. Nanotechnol. 2011, 2, 374–383, doi:10.3762/bjnano.2.43

• scale of diffusion, τD. Based on the well-known spatial extension of the observation volume, the diffusion coefficient, D, and, by using the Stokes–Einstein equation (see Experimental), the hydrodynamic radius of the fluorescent particle, RH, can be calculated. Consequently, a NP size increase due to

• endowing the NPs with an overall negative charge and excellent colloidal stability [30]. To determine the affinity of the proteins to the NPs as well as the increase in RH, we took 2fFCS data on NPs freely diffusing in solutions, which contained the proteins at concentrations varying over several orders of

• foci and the cross-correlation curve. Note that FCS data and, therefore, also the derived RH values, are averages determined from a few thousand single-particle bursts. The autocorrelation curves in Figure 1 display two decay processes. The step on the millisecond time scale is due to NP diffusion and

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

• favorable valley as compared to the formation of a 2D adlayer phase covering the entire surface, or islands of that phase covering part of the surface. Comparable structures were reported for graphene/Rh(111) [18]. Pronounced lateral variations in the adsorption potential on metal supported graphene

• limitation to specific adsorption sites in combination with the distinct positions of the hydrogen bond donors and acceptors within the molecule results in the formation of 1D chain structures (Figure 3b), similar to findings recently reported for the adsorption of PTCDI molecules on graphene/Rh(111) [18

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

• RH%, are presented and discussed. The dependency of the energy dissipation during the manipulation was particularly studied as a function of size, coating of particles, substrate and temperature. Finally, interpretation of the physico-chemical mechanisms involved at both interfaces – tip–particle and

• the effect of functional (hydrophilic vs hydrophobic) molecules grafted on the Au nanoparticles on their mobility. In addition, we will address the important issue of environmental conditions (T, RH%), surface topography and tip scan velocities on the manipulation performance of gold nanoparticles

• ) substrate [41][42][43]. As we can see here, the eventual role of relative humidity (RH%) which is an environmental parameter, strongly depends on the chemistry of the NP–substrate interface. Another environmental parameter, namely temperature, also affects the mobility of the nanoparticles. The influence of

Single-pass Kelvin force microscopy and dC/dZ measurements in the intermittent contact: applications to polymer materials

• Sergei Magonov and
• John Alexander

Beilstein J. Nanotechnol. 2011, 2, 15–27, doi:10.3762/bjnano.2.2

• measurements were made in air at 20–25% humidity. An environmental chamber of the microscope was used for studies in humid air (2% < RH < 95%, as measured by a humidity meter) and also for experiments in organic solvent vapors. One or two milliliters of water, methanol or toluene was injected into the

• the images of the 7M3S blend obtained after the sample was exposed to high humidity (RH > 95%) overnight (Figure 8C). The surface potential image was unchanged but multiple droplets appeared inside the dimples in the topography image. Most likely these are due to condensed water droplets on

• might suspect some environmental effects in our preliminary measurements at low humidity (3% RH) and in different gases (N2, Ar) as revealed by the the contrast variations. The humidity-induced changes are very noticeable and well as those caused by methanol and toluene vapors. These observations might

The description of friction of silicon MEMS with surface roughness: virtues and limitations of a stochastic Prandtl–Tomlinson model and the simulation of vibration-induced friction reduction

• W. Merlijn van Spengen,
• Viviane Turq and
• Joost W. M. Frenken

Beilstein J. Nanotechnol. 2010, 1, 163–171, doi:10.3762/bjnano.1.20

• normal force, while keeping the support position speed and environmental conditions constant. This resulted in a friction force that is more or less linear in the normal force, with a friction coefficient of 0.27 at a temperature of 27 °C and 25% RH (Figure 4). The fact that the friction force becomes

• .; Frenken, J. W. M. Tribol. Lett. 2007, 28, 149–156.] Typical 1000-cycle-average friction loops obtained with the tribometer of Figure 1 [19], at 27 °C and a relative humidity (RH) of 30%. The sliding speed was constant at 5 µm/s. Support position 0 μm is where the loop was started every cycle. This loop is

Ultrafine metallic Fe nanoparticles: synthesis, structure and magnetism

• Olivier Margeat,
• Marc Respaud,
• Catherine Amiens,
• Pierre Lecante and
• Bruno Chaudret

Beilstein J. Nanotechnol. 2010, 1, 108–118, doi:10.3762/bjnano.1.13

• ferromagnetic metals [1][2][3][4]. More surprisingly, the study of small Rh NPs revealed a paramagnetic to ferromagnetic phase transition induced by size reduction for clusters containing less than 40 atoms [5]. Band structure calculations have investigated the role of size reduction and demonstrated that it

• various temperatures between 293 K and 5 K, are shown in Figure 4. The measurements were performed with a 57Co source in a Rh matrix and were calibrated against bulk α-Fe. Upon decreasing the temperature, the spectrum progressively splits but still remains broad, even at the lowest temperature. Such