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

• . The DODA–POM hybrid films, after AFM imaging, were treated in an UV–ozone chamber (Jelight USA) for 10 min. Atomic force microscopy AFM experiments were performed by using a Nanoscope V multimode AFM (Bruker AXS) in tapping mode under ambient conditions (23 °C and 56% RH). Thin films of the POM, DODA

Effects of palladium on the optical and hydrogen sensing characteristics of Pd-doped ZnO nanoparticles

• Anh-Thu Thi Do,
• Hong Thai Giang,
• Thu Thi Do,
• Ngan Quang Pham and
• Giang Truong Ho

Beilstein J. Nanotechnol. 2014, 5, 1261–1267, doi:10.3762/bjnano.5.140

• relative humidity of 65% RH. To keep the operating temperature of the sensor in the range of 200–300 °C, an applied voltage Vapplied of 1.7 V and a current of about 120 mA are required. The obtained linear curve implied that it is possible to control the operating temperature by turning the applied voltage

• of 65% RH, the linear dependence of the sensitivity of the Pd/ZnO-based sensor on hydrogen concentrations in the range of 0–25% LEL was observed as shown in Figure 4b. The gas sensing mechanism usually accepted for semiconductor sensors explains the functionality due to reactions of hydrogen with the

• ) the specificity of the Pd/ZnO sample at 1 vol % of H2, CO and C3H8 with a humidity of 65% RH. Response characteristics of the hydrogen sensor based on Pd/ZnO nanoparticles. Stability over time of the investigated sensor as a function of (a) time and (b) in hydrogen atmosphere.

Nanoporous composites prepared by a combination of SBA-15 with Mg–Al mixed oxides. Water vapor sorption properties

• Amaury Pérez-Verdejo,
• Alvaro Sampieri,
• Heriberto Pfeiffer,
• Mayra Ruiz-Reyes,
• Juana-Deisy Santamaría and
• Geolar Fetter

Beilstein J. Nanotechnol. 2014, 5, 1226–1234, doi:10.3762/bjnano.5.136

• are homogeneously dispersed. Vapor sorption behavior The water vapor adsorption–desorption isotherms of all samples were acquired at 60 °C with a rate of 0.5%·min−1 of relative humidity (RH) until to achieve 80% of RH (Figure 5). The calcined hydrotalcite (HT) adsorbs up to 5.0 mmol H2O/gHT and the

• hydrotalcite. This extraordinary amount of adsorbed water can also be related to the high surface area of this composite, 806 m2/g. Moreover, a wider hysteresis, between 80% and 40% of RH%, is observed for this sample, (Mg/Al)/SBA, Figure 5, indicating that water is slowly desorbed. Such behavior can be

• behavior observed in the (Mg/Al)/SBA is manly, a capillary condensation in intra-wall micropores. Some experiments were carried out at different RH (20, 40, 60 or 80%) through a continuous increase of the temperature from 35 to 70 °C to determine the maximum capacity of the water vapor adsorption of the HT

Enhanced photocatalytic hydrogen evolution by combining water soluble graphene with cobalt salts

• Jing Wang,
• Ke Feng,
• Hui-Hui Zhang,
• Bin Chen,
• Zhi-Jun Li,
• Qing-Yuan Meng,
• Li-Ping Zhang,
• Chen-Ho Tung and
• Li-Zhu Wu

Beilstein J. Nanotechnol. 2014, 5, 1167–1174, doi:10.3762/bjnano.5.128

• ][27][28][29][30][31][32][33]. Specifically, graphene has been involved in photocatalytic hydrogen production systems [34], such as TiO2-(N)RGO-Pt [35][36][37][38], g-C3N4-RGO-Pt [39], CdS-RGO-Pt [40][41][42][43], MoS2-NRGO [44][45], EY-RGO-Pt [46] and BiVO4-RGO-Ru/SrTiO3:Rh [47] (RGO: reduced graphene

The study of surface wetting, nanobubbles and boundary slip with an applied voltage: A review

• Yunlu Pan,
• Bharat Bhushan and
• Xuezeng Zhao

Beilstein J. Nanotechnol. 2014, 5, 1042–1065, doi:10.3762/bjnano.5.117

• conditions (temperature of 22 ± 1 °C, humidity of 45–55% RH). The voltage was applied as shown in Figure 11. For each applied voltage, at least three images at different areas were recorded to confirm the scanning itself did not result in the change of the nanobubbles. Besides DI water, three kinds of saline

Volcano plots in hydrogen electrocatalysis – uses and abuses

• Paola Quaino,
• Fernanda Juarez,
• Elizabeth Santos and
• Wolfgang Schmickler

Beilstein J. Nanotechnol. 2014, 5, 846–854, doi:10.3762/bjnano.5.96

• indicate the older values. None such measurements have been made for other metals of this group like Re and Rh, and the rates on these metals may well be higher than indicated. In any case, with the exception of Co and Ni, the rates are fast on these metals. They seem to be about one order of magnitude

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