Stability and activity of platinum nanoparticles in the oxygen electroreduction reaction: is size or uniformity of primary importance?

• Kirill O. Paperzh,
• Anastasia A. Alekseenko,
• Vadim A. Volochaev,
• Ilya V. Pankov,
• Olga A. Safronenko and
• Vladimir E. Guterman

Beilstein J. Nanotechnol. 2021, 12, 593–606, doi:10.3762/bjnano.12.49

• platinum NPs and loss of contact with the support [24][25][26], as well as the isolation of particles by adsorbed carbon monoxide released due to carbon oxidation [27][28][29][30]. Each of the mechanisms previously described can play a greater or smaller role, depending on the conditions of the catalysts

• ). A similar difference is observed when we compared G40 and the JM40 analog (Figure 2). We estimated the uniformity of the spatial NP distribution over the support surface. To this end, for each Pt/M material in the TEM micrographs, we calculated the fraction of NPs that were not in contact (non

• -overlapping) with other NPs or in contact with one, two, or three other NPs. In this case, with the assumption that the smaller the number of intersections of NP images in the micrographs, the more uniformly distributed over the carrier surface the NPs. The disadvantages of such a simplified system used for

Impact of GaAs(100) surface preparation on EQE of AZO/Al₂O₃/p-GaAs photovoltaic structures

• Piotr Caban,
• Rafał Pietruszka,
• Jarosław Kaszewski,
• Monika Ożga,
• Bartłomiej S. Witkowski,
• Krzysztof Kopalko,
• Piotr Kuźmiuk,
• Katarzyna Gwóźdź,
• Ewa Płaczek-Popko,
• Krystyna Lawniczak-Jablonska and
• Marek Godlewski

Beilstein J. Nanotechnol. 2021, 12, 578–592, doi:10.3762/bjnano.12.48

• ) [23][24][25]. Therefore, one should limit the contact time of the GaAs substrate with air/water to an absolute minimum. The attempts that were made to either stop or at least reduce this phenomenon led to the use of surface passivation techniques. One of the well-known and effective methods to protect

• the experiment, the substrate was equipped with an e-beam evaporated (Kurt J. Lesker PVD75) and annealed Au/Zn/Au bottom ohmic contact, which was protected with Kapton tape before further processing steps. In total, eight GaAs samples, denoted as A1–A4 and B1–B4, were fabricated and they differed in

• the same or similar etching rates). After etching in a mixture of CA + H2O2 + H2O, the samples were washed in DIW for 1 min in a USC. Prior contact with an oxidizer as well as the subsequent water bath also resulted in an infinitesimal oxide layer reformation on the surface. This oxide layer was, then

Properties of graphene deposited on GaN nanowires: influence of nanowire roughness, self-induced nanogating and defects

• Jakub Kierdaszuk,
• Piotr Kaźmierczak,
• Justyna Grzonka,
• Aleksandra Krajewska,
• Aleksandra Przewłoka,
• Wawrzyniec Kaszub,
• Zbigniew R. Zytkiewicz,
• Marta Sobanska,
• Maria Kamińska,
• Andrzej Wysmołek and
• Aneta Drabińska

Beilstein J. Nanotechnol. 2021, 12, 566–577, doi:10.3762/bjnano.12.47

• different nanowire substrates shows that bigger differences in nanowires height increase graphene strain, while a higher number of nanowires in contact with graphene locally reduces the strain. Moreover, the value of graphene carrier concentration is found to be correlated with the density of nanowires in

• contact with graphene. The lowest concentration of defects is observed for graphene deposited on nanowires with the lowest density. The contact between graphene and densely arranged nanowires leads to a large density of vacancies. On the other hand, grain boundaries are the main type of defects in

• , such as strain induced by mechanical contact between materials or gating of graphene by neighbouring layers, are important for further applications. Furthermore, electron scattering on defects modifies graphene properties in several ways, for example, additional scattering centres reduce carrier

Local stiffness and work function variations of hexagonal boron nitride on Cu(111)

• Abhishek Grewal,
• Yuqi Wang,
• Matthias Münks,
• Klaus Kern and
• Markus Ternes

Beilstein J. Nanotechnol. 2021, 12, 559–565, doi:10.3762/bjnano.12.46

• the contact potential difference measured by Kelvin probe force microscopy. Using 3D force profiles of the same area we determine the relative stiffness of the Moiré region allowing us to analyse both electronic and mechanical properties of the 2D layer simultaneously. We obtain a sheet stiffness of

• non-contact atomic force microscopy (nc-AFM) to study h-BN on Cu(111). This template has interesting properties because the dielectric layer is only very weakly bound to the metal and shows an electronically induced Moiré superstructure [25][26]. First STM studies on this system pointed to only a

• by the applied voltage, which compensates the contact potential difference between Φ of the tip and Φ of the sample [44]. Using the shift of the FER we find an average variation between valley and rim regions of ΔΦ = 148 ± 17 meV, which agrees well with previous observations [27][45]. Interestingly

Influence of electrospray deposition on C₆₀ molecular assemblies

• Antoine Hinaut,
• Sebastian Scherb,
• Sara Freund,
• Zhao Liu,
• Thilo Glatzel and
• Ernst Meyer

Beilstein J. Nanotechnol. 2021, 12, 552–558, doi:10.3762/bjnano.12.45

• the first molecules studied in HV-ESD experiments [5][30]. Here, we present a comparison between TE and HV-ESD regarding the adsorption and structure formation of C60 molecules on surfaces at low coverages, that is, below one monolayer down to single molecules. We used a non-contact atomic force

• in Figure 3c. The islands are clearly different to what is obtained after TE of C60, also shown by the zoom on such an island in Figure 3e. Their average contact area, that is, the surface occupied by the first layer on the KBr surface, is about 1100 nm2, less than a tenth of what is obtained after

• were obtained. Room-temperature AFM Room-temperature nc-AFM measurements were performed with a custom-built non-contact atomic force microscope with Nanonis electronics RC5. PPP-NCL cantilevers (Nanosensor) were used as sensor (typical resonance frequency of f1 = 170 kHz, oscillation amplitude A1 = 2–5

The preparation temperature influences the physicochemical nature and activity of nanoceria

• Robert A. Yokel,
• Wendel Wohlleben,
• Johannes Georg Keller,
• Matthew L. Hancock,
• Jason M. Unrine,
• D. Allan Butterfield and
• Eric A. Grulke

Beilstein J. Nanotechnol. 2021, 12, 525–540, doi:10.3762/bjnano.12.43

• stable complexes with phosphate but phosphate inhibits nanoceria dissolution, it was hypothesized that phosphates not in direct contact with nanoceria would create a sink for released cerium ions and increase the nanoceria dissolution rate. Assuming that NM-212 was calcined to a crystalline form with

• pH 4.5. This experiment was repeated with 40 or 75 mg LN resin and sampling up to 3360 h. This experiment was similarly conducted with 75 mg HTP at pH 4.5 and pH 7 with samples collected up to 2016 h. To test the hypothesis that phosphates not in direct contact with nanoceria increase the nanoceria

• (log Ksp = 10−26 to 10−23 for Ce(III) phosphate in 0.01 to 12 M H3PO4, 0.1 M NaH2PO4, or 0.1 M HCl [66][67][68]; log Ksp = 10−115 for Ce(IV) phosphate in 0.01 to 12 M H3PO4 and 10−34 at pH 0.4 [66][69]). The present study assessed the hypothesis that phosphate groups not in direct contact with

Determining amplitude and tilt of a lateral force microscopy sensor

• Oliver Gretz,
• Alfred J. Weymouth,
• Thomas Holzmann,
• Korbinian Pürckhauer and
• Franz J. Giessibl

Beilstein J. Nanotechnol. 2021, 12, 517–524, doi:10.3762/bjnano.12.42

• atomic force microscopy (AFM) is a non-contact atomic force microscopy technique where the frequency shift (Δf) of an oscillating tip is detected [1]. The frequency shift is a measure of the total force gradient acting on the tip, which includes both long-range and short-range contributions. A typical

Simulation of gas sensing with a triboelectric nanogenerator

• Kaiqin Zhao,
• Hua Gan,
• Huan Li,
• Ziyu Liu and
• Zhiyuan Zhu

Beilstein J. Nanotechnol. 2021, 12, 507–516, doi:10.3762/bjnano.12.41

• can also be used as sensors [22]. TENGs, originally proposed by Prof. Zhongling Wang [23], are microgenerators that convert mechanical energy into electrical energy based on the triboelectric effect [24]. In most TENG simulations, a triboelectric polymer material is in direct contact with an electrode

• layer with very small separation distance (less than 1 mm) [25], and the effective contact area of the friction material is increased by texturing its surface [26][27] to improve its electrical output. This setup is widely applied in vertical contact separation mode [28][29], sliding mode [30][31

• ], single electrode mode [32][33][34], and independent layer mode [35]. In order to explain the charge transfer process between two friction materials in contact, various models have been proposed and explored, such as electron cloud model [36][37][38], ion transfer model [39], and material transfer model

Surface-enhanced Raman scattering of water in aqueous dispersions of silver nanoparticles

• Paulina Filipczak,
• Krzysztof Hałagan,
• Jacek Ulański and
• Marcin Kozanecki

Beilstein J. Nanotechnol. 2021, 12, 497–506, doi:10.3762/bjnano.12.40

• was found that only one water molecule per 10 million is in direct contact with the surface of AgNPs. It is also worthy to mention that the model used to calculate the part of the water molecules in the direct vicinity of AgNPs yielded an overestimated value (the detailed calculations are described in

• molecules. The SERS effect is present only for water molecules that are in direct contact with AgNPs; however, the dynamic properties of water molecules close to the metal surface probably differ from the ones in the bulk up to a couple of hydration layers. This suggests that at least there might be a

A review on nanostructured silver as a basic ingredient in medicine: physicochemical parameters and characterization

• Gabriel M. Misirli,
• Kishore Sridharan and
• Shirley M. P. Abrantes

Beilstein J. Nanotechnol. 2021, 12, 440–461, doi:10.3762/bjnano.12.36

• effective in inhibiting SARS-CoV-2 by using AgNPs to coat facial masks [77][120]. These results are suggestive of the development of new measures in which AgNPs can be used to prevent SARS-CoV-2 infection. Biological interactions of AgNPs When in contact with human plasma, AgNPs adsorb biomolecules such as

Reconstruction of a 2D layer of KBr on Ir(111) and electromechanical alteration by graphene

• Zhao Liu,
• Antoine Hinaut,
• Stefan Peeters,
• Sebastian Scherb,
• Ernst Meyer,
• Maria Clelia Righi and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2021, 12, 432–439, doi:10.3762/bjnano.12.35

• with unconventional stoichiometries have been observed indirectly on graphene surfaces [37]. Here, we report on the formation of irregularly shaped KBr islands with corrugated stripe structures, observed on the (111) surface of Ir and analyzed by non-contact atomic force microscopy (nc-AFM) at room

Solution combustion synthesis of a nanometer-scale Co₃O₄ anode material for Li-ion batteries

• Monika Michalska,
• Huajun Xu,
• Qingmin Shan,
• Shiqiang Zhang,
• Yohan Dall'Agnese,
• Yu Gao,
• Amrita Jain and
• Marcin Krajewski

Beilstein J. Nanotechnol. 2021, 12, 424–431, doi:10.3762/bjnano.12.34

• represent the charge transfer at the electrode–electrolyte interface (Rct) and the Warburg impedance (W), respectively. The semicircle at high frequencies is mainly attributed to SEI resistance (RSEI) and contact resistance (Rf) [13][15][20][21][25][38]. At this point, it should be also mentioned that the

• circuit corresponding to the electrochemical impedance spectroscopy (EIS) measurements for the cell (a) before cycling, and (b) after cycling; Rf – contact resistance, RSEI – the solid–electrolyte interface (SEI) resistance, CSEI – the surface capacitance, Rct – the charge transfer resistance at the

Colloidal particle aggregation: mechanism of assembly studied via constructal theory modeling

• Scott C. Bukosky,
• Sukrith Dev,
• Monica S. Allen and
• Jeffery W. Allen

Beilstein J. Nanotechnol. 2021, 12, 413–423, doi:10.3762/bjnano.12.33

• sufficiently thin double layer will allow the particles to come into closer contact where van der Waals attraction can occur. Consequently, increasing the electrolyte concentration or decreasing the fluid dielectric constant will decrease the Debye length and promote aggregation. The results in Figure 5 and

A stretchable triboelectric nanogenerator made of silver-coated glass microspheres for human motion energy harvesting and self-powered sensing applications

• Hui Li,
• Yaju Zhang,
• Yonghui Wu,
• Hui Zhao,
• Weichao Wang,
• Xu He and
• Haiwu Zheng

Beilstein J. Nanotechnol. 2021, 12, 402–412, doi:10.3762/bjnano.12.32

• procedure of the TENG devices. More recently, Qian et al. proposed a nylon-regulated TENG in contact-separated working mode, whose open-circuit voltage and short-circuit current can reach up to 1.17 kV and 138 µA, respectively [16]. Although this is a tremendous advancement in output performance, the

• contact-separated working mode with double electrodes makes it difficult to connect the current conducting wires to moving objects when trying to harvest mechanical energy. Besides, the organic–inorganic composites prepared by embedding relatively hard SCGMs into a soft silicone rubber matrix reduce the

• File 1). Also, it can be rolled and twisted easily, as shown in Figure 1e. Figure 2a illustrates the electricity generation mechanism of the single-electrode mode S-TENG, which is based on a conjunction of contact triboelectrification and electrostatic induction [2][20][21][22][23]. In the initial

The impact of molecular tumor profiling on the design strategies for targeting myeloid leukemia and EGFR/CD44-positive solid tumors

• Nikola Geskovski,
• Nadica Matevska-Geshkovska,
• Simona Dimchevska Sazdovska,
• Marija Glavas Dodov,
• Kristina Mladenovska and
• Katerina Goracinova

Beilstein J. Nanotechnol. 2021, 12, 375–401, doi:10.3762/bjnano.12.31

• identified in relapsed CML patients receiving imatinib. However, the most frequent alterations occur in three different regions and seven specific residues, that is, in the docking site for phosphate moieties of ATP named P-loop (M244V, G250E, Y253F/H, and E255K/V), in the contact site related to selective

Spontaneous shape transition of Mn_xGe_1−x islands to long nanowires

• S. Javad Rezvani,
• Luc Favre,
• Gabriele Giuli,
• Yiming Wubulikasimu,
• Isabelle Berbezier,
• Augusto Marcelli,
• Luca Boarino and
• Nicola Pinto

Beilstein J. Nanotechnol. 2021, 12, 366–374, doi:10.3762/bjnano.12.30

• = α0, with: where e is the Neper number, ϕ = e−3/2cot(θ), with θ the contact angle of the island facet with the substrate. Γ = γecsc(θ) − γscot(θ) with γe and γs are the surface energy per unit area of the edge facet and the substrate, respectively. , where σb, ν and μ are the stress tensor in the

Structural and optical characteristics determined by the sputtering deposition conditions of oxide thin films

• Petronela Prepelita,
• Florin Garoi and
• Valentin Craciun

Beilstein J. Nanotechnol. 2021, 12, 354–365, doi:10.3762/bjnano.12.29

• first 2 to 6 nanometers of the surface of a sample, including the contaminant layer. The chemical composition of oxide films, obtained by XPS, can be slightly different from that of the target due to surface diffusion phenomena and surface-specific chemical processes in contact with the atmosphere. The

Nickel nanoparticle-decorated reduced graphene oxide/WO₃ nanocomposite – a promising candidate for gas sensing

• Ilka Simon,
• Alexandr Savitsky,
• Rolf Mülhaupt,
• Vladimir Pankov and
• Christoph Janiak

Beilstein J. Nanotechnol. 2021, 12, 343–353, doi:10.3762/bjnano.12.28

• consideration. When Ni@rGO/WO3 sensors are exposed to NO2, with NO2, which is a strong oxidizing gas accepts electrons from WO3. As a result, NO2 transforms into NO2− on the surface of WO3. This process leads to accumulation of holes and an increase in sensor sensitivity. In addition, the rGO/WO3 contact also

• placed in a tube furnace with a temperature regulator. To enhance electrical conductivity and to improve contact Ag electrodes were deposited on parallel sides of the pellets. The measurement procedure was carried out for NO2 and acetone in a stationary regime in a precisely controlled atmosphere (10 ppm

Intracranial recording in patients with aphasia using nanomaterial-based flexible electronics: promises and challenges

• Qingchun Wang and
• Wai Ting Siok

Beilstein J. Nanotechnol. 2021, 12, 330–342, doi:10.3762/bjnano.12.27

• covering almost the whole brain. The application of novel nanomaterials has the potential to overcome the limitations of conventional electrode arrays. IEEG electrode arrays electroplated with nanoparticles could lower impedance and allow for a closer contact with cortical cells, thereby providing more

• high quality. For instance, new models are advanced with significantly reduced thickness, which enables reliable contact with the cortex surface. Thus, more accurate recordings can be acquired. Furthermore, long-term implantation has been used in nonhuman primates or rats that presented steady neural

Exploring the fabrication and transfer mechanism of metallic nanostructures on carbon nanomembranes via focused electron beam induced processing

• Christian Preischl,
• Linh Hoang Le,
• Elif Bilgilisoy,
• Armin Gölzhäuser and
• Hubertus Marbach

Beilstein J. Nanotechnol. 2021, 12, 319–329, doi:10.3762/bjnano.12.26

• AFM experiments were performed with a JPK NanoWizard 4 by using non-contact mode. Cross-linking of SAMs into CNMs was achieved by using electron flood guns employing 100 eV electrons and an electron dose of 60 mC/cm2. Before starting the transfer process, the cross-linked CNMs were spin coated with a

The patterning toolbox FIB-o-mat: Exploiting the full potential of focused helium ions for nanofabrication

• Victor Deinhart,
• Lisa-Marie Kern,
• Jan N. Kirchhof,
• Sabrina Juergensen,
• Joris Sturm,
• Enno Krauss,
• Thorsten Feichtner,
• Sviatoslav Kovalchuk,
• Michael Schneider,
• Dieter Engel,
• Bastian Pfau,
• Bert Hecht,
• Kirill I. Bolotin,
• Stephanie Reich and
• Katja Höflich

Beilstein J. Nanotechnol. 2021, 12, 304–318, doi:10.3762/bjnano.12.25

• electrically contact the graphene sheet and actuate the resonators electrostatically. The motion of the devices is detected using a Michelson interferometer [48]. Figure 6a depicts a secondary electron HIM image of a patterned trampoline graphene resonator. A He ion current of 3 pA was employed at an

Doxorubicin-loaded gold nanorods: a multifunctional chemo-photothermal nanoplatform for cancer management

• Uzma Azeem Awan,
• Abida Raza,
• Shaukat Ali,
• Rida Fatima Saeed and
• Nosheen Akhtar

Beilstein J. Nanotechnol. 2021, 12, 295–303, doi:10.3762/bjnano.12.24

• hemoglobin in the supernatant of GNPs-RBCs mixture by monitoring absorbance intensity at 570 nm. The absence of a marked hemotoxicity of this sample is mainly related to the presence of the polymer. The GNR surface had no direct contact with the RBCs because it was completely passivated by the PSS coating

Characterization, bio-uptake and toxicity of polymer-coated silver nanoparticles and their interaction with human peripheral blood mononuclear cells

• Sahar Pourhoseini,
• Reilly T. Enos,
• Angela E. Murphy,
• Bo Cai and
• Jamie R. Lead

Beilstein J. Nanotechnol. 2021, 12, 282–294, doi:10.3762/bjnano.12.23

• dermal and ocular contact [18]. As AgNPs enter the body through injection or degradation of biomaterials, they are translocated to the circulatory system and can come in direct contact with human peripheral blood mononuclear cells (PBMCs) before ultimately being distributed to the main organs where they

The nanomorphology of cell surfaces of adhered osteoblasts

• Christian Voelkner,
• Mirco Wendt,
• Regina Lange,
• Max Ulbrich,
• Martina Gruening,
• Susanne Staehlke,
• Barbara Nebe,
• Ingo Barke and
• Sylvia Speller

Beilstein J. Nanotechnol. 2021, 12, 242–256, doi:10.3762/bjnano.12.20

• micrometers down to the nanometer scale. The cell surface plays a particularly important role. Electric signaling, including information processing, takes place at the membrane, as well as adhesion and contact. For osteoblasts, adhesion and spreading are crucial processes with regard to bone implants. Here we

• (only 200 µm2). Therefore, we refrained from further utilizing PDMS substrates. Zeta potential and water contact angle were measured to be 8.6 mV and 68°, respectively, for PPAAm [62]. In case of the Au layer, −119 mV and 101°, respectively, were determined. Zeta potential measurements were performed

• software GraphPad Prism Version 6.05 (n = 3). Water contact angle values were obtained by the sessile drop method using the drop shape analyzer DSA25 (Krüss, Hamburg, Germany). Drop shape images of 1 µL water drops were acquired with the digital camera of the DSA25 under atmospheric conditions at room

Determination of elastic moduli of elastic–plastic microspherical materials using nanoindentation simulation without mechanical polishing

• Hongzhou Li and
• Jialian Chen

Beilstein J. Nanotechnol. 2021, 12, 213–221, doi:10.3762/bjnano.12.17

• encountered in engineering. The simulated results indicate that contact height is unsuitable to replace contact depth for obtaining the indentation elastic modulus of microspherical materials. The extracted elastic modulus of a microsphere using the Oliver–Pharr method with the simulated unloading curve

• precisely calculate the indentation response from a given set of elastic–plastic properties (forward algorithms), and to extract elastic–plastic properties from a given set of indentation data (reverse algorithms) [8]. Pileup (or sink-in) results in contact areas bigger (or smaller) than the cross-sectional

• area of the indenter at a specified depth. These effects can result in measurement errors of mechanical properties [9]. Without taking into account that the real contact area and the cross-sectional area of the indenter are different, the measured indentation modulus/hardness would be too high in the