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

• graphene oxide, rGO) chemically or thermally. Through the partial removal of oxygen groups, the conductivity can be restored. Additionally, defects and vacancies are created [26]. Because of the ultra-high surface area per atom and the high electron transport along the graphene plane, rGO has a rapid and

• charges (possibly, a p–n junction is formed). It was shown [59] that electrons that were transferred from the n-type semiconductor and stored in the rGO sheets are withdrawn upon exposure to gas, thereby restoring the hole concentration and p-type conductivity of rGO. This is made possible by the energy

• band alignment between the semiconductor and rGO, the electron acceptor functionalization of the analyzed gas, and the p-type conductivity of the rGO. Thus, the electron-depleted WO3 surface is more sensitive to the adsorption of acetone molecules and the transition of electrons from the adsorbed gas

Scanning transmission helium ion microscopy on carbon nanomembranes

• Daniel Emmrich,
• Annalena Wolff,
• Nikolaus Meyerbröker,
• Jörg K. N. Lindner,
• André Beyer and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2021, 12, 222–231, doi:10.3762/bjnano.12.18

• originate from a molecular thin film, they can be as thin as 1 nm. The conductivity of such membranes is low, which poses a challenge to SE imaging with charged-particle microscopes such as SEM or HIM [24]. This work demonstrates that the holder is easily optimized for such difficult samples. It is possible

• measure the pure STIM signal, SE emitted directly from the sample need to be blocked. Ideally, the resulting signal consists exclusively of SE released by transmitted ions. Three measures were taken to filter out direct SE. Firstly, CNMs have a low conductivity, which leads to charging and reduces the SE

• , HIM and Raman spectroscopy were performed on the samples after the EFTEM experiments. The SE image in Figure 7b shows that membrane turned brighter in the areas previously imaged with EFTEM, which is indicative of a higher electric conductivity, as demonstrated in the following. In Figure 7c, a Raman

A review on the biological effects of nanomaterials on silkworm (Bombyx mori)

• Sandra Senyo Fometu,
• Guohua Wu,
• Lin Ma and
• Joan Shine Davids

Beilstein J. Nanotechnol. 2021, 12, 190–202, doi:10.3762/bjnano.12.15

• graphitic structure enhanced its electrical conductivity [162]. Graphene has excellent electrical conductivity, optical properties, and mechanical strength [163][164][165][166], and these traits were conferred to the silk fibers. It was also indicated that silkworms fed with a lower concentration (0.2 wt

Toward graphene textiles in wearable eye tracking systems for human–machine interaction

• Ata Jedari Golparvar and
• Murat Kaya Yapici

Beilstein J. Nanotechnol. 2021, 12, 180–189, doi:10.3762/bjnano.12.14

• this way, “passive” graphene textile electrodes were formed, which can be directly used to capture surface biopotentials without further modification. Conductivity measurements showed resistance values of the textiles between 1 and 10 kΩ and skin-electrode impedance values from 87.5 kΩ (at 10 Hz) to

• 11.6 kΩ (at 1 kHz). Additionally, since the operation of the textile electrodes relies on charge flow, moisture and sweat can increase the interface conductivity of the skin electrodes and provide an even better signal-to-noise ratio (SNR) in long-term monitoring applications in contrast to “wet

Imaging of SARS-CoV-2 infected Vero E6 cells by helium ion microscopy

• Natalie Frese,
• Patrick Schmerer,
• Martin Wortmann,
• Matthias Schürmann,
• Matthias König,
• Michael Westphal,
• Friedemann Weber,
• Holger Sudhoff and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2021, 12, 172–179, doi:10.3762/bjnano.12.13

• addition to the improved conductivity of the specimen, the deposited layer may contribute to the electron density of the surface, thus increasing secondary electron yield. This effect, commonly referred to as electron- and/or ion beam-induced deposition, is commonly observed in charged-particle microscopes

• to increased conductivity, this region appears significantly brighter than the rest of the image. (b1–3) HIM images of a cell infected at MOI 1 at different magnifications (FOV 20 µm, 5 µm, and 450 nm) with charge compensation. (c1–3) HIM images of the same cell (FOV 20 µm, 2 µm, and 450 nm) after

Paper-based triboelectric nanogenerators and their applications: a review

• Jing Han,
• Nuo Xu,
• Yuchen Liang,
• Mei Ding,
• Junyi Zhai,
• Qijun Sun and
• Zhong Lin Wang

Beilstein J. Nanotechnol. 2021, 12, 151–171, doi:10.3762/bjnano.12.12

• paper-based 3D foldable device submitted to a direct laser patterning method, which can convert ink-soaked paper substrates to multifunctional carbide/graphene (MCG) composites [92]. The composites have shown good conductivity even after repeated mechanical bending and folding tests. Moreover, the laser

• flexible conductive materials, metallic materials (e.g., copper, zinc, silver, and gold) are still frequently used as electrodes for flexible electronics due to their excellent electrical conductivity. By using the Kapton tape to attach soft stencils to paper, various metals can be deposited through the

• conductivity. VF is a simple and rapid method to cast functional materials onto solution-processable substrates without the need to implement any time-consuming and high-cost processes (e.g., evacuation, thermal/e-beam heating, and radio-frequency sputtering). The conductivity is also easily adjustable by

A review on the green and sustainable synthesis of silver nanoparticles and one-dimensional silver nanostructures

• Sina Kaabipour and
• Shohreh Hemmati

Beilstein J. Nanotechnol. 2021, 12, 102–136, doi:10.3762/bjnano.12.9

• characteristics including antimicrobial activity, electrical conductivity, thermal conductivity, optical characteristics, and mechanical properties. The antimicrobial characteristic of silver nanoparticles (AgNPs) has made them highly applicable in the biomedical and therapeutic fields [69][70][71]. Currently

• infections, and also inhibit the growth of bacterial biofilms [14][15][16]. AgNPs were also used in developing strong thermally conductive materials. They were used in polymer composites to increase thermal conductivity (K) [77][78] for cooling applications in electronic equipment. Furthermore, AgNPs have

• demonstrated unique electrical properties. AgNPs coated on polycarbonate substrates were previously used to increase the electrical conductivity of polycarbonate composites [79]. AgNPs have also demonstrated minimum or no adverse effects on mechanical strength when embedded in polymeric materials or composites

ZnO and MXenes as electrode materials for supercapacitor devices

• Ameen Uddin Ammar,
• Ipek Deniz Yildirim,
• Feray Bakan and
• Emre Erdem

Beilstein J. Nanotechnol. 2021, 12, 49–57, doi:10.3762/bjnano.12.4

• alternatives to metal oxides are two-dimensional (2D) MXenes. Their properties include environmental sustainability, lamellar structure, high transformation efficiency, high surface hydrophilicity, and good electrical conductivity [14]. Therefore, in the following section we discuss the main properties of

• biocompatibility, photothermal efficiency, low Seebeck coefficient, as well as good conductivity. They synthesized tantalum carbide MXene sheets from a tantalum aluminum carbide (Ta4AlC3) MAX phase through etching the intermediate aluminium with the aid of hydrofluoric acid (HF). Analysis of the synthesized

• of N-CuMe2Pc nanorods. The sample M10P2, in which 10 mg of MXene and 2 mg N-CuMe2Pc were used, exhibited high ionic conductivity and the measured value of the specific capacitance was 786 F·g−1 [16]. Li et al. synthesized monolayer wrinkled Ti3C2Tx grafted with HF and decorated with N-doped carbon by

Bio-imaging with the helium-ion microscope: A review

• Matthias Schmidt,
• James M. Byrne and
• Ilari J. Maasilta

Beilstein J. Nanotechnol. 2021, 12, 1–23, doi:10.3762/bjnano.12.1

• contrast mechanism occurs when HIM is used to study insulating or poorly conducting materials such as most biological specimens. Here, differences in local conductivity result in the accumulation of positive charges under the ion beam, which hampers the emission of secondary electrons and results in a

Piezotronic effect in AlGaN/AlN/GaN heterojunction nanowires used as a flexible strain sensor

• Jianqi Dong,
• Liang Chen,
• Yuqing Yang and
• Xingfu Wang

Beilstein J. Nanotechnol. 2020, 11, 1847–1853, doi:10.3762/bjnano.11.166

• spreading of the current. Next, 500 nm of an unintentionally doped GaN layer was deposited to protect the lower layer during the selective EC etching. A heavily doped GaN (N+-GaN) sacrificial layer, sandwiched by two thin N++-GaN layers was inserted under the AlGaN/AlN/GaN layer to enhance the conductivity

• conductivity, the heavily doped GaN preferentially reacts with the oxalic acid solution in an applied electric field. The lateral etching rates on both sides of N+-GaN were approximately the same during EC wet etching (Figure 2e). Finally, a single NW was obtained to prepare the strain sensor (Figure 2f). The

Self-standing heterostructured NiC_x-NiFe-NC/biochar as a highly efficient cathode for lithium–oxygen batteries

• Shengyu Jing,
• Xu Gong,
• Shan Ji,
• Linhui Jia,
• Bruno G. Pollet,
• Sheng Yan and
• Huagen Liang

Beilstein J. Nanotechnol. 2020, 11, 1809–1821, doi:10.3762/bjnano.11.163

• properties (similar to PGMs), high durability, and high electrical conductivity, transition metal carbides have recently become an active research topic. As such, they have been intensively studied as promising alternatives to PGM catalysts in the development of alternative ORR and OER catalysts [24][25

• in comparison to its crystalline counterpart, since the film-like Li2O2 has an improved ionic conductivity [57]. After the first charge, the obtained SEM images (Figure 7b and Figure 7d) show that most of the newly formed Li2O2 was decomposed. However, a small amount of Li2O2 still remained on the

• sample due to the relatively low electronic conductivity of Li2O2 formed on the surface of the cathode. After the first charge, RΩ was still higher than that of the fresh sample, but lower than that of the sample after the first discharge, indicating that there was still some remaining Li2O2. As shown in

Mapping of integrated PIN diodes with a 3D architecture by scanning microwave impedance microscopy and dynamic spectroscopy

• Rosine Coq Germanicus,
• Peter De Wolf,
• Florent Lallemand,
• Catherine Bunel,
• Serge Bardy,
• Hugues Murray and
• Ulrike Lüders

Beilstein J. Nanotechnol. 2020, 11, 1764–1775, doi:10.3762/bjnano.11.159

• volume of the sample material under the tip. Optimized for an incident frequency of approx. 3 GHz, the subsurface analysis volume extends to a depth of approx. 100 nm. For a material with a conductivity σ and a permittivity ε, the AFM sMIM tip–sample impedance is a complex impedance [26], equivalent to a

• vertical PIN diode with the associated metallic contacts of the anode. Although the sMIM-R signal shows a low signal-to-noise ratio, it is still possible to differentiate metallic materials from semiconductor layers. Also, the conductivity continuity between the metallic contact and the p+ anode can be

Absorption and photoconductivity spectra of amorphous multilayer structures

• Oxana Iaseniuc and
• Mihail Iovu

Beilstein J. Nanotechnol. 2020, 11, 1757–1763, doi:10.3762/bjnano.11.158

• Ge0.30As0.04S0.66, without and with Al electrodes, were prepared by thermal evaporation in vacuum (P = 10−5 Torr) of the synthesized initial glasses onto glass substrates. Longitudinal, instead of lateral, conductivity measurements were carried out. The thickness of each layer was chosen such that the distribution

• prepared. The experimental samples had a sandwich configuration with two Al electrodes, of which the top electrode was transparent to the incident light. The dark conductivity σd and the spectral distribution of the stationary photocurrent Iph = f(λ) have been measured under constant-current conditions

Imaging and milling resolution of light ion beams from helium ion microscopy and FIBs driven by liquid metal alloy ion sources

• Nico Klingner,
• Gregor Hlawacek,
• Paul Mazarov,
• Wolfgang Pilz,
• Fabian Meyer and
• Lothar Bischoff

Beilstein J. Nanotechnol. 2020, 11, 1742–1749, doi:10.3762/bjnano.11.156

• ], the fabrication of graphene nanomeshes [8], the formation of single Si nanocrystals embedded in SiO2 for single-electron transistors [9], the spatially resolved engineering of the thermal conductivity in individual Si nanowires [10], as well as the creation of nano-Josephson superconducting tunnel

Seebeck coefficient of silicon nanowire forests doped by thermal diffusion

• Shaimaa Elyamny,
• Elisabetta Dimaggio and
• Giovanni Pennelli

Beilstein J. Nanotechnol. 2020, 11, 1707–1713, doi:10.3762/bjnano.11.153

• conductivity of nanostructures, will yield a high efficiency of the conversion of thermal to electrical energy. Keywords: nanowires; Seebeck coefficient; thermal conductivity; thermoelectricity; Introduction Thermoelectric generators for direct conversion of heat into electrical power will certainly play a

• sustainable. Silicon has a very high power factor S2σ [1][2][3][4] (S is the Seebeck coefficient and σ is the electrical conductivity). This, combined with the reduced thermal conductivity when nanostructured [5][6][7][8][9][10], makes it very suitable for thermoelectric applications. As added value, silicon

• fabricated on the top of a silicon nanowire forest, which can be achieved by copper electrodeposition [18]. 2) The optimum doping concentration of the nanowires for the exploitation of the maximum power factor of silicon [3] needs to be found. Both the Seebeck coefficient and the electrical conductivity

Piezoelectric sensor based on graphene-doped PVDF nanofibers for sign language translation

• Shuai Yang,
• Xiaojing Cui,
• Rui Guo,
• Zhiyi Zhang,
• Shengbo Sang and
• Hulin Zhang

Beilstein J. Nanotechnol. 2020, 11, 1655–1662, doi:10.3762/bjnano.11.148

• piezoelectric sensor. Ti3C2 MXene and Ag NWs maintain the good conductivity of the electrode and avoid possible short-circuit problems occurring after magnetron sputtering. Also, a stable flexibility of the structure is maintained. GR is added with six different mass fractions, that is, 0, 0.2, 0.4, 0.6, 0.8

A self-powered, flexible ultra-thin Si/ZnO nanowire photodetector as full-spectrum optical sensor and pyroelectric nanogenerator

• Liang Chen,
• Jianqi Dong,
• Miao He and
• Xingfu Wang

Beilstein J. Nanotechnol. 2020, 11, 1623–1630, doi:10.3762/bjnano.11.145

• etching. More specifically, a 500 μm p-type high conductivity Si substrate was dipped into potassium hydrate (KOH) solution with a concentration of 50% at 130 °C for 6–8 h. Then, the obtained 45 μm p-Si was washed with acetone, isopropanol, and deionized water. Secondly, a thin ZnO seed layer was

PTCDA adsorption on CaF₂ thin films

• Philipp Rahe

Beilstein J. Nanotechnol. 2020, 11, 1615–1622, doi:10.3762/bjnano.11.144

• name two examples, the conductivity through a NaCl bilayer still dominates the conductivity along a molecular wire [4] and only the usage of thick NaCl films has enabled charge stability of single molecules [5]. A particularly well-studied case of surface-specific molecular properties is the adsorption

• , coupling to defects within the CaF1 layer, or charge transfer into the LUMO. Imaging at a positive sample bias of +1.5 V was performed in constant-height mode as the reduced sample conductivity at positive bias impeded operation in constant-current mode. Still, conductivity through PTCDA molecules is also

Detecting stable adsorbates of (1S)-camphor on Cu(111) with Bayesian optimization

• Jari Järvi,
• Patrick Rinke and
• Milica Todorović

Beilstein J. Nanotechnol. 2020, 11, 1577–1589, doi:10.3762/bjnano.11.140

• been applied in detecting molecular conformers [25] and adsorbate structures [26][27], in identifying stable molecular compounds [28], and in discovering materials with low thermal hysteresis [29] or thermal conductivity [30]. Typically, previous studies have employed customized material-specific

Electrokinetic characterization of synthetic protein nanoparticles

• Daniel F. Quevedo,
• Cody J. Lentz,
• Adriana Coll de Peña,
• Yazmin Hernandez,
• Nahal Habibi,
• Rikako Miki,
• Joerg Lahann and
• Blanca H. Lapizco-Encinas

Beilstein J. Nanotechnol. 2020, 11, 1556–1567, doi:10.3762/bjnano.11.138

• micro- and the nanoscale [29][39][40][41] as well as the sorting of protein nanocrystals with a streaming insulator-based DEP technique [42][43][44]. The Swami and Chou groups have studied protein particle enrichment in high-conductivity media employing devices with nanoscale gaps and reported both

• low-conductivity EK media used in the subsequent experiments. To test the potential of using EK microfluidics as a high-throughput SPNP purification technique, our particles had to be fluorescently labeled to be visualized with a fluorescence microscope. To accomplish this, we incorporated

• the particles had a similar shape and were indistinguishable from each other when visualized using SEM. While surprising, considering the different isoelectric points, the lack of a difference in ζp value was likely due to the low-conductivity suspension media used. Conversely, when the particles were

Helium ion microscope – secondary ion mass spectrometry for geological materials

• Matthew R. Ball,
• Richard J. M. Taylor,
• Joshua F. Einsle,
• Fouzia Khanom,
• Christelle Guillermier and
• Richard J. Harrison

Beilstein J. Nanotechnol. 2020, 11, 1504–1515, doi:10.3762/bjnano.11.133

• conductivity across the sample surface, it can dampen the signal to a point where some elements fall below the background noise level. However, the primary beam is not designed for the rapid removal of material and if the applied coating is thicker than 5–10 nm, its removal can take an unreasonable amount of

One-step synthesis of carbon-supported electrocatalysts

• Sebastian Tigges,
• Nicolas Wöhrl,
• Ivan Radev,
• Ulrich Hagemann,
• Markus Heidelmann,
• Thai Binh Nguyen,
• Stanislav Gorelkov,
• Stephan Schulz and
• Axel Lorke

Beilstein J. Nanotechnol. 2020, 11, 1419–1431, doi:10.3762/bjnano.11.126

• discussed in the following. Traditional multistep synthesis methods for Pt/C catalysts use supports, which are partially graphitized for reaching the required high electrical conductivity and durability. Therefore, the support surface is characterized by a low density of binding sites for anchoring Pt-NP

• , on which the Pt-NPs can then easily diffuse. Hence, these supports often require additional functionalization steps for avoiding metal particle agglomeration, which reduces the electrical conductivity and durability of the support. In sharp contrast, the one-step synthesis of Pt/CNW presented herein

Transient coating of γ-Fe₂O₃ nanoparticles with glutamate for its delivery to and removal from brain nerve terminals

• Konstantin Paliienko,
• Artem Pastukhov,
• Michal Babič,
• Daniel Horák,
• Olga Vasylchenko and
• Tatiana Borisova

Beilstein J. Nanotechnol. 2020, 11, 1381–1393, doi:10.3762/bjnano.11.122

• of glutamate and aspartate by chemically modified γ-Fe2O3 nanoparticles. The glutamate and aspartate solutions were prepared in HNO3 at pH 3.0 and under nitrogen flux. The chemisorption was investigated in acidic medium by measuring the changes in the conductivity of the solution during addition of

Atomic defect classification of the H–Si(100) surface through multi-mode scanning probe microscopy

• Jeremiah Croshaw,
• Thomas Dienel,
• Taleana Huff and
• Robert Wolkow

Beilstein J. Nanotechnol. 2020, 11, 1346–1360, doi:10.3762/bjnano.11.119

• , with the charge-induced band bending enhancing the conductivity locally around its location, as seen in Figure 2b-2. In the constant-height STM frame in Figure 2b-3 a reduction of current due to the charge-induced band bending is again observed, along with a distortion of the density of states of the

• , as indicated by the height scales in the constant current STM images in Figure 2k-1,2. In the constant height STM image of Figure 2k-3, it shows only a slight increase in conductivity localized to a single atomic site, suggesting that the Si atom on one side of the dimer is perhaps replaced by this

• ). STM imaging in Figure 2c-1 and Figure 2c-3 show an enhancement in conductivity at dimers neighbouring the reconstruction and a reduction above the H2Si atoms. Figure 2c-2 shows a dimer row that has been formed between two of the regular dimer rows, with Figure 2c-3 also highlighting this realignment

Effect of localized helium ion irradiation on the performance of synthetic monolayer MoS₂ field-effect transistors

• Jakub Jadwiszczak,
• Pierce Maguire,
• Conor P. Cullen,
• Georg S. Duesberg and
• Hongzhou Zhang

Beilstein J. Nanotechnol. 2020, 11, 1329–1335, doi:10.3762/bjnano.11.117

• Technology, Universität der Bundeswehr München, Werner-Heisenberg-Weg 39, 85577 Neubiberg, Germany 10.3762/bjnano.11.117 Abstract Helium ion irradiation is a known method of tuning the electrical conductivity and charge carrier mobility of novel two-dimensional semiconductors. Here, we report a systematic

• cm−2 [13][14][15][16][17], as well as good electrical conductivity for up to approx. 1018 ions cm−2 [9][10][18]. Sulfur vacancies (SVs) and the formation of a dislocation–divacancy complex can lead to significant n-doping in MoS2 [19], which shifts the threshold voltage (Vth) of the FET to higher