Enhancement of the piezoelectric coefficient in PVDF-TrFe/CoFe₂O₄ nanocomposites through DC magnetic poling

• Marco Fortunato,
• Alessio Tamburrano,
• Maria Paola Bracciale,
• Maria Laura Santarelli and
• Maria Sabrina Sarto

Beilstein J. Nanotechnol. 2021, 12, 1262–1270, doi:10.3762/bjnano.12.93

• temperatures. This process, usually referred to as electrical poling, requires the deposition of contact electrodes on the sample surface and the use of high-voltage apparatus. In the present work, in order to overcome these constraints, we have produced, characterized, and studied a polymer nanocomposite

• , the dipoles in PVDF/PVDF-TrFe must be oriented along a preferential direction. The dipole orientation is generally obtained by electrical poling, that is, the application of a strong DC electric field (ca. 106 V·cm−1) at elevated temperature (ca. 120 °C) through top and bottom electrodes [18]. However

Electrical, electrochemical and structural studies of a chlorine-derived ionic liquid-based polymer gel electrolyte

• Ashish Gupta,
• Amrita Jain,
• Manju Kumari and
• Santosh K. Tripathi

Beilstein J. Nanotechnol. 2021, 12, 1252–1261, doi:10.3762/bjnano.12.92

• presence of a long tail in lower frequency regions also suggests that a larger capacitance is associated with the electrodes. Figure 8 shows the variation of the ac conductivity as a function of frequency at various temperatures for ionic liquid-based polymer gel electrolytes ({(PVdF-HFP)-[BDiMIM][Cl]} (4

• polarization curve of an ionic liquid-based polymer gel electrolyte system is shown in Figure 11. According to this method, the optimized film of a polymer gel electrolyte is sandwiched in between two symmetrical stainless steel (SS) electrodes and the film is polarized by applying a potential of 1.0 V

• following equation: where l is the thickness of the sample, A is the geometric surface area, and Rb is the bulk electrolyte resistance which is measured by using Nyquist plots. For conductivity measurements, the samples were cut into uniform sizes and sandwiched between two stainless steel electrodes

Impact of electron–phonon coupling on electron transport through T-shaped arrangements of quantum dots in the Kondo regime

• Patryk Florków and
• Stanisław Lipiński

Beilstein J. Nanotechnol. 2021, 12, 1209–1225, doi:10.3762/bjnano.12.89

• below: where is the double dot or double orbital Anderson Hamiltonian for T-shaped geometry, which is written as: where the first term describes electrons in the electrodes and the next two terms represent electrons residing on the open (djσ) and the interacting (fjσ) dots, respectively. j enumerates

• tunneling between the electrodes and open dots and between the dots. In case of no e–ph coupling intra- and interdot interactions are assumed to be equal (U = U’). is the phonon Hamiltonian and is the Holstein electron–phonon coupling term [65]. where ω0 is the frequency and bj is the annihilation

• electrodes (for the rectangular density of states of electrodes 1/2D for |E| < D, Γ = πt2/D). For the case when phonons are coupled to the open dot Γ should be replaced by , . Gdjσ denotes the Green’s function of OQDj, which according to Equation 12 can be approximately expressed as with for l = 1 and for

The effect of cobalt on morphology, structure, and ORR activity of electrospun carbon fibre mats in aqueous alkaline environments

• Markus Gehring,
• Tobias Kutsch,
• Osmane Camara,
• Alexandre Merlen,
• Hermann Tempel,
• Hans Kungl and
• Rüdiger-A. Eichel

Beilstein J. Nanotechnol. 2021, 12, 1173–1186, doi:10.3762/bjnano.12.87

• , Institute of Physical Chemistry, 52056 Aachen, Germany IM2NP, CNRS, Aix-Marseille Université, Université de Toulon, Toulon, France 10.3762/bjnano.12.87 Abstract An innovative approach for the design of air electrodes for metal–air batteries are free-standing scaffolds made of electrospun polyacrylonitrile

• at high carbonisation temperatures it forms particles with diameters up to 300 nm. Free-standing, current-collector-free electrodes assembled from carbonised cobalt-decorated fibre mats display promising performance for the oxygen reduction reaction in aqueous alkaline media. High current densities

• at an overpotential of 100 mV and low overpotentials at current densities of 333 μA·cm−2 were found for all electrodes made from cobalt-decorated fibre mats carbonised at temperatures between 800 and 1000 °C. Keywords: carbon fibres; cobalt-decorated fibres; electrospinning; metal–air batteries

Open-loop amplitude-modulation Kelvin probe force microscopy operated in single-pass PeakForce tapping mode

• Gheorghe Stan and
• Pradeep Namboodiri

Beilstein J. Nanotechnol. 2021, 12, 1115–1126, doi:10.3762/bjnano.12.83

• about 0.9 V; the asymmetry cancels out when the CPD approaches zero. The AFM probe–sample configuration for KPFM measurement purpose is approximated to that of a plane capacitor, with the electrostatic force between the two electrodes having a parabolic voltage dependence, with V the applied bias

Assessment of the optical and electrical properties of light-emitting diodes containing carbon-based nanostructures and plasmonic nanoparticles: a review

• Keshav Nagpal,
• Erwan Rauwel,
• Frédérique Ducroquet and
• Protima Rauwel

Beilstein J. Nanotechnol. 2021, 12, 1078–1092, doi:10.3762/bjnano.12.80

• . The optoelectronic properties of SWNT thin films make them ideal for transparent conducting flexible electrodes in LED. In Figure 2, Aguirre et al. pre-fabricated vertical sheets of SWNT and then transferred them onto a glass substrate [21]. The maximum brightness and efficiency achieved in these SWNT

• -layer (4L) graphene and (b) the I–V characteristics of UV LED with and without few-layer graphene-based conductive electrodes. Figure 1a and Figure 1b were adapted from [39], with the permission of AIP Publishing. This content is not subject to CC BY 4.0. Cross-sectional scanning electron microscopy

Progress and innovation of nanostructured sulfur cathodes and metal-free anodes for room-temperature Na–S batteries

• Marina Tabuyo-Martínez,
• Bernd Wicklein and
• Pilar Aranda

Beilstein J. Nanotechnol. 2021, 12, 995–1020, doi:10.3762/bjnano.12.75

• , Na dendrite growth, and slow reaction kinetics by nanostructuring both the sulfur cathode and the Na anode. Moreover, a survey of recent patents on room temperature (RT) Na–S batteries revealed that nanostructured sulfur and sodium electrodes are still in the minority, which suggests that much

• intermediates. Consequently, the shuttle effect is minimized resulting in excellent cycle stability for 1000 cycles with 0.035% capacity decay per cycle. The research based on covalently bonded sulfur–carbon cathodes has been mostly focused on electrodes with a polyacrylonitrile (PAN) skeleton [38][39][40][41

• elemental sulfur at 450 °C for 6 h in an inert gas atmosphere. Both electrodes exhibit an excellent cycling performance because the shuttle effect and the low conductivity of elemental sulfur are avoided [39][40]. However, its applicability is hindered due to the low capacity values achieved. The former

Uniform arrays of gold nanoelectrodes with tuneable recess depth

• Elena O. Gordeeva,
• Ilya V. Roslyakov,
• Alexey P. Leontiev,
• Alexey A. Klimenko and
• Kirill S. Napolskii

Beilstein J. Nanotechnol. 2021, 12, 957–964, doi:10.3762/bjnano.12.72

• approaches for the preparation of such systems is templated electrodeposition. In the present study, porous anodic alumina templates are used to prepare Au nanoelectrode arrays. Multistage electrodeposition is proposed for the formation of recessed electrodes with the ability to tune the distance between the

• electrodes with a small radius (usually less than 50 nm), which is comparable or less than the thickness of the electric double layer [1][2]. The main advantages of such systems include high mass-transfer rates under steady-state diffusion, diminished electric double layer capacitance, and short response

• direct-writing using electron beam lithography [11][12] or ion beam milling [13][14]) are limited by the ensemble area and expensive in mass production, but allow one to precisely tune the parameters of an array (a geometry of individual electrodes and the distance between them) over a wide range. An

The role of deep eutectic solvents and carrageenan in synthesizing biocompatible anisotropic metal nanoparticles

• Nabojit Das,
• Akash Kumar and
• Raja Gopal Rayavarapu

Beilstein J. Nanotechnol. 2021, 12, 924–938, doi:10.3762/bjnano.12.69

• surface coating with nanoparticles through electrodeposition. A general electrodeposition setup consists of three electrodes, that is cathode, anode, and a reference electrode [78]. The solvation property and the conductivity of DESs also play a critical role in determining the physical structure, yield

Effects of temperature and repeat layer spacing on mechanical properties of graphene/polycrystalline copper nanolaminated composites under shear loading

• Chia-Wei Huang,
• Man-Ping Chang and
• Te-Hua Fang

Beilstein J. Nanotechnol. 2021, 12, 863–877, doi:10.3762/bjnano.12.65

• properties in various fields, such as supercapacitors, integrated electrodes, catalysis, and sensors [10][11][12][13]. Furthermore, the interaction between graphene and matrix materials directly affects the mechanical properties of composites [14]. The van der Waals force between graphene and metals can

9.1% efficient zinc oxide/silicon solar cells on a 50 μm thick Si absorber

• Rafal Pietruszka,
• Bartlomiej S. Witkowski,
• Monika Ozga,
• Katarzyna Gwozdz,
• Ewa Placzek-Popko and
• Marek Godlewski

Beilstein J. Nanotechnol. 2021, 12, 766–774, doi:10.3762/bjnano.12.60

• structured top electrodes were examined by numerous measuring techniques. Scanning electron microscopy revealed a grain-like morphology of the magnesium-doped zinc oxide film. The size of the grains is closely related to the structure of the nanorods. The external quantum efficiency of the cells was measured

• , allowing us to construct a 3D top electrode and to improve light collection/harvesting in cells with such electrodes. Figure 3 shows cross sections of the studied photovoltaic structures. The cell labeled as sample A contains ZnONR grown via the hydrothermal method. On the nanorods, an MZO film was

Recent progress in magnetic applications for micro- and nanorobots

• Ke Xu,
• Shuang Xu and
• Fanan Wei

Beilstein J. Nanotechnol. 2021, 12, 744–755, doi:10.3762/bjnano.12.58

• improve and perfect micro- and nanorobotic systems. A combination of magnetic drive and micromixer can also be applied to MNRs. For example, there have been a variety of electromagnetic micromixers, including external permanent magnets, electromagnets, microstirrers, and integrated electrodes. The

Nanogenerator-based self-powered sensors for data collection

• Yicheng Shao,
• Maoliang Shen,
• Yuankai Zhou,
• Xin Cui,
• Lijie Li and
• Yan Zhang

Beilstein J. Nanotechnol. 2021, 12, 680–693, doi:10.3762/bjnano.12.54

• under exposure to oxygen (O2), hydrogen sulfide (H2S) gas, and water vapor. The sensitivity to H2S gas was as low as 100 ppm. The design of the whole self-powered sensor system consists of three parts. A ZnO NW array as the piezoelectric energy generation module, Ti foil and Al layer as electrodes, and

• consisted of top and bottom Cr/Au electrodes, ZnO NWs on the electrodes and a flexible polyester substrate. Figure 6a shows the PENG fixed to the inner surface of the tire with adhesive tape. The output voltage of the PENG changed with the deformation of the tire during rolling. Figure 6b shows the output

A review of defect engineering, ion implantation, and nanofabrication using the helium ion microscope

• Frances I. Allen

Beilstein J. Nanotechnol. 2021, 12, 633–664, doi:10.3762/bjnano.12.52

• irradiating just one side of a portion of WSe2 bridging two metal contacts to create semiconducting (pristine) and insulating (irradiated) halves contacted by the source and drain electrodes (Figure 2b). Direct-write of further logic circuits into single flakes of WSe2 and WS2 has also been demonstrated [26

High-yield synthesis of silver nanowires for transparent conducting PET films

• Gul Naz,
• Hafsa Asghar,
• Muhammad Ramzan,
• Muhammad Arshad,
• Rashid Ahmed,
• Muhammad Bilal Tahir,
• Bakhtiar Ul Haq,
• Nadeem Baig and
• Junaid Jalil

Beilstein J. Nanotechnol. 2021, 12, 624–632, doi:10.3762/bjnano.12.51

• electrodes made of sputtered indium tin oxide (ITO) films [1][2][3]. These films are widely used because of their high transmittance, low sheet resistance, and high electrical conductivity. Yet, they still have some major drawbacks such as high cost, intrinsic brittleness due to the ceramic nature [4], and

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

• interesting experimental material to study [1][2][3]. Importantly, it is a promising material for new kinds of low-dimensional transistors, gas sensors, ultra-capacitors, electrodes for solar cells, and for van der Waals heterostructures. In order to construct these devices, an interaction between graphene

On the stability of microwave-fabricated SERS substrates – chemical and morphological considerations

• Limin Wang,
• Aisha Adebola Womiloju,
• Christiane Höppener,
• Ulrich S. Schubert and
• Stephanie Hoeppener

Beilstein J. Nanotechnol. 2021, 12, 541–551, doi:10.3762/bjnano.12.44

• Raman signals can be significantly improved when the measurements are performed on roughened silver electrodes [5], an understanding of the SERS enhancement process has been gained from a large number of investigations. This has rationalized the requirements for a good performance of SERS substrates

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

• , however, does not take the real geometry of the sensor and electrodes into account. At low temperatures, the most common method is to use STM to calibrate the amplitude, provided that STM is available and that the sample is conducting. This method is often used for normal AFM, where the cantilever

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

• discovery of the SERS effect in 1974 [27], most of the research is focused on biomolecules and medical applications [28][29]. The SERS effect of water has been studied since 1980. There are reports on the SERS effect of water in aqueous solutions of electrolytes placed between metal electrodes (Ag, Au, Cu

Boosting of photocatalytic hydrogen evolution via chlorine doping of polymeric carbon nitride

• Malgorzata Aleksandrzak,
• Michalina Kijaczko,
• Wojciech Kukulka,
• Daria Baranowska,
• Martyna Baca,
• Beata Zielinska and
• Ewa Mijowska

Beilstein J. Nanotechnol. 2021, 12, 473–484, doi:10.3762/bjnano.12.38

• three cycles of light on–off, the performance of both electrodes tends to stabilize, indicating that the photocatalysts are stable under visible-light irradiation [55]. The measurements obtained from electrochemical impedance spectroscopy (EIS) are shown in Figure 9b. It is known that the arc radius of

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

• , the lithium storage reactions associated with TMO electrodes are accompanied with large volume changes during lithiation–delithiation processes [1][2][3][4][6], but their volume variations are less significant [1]. This may lead to electrode pulverization and subsequent detachment of active materials

• cycle of Co3O4 electrodes and it has been frequently reported for Co3O4 nanostructures with various shapes [15][21][23][24][25][26][27][30][31][34][36]. This capacity fade is usually ascribed to an irreversible electrolyte decomposition, the formation of the SEI layer, and the formation of stable Li2O

• oscillates around 690 mAh·g−1 up to the 70th cycle. Then, it gradually fades and reaches about 533 mAh·g−1 after 100 cycles. Nevertheless, the measured capacity is still 1.43 times higher than the theoretical capacity of commercially used graphite electrodes (372 mAh·g−1 [10][21]). This behavior is

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

• 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

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

• , which leads to a rapid electron transfer from the surface reaction of the target gas with the MOS to the electrodes [35]. Additionally, MOS and graphene can form junctions at their interface. For example, p–p homojunctions can be formed between NiO and rGO to increase the gas sensing responsivity and

• 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

• reading processing. We then outline the strengths and weaknesses of iEEG in studying human cognition and the development of intracranial recordings that use brain-compatible flexible electrodes. We close by discussing the potential advantages and challenges of future investigations adopting nanomaterial

• , but its spatial resolution is rather poor. By placing electrodes on the scalp, EEG detects electrical activations of the brain. EEG has been used rather extensively in clinical settings to diagnose conditions such as epilepsy, brain tumours or damage, stroke, seizures, and sleep disorders by detecting

• aberrant EEG activity [3]. However, the quality of brain signals recorded from deep subcortical regions, such as the insula and hippocampus, remains questionable [4]. Similar to EEG, iEEG also uses electrodes to detect brain neural activity, but the electrodes are either placed on the surface of the brain

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

• measurement of I–V characteristics [21]. The bias voltage applied between pipette and bath electrode was approximately 100 mV. Both electrodes were non-polarizable (Ag/AgCl). For SICM topography measurements the nanopipette approached the surface until the setpoint of 0.98 nA (corresponding to an ion current