Tuning the performance of vanadium redox flow batteries by modifying the structural defects of the carbon felt electrode

• Ditty Dixon,
• Deepu Joseph Babu,
• Aiswarya Bhaskar,
• Hans-Michael Bruns,
• Joerg J. Schneider,
• Frieder Scheiba and
• Helmut Ehrenberg

Beilstein J. Nanotechnol. 2019, 10, 1698–1706, doi:10.3762/bjnano.10.165

• the electrical conductivity, leading to performance loss. Furthermore, it has been proposed by Schweiss et al. that an increase in the amorphous content in the felt can increase the hydrogen evolution reaction [12]. In one way or the other, functionalization with heteroatoms will always reduce the

• increase in electrical conductivity as well as active sites [16]. In this work, a carbon felt electrode with minimum oxygen functional groups and a larger amount of defects in the form of N-doping and edge sites was prepared by employing the N2 plasma technique. The N2-plasma-treated sample showed enhanced

Effects of surface charge and boundary slip on time-periodic pressure-driven flow and electrokinetic energy conversion in a nanotube

• Mandula Buren,
• Yongjun Jian,
• Yingchun Zhao,
• Long Chang and
• Quansheng Liu

Beilstein J. Nanotechnol. 2019, 10, 1628–1635, doi:10.3762/bjnano.10.158

• nanotube, the net electric current over the cross section of the nanotube is zero, i.e., where σ = 2z2e2Dn0/(kBT) is the electric conductivity and D is the diffusivity of ions in the electrolyte. From the equation Is + Ic=0, the streaming electric field Es can be obtained in the form: Dimensionless

Upcycling of polyurethane waste by mechanochemistry: synthesis of N-doped porous carbon materials for supercapacitor applications

• Christina Schneidermann,
• Pascal Otto,
• Desirée Leistenschneider,
• Sven Grätz,
• Claudia Eßbach and
• Lars Borchardt

Beilstein J. Nanotechnol. 2019, 10, 1618–1627, doi:10.3762/bjnano.10.157

• from coconut shells and other biomass waste [19][20][21]. However, the industrial use of plastics for this purpose has not been established yet. The main properties of porous carbon materials [22][23] such as high specific surface area and high electrical conductivity allow for a variety of

• carbon materials can be functionalized with heteroatoms such as nitrogen, which was reported to affect the electrical conductivity [39][40][41][42], the energy storage capacity, and the wettability of the electrodes with electrolyte [43][44][45]. Commonly, nitrogen is inserted into the carbon framework

• increased with increasing nitrogen content. Thus, nitrogen-doping has no beneficial influence on the conductivity of the electrodes in contrast to expectations. The materials have been processed to free-standing electrodes and characterized as symmetrical supercapacitors in three different electrolytes: 1 M

Kelvin probe force microscopy work function characterization of transition metal oxide crystals under ongoing reduction and oxidation

• Dominik Wrana,
• Karol Cieślik,
• Wojciech Belza,
• Christian Rodenbücher,
• Krzysztof Szot and
• Franciszek Krok

Beilstein J. Nanotechnol. 2019, 10, 1596–1607, doi:10.3762/bjnano.10.155

• obtaining work function and conductivity maps on the same area by combining noncontact and contact modes of atomic force microscopy (AFM). As most of the real applications require ambient operating conditions, we have additionally checked the impact of air venting on the work function of the TiO/SrTiO3(100

• method employing KPFM and local conductivity AFM for the characterization of the work function of transition metal oxides may help in understanding the impact of reduction and oxidation on electronic properties, which is of high importance in the development of effective sensing and catalytic devices

• conductivity. Here, a huge advantage over other materials is the possibility of oxides that self-dope via the introduction of oxygen vacancies [13], which is also a reason why there are not many reliable experimental studies on the work function of transition metal oxides (with one notable exception [14

Materials nanoarchitectonics at two-dimensional liquid interfaces

• Katsuhiko Ariga,
• Michio Matsumoto,
• Taizo Mori and
• Lok Kumar Shrestha

Beilstein J. Nanotechnol. 2019, 10, 1559–1587, doi:10.3762/bjnano.10.153

• uniform two-dimensional nanocarbon films, so-called carbon nanosheets, with ca. 10 nm thickness with dispersed nanopore structural motifs. The electrical conductivity of the transferred film was significantly increased after the thermal carbonization process. Nitrogen-doping was carried out simply by

• mixing nitrogen-containing compounds such as pyridine into the original solution of the carbon nanoring molecule. The prepared nitrogen-doped carbon nanosheets exhibited a higher electrical conductivity than the non-doped ones did. It should be noted that these nanomaterial fabrications can be conducted

High-temperature resistive gas sensors based on ZnO/SiC nanocomposites

• Vadim B. Platonov,
• Marina N. Rumyantseva,
• Alexander S. Frolov,
• Alexey D. Yapryntsev and
• Alexander M. Gaskov

Beilstein J. Nanotechnol. 2019, 10, 1537–1547, doi:10.3762/bjnano.10.151

• (XPS). The electrophysical and gas sensing properties of the materials were investigated by in situ conductivity measurements in the presence of the reducing gases CO and NH3 (20 ppm), in dry conditions (relative humidity at 25 °C RH25 = 0) and in humid air (RH25 = 30%) in the temperature range 400–550

• °C. The ZnO/SiC nanocomposites were characterized by a higher concentration of chemisorbed oxygen, higher activation energy of conductivity, and higher sensor response towards CO and NH3 as compared with ZnO nanofibers. The obtained experimental results were interpreted in terms of the formation of

• composite nanomaterials using highly dispersed silicon carbide (SiC). The unique physical and chemical properties of silicon carbide – wide band gap (Eg = 2.4–3.2 eV), high Debye temperature 1400 K, high thermal conductivity of 4.9 W/cm·K, low reactivity to oxygen and water vapor – ensure the stability of

Rapid thermal annealing for high-quality ITO thin films deposited by radio-frequency magnetron sputtering

• Petronela Prepelita,
• Ionel Stavarache,
• Doina Craciun,
• Florin Garoi,
• Catalin Negrila,
• Beatrice Gabriela Sbarcea and
• Valentin Craciun

Beilstein J. Nanotechnol. 2019, 10, 1511–1522, doi:10.3762/bjnano.10.149

• accomplishment of this work consists in obtaining ITO films of high quality, that is, good uniformity, high transparency (93%), and good conductivity (1.35 × 104 Ω−1 cm−1). The novelty of this study lies in the RTA process applied to the ITO films, which exhibited a beneficial influence on the structural

• conductivity values were measured using a two-channel B2901A measurement unit (KEYSIGHT technology). Results and Discussion The analysis of the morphology of the nanostructured surface of both the as-deposited and RTA-processed ITO thin films was conducted using SEM. This method allows for the layer thickness

• of the thin films. This leads to a reduction of the intervals between them and, consequently, of the bandgap. The width of the bandgap corresponding to direct transitions increases with application of the annealing treatment for the studied ITO samples. The optical conductivity coefficient dependence

Flexible freestanding MoS₂-based composite paper for energy conversion and storage

• Florian Zoller,
• Jan Luxa,
• Thomas Bein,
• Dina Fattakhova-Rohlfing,
• Daniel Bouša and
• Zdeněk Sofer

Beilstein J. Nanotechnol. 2019, 10, 1488–1496, doi:10.3762/bjnano.10.147

• graphite (372 mA·h·g−1) [6]. However, poor electrical conductivity, capacity fading and large volume changes upon charge and discharge make the commercialization of MoS2 in LIBs problematic [6][7]. In order to address this issue, the fabrication of MoS2 composites and carbonaceous support materials (such

• ][34]. However, MoS2 possesses only a low intrinsic conductivity, which hinders the charge transport [35]. Using MoS2 together with conducting support materials, such as multiwalled carbon nanotubes (MWCNTs) has already been demonstrated to improve the catalytic properties [35]. Herein, we report on

• high flexibility and combines the high conductivity of SWCNTs and electrochemical potential of MoS2. We also show that the material finds use as an anode in LIBs, supercapacitor electrodes and HER catalyst. The application for LIBs seems particularly promising as this composite material requires no

Hierarchically structured 3D carbon nanotube electrodes for electrocatalytic applications

• Pei Wang,
• Katarzyna Kulp and
• Michael Bron

Beilstein J. Nanotechnol. 2019, 10, 1475–1487, doi:10.3762/bjnano.10.146

• discovery in 1991 [1] due to their high electrical conductivity, large surface area, good chemical stability, high mechanical strength and high aspect ratio and are considered as promising materials for diverse applications such as field emission displays, energy storage devices, sensors, and so on [2][3][4

• support is as important as the active material in order to form an optimum catalyst. For electrocatalytic applications, the support should possess high electrical conductivity, large surface area and good chemical and mechanical stability. Furthermore, the electrode prepared with the catalyst should

• transfer resistance with respect to the primary CNTs as determined by electrochemical impedance spectroscopy. Thus, we speculate that the improvement in Pt dispersion is due to a better conductivity within the 3D network and a facilitated electron transfer, which may facilitate Pt nucleation at the CNT

Direct observation of oxygen-vacancy formation and structural changes in Bi₂WO₆ nanoflakes induced by electron irradiation

• Hong-long Shi,
• Bin Zou,
• Zi-an Li,
• Min-ting Luo and
• Wen-zhong Wang

Beilstein J. Nanotechnol. 2019, 10, 1434–1442, doi:10.3762/bjnano.10.141

• temperature increase through electron-beam irradiation was calculated according to the following formula [31]: where I, k, e, b, r0, and ΔE are the beam current, thermal conductivity, electron charge, sample radius, beam radius, and the total energy loss per electron in a sample of thickness d, respectively

Selective gas detection using Mn₃O₄/WO₃ composites as a sensing layer

• Yongjiao Sun,
• Zhichao Yu,
• Wenda Wang,
• Pengwei Li,
• Gang Li,
• Wendong Zhang,
• Lin Chen,
• Serge Zhuivkov and
• Jie Hu

Beilstein J. Nanotechnol. 2019, 10, 1423–1433, doi:10.3762/bjnano.10.140

• from the conduction band of WO3. Surface-adsorbed oxygen ions (O2−, O−, O2−) and a thick electron depletion layer of WO3 will form, giving rise to a low conductivity via the loss of free electrons, as shown in Figure 12a. Conversely, when exposed to reducing gases (such as H2S, NH3 and CO), the redox

• reaction between surface-adsorbed oxygen ions and reducing gas molecules will causes an increase of conductivity because the trapped electrons could be released back to the conduction band of WO3, as shown in Figure 12b. The reaction formulas are represented as follows in Equations 3–5. For the Mn3O4/WO3

Kelvin probe force microscopy of the nanoscale electrical surface potential barrier of metal/semiconductor interfaces in ambient atmosphere

• Petr Knotek,
• Tomáš Plecháček,
• Jan Smolík,
• Petr Kutálek,
• Filip Dvořák,
• Milan Vlček,
• Jiří Navrátil and
• Čestmír Drašar

Beilstein J. Nanotechnol. 2019, 10, 1401–1411, doi:10.3762/bjnano.10.138

• efficiency of the material could be expressed in terms of figure-of-merit, ZT, defined as dimensionless quantity ZT = S2·σ·T/κ , where S is the thermopower (Seebeck coefficient), σ is the electrical conductivity, T is the absolute temperature and κ is the thermal conductivity. There were many concepts for

• (NIs/NPs) into the bulk semiconducting matrices has been proposed [4][5][6] and supported in theoretical works [7][8][9]. Such NIs or NPs are able to enhance ZT via a reduction of the thermal conductivity by phonon scattering [10][11][12][13][14], by modulated carrier doping or by the carrier energy

• harm to other transport parameters. The characterization of NIs or NPs in TE materials is realized most frequently by the different modes of atomic force microscopy (AFM): i) by comparing the conductivity/resistivity (CAFM) or I–V curves measurement in the direct-contact of the conductive tip and the

A biomimetic nanofluidic diode based on surface-modified polymeric carbon nitride nanotubes

• Kai Xiao,
• Baris Kumru,
• Lu Chen,
• Lei Jiang,
• Bernhard V. K. J. Schmidt and
• Markus Antonietti

Beilstein J. Nanotechnol. 2019, 10, 1316–1323, doi:10.3762/bjnano.10.130

• the carbon nitride nanotubes (Figure S4, Supporting Information File 1). Figure 3 showed the conductance as a function of salt concentration (KCl) both in bulk solution and across the CNNM. The conductivity of the bulk solution is proportional to the concentration of KCl, while the ionic conductance

Multicomponent bionanocomposites based on clay nanoarchitectures for electrochemical devices

• Giulia Lo Dico,
• Bernd Wicklein,
• Lorenzo Lisuzzo,
• Giuseppe Lazzara,
• Pilar Aranda and
• Eduardo Ruiz-Hitzky

Beilstein J. Nanotechnol. 2019, 10, 1303–1315, doi:10.3762/bjnano.10.129

• biocomposite: HNTs act as nanocontainers for bioactive species, GNPs provide electrical conductivity (enhanced by doping with MWCNTs) and, the CHI polymer matrix introduces mechanical and membrane properties that are of key significance for the development of electrochemical devices. The resulting

• nanofillers to ensure the mechanical strength and electrical conductivity of the prepared bionanocomposite films and foams [26]. Moreover, MWCNTs are supposed to act as nanowires improving the contact between the active site of the immobilized enzymes and an electrode surface via direct electron transfer [39

• ]. The resulting multicomponent systems have advantages such as high electrical conductivity and flexibility that make the bionanocomposite films appropriate components for biosensors [35][40] for glucose detection, while the relatively high porosity of the bioactive foams enhances the power density and

Fabrication of phase masks from amorphous carbon thin films for electron-beam shaping

• Lukas Grünewald,
• Dagmar Gerthsen and
• Simon Hettler

Beilstein J. Nanotechnol. 2019, 10, 1290–1302, doi:10.3762/bjnano.10.128

• irradiation, which in turn increases scattering. In this work we investigated amorphous carbon (aC) as an alternative PM material. Amorphous carbon, like SixNy, offers high mechanical stability, low scattering probability and in addition high electrical conductivity. Because of these properties, aC is

Alloyed Pt₃M (M = Co, Ni) nanoparticles supported on S- and N-doped carbon nanotubes for the oxygen reduction reaction

• Stéphane Louisia,
• Yohann R. J. Thomas,
• Pierre Lecante,
• Marie Heitzmann,
• M. Rosa Axet,
• Pierre-André Jacques and
• Philippe Serp

Beilstein J. Nanotechnol. 2019, 10, 1251–1269, doi:10.3762/bjnano.10.125

• -based alloys can also been used [24][25]. Therefore, it seems important to develop nanostructured catalysts supported on a material with electronic conductivity and surface area close to the common CB but with more resistance towards corrosion. Interestingly, it has recently been shown that the

• -CNTs) and S-doped CNT (S-CNTs). To further increase the corrosion resistance and the electrical conductivity of the N-CNTs, they were annealed at 1000 °C to produce N-CNTHT. The introduction of nitrogen or sulfur into the CNT structure has an effect on the structural properties of the prepared

• management and interaction with the electrolyte, iii) a good dispersibility in the ink to limit mass transfer, and iv) structural features allowing high conductivity and chemical stability. As some of these characteristics are not compatible (e.g., a high metal dispersion should be favored on defective

Porous N- and S-doped carbon–carbon composite electrodes by soft-templating for redox flow batteries

• Maike Schnucklake,
• László Eifert,
• Jonathan Schneider,
• Roswitha Zeis and
• Christina Roth

Beilstein J. Nanotechnol. 2019, 10, 1131–1139, doi:10.3762/bjnano.10.113

• conductivity in the acidic and corrosive electrochemical environment of the battery system. Moreover, they are comparatively inexpensive [5]. One disadvantage is their poor electrochemical activity, which makes an activation step necessary [6]. A common way to achieve higher activities is the thermal treatment

• to serve as electrodes in the VRFB, since they combine the desired properties of the two components, namely good electron conductivity and high surface area. The carbon fibers as supporting material possess a high electron conductivity, while the amorphous carbon coating provides the catalytic

Direct growth of few-layer graphene on AlN-based resonators for high-sensitivity gravimetric biosensors

• Jimena Olivares,
• Teona Mirea,
• Lorena Gordillo-Dagallier,
• Bruno Marco,
• José Miguel Escolano,
• Marta Clement and
• Enrique Iborra

Beilstein J. Nanotechnol. 2019, 10, 975–984, doi:10.3762/bjnano.10.98

• porous gold films [9], owing to their outstanding properties in terms of electrical conductivity combined with their chemical stability and their ability to alter their chemistry under controlled conditions. Recently, functionalized graphene and graphene oxide have attracted the attention of the

Capillary force-induced superlattice variation atop a nanometer-wide graphene flake and its moiré origin studied by STM

• Loji K. Thomas and
• Michael Reichling

Beilstein J. Nanotechnol. 2019, 10, 804–810, doi:10.3762/bjnano.10.80

• pyrolytic graphite with a high degree of crystallographic orientation of the c-axis. Polycrystalline HOPG consists of micrometer-sized grains and has been widely used as a substrate in STM studies [1][2][3] due to its high conductivity, atomic flatness and chemical inertness [4]. The surface also contains

An efficient electrode material for high performance solid-state hybrid supercapacitors based on a Cu/CuO/porous carbon nanofiber/TiO₂ hybrid composite

• Mamta Sham Lal,
• Thirugnanam Lavanya and
• Sundara Ramaprabhu

Beilstein J. Nanotechnol. 2019, 10, 781–793, doi:10.3762/bjnano.10.78

• amount of charge than double layer supercapacitors and exhibits superior energy density [6]. Pseudo-supercapacitors have limited electrical conductivity and slow charge–discharge kinetics, resulting in a significant decrease in power density. Supercapacitors have been explored by realizing both faradaic

• have been envisaged as a prospective electrode material due to its good mechanical strength, high surface area, relatively high conductivity [11][12]. Hence, carbon nanofibers produced by electrospinning, which is a cost-effective, simple and industry-viable technology, offer high production rate, high

• and effective strategy that can enhance the electrical conductivity and provide relatively high specific capacity (increased by 10–30%). However, the electrochemical performance of this material deteriorates due to the large volume expansion during cycling. This results in a gradual loss of

Trapping polysulfide on two-dimensional molybdenum disulfide for Li–S batteries through phase selection with optimized binding

• Sha Dong,
• Xiaoli Sun and
• Zhiguo Wang

Beilstein J. Nanotechnol. 2019, 10, 774–780, doi:10.3762/bjnano.10.77

• efficiency, active material loss, and rapid capacity fading hinder the practical application of Li–S batteries [6]. The insulating nature of sulfur and its lithiation products, Li2S2 and Li2S, leads to low electrical conductivity of the cathode and low rate capability. Dissolved higher-order lithium

• shuttle effect. The shuttle effect aggravates the cyclic performance of the Li–S battery. During recent years, many approaches have been devoted to suppressing the shuttle effect and improving the conductivity. Physical confinement of LPSs within host materials with large surface area, such as carbon

• electrical conductivity [10]. However, the adsorption of polarized LPSs on non-polarized graphene is weak; heteroatom doping is necessary for improving the anchoring effect. Nitrogen doping has been used to modify the anchoring behavior of graphene, and the N-doped graphene showed improved anchoring of Li2Sx

An iridescent film of porous anodic aluminum oxide with alternatingly electrodeposited Cu and SiO₂ nanoparticles

• Menglei Chang,
• Huawen Hu,
• Haiyan Quan,
• Hongyang Wei,
• Zhangyi Xiong,
• Jiacong Lu,
• Pin Luo,
• Yaoheng Liang,
• Jianzhen Ou and
• Dongchu Chen

Beilstein J. Nanotechnol. 2019, 10, 735–745, doi:10.3762/bjnano.10.73

• the electrical conductivity of the sample) before scanning. Cu can be seen as numerous particles at the nanoscale homogeneously distributed over the entire surface. In sample S2 (Figure 4b), Si can be observed all over the sample surface, revealing the uniform deposition of SiO2. The electrodeposited

A carrier velocity model for electrical detection of gas molecules

• Ali Hosseingholi Pourasl,
• Sharifah Hafizah Syed Ariffin,
• Mohammad Taghi Ahmadi,
• Razali Ismail and
• Niayesh Gharaei

Beilstein J. Nanotechnol. 2019, 10, 644–653, doi:10.3762/bjnano.10.64

• other hand, the charge transfer between GNRs and the adsorbed target molecule can change the concentration of the carriers and modulate the conductivity of the GNR. In addition, because of the atomic forces and charge transfer, molecular adsorption can lead to modification of the energy band diagram and

• the band gap and charge transfer occurred, which implies that CO acts as a donor; therefore, the CO adsorption can increase the electron concentration. Increasing the carrier concentration can increase the conductivity. For NO adsorption, a reduction in the carrier concentration will decrease the AGNR

• conductivity. Furthermore, the energy gap increase results in a conductance decrease of the AGNR as well. These effects on the physical properties and the charge travel between the channel and gas molecules lead to some changes in the electrical characteristics of the AGNR-FET sensor. Figure 6a,b present the I

Enhancement in thermoelectric properties due to Ag nanoparticles incorporated in Bi₂Te₃ matrix

• Srashti Gupta,
• Dinesh Chandra Agarwal,
• Bathula Sivaiah,
• Sankarakumar Amrithpandian,
• Kandasami Asokan,
• Ajay Dhar,
• Binaya Kumar Panigrahi,
• Devesh Kumar Avasthi and
• Vinay Gupta

Beilstein J. Nanotechnol. 2019, 10, 634–643, doi:10.3762/bjnano.10.63

• nanoparticles on thermoelectric properties can be understood on the basis of a carrier-filtering effect that results in an increase in thermopower along with a control over the reduction in electrical conductivity to maintain a high power factor yielding a high figure of merit. Keywords: bismuth telluride

• = S2σT/k) and to enhance figure of merit (ZT), one needs to increase the power factor (S2σ, where S is the Seebeck coefficient or thermopower, σ is the electrical conductivity) or to decrease thermal conductivity (k). In bulk, all three parameters (S, σ, k) are interdependent. In bulk Bi2Te3, ZT is close

• applications but these materials are not very efficient because of their low ZT [8][9]. To increase ZT, nanostructures play an important role in the simultaneous increase in power factor and reduction in phonon thermal conductivity (kph) [10]. Recently, Faleev et al. [11] and Zebardaji et al. [12] performed

Review of time-resolved non-contact electrostatic force microscopy techniques with applications to ionic transport measurements

• Aaron Mascaro,
• Yoichi Miyahara,
• Tyler Enright,
• Omur E. Dagdeviren and
• Peter Grütter

Beilstein J. Nanotechnol. 2019, 10, 617–633, doi:10.3762/bjnano.10.62

• dielectric constant (εr > 10), which is similar to those found in many solid ionic conductors such as LiFePO4 and LiCoO2, and for its low electronic conductivity and lack of mobile ions. This experiment is therefore a reliable validation of the z-dependence of the tip–sample capacitance expected for actual