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

• silver paste and connected to the anode of the electrolytic cell, and the cathode was the Pt sheet. Oxalic solution (0.3 M) was used as the electrolyte. The applied voltage was 20 V and the duration of its application was 10 min. After selective EC wet etching, the sample with suspended NWs was placed in

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

• . The structure of NiCx-NiFe-NC efficiently improved the electron and ion transfer between the cathode and the electrolyte during the electrochemical processes, resulting in superior electrocatalytic properties in lithium–oxygen batteries. This study indicates that nickel carbide supported on N-doped

• the anode, and LiCF3SO3 dissolved in tetraethylene glycol dimethyl ether was used as the electrolyte. A glass filter (Whatman grade GF/D) was used as the separator in these coin cells. The cell assembly was carried out in an Ar-filled glove box (H2O < 0.5 ppm, O2 < 0.5 ppm). The sealed coin cells were

• . Moreover, the decomposition of the electrolyte at a high voltage is another possible reason, resulting in the decrease of the capacity during the cycling test. However, the specific capacity of NiFe-PBA/PP-900 remained at 4.9 mAh·cm−2 after the cell was cycled for five times (Figure 6c). This value is

Fabrication of nano/microstructures for SERS substrates using an electrochemical method

• Jingran Zhang,
• Tianqi Jia,
• Xiaoping Li,
• Junjie Yang,
• Zhengkai Li,
• Guangfeng Shi,
• Xinming Zhang and
• Zuobin Wang

Beilstein J. Nanotechnol. 2020, 11, 1568–1576, doi:10.3762/bjnano.11.139

• succession. No further purification was carried out. A customized DC power supply was used to conduct the PEO. Figure 1 shows the schematic diagram of nanopore formation using PEO processing. The specimens and carbon tubes were utilized as the anode and cathode, respectively, and the electrolyte solution was

• prepared with 2 g/L KOH and 10 g/L Na3PO4 in deionized water. The PEO treatment was performed in constant-current mode with a fixed constant current density of 25 mA/cm2. The frequency and duty ratio were 500 Hz and 50%, respectively. The electrolyte temperature was regulated within 30 ± 2 °C by a

• roughness and shows the potential for storing micro- or nanoparticles. During PEO treatment, the intrinsic passivation layer of the Mg alloy is disrupted in random positions through local melting during electrical breakdowns. After cooling by the electrolyte, a stable oxide layer containing arrayed pores is

Antimicrobial metal-based nanoparticles: a review on their synthesis, types and antimicrobial action

• Matías Guerrero Correa,
• Fernanda B. Martínez,
• Cristian Patiño Vidal,
• Camilo Streitt,
• Juan Escrig and
• Carol Lopez de Dicastillo

Beilstein J. Nanotechnol. 2020, 11, 1450–1469, doi:10.3762/bjnano.11.129

• -condensation of the vapors on the cold surface of the vacuum reactor. Sergeev et al. [45] obtained Ag nanoparticles with sizes ranging from 20 to 150 nm using this technique. The electrochemical anodization method is based on the reactions that occur between the electrode and the electrolyte. In this method

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

• particle size but also the morphology of the entire Pt/CNW structure plays a significant role – the highest ECSA and utilization are obtained for the Pt/CNW layer with the most dense structure (shorter CNWs), most likely resulting from improved contact between the Pt particles and the liquid electrolyte

• with the liquid electrolyte during CV, a sufficient ECSA and utilization were obtained. The presented synthesis method is highly versatile, as a multitude of different metal acetylacetonates is commercially available, which facilitates the deposition of a variety of metal/CNW hybrids for optimization

• three-electrode electrochemical cell (glassy cell: double wall, temperature-controlled at 25 °C) filled with 0.1 M HClO4 electrolyte (AppliChem PanReac, 70%, for analysis, ACS, ISO). The working electrode is a GCE (diameter 4 mm, Catalog No. 013338, ALS Co., Ltd.) coated with the catalyst (by using the

Structure and electrochemical performance of electrospun-ordered porous carbon/graphene composite nanofibers

• Yi Wang,
• Yanhua Song,
• Chengwei Ye and
• Lan Xu

Beilstein J. Nanotechnol. 2020, 11, 1280–1290, doi:10.3762/bjnano.11.112

• 50 °C. Then the dried CGCNF membranes were weighed to an accuracy of 0.001 g and clamped to a platinum plate electrode holder. After clamping, the CGCNF membranes were directly used as cell electrodes and immersed into an electrolyte solution. The electrochemical measurements were performed in a

• standard three-electrode cell at room temperature. A graphite rod was used as the counter electrode, Hg/HgO was used as the reference electrode, and a 6.0 M KOH aqueous solution was used as the electrolyte solution. The electrochemical performance of the CCGNFs was investigated using an electrochemical

• pores were formed not only at the surface of the CCGNFs but also inside these fibers. The pore formation not only increased the specific surface area of the CGCNFs but also had a significant influence on the ionic conduction in the electrolyte solution, thereby affecting the final electrochemical

Role of redox-active axial ligands of metal porphyrins adsorbed at solid–liquid interfaces in a liquid-STM setup

• Thomas Habets,
• Sylvia Speller and
• Johannes A. A. W. Elemans

Beilstein J. Nanotechnol. 2020, 11, 1264–1271, doi:10.3762/bjnano.11.110

• of these complications may be eliminated by adding a third, reference electrode to the setup and by using a conducting electrolyte (so that it turns into a so-called electrochemical (EC) STM [20][21]). At the same time, the absence of an electrolyte, which typically contains a high concentration of

• -phenyloctane solvent basically makes it an electrolyte, albeit an unconventional one. Assuming that the observed additional currents are caused by the proposed redox reactions (Equation 1 and Equation 2), Mn(II)TUP is generated, which may dissociate from the solid–liquid interface and dissolve in the

Gas sorption porosimetry for the evaluation of hard carbons as anodes for Li- and Na-ion batteries

• Yuko Matsukawa,
• Fabian Linsenmann,
• Maximilian A. Plass,
• George Hasegawa,
• Katsuro Hayashi and
• Tim-Patrick Fellinger

Beilstein J. Nanotechnol. 2020, 11, 1217–1229, doi:10.3762/bjnano.11.106

• were gradually substituted by graphite in commercial LIB cells, and one of the main limitations in current SIB research, is the relatively high irreversible capacity due to the formation of a solid electrolyte interface (SEI) layer. The irreversible capacity is believed to originate from electrolyte

• decomposition at potentials below the stability window of the electrolyte (for LIBs typically around 0.8 VLi) [21]. Since the dielectric SEI passivates the electrode, an irreversible capacity proportional to the electrochemical active surface area is expected. Accordingly, the reduction of the specific surface

• either the reversible or the irreversible capacity [25]. Pores that can be accessed by solvent molecules of the electrolyte will contribute to the irreversible capacity, while smaller ones are suitable for the adsorption of alkali metal ions protected from side reactions with solvent molecules from the

Plant growth regulation by seed coating with films of alginate and auxin-intercalated layered double hydroxides

• Vander A. de Castro,
• Valber G. O. Duarte,
• Danúbia A. C. Nobre,
• Geraldo H. Silva,
• Vera R. L. Constantino,
• Frederico G. Pinto,
• Willian R. Macedo and
• Jairo Tronto

Beilstein J. Nanotechnol. 2020, 11, 1082–1091, doi:10.3762/bjnano.11.93

• , and evaluated the influence of temperature, pH value, and electrolyte solutions on the in vitro release. At a temperature of 25 °C, the release of NAA and IBA was quick in the first 100 min, followed by a gradual release profile. The increase in temperature led to a higher release of NAA and IBA

Electrochemical nanostructuring of (111) oriented GaAs crystals: from porous structures to nanowires

• Elena I. Monaico,
• Eduard V. Monaico,
• Veaceslav V. Ursaki,
• Shashank Honnali,
• Vitalie Postolache,
• Karin Leistner,
• Kornelius Nielsch and
• Ion M. Tiginyanu

Beilstein J. Nanotechnol. 2020, 11, 966–975, doi:10.3762/bjnano.11.81

• . Possibilities to produce multilayer porous structures are demonstrated. At the same time, one-step anodization in a HNO3 electrolyte is shown to lead to the formation of GaAs triangular shape nanowires with high aspect ratio (400 nm in diameter and 100 µm in length). The new data are compared to those

• previously obtained through anodizing GaAs(100) wafers in alkaline KOH electrolyte. An IR photodetector based on the GaAs nanowires is demonstrated. Keywords: anodization; crystallographically oriented pores; gallium arsenide (GaAs); nanowires; neutral electrolyte; photocurrent; porous GaAs; Introduction

• porosification process of (111) oriented GaAs crystals, three different current densities and three different voltages were used for galvanostatic and potentiostatic modes, respectively. SEM images of a GaAs crystal anodized on both surfaces in 1.75 M NaCl electrolyte are given in Figure 1. The porous features

Atomic layer deposition for efficient oxygen evolution reaction at Pt/Ir catalyst layers

• Stefanie Schlicht,
• Korcan Percin,
• Stefanie Kriescher,
• André Hofer,
• Claudia Weidlich,
• Matthias Wessling and
• Julien Bachmann

Beilstein J. Nanotechnol. 2020, 11, 952–959, doi:10.3762/bjnano.11.79

• of the salts followed by their thermal decomposition. In the alternative method, more academic in nature, atomic layer deposition (ALD) is applied to the felts after anodization. ALD allows for a controlled coating with ultralow noble-metal loadings in narrow pores. In acidic electrolyte, the ALD

• significant cost of theses noble metals renders it necessary to minimize their loading and maintain optimal access of the electrolyte to every active site of their surface. Numerous studies have been dedicated to the development of such bimetallic catalysts in various compositions [11], using various coating

• methods [12] as well as particles of various sizes [13] and shapes [14]. However, each study is presented as a self-sufficient piece of work with limited critical comparison to the state of the art. The conditions under which electrochemical performance is quantified (electrode substrate, electrolyte

A set of empirical equations describing the observed colours of metal–anodic aluminium oxide–Al nanostructures

• Cristina V. Manzano,
• Jakob J. Schwiedrzik,
• Gerhard Bürki,
• Laszlo Pethö,
• Johann Michler and
• Laetitia Philippe

Beilstein J. Nanotechnol. 2020, 11, 798–806, doi:10.3762/bjnano.11.64

• anodization conditions used in this study were as follows: 0.3 M oxalic acid as electrolyte, an applied potential of 40 V and a temperature of 3 °C. Different thicknesses were obtained by applying different second anodization times. Different AAO films were anodized under the same conditions (same porosity

Nickel nanoparticles supported on a covalent triazine framework as electrocatalyst for oxygen evolution reaction and oxygen reduction reactions

• Secil Öztürk,
• Yu-Xuan Xiao,
• Dennis Dietrich,
• Beatriz Giesen,
• Juri Barthel,
• Jie Ying,
• Xiao-Yu Yang and
• Christoph Janiak

Beilstein J. Nanotechnol. 2020, 11, 770–781, doi:10.3762/bjnano.11.62

• all CTF species. ORR and OER are two reverse reaction sequences. In alkaline electrolyte, the mechanism of OER/ORR goes through the following elementary steps where S* is an active surface site or a surface-bound/adsorbed intermediate species, such as S–OH*, S–O* (in the literature often only * is

Effect of Ag loading position on the photocatalytic performance of TiO₂ nanocolumn arrays

• Jinghan Xu,
• Yanqi Liu and
• Yan Zhao

Beilstein J. Nanotechnol. 2020, 11, 717–728, doi:10.3762/bjnano.11.59

• alcohol. The anodized electrolyte solution was 0.2 M H2SO4, the oxidation voltage was 20 V, the ambient temperature was maintained at 0 °C, and the oxidation time was 6 h. After the oxidation was completed, the aluminum sheet was immersed in 1.8 wt % H2CrO4 to remove the first oxide layer. The sample was

Exfoliation in a low boiling point solvent and electrochemical applications of MoO₃

• Matangi Sricharan,
• Bikesh Gupta,
• Sreejesh Moolayadukkam and
• H. S. S. Ramakrishna Matte

Beilstein J. Nanotechnol. 2020, 11, 662–670, doi:10.3762/bjnano.11.52

• were then dripped on the GCE. All electrochemical measurements were performed in 1 M H2SO4 electrolyte. Two-electrode system: The optimized ratio obtained from measurements of the three-electrode configuration were used to fabricate two-electrode devices. The respective amounts of MoO3 and carbon black

• steel current collectors, separated by filter paper dipped in 1 M H2SO4 electrolyte. Results and Discussion LPE assisted by tip sonication is an effective technique to peel off mono- and few-layers from layered bulk materials. In the crystal structure of α-MoO3 the atoms are connected to layers through

• response with a small iR drop. This can be attributed to the better conductivity after adding CB. To study the stability of the composite, cyclic voltammetry was carried out up to 2000 cycles. Initially, the capacitance increases, which may be attributed to the wetting of the electrode with the electrolyte

Comparison of fresh and aged lithium iron phosphate cathodes using a tailored electrochemical strain microscopy technique

• Matthias Simolka,
• Hanno Kaess and
• Kaspar Andreas Friedrich

Beilstein J. Nanotechnol. 2020, 11, 583–596, doi:10.3762/bjnano.11.46

• solid electrolyte interface (SEI) on graphite anodes and HOPG [14][15][16], Li metal [17] and on cathode materials [18][19] as well as the changes in particle size during ageing [19][20]. Other AFM modes used for the analysis of ageing are, for example, Kelvin probe force microscopy (KPFM) and

• location. Additionally, since in a dry argon atmosphere no water meniscus is available to serve as electrolyte, side reactions are avoided. Further information of the non-Vegard expansion related influences is given in the supporting information in [34]. It is possible that the ESM signal is not solely

• capacity loss from first charge to first discharge is attributed to surface layer generation (anode: solid electrolyte interface, SEI; cathode: solid permeable interface, SPI) on both electrodes, since they were rinsed before the full-cell assembly. After the first cycle, the capacity stays constant (not

Preparation and in vivo evaluation of glyco-gold nanoparticles carrying synthetic mycobacterial hexaarabinofuranoside

• Gennady L. Burygin,
• Polina I. Abronina,
• Nikita M. Podvalnyy,
• Sergey A. Staroverov,
• Leonid O. Kononov and
• Lev A. Dykman

Beilstein J. Nanotechnol. 2020, 11, 480–493, doi:10.3762/bjnano.11.39

• thermodynamically unstable and require stabilization. The sol stability can be increased by coating the GNPs with a ligand layer. As a result, the particle surface acquires the properties of the stabilizing agent under use. These stabilized GNPs can be lyophilized and become much less sensitive to electrolyte

Electrochemically derived functionalized graphene for bulk production of hydrogen peroxide

• Munaiah Yeddala,
• Pallavi Thakur,
• Anugraha A and
• Tharangattu N. Narayanan

Beilstein J. Nanotechnol. 2020, 11, 432–442, doi:10.3762/bjnano.11.34

• decreases from G-M1 to G-M4 (where G refers to graphene and M1, M2, M3, and M4 refer to the respective molarity of the electrolyte used for the exfoliation), and the elemental composition calculated from the survey spectrum of the materials revealed that the degree of oxygen functionalization varies from

• its layered nature (Supporting Information File 1, Figure S2). Here the thickness variation is confirmed using atomic force microscopy (AFM), and the results are given in Figure S3. This indicates that with an increase in the concentration of the electrolyte, the thickness is increased from 40 nm to

• 140 nm (Figure S3), which corresponds with the TEM analysis [43] and BET-based surface area data. Hence from the TEM, BET, and AFM analysis, it can be concluded that the electrolyte concentration is important for the electrochemical exfoliation assisted synthesis of ultrathin graphene layers, and the

Synthesis and enhanced photocatalytic performance of 0D/2D CuO/tourmaline composite photocatalysts

• Changqiang Yu,
• Min Wen,
• Zhen Tong,
• Shuhua Li,
• Yanhong Yin,
• Xianbin Liu,
• Yesheng Li,
• Tongxiang Liang,
• Ziping Wu and
• Dionysios D. Dionysiou

Beilstein J. Nanotechnol. 2020, 11, 407–416, doi:10.3762/bjnano.11.31

• . The transient photocurrent was measured with two Interface 1010E electrochemical workstations (Gamry, USA) using Na2SO3 (0.2 M) and Na2S (0.2 M) solutions with a volume ratio of 1:1 as electrolyte under LED lamp (λ = 470 nm) irradiation for 20 min. The samples were prepared as follows: Firstly, 10 mg

High-performance asymmetric supercapacitor made of NiMoO₄ nanorods@Co₃O₄ on a cellulose-based carbon aerogel

• Meixia Wang,
• Jing Zhang,
• Xibin Yi,
• Benxue Liu,
• Xinfu Zhao and
• Xiaochan Liu

Beilstein J. Nanotechnol. 2020, 11, 240–251, doi:10.3762/bjnano.11.18

• ), the capacitance of which originates from the electrostatic adsorption of reversible ions at the electrode/electrolyte interface, and pseudocapacitors, for which the capacitance arises from reversible Faradaic reactions correlating with electroactive species [7][8]. Compared to EDLCs, pseudocapacitors

• but also provide 3D pathways for fast electrolyte ion diffusion and electron transport. To date, Ni foam [27], copper grid [28] and titanium mesh [29] have been mostly selected as collectors, whereas the high cost of these materials limited their practical application. Carbon aerogel (CA) has been

• nanofibers of CA, which could provide diffusion channels for electrolyte ions and could be a conductive substrate to serve as a backbone; the second consists of interlaced NiMoO4 nanorods and acts as a bridge in the ternary hierarchical structure, which offers a large surface area for loading of active

Simple synthesis of nanosheets of rGO and nitrogenated rGO

• Pallellappa Chithaiah,
• Madhan Mohan Raju,
• Giridhar U. Kulkarni and
• C. N. R. Rao

Beilstein J. Nanotechnol. 2020, 11, 68–75, doi:10.3762/bjnano.11.7

• voltammetry and CD experiments with three-electrode system using 1 M H2SO4 as electrolyte (Figure 8). CV curves of rGO and H-rGO at different scan rates from 5 to 200 mV·s−1 vs Hg/Hg2SO4 are shown in Figure 8a and Figure 8b, respectively. These curves show increase in current density with decreasing scan rate

• glassy carbon working electrode (3 mM), a platinum wire counter electrode and a Hg/Hg2SO4 reference electrode with 1 M H2SO4 electrolyte. The specific capacitance (SC) of rGO and H-rGO was calculated from CV curves, according to Equation 1: where ∫IdV is the area under the CV curve, m is the mass of the

Synthesis of amorphous and graphitized porous nitrogen-doped carbon spheres as oxygen reduction reaction catalysts

• Maximilian Wassner,
• Markus Eckardt,
• Andreas Reyer,
• Thomas Diemant,
• Michael S. Elsaesser,
• R. Jürgen Behm and
• Nicola Hüsing

Beilstein J. Nanotechnol. 2020, 11, 1–15, doi:10.3762/bjnano.11.1

• measurements under controlled electrolyte transport, employing a rotating ring disk electrode (RRDE) setup (section 2 in “Results and Discussion”). We will compare the ORR performance with those of the previously reported TiON@NCS and TaON@NCS composite materials. A more detailed account of the electrochemical

• with higher reaction temperatures. 2 Electrochemical and electrocatalytic results The electrocatalytic ORR activities of the amorphous and graphitized N-doped carbon materials in acidic electrolyte (0.5 M H2SO4) are compiled in Figure 8, showing (Figure 8a,d) the ORR current densities, (Figure 8b,e

• frits from the main cell. The RHE itself consists of a Pt plate in a glass tube containing the respective electrolyte used for the measurement and a H2 bubbler. In the following, all potentials will be quoted versus that of the RHE. The potential was controlled by a bi-potentiostat (Pine Instruments

Antimony deposition onto Au(111) and insertion of Mg

• Lingxing Zan,
• Da Xing,
• Abdelaziz Ali Abd-El-Latif and
• Helmut Baltruschat

Beilstein J. Nanotechnol. 2019, 10, 2541–2552, doi:10.3762/bjnano.10.245

• ) electrolyte into/from a Sb-modified electrode shows a positive shift (400 mV) of the onset potential of Mg deposition compared to that of a bare Au electrode. From the charge of the Mg deposition, we find that the ratio of Mg to Sb is 1:1, which is somewhat less than expected for the Mg3Sb2 alloy. Keywords

• formation of a solid electrolyte interface (SEI) layer in Li systems. One of the main challenges in the commercialization of Mg-ion batteries is the incompatibility of the magnesium anode with the electrolytes because of the formation of this Mg2+ film. Recently, Sb has been suggested as an alternative

• electrodeposited Bi0.88Sb0.12 alloy by Arthur et al. [7]. However, the capacity declines to 215 mAh/g after 100 cycles with an electrolyte mixture of ethylmagnesium chloride, diethylaluminum chloride and anhydrous THF. A detailed, fundamental study of magnesium deposition/dissolution at a Sb-modified Au electrode

Polyvinylpyrrolidone as additive for perovskite solar cells with water and isopropanol as solvents

• Chen Du,
• Shuo Wang,
• Xu Miao,
• Wenhai Sun,
• Yu Zhu,
• Chengyan Wang and
• Ruixin Ma

Beilstein J. Nanotechnol. 2019, 10, 2374–2382, doi:10.3762/bjnano.10.228

• photoanode and CH3NH3PbX3 (X = I, Br) as light absorbing material to derive perovskite dye-sensitized solar cells with conversion efficiencies of 3.81% (X = I) and 3.13% (X = Br). However, the corrosion of the perovskite material used in the electrolyte results in a poor stability of the devices [5]. In July

Adsorption and desorption of self-assembled L-cysteine monolayers on nanoporous gold monitored by in situ resistometry

• Elisabeth Hengge,
• Eva-Maria Steyskal,
• Rupert Bachler,
• Alexander Dennig,
• Bernd Nidetzky and
• Roland Würschum

Beilstein J. Nanotechnol. 2019, 10, 2275–2279, doi:10.3762/bjnano.10.219

• commercial Ag/AgCl reference electrode (saturated KCl with a 3 M KNO3 salt bridge), relative to which all potentials will be stated in the following. Whenever the cell electrolyte was changed, the setup was immersed in distilled water for several hours for rinsing. Dealloying was performed in 0.1 M HClO4

• . After this desorption peak, significantly higher currents flow near the upper potential limit (Figure 2b, dashed red and grey curves), which are assigned to cysteine oxidation in the solution [18] as the desorbed cysteine is now dissolved in the electrolyte. The double-layer capacitance now amounts to