Growth and morphological analysis of segmented AuAg alloy nanowires created by pulsed electrodeposition in ion-track etched membranes

• Ina Schubert,
• Loic Burr,
• Christina Trautmann and
• Maria Eugenia Toimil-Molares

Beilstein J. Nanotechnol. 2015, 6, 1272–1280, doi:10.3762/bjnano.6.131

• File 1. In a next step, a Au layer was sputtered on one side of the polymer template, serving as the cathode for the deposition. It was reinforced with Cu, electrodeposited at room temperature in a two electrode set-up at a potential of −0.5 V between the Cu anode and cathode. The electrodeposition of

• five seconds of the first pulse. The decrease is due to the reduction of ions in the vicinity of the cathode and the formation of a depletion zone growing into the bulk solution. An approximately constant current is flowing during the growth of cylindrical wires. When the voltage is switched to U2 an

Charge carrier mobility and electronic properties of Al(Op)₃: impact of excimer formation

• Andrea Magri,
• Pascal Friederich,
• Bernhard Schäfer,
• Valeria Fattori,
• Xiangnan Sun,
• Timo Strunk,
• Velimir Meded,
• Luis E. Hueso,
• Wolfgang Wenzel and
• Mario Ruben

Beilstein J. Nanotechnol. 2015, 6, 1107–1115, doi:10.3762/bjnano.6.112

• −5.83 eV, respectively. As a result of the lower LUMO energy of Al(Op)3 compared to Alq3, the injection of electrons should be not only possible, but enhanced, as a consequence of the reduced mismatch with a cathode such as aluminum with a work function of Φ ≈ 4.3 eV. In addition, considering the

• consequence, the electron injection from a cathode should be more efficient in Al(Op)3 layers compared to Alq3. Nonetheless, the Al(Op)3 HOMO energy is high enough to prevent hole diffusion. The major drawback of the extended and flat aromatic system, which can accept and efficiently delocalize up to three

Superluminescence from an optically pumped molecular tunneling junction by injection of plasmon induced hot electrons

• Kai Braun,
• Xiao Wang,
• Andreas M. Kern,
• Hilmar Adler,
• Heiko Peisert,
• Thomas Chassé,
• Dai Zhang and
• Alfred J. Meixner

Beilstein J. Nanotechnol. 2015, 6, 1100–1106, doi:10.3762/bjnano.6.111

• ]. The situation here is analogue to a light emitting diode (LED) consisting of a pn-junction. When a voltage is applied to the anode lead of the LED that is more positive than the voltage applied to the cathode lead by at least the forward voltage drop of the LED, a current flows and results in emitted

From lithium to sodium: cell chemistry of room temperature sodium–air and sodium–sulfur batteries

• Philipp Adelhelm,
• Pascal Hartmann,
• Conrad L. Bender,
• Martin Busche,
• Christine Eufinger and
• Juergen Janek

Beilstein J. Nanotechnol. 2015, 6, 1016–1055, doi:10.3762/bjnano.6.105

• . The major difference compared to Li-ion batteries is that the battery is designed as an open system that enables uptake and release of atmospheric oxygen at the cathode during cycling (hence the name “lithium–air battery”, which is misleading as mostly pure oxygen gas is used). During discharge

• , lithium is oxidized at the negative electrode and oxygen is reduced on the positive electrode. Similar to a fuel cell cathode, the positive electrode is a porous, electron-conducting support (gas diffusion layer, GDL) that enables oxygen transport, oxygen reduction (ORR) and oxygen evolution (OER) during

• capacities as high as 3000 mAh/gcarbon by introducing α-MnO2 nanowires as catalyst in the oxygen cathode [31]. From 2008 onwards, the number of publications on Li/O2 batteries rapidly increased. The progress in Li/O2 research and development is the subject of numerous review articles [22][32][33][34

Multiscale modeling of lithium ion batteries: thermal aspects

• Arnulf Latz and
• Jochen Zausch

Beilstein J. Nanotechnol. 2015, 6, 987–1007, doi:10.3762/bjnano.6.102

• the help of volume averaging applied to the phenomenological pore scale model. Full 3D simulations of thermal effects in electrode microstructures do, to the best of our knowledge, not exist; except for [50] in which the heat sources in a microstructure of a LiCoO2 cathode are obtained with the help

• porosity ε was set to 0.5 such that the capacity of each electrode is equal. The geometries are shown in Figure 1. The left and the right electrode are the anode and the cathode, respectively. They are connected to current collectors through which electrons enter. Note that although electrodes are equal

Fabrication of high-resolution nanostructures of complex geometry by the single-spot nanolithography method

• Alexander Samardak,
• Margarita Anisimova,
• Aleksei Samardak and
• Alexey Ognev

Beilstein J. Nanotechnol. 2015, 6, 976–986, doi:10.3762/bjnano.6.101

• baking, the samples were exposed in E-Line EBL system (Raith, Germany). The spot size, cathode acceleration voltage, beam current and aperture size were 2 nm, 10 kV, 0.072 nA and 30 µm, respectively. Some experiments were performed at an acceleration voltage of 15 and 20 kV. The vacuum pressure in the

• 20 nm; (b) square ring with a line width of 22 nm. Demonstration of the proximity effect using nanostructures fabricated on a PMMA A2 resist with a thickness of 75 nm at a cathode acceleration voltage of 10 kV, exposure dose of 0.1 pC and ds = 10 nm. An example of a complex polymer pattern with a

Experimental determination of the light-trapping-induced absorption enhancement factor in DSSC photoanodes

• Serena Gagliardi and
• Mauro Falconieri

Beilstein J. Nanotechnol. 2015, 6, 886–892, doi:10.3762/bjnano.6.91

• , nanostructured titania layer, and is mainly related to its morphology and optical properties. In this study, some simplifying assumptions were made by neglecting: (a) the presence of the electrolyte filling the pores, which presumably reduces the LT and (b) the presence of the cathode acting as a back reflector

Synthesis of boron nitride nanotubes and their applications

• Saban Kalay,
• Zehra Yilmaz,
• Ozlem Sen,
• Melis Emanet,
• Emine Kazanc and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2015, 6, 84–102, doi:10.3762/bjnano.6.9

• an arc discharge method resulting in a 1–3 nm inner diameter and a length of 200 nm [20]. An arc discharge was generated between a hexagonal BN (h-BN)-filled tungsten rod as an anode and a cooled copper electrode as cathode. The dark gray BNNTs were collected from the surface of the copper cathode

Materials and characterization techniques for high-temperature polymer electrolyte membrane fuel cells

• Roswitha Zeis

Beilstein J. Nanotechnol. 2015, 6, 68–83, doi:10.3762/bjnano.6.8

• components. A conventional high-temperature membrane electrode assembly (HT-MEA) primarily consists of a polybenzimidazole (PBI)-type membrane containing phosphoric acid and two gas diffusion electrodes (GDE), the anode and the cathode, attached to the two surfaces of the membrane. This review article

• specific adsorption of the phosphoric acid electrolyte is known to hamper the oxygen reduction reaction activity on the cathode side. Moreover, the low solubility and diffusivity of oxygen in concentrated phosphoric acid has a negative effect on the ORR [14][15]. These problems are specific to phosphoric

• membrane is essentially solid and is therefore easier to handle. It is also more tolerant towards pressure differences between cathode and anode and the leaching of phosphoric acid from the PBI polymer during fuel cell operation is less of a concern. Besides PBI, there exist a great number of synthetically

Hybrid spin-crossover nanostructures

• Carlos M. Quintero,
• Gautier Félix,
• Iurii Suleimanov,
• José Sánchez Costa,
• Gábor Molnár,
• Lionel Salmon,
• William Nicolazzi and
• Azzedine Bousseksou

Beilstein J. Nanotechnol. 2014, 5, 2230–2239, doi:10.3762/bjnano.5.232

• light emitting thin film composed of chlorophyll a (Chl a) mixed with the SCO complex [Fe(dpp)2](BF)4 (dpp = 2,6-di(pyrazol-1-yl)pyridine) spin-coated on an indium tin oxide (ITO) substrate (anode) and then covered by a 30 nm thick Al cathode (see Figure 6a) [28]. With this configuration, the

• cathode to the anode through the SCO complex. Second, a shift in the energy level of the molecular orbital concerning the electron transport in the SCO complex relative to that of Chl a (Figure 6b) [30] is possible. Thus, at high temperatures (HS state) the injected electrons effectively excite the Chl a

Cathode lens spectromicroscopy: methodology and applications

• T. O. Menteş,
• G. Zamborlini,
• A. Sala and
• A. Locatelli

Beilstein J. Nanotechnol. 2014, 5, 1873–1886, doi:10.3762/bjnano.5.198

• microscopy (LEEM); magnetism; nanostructures; X-ray magnetic circular dichroism (XMCD); X-ray photoemission electron microscopy (XPEEM); Introduction The cathode lens, or immersion objective lens, is used to image electrons emitted from surfaces [1]. In a microscope that uses this type of objective, the

• sample surface acts as the cathode held at a negative potential, whereas the anode (objective lens) has a central aperture to allow for the passage of the emitted electrons towards the imaging column. The imaged electrons may originate from different processes such as thermionic emission, secondary

• Elettra. The bulk of this work is dedicated to applications of the SPELEEM technique. We put special emphasis on graphene, which has been extensively studied by using cathode lens microscopy, LEEM in particular, with numerous studies of epitaxial graphene grown on a variety of transition metal and silicon

Nanocrystalline ceria coatings on solid oxide fuel cell anodes: the role of organic surfactant pretreatments on coating microstructures and sulfur tolerance

• Chieh-Chun Wu,
• Ling Tang and
• Mark R. De Guire

Beilstein J. Nanotechnol. 2014, 5, 1712–1724, doi:10.3762/bjnano.5.181

• ). In typical solid oxide fuel cells (SOFCs), oxygen molecules are reduced to oxide ions at the air electrode (the cathode) by electrons from the external circuit. The oxide ions cross the electrolyte and combine with H2 at the fuel electrode (the anode, the focus of the present study) to form H2O

• , releasing electrons into an external circuit to do electrical work before they pass to the cathode for consumption in the oxygen reduction reaction. It is well known that the performance of SOFC anodes, typically composites of nickel metal with a zirconia or ceria ionic conductor, is degraded by sulfur

• sulfur tolerance to the anode. Aspects of the sulfonate treatment, particularly the oxone oxidation step, may have adversely affected the anode surface chemistry. (As explained in the Experimental section, we observed chemical damage to the cathode if the oxone solution contacted it, and subsequently

Liquid fuel cells

• Grigorii L. Soloveichik

Beilstein J. Nanotechnol. 2014, 5, 1399–1418, doi:10.3762/bjnano.5.153

• membrane (Figure 1). In all cases the structure of the fuel cell is similar and consists of a cathode and an anode with a current collector (bipolar plate), a gas diffusion layer, and a catalyst layer. The electrodes are separated by an ion-conducting insulating membrane (Figure 1). Bipolar or field plates

• cells are based on proton exchange membranes (PEM), through which protons are transported (Figure 1a). The chemistry of anode and cathode reactions in the PEM hydrogen–oxygen regenerative fuel cell (RFC) is described by Equation 2 and Equation 3, respectively. Commonly used PEMs are generally based on

• based on the transport of hydroxide ions through an anion-exchange membrane (AEM); the anode and cathode reactions are shown in Equation 4 and Equation 5, respectively (Figure 2b). They have the advantage of a lower redox potential for ORR in basic media (Equation 5). First such cells were developed at

Magnesium batteries: Current state of the art, issues and future perspectives

• Rana Mohtadi and
• Fuminori Mizuno

Beilstein J. Nanotechnol. 2014, 5, 1291–1311, doi:10.3762/bjnano.5.143

• the most recent developments made and offer our perspectives on how to overcome some of the remaining challenges. Keywords: cathode; electrolyte; magnesium anode; magnesium battery; magnesium metal; Introduction Fueled by an ever increasing demand for electrical energy to power the numerous aspects

• fascinating advancements in Li-ion batteries have resulted in a state of the art battery which uses graphitized carbon as the anode, a transition metal oxide as the cathode, coupled such that 240 Wh kg−1, 640 Wh L−1 are provided for thousands of cycles [1]. The wide spread use of Li-ion battery, has been and

• complex system employing several components, the review will individually address progresses related to the major components which are the anode, the electrolyte and the cathode. For each of these components, the existing hurdles are individually outlined and our suggestions for future research needs are

Self-organization of mesoscopic silver wires by electrochemical deposition

• Sheng Zhong,
• Thomas Koch,
• Stefan Walheim,
• Harald Rösner,
• Eberhard Nold,
• Aaron Kobler,
• Torsten Scherer,
• Di Wang,
• Christian Kübel,
• Mu Wang,
• Horst Hahn and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2014, 5, 1285–1290, doi:10.3762/bjnano.5.142

• of concentrated AgNO3 electrolyte is formed between frozen electrolyte and the glass plates of the deposition cell (Figure 1a). Thereafter, a constant voltage is applied across the two electrodes, and deposits first nucleate from the cathode, grow laterally into the aqueous electrolyte, and form

• . Scanning electron microscopy (SEM) shows that the silver wires are growing parallel to the glass substrate (Figure 2). Bunches of silver wires initially nucleate on the cathode and propagate laterally on the glass substrate parallel to the local electric field. Eventually silver wires cover the glass

• following model: Initial silver wires nucleate on the cathode and grow towards the anode, presumably with [112] as the preferred growth direction. Behind the growth front the wires do not increase their diameter due to the depletion effect. These two factors allow the wires, once they are initiated along

Review of nanostructured devices for thermoelectric applications

• Giovanni Pennelli

Beilstein J. Nanotechnol. 2014, 5, 1268–1284, doi:10.3762/bjnano.5.141

• microscopic cathode injecting holes in the underlying silicon (i.e., withdrawing electrons from silicon) and the silicon undergoes oxidative dissolution in the presence of HF. Therefore, silicon in direct contact with the metal is dissolved so that the metal sinks into the substrate, and the metal–silicon

Surface processes during purification of InP quantum dots

• Natalia Mordvinova,
• Pavel Emelin,
• Alexander Vinokurov,
• Sergey Dorofeev,
• Artem Abakumov and
• Tatiana Kuznetsova

Beilstein J. Nanotechnol. 2014, 5, 1220–1225, doi:10.3762/bjnano.5.135

• acetone were separated by centrifugation and re-dissolved in toluene. Electrophoresis was carried out in acetone in an U-shaped quartz tube, the distance between two electrodes is 10 cm. The QDs were placed near the cathode and deposited on the anode made of stainless steel at the voltage of 1 kV and were

Effects of the preparation method on the structure and the visible-light photocatalytic activity of Ag₂CrO₄

• Difa Xu,
• Shaowen Cao,
• Jinfeng Zhang,
• Bei Cheng and
• Jiaguo Yu

Beilstein J. Nanotechnol. 2014, 5, 658–666, doi:10.3762/bjnano.5.77

• contaminants both in air and aqueous solution. However, Ag2CrO4 is neglected although it has been explored as cathode for lithium cells in early years [37][38][39]. Actually, the band gap of Ag2CrO4 is narrow enough (about 1.75 eV) to obtain strong absorption in visible-light region [40], and thus may enable

Plasma-assisted synthesis and high-resolution characterization of anisotropic elemental and bimetallic core–shell magnetic nanoparticles

• M. Hennes,
• A. Lotnyk and
• S. G. Mayr

Beilstein J. Nanotechnol. 2014, 5, 466–475, doi:10.3762/bjnano.5.54

• ions get fully accelerated by the applied voltage. Indeed, energy loss mechanisms, such as elastic collisions and charge transfer during sputtering, might play a crucial role in our setup, in which the mean free path of gas atoms can drop well below the extension of the cathode dark space. This will

• any sputterable material, thus paving the way for synthesis of novel multifunctional NPs. Schematic drawing of the home-built UHV setup used in the present study. CM: capacitance manometers, CC: cold cathode, TMP: turbo molecular pump, CW: cooling water, v: valve, pv: gate valve, SG: sputter gun, n

Confinement dependence of electro-catalysts for hydrogen evolution from water splitting

• Mikaela Lindgren and
• Itai Panas

Beilstein J. Nanotechnol. 2014, 5, 195–201, doi:10.3762/bjnano.5.21

• assembly for the cathode process during water splitting. A computational model was designed to determine how alloying elements control the fraction of H2 released during zirconium oxidation by water relative to the amount of hydrogen picked up by the corroding alloy. This model is utilized to determine the

• industrial electric energy consumption in the USA [1]. Decisive factors jointly determining the efficiency of the electrochemical process are the reactions at the oxidizing anode as well as at the hydrogen evolving cathode. In two inspiring experimental studies [2][3], Subbaraman et al. reported enhanced

• according to This can be subdivided into an anode process where the [ZrIV–O–ZrIV] oxide grain boundary is recovered, and a cathode process is employed to decide the oxidation state X. The subsequent chemical drive for H2 release into the confining grain boundary determines M and recovers the [ZrIV–O–MX

Design criteria for stable Pt/C fuel cell catalysts

• Josef C. Meier,
• Carolina Galeano,
• Ioannis Katsounaros,
• Jonathon Witte,
• Hans J. Bongard,
• Angel A. Topalov,
• Claudio Baldizzone,
• Stefano Mezzavilla,
• Ferdi Schüth and
• Karl J. J. Mayrhofer

Beilstein J. Nanotechnol. 2014, 5, 44–67, doi:10.3762/bjnano.5.5

• facile hydrogen oxidation reaction (HOR) at the anode side as well as the more sluggish oxygen reduction reaction (ORR) at the cathode side of the fuel cell [2]. The state of the art electrocatalyst for both electrodes are Pt or Pt-alloys dispersed in the form of nanoparticles on a carbon support, in

• order to achieve a maximum of active sites. Practical performance, however, not only demands high activities per mass for the ORR, but also stability against the aggressive conditions that occur in the fuel cell under operation, particularly on the cathode side [3]. While significant knowledge on

• conditions, as they can lead to severe potential changes at the cathode, which result in a rapid degradation of the catalyst [17][18][19][20][21][22]. Over recent years, attempts to circumvent the severe loss of ECSA and the degradation under various conditions have been mainly based on approaches to enhance

Synthesis and electrochemical performance of Li₂Co_1−xM_xPO₄F (M = Fe, Mn) cathode materials

• Nellie R. Khasanova,
• Oleg A. Drozhzhin,
• Stanislav S. Fedotov,
• Darya A. Storozhilova,
• Rodion V. Panin and
• Evgeny V. Antipov

Beilstein J. Nanotechnol. 2013, 4, 860–867, doi:10.3762/bjnano.4.97

• voltammetry supported a single-phase de/intercalation mechanism in the Li2Co0.9Mn0.1PO4F material. Keywords: energy related; fluorophosphates; high-energy cathode materials; high-voltage electrolyte; Li-ion batteries; nanomaterials; reversible capacity; Introduction In recent years the range of application

• most of the cells in use have almost reached their intrinsic limits, and no significant improvements are expected. Therefore, current research in this field is directed towards the development of new high-performance materials. The specific energy of Li-ion batteries can be enhanced by applying cathode

• operating potential because of the increased ionicity of the M–F bond. Furthermore, A2MPO4F cathode materials may reach capacity values larger than 200 mA·h·g−1, if more than one lithium atom would participate in the reversible de/intercalation process. Li2CoPO4F, which exhibits an electrochemical activity

Influence of particle size and fluorination ratio of CF_x precursor compounds on the electrochemical performance of C–FeF₂ nanocomposites for reversible lithium storage

• Ben Breitung,
• M. Anji Reddy,
• Venkata Sai Kiran Chakravadhanula,
• Michael Engel,
• Christian Kübel,
• Annie K. Powell,
• Horst Hahn and
• Maximilian Fichtner

Beilstein J. Nanotechnol. 2013, 4, 705–713, doi:10.3762/bjnano.4.80

• Inorganic Chemistry, Engesserstrasse 15, D-76128 Karlsruhe, Germany 10.3762/bjnano.4.80 Abstract Systematical studies of the electrochemical performance of CFx-derived carbon–FeF2 nanocomposites for reversible lithium storage are presented. The conversion cathode materials were synthesized by a simple one

• electrochemical behavior of the conversion cathode material. The particle size of the CFx precursor particles was varied by ball milling as well as by choosing different C/F ratios. The investigations led to optimized C–FeF2 conversion cathode materials that showed specific capacities of 436 mAh/g at 40 °C after

• cathode materials with specific capacities of 150 mAh/g for LiCoO2 [6] up to 170 mAh/g for LiFePO4 [7] conversion cathode materials can theoretically provide more than three times higher theoretical specific capacities. The theoretical capacity of the herein investigated FeF2/Li+ conversion system amounts

Optimization of solution-processed oligothiophene:fullerene based organic solar cells by using solvent additives

• Gisela L. Schulz,
• Marta Urdanpilleta,
• Roland Fitzner,
• Eduard Brier,
• Elena Mena-Osteritz,
• Egon Reinold and
• Peter Bäuerle

Beilstein J. Nanotechnol. 2013, 4, 680–689, doi:10.3762/bjnano.4.77

• % higher amount of PC61BM than the film deposited from CB. The PCBM-rich regions are visible as dark depressions in the top left quadrant of the phase image shown in Figure 6b. Since the surface of the active layer under investigation contacts the cathode in the device, it would be reasonable to claim that

Electrochemical and electron microscopic characterization of Super-P based cathodes for Li–O₂ batteries

• Mario Marinaro,
• Santhana K. Eswara Moorthy,
• Jörg Bernhard,
• Ludwig Jörissen,
• Margret Wohlfahrt-Mehrens and
• Ute Kaiser

Beilstein J. Nanotechnol. 2013, 4, 665–670, doi:10.3762/bjnano.4.74

• (trifluoromethane)sulfonimide lithium salt (LiTFSI)/tetraglyme electrolyte were investigated by galvanostatic cycling and electrochemical impedance spectroscopy measurements. Ex-situ X-ray diffraction and scanning electron microscopy were used to evaluate the formation/dissolution of Li2O2 particles at the cathode

• electrolyte. The electrochemical behaviors of the batteries were investigated by galvanostatic cycling and electrochemical impedance spectroscopy. The physico–chemical investigation of the lithium-oxide phases that form and dissolve at the cathode side upon discharge and charge of Li–O2 batteries has been

• kV. The images were acquired using a secondary-electron detector with an in-lens configuration. Results and Discussion The first galvanostatic discharge/charge curve of a typical Li–O2 battery that has a carbon-based cathode, a lithium metal anode and LiTFSI/tetraglyme electrolyte is reported in