BN/Ag hybrid nanomaterials with petal-like surfaces as catalysts and antibacterial agents

• Konstantin L. Firestein,
• Denis V. Leybo,
• Alexander E. Steinman,
• Andrey M. Kovalskii,
• Andrei T. Matveev,
• Anton M. Manakhov,
• Irina V. Sukhorukova,
• Pavel V. Slukin,
• Nadezda K. Fursova,
• Sergey G. Ignatov,
• Dmitri V. Golberg and
• Dmitry V. Shtansky

Beilstein J. Nanotechnol. 2018, 9, 250–261, doi:10.3762/bjnano.9.27

• ] that BN/Ag hybrid nanomaterials may possess high activity and stability as catalysts for oxidation of organic compounds. Moreover, N-impurities and other defects in thin layers of raw h-BN can act as active centers for oxygen reduction reactions [15]. Generally, the catalytic activity of BN/Ag hybrid

• treatment, which, as known, can withstand temperatures in excess of 900 °C without chemical degradation [17]. Since Ag2O decomposes at temperatures above 280 °C, it is reasonable to assume that Ag NPs (formed during decomposition) possess high activity in oxygen reduction reaction being catalysts at

Freestanding graphene/MnO₂ cathodes for Li-ion batteries

• Şeyma Özcan,
• Aslıhan Güler,
• Tugrul Cetinkaya,
• Mehmet O. Guler and
• Hatem Akbulut

Beilstein J. Nanotechnol. 2017, 8, 1932–1938, doi:10.3762/bjnano.8.193

• charge–discharge cycles [17]. MnO2 has many crystallographic polymorphs including α-, β-, δ-, γ-, ε-, and λ-MnO2. The electrochemical characteristics of MnO2, such as electrocatalytic activity, specific capacity and oxygen reduction reaction, vary according to its crystalline structure and morphology [18

Synthesis of graphene–transition metal oxide hybrid nanoparticles and their application in various fields

• Arpita Jana,
• Elke Scheer and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2017, 8, 688–714, doi:10.3762/bjnano.8.74

• and also to improve the volume change. In that context, graphene has been hybridised with Cr2O3 to improve the properties of the materials and the other strategy is to develop Cr2O3 materials on the nanoscale. Graphene–Cr2O3 hybrids have been explored with respect to the oxygen reduction reaction (ORR

• TMO–graphene materials, this hybrid is also used as an anode for LIBs [168][169] because it exhibits high oxygen reduction activity. Liang et al. showed that Co3O4–N-doped graphene exhibits similar catalytic activity like Co3O4–graphene hybrids but superior stability to Pt in alkaline solution [170

• micropipette tip which can detect nonenzymatic glucose [173]. N-doped graphene/Co3O4 has been used for selective oxidation of olefins and alcohols [174], LIBs [175], and oxygen reduction [176], and as a water electrolysis catalyst [177]. Co3O4 NPs were anchored on conducting graphene and used as an anode for

Orientation of FePt nanoparticles on top of a-SiO₂/Si(001), MgO(001) and sapphire(0001): effect of thermal treatments and influence of substrate and particle size

• Martin Schilling,
• Paul Ziemann,
• Zaoli Zhang,
• Johannes Biskupek,
• Ute Kaiser and
• Ulf Wiedwald

Beilstein J. Nanotechnol. 2016, 7, 591–604, doi:10.3762/bjnano.7.52

• transmission electron microscopy (HRTEM); nanoparticles; reflection high-energy electron diffraction (RHEED); solid-phase epitaxy; texture; Introduction Due to their attractive catalytic properties for oxygen reduction reactions (ORR) [1][2] as well as their high magnetocrystalline anisotropy energy density

Nitrogen-doped graphene films from chemical vapor deposition of pyridine: influence of process parameters on the electrical and optical properties

• Andrea Capasso,
• Theodoros Dikonimos,
• Francesca Sarto,
• Alessio Tamburrano,
• Giovanni De Bellis,
• Maria Sabrina Sarto,
• Giuliana Faggio,
• Angela Malara,
• Giacomo Messina and
• Nicola Lisi

Beilstein J. Nanotechnol. 2015, 6, 2028–2038, doi:10.3762/bjnano.6.206

• nitrogen might also confer useful chemical properties to graphene, e.g., rendering it catalytic to oxygen reduction reactions [24] or enhancing its lithium intercalation properties for battery applications [25]. Nitrogen doping was originally achieved ex situ by the post-growth treatment of pristine CVD

Comprehensive characterization and understanding of micro-fuel cells operating at high methanol concentrations

• Aldo S. Gago,
• Juan-Pablo Esquivel,
• Neus Sabaté,
• Joaquín Santander and
• Nicolas Alonso-Vante

Beilstein J. Nanotechnol. 2015, 6, 2000–2006, doi:10.3762/bjnano.6.203

• cathode, at a given current density, decreases gradually, 0.88 to 0.6 V vs RHE, as the fuel concentration increases. The reason is that the fuel crossover effect (mixed-potential developed between the oxygen reduction reaction (ORR) and the methanol oxidation reaction (MOR)) is more important [31]. The

Scalable, high performance, enzymatic cathodes based on nanoimprint lithography

• Dmitry Pankratov,
• Richard Sundberg,
• Javier Sotres,
• Dmitry B. Suyatin,
• Ivan Maximov,
• Sergey Shleev and
• Lars Montelius

Beilstein J. Nanotechnol. 2015, 6, 1377–1384, doi:10.3762/bjnano.6.142

• : bilirubin oxidase; bio-electrocatalysis; direct electron transfer; nanoimprint lithography; oxygen reduction reaction; Introduction Reduction of oxygen (O2) is the key reaction in many natural and artificial systems, and indeed, this reaction is one of the most interesting research issues in both academia

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

• , 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

• made the same observation in 2002 and concluded that large particles could only grow if the oxide (Li2O2) is (a) soluble in the electrolyte (b) able to migrate on electrode surface or (c) capable of catalyzing the oxygen reduction [30]. Theoretical studies are particularly focused on possibility (c

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

• exhibit high proton conductivity in low-hydration and even anhydrous states. Of special concern for phosphoric-acid-doped PBI-type membranes is the acid loss and management during operation. The slow oxygen reduction reaction in HT-PEMFCs remains a challenge. Phosphoric acid tends to adsorb onto the

• 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

• acid and not intrinsic to HT-PEMFCs. Alternative electrolytes such as ionic liquids or solid acids might solve the problem and accelerate the oxygen reduction reaction kinetics. The benefits of operating the fuel cell at elevated temperatures include improved catalyst activity, higher tolerance to

Manganese oxide phases and morphologies: A study on calcination temperature and atmospheric dependence

• Matthias Augustin,
• Daniela Fenske,
• Ingo Bardenhagen,
• Anne Westphal,
• Martin Knipper,
• Thorsten Plaggenborg,
• Joanna Kolny-Olesiak and
• Jürgen Parisi

Beilstein J. Nanotechnol. 2015, 6, 47–59, doi:10.3762/bjnano.6.6

• the calcination temperature and the presence of an oxidizing or neutral atmosphere. Furthermore, to demonstrate the application potential of the synthesized MnOx species, we studied their catalytic activity for the oxygen reduction reaction in aprotic media. Linear sweep voltammetry revealed the best

• reaction intermediates, especially those involving oxygen. These properties are especially important for catalytic applications such as water oxidation [9][10][11] and the oxygen reduction and evolution reactions in metal/air battery systems [12][13][14][15][16]. Additionally, the advantages of manganese

• oxygen reduction reaction (ORR), linear sweep measurements were carried out. Figure 9 shows linear sweep measurements recorded at 50 mV/s comparing the activity of various 10% MnOx/carbon electrodes to a pure carbon electrode as a reference material for the ORR in aprotic electrolyte. The ORR peak

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

• , 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

Donor–acceptor graphene-based hybrid materials facilitating photo-induced electron-transfer reactions

• Anastasios Stergiou,
• Georgia Pagona and
• Nikos Tagmatarchis

Beilstein J. Nanotechnol. 2014, 5, 1580–1589, doi:10.3762/bjnano.5.170

• EDTA and re-complexes after fresh addition of Fe(II) (Scheme 2). Furthermore, Fe–tpy–GO was tested as a catalyst for the oxygen reduction reaction (ORR) and found to be durable against carbon monoxide poisoning and to exhibit a higher fuel selectivity compared with commercially available Pt/C electro

Liquid fuel cells

• Grigorii L. Soloveichik

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

• reaction (HOR) and oxygen reduction reaction (ORR), but it is very expensive. To reduce the Pt loading and therefore the cost for the electrocatalyst, Pt-containing alloys and structured nanoparticles, e.g., “core–shell” materials with less expensive metals are being investigated. Alkaline fuel cells are

• promising fuels [71][73]. The operation of alkaline ethanol LFC has potential benefits compared with PEM LFC including faster kinetics of both ethanol oxidation and oxygen reduction in basic media and lower fuel crossover due to a reversed electro-osmotic effect of anion movement in the membrane. The major

Synthesis, characterization, and growth simulations of Cu–Pt bimetallic nanoclusters

• Subarna Khanal,
• Ana Spitale,
• Nabraj Bhattarai,
• Daniel Bahena,
• J. Jesus Velazquez-Salazar,
• Sergio Mejía-Rosales,
• Marcelo M. Mariscal and
• Miguel José-Yacaman

Beilstein J. Nanotechnol. 2014, 5, 1371–1379, doi:10.3762/bjnano.5.150

• bimetallic (Pt–Co, Pt–Fe, Pt–Ni, Pt–Pd) nanocrystals with octahedral and cubic shape and examined their facet-dependent catalytic performance for the oxygen reduction reaction (ORR). Guo and co-workers [33] synthesized FePt and CoPt nanowires by organic-phase decomposition and demonstrated that these systems

Volcano plots in hydrogen electrocatalysis – uses and abuses

• Paola Quaino,
• Fernanda Juarez,
• Elizabeth Santos and
• Wolfgang Schmickler

Beilstein J. Nanotechnol. 2014, 5, 846–854, doi:10.3762/bjnano.5.96

• of them has been successful [12]. For practical applications in fuel cells, the problem is not hydrogen oxidation but oxygen reduction, which is slow and inefficient. The full reduction involves four electron transfer steps, and possibly other chemical steps. The overall rate on a given substrate

• depends strongly on the pH value, and is also affected by anions. It is not surprising, that the details of the mechanism are still very much a subject of debate. Nevertheless, several attempts have been made to construct volcano plots for oxygen reduction as well. Really this topic is outside of the

• , which has to be compared with the standard potential for oxygen reduction at pH 0, 1.229 V SHE. Obviously, on a good catalyst for this reaction the adsorption energy must be of the order of 1 eV – which is exactly the energy of adsorption of OOH on Pt(111) [37]. We have replotted the theoretical

Carbon dioxide hydrogenation to aromatic hydrocarbons by using an iron/iron oxide nanocatalyst

• Hongwang Wang,
• Jim Hodgson,
• Tej B. Shrestha,
• Prem S. Thapa,
• David Moore,
• Xiaorong Wu,
• Myles Ikenberry,
• Deryl L. Troyer,
• Donghai Wang,
• Keith L. Hohn and
• Stefan H. Bossmann

Beilstein J. Nanotechnol. 2014, 5, 760–769, doi:10.3762/bjnano.5.88

• oxygen reduction reaction [46][47][48] have been reported. Synthesis of Fe/Fe3O4 nanoparticles Here we report the selective formation of aromatic hydrocarbons from CO2 hydrogenation reactions catalyzed by an Fe/Fe3O4 nanocatalyst. Recently, Sun’s group reported a facile method for synthesizing highly

Resonance of graphene nanoribbons doped with nitrogen and boron: a molecular dynamics study

• Ye Wei,
• Haifei Zhan,
• Kang Xia,
• Wendong Zhang,
• Shengbo Sang and
• Yuantong Gu

Beilstein J. Nanotechnol. 2014, 5, 717–725, doi:10.3762/bjnano.5.84

• the electronic and quantum transport properties of graphene. Such doped graphene is envisioned with exciting applications as high-performance FET devices [8], and metal-free electrocatalyst for oxygen reduction fuel cells [9]. In addition to doping, various graphene derivatives have also been

Constant-distance mode SECM as a tool to visualize local electrocatalytic activity of oxygen reduction catalysts

• Michaela Nebel,
• Thomas Erichsen and
• Wolfgang Schuhmann

Beilstein J. Nanotechnol. 2014, 5, 141–151, doi:10.3762/bjnano.5.14

• microscopy (4D SF/CD-SECM) was utilized for the investigation of the activity distribution of oxygen reduction catalysts. Carbon-supported Pt model catalyst powders have been immobilized in recessed microelectrodes and compared to a spot preparation technique. Microcavities serve as platform for the binder

• high-resolution SECM experiments to powder-based catalyst preparations. Keywords: electrocatalysis; oxygen reduction; recessed microelectrodes; redox-competition SECM; SECM; scanning electrochemical microscopy; shearforce-based constant-distance mode; Introduction In scanning electrochemical

• control mechanism. The concept of 4D CD-SECM was recently extended to intermittent contact-SECM [16]. Here, we describe the adaptation of the 4D SF/CD-SECM to the investigation of the activity of powdery oxygen reduction catalysts. In order to understand the properties of catalyst powders on a local scale

The role of oxygen and water on molybdenum nanoclusters for electro catalytic ammonia production

• Jakob G. Howalt and
• Tejs Vegge

Beilstein J. Nanotechnol. 2014, 5, 111–120, doi:10.3762/bjnano.5.11

• therefore desorb thermally from the surface, except at very low oxygen coverages. The study of oxygen reduction produces adsorption energies for O, OH, H2O at different coverages. No apparent correlation is found between the adsorption energies of EO, EOH and EH2O on the cluster, see Figure S2 and Figure S3

• [2]. Instead of protonating the adsorbed nitrogen molecule, the potential could drive the reduction of oxygen. In Table 5, the potentials for driving the oxygen reduction processes are presented. Here, a potential of −0.77 V is required for the high oxygen coverage case, while the last reduction step

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

Some reflections on the understanding of the oxygen reduction reaction at Pt(111)

• Ana M. Gómez-Marín,
• Ruben Rizo and
• Juan M. Feliu

Beilstein J. Nanotechnol. 2013, 4, 956–967, doi:10.3762/bjnano.4.108

• Ana M. Gomez-Marin Ruben Rizo Juan M. Feliu Instituto de Electroquímica, Universidad de Alicante, Apt. 99, Alicante, E-03080, Spain 10.3762/bjnano.4.108 Abstract The oxygen reduction reaction (ORR) is a pivotal process in electrochemistry. Unfortunately, after decades of intensive research, a

• electrocatalysts for fuel-cell cathodes is only possible through a cooperative approach between theory and experiments. Keywords: hydrogen peroxide oxidation; hydrogen peroxide reduction; oxygen reduction; Pt(111); stepped surfaces; Introduction Nowadays, the oxygen reduction reaction (ORR) is arguably one of

• higher PtO coverages that could further produce more oxidized forms. In these latter cases, however, the surface will start to disorder and would no longer be a flat, well-ordered Pt(111) surface. Oxygen reduction reaction (ORR) on Pt(111) The cyclic voltammetric profile (CV) for the ORR on Pt(111), in

Lithium peroxide crystal clusters as a natural growth feature of discharge products in Li–O₂ cells

• Tatiana K. Zakharchenko,
• Anna Y. Kozmenkova,
• Daniil M. Itkis and
• Eugene A. Goodilin

Beilstein J. Nanotechnol. 2013, 4, 758–762, doi:10.3762/bjnano.4.86

• oxygen reduction reaction (ORR). This feature limits the rechargeability of Li–O2 cells, but at the same time it can be beneficial for both capacity improvement and gain in recharge rate if a proper liquid phase mediator can be found. Keywords: lithium–air batteries; lithium peroxide; oxygen reduction

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

• products during the operation of a typical Li–O2 battery. In this context, recently published literature [1][2][3] gives new insights about the mechanism through which the reduction and the oxidation of oxygen occur in aprotic environments. During discharge, the oxygen reduction reaction (ORR) proceeds in

Novel composite Zr/PBI-O-PhT membranes for HT-PEFC applications

• Mikhail S. Kondratenko,
• Igor I. Ponomarev,
• Marat O. Gallyamov,
• Dmitry Y. Razorenov,
• Yulia A. Volkova,
• Elena P. Kharitonova and
• Alexei R. Khokhlov

Beilstein J. Nanotechnol. 2013, 4, 481–492, doi:10.3762/bjnano.4.57

• of the AL and models the following processes: charge-transfer during the oxygen reduction reaction, double layer charging and ohmic losses due to finite proton conductivity of the AL. The following parameters were obtained as a result of the impedance spectra approximation: the undistributed ohmic

Hydrogen-plasma-induced magnetocrystalline anisotropy ordering in self-assembled magnetic nanoparticle monolayers

• Alexander Weddemann,
• Judith Meyer,
• Anna Regtmeier,
• Irina Janzen,
• Dieter Akemeier and
• Andreas Hütten

Beilstein J. Nanotechnol. 2013, 4, 164–172, doi:10.3762/bjnano.4.16

• reported, which can be divided in two time scales: oxygen reduction increases the particle magnetization during the first 20 min, which is followed by an alteration of the magnetic response shape. The latter depends on the respective particle species. Based on the Landau–Lifshitz equations for a discrete

• sample I and II, Ir and Pt were chosen as the respective layer materials; the layer thickness was set to 10 nm in both cases. Different materials were employed to ease the evaluation of the X-ray diffraction (XRD) measurements (see below). On short time scales of approximately 20 min, an oxygen reduction