Liquid fuel cells

• Grigorii L. Soloveichik

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

• streams, and enhanced safety. This review focuses on the use of different types of organic fuels as an anode material for LFCs. An overview of the current state of the art and recent trends in the development of LFC and the challenges of their practical implementation are presented. Keywords: anion

• 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

• without reforming. For example, toluene, n-decane, and synthetic diesel fuel were fed to a SOFC at 700 °C to generate a power density of about 100 mW/cm2 [4]. Recently, a much higher power density (about 600 mW/cm2 at 750 °C) has been demonstrated by using a multi-functional anode and iso-octane as fuel

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

• to as the “ultimate lithium metal anode”. If we wish to move forward towards achieving an ultimate energy density goal, technologies beyond Li-ion batteries would be needed. Fortunately, in recent years, such desire has led to an increased interest in other chemistries that employ metals poised to

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

• aligned wires which grow towards the anode (Figure 1b). It takes several minutes before the deposit occupy an area of about 0.5 cm2. When electrodeposition is finished, the temperature is increased to melt the ice (Figure 1c). The wire deposits stack on the glass substrate and can be easily taken out of

• 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

• (anode), sidebranches will be triggered. Since the sides of the silver wires are rough, there is no significant energy barrier to prevent the generation of sidebranches. When this sidebranching mechanism works, the sidebranches should develop on only one side of the wires, that is, from the side facing

Nanoporous composites prepared by a combination of SBA-15 with Mg–Al mixed oxides. Water vapor sorption properties

• Amaury Pérez-Verdejo,
• Alvaro Sampieri,
• Heriberto Pfeiffer,
• Mayra Ruiz-Reyes,
• Juana-Deisy Santamaría and
• Geolar Fetter

Beilstein J. Nanotechnol. 2014, 5, 1226–1234, doi:10.3762/bjnano.5.136

• as (Mg-Al)/SBA. Characterization techniques X-ray diffraction (XRD) patterns were recorded with a Bruker axs D8 advance diffractometer coupled to a copper anode X-ray tube. N2 adsorption–desorption isotherms were measured with a Micromeritics ASAP 2020 system at −196 °C. Prior to analysis, the

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

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

• 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

• the reduction with hydrogen that permeates the ionomer from the anode chamber of the cell [44][45][46]. Platinum dissolution is expected to be especially severe for smaller platinum particles, which have a higher surface energy and are thus considered to dissolve already at lower potentials than bulk

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

• demonstrated by Poizot et al. who used transition-metal oxides as anode materials [9]. Metal fluorides are also prominent examples as they reversibly react with lithium at relatively high voltages so that they can be used as cathode materials [5][8][12][13][14][15][16]. Fluorine is the lightest and smallest

A facile synthesis of a carbon-encapsulated Fe₃O₄ nanocomposite and its performance as anode in lithium-ion batteries

• Raju Prakash,
• Katharina Fanselau,
• Shuhua Ren,
• Tapan Kumar Mandal,
• Christian Kübel,
• Horst Hahn and
• Maximilian Fichtner

Beilstein J. Nanotechnol. 2013, 4, 699–704, doi:10.3762/bjnano.4.79

• nanocomposite exhibits well constructed core–shell and nanotube structures, with Fe3O4 cores and graphitic shells/tubes. The as-synthesized material could be used directly as anode in a lithium-ion cell and demonstrated a stable capacity, and good cyclic and rate performances. Keywords: electrochemistry; iron

• LIBs with superior performance, numerous strategies to find new materials are currently being explored [3]. Fe3O4 is widely regarded as one of the high energy-density anode materials for LIBs, and is based on the conversion mechanism (Fe3O4 + 8 Li+ + 8 e− ↔ 3 Fe + 4 Li2O) [4][5][6]. The theoretical

• specific capacity of Fe3O4 is 926 mAh·g−1, which is far beyond that of a graphite anode (372 mAh·g−1). However, because of agglomerations and the significant volume change of active materials during the redox reaction, Fe3O4 anodes have suffered greatly from poor cyclic performances. A variety of

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

• 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

• galvanostatic discharge/charge curve of a typical Li–O2 battery consisting of a carbon-based cathode, lithium metal anode and LiTFSI/tetraglyme as electrolyte. Electrochemical impedance spectra of pristine (black), once discharged (red) and re-charged (green) electrodes. X-ray diffractograms of pristine

Preparation of electrochemically active silicon nanotubes in highly ordered arrays

• Tobias Grünzel,
• Young Joo Lee,
• Karsten Kuepper and
• Julien Bachmann

Beilstein J. Nanotechnol. 2013, 4, 655–664, doi:10.3762/bjnano.4.73

• , have been reported for Si anode materials [24]. Due to the low natural abundance of 29Si and small quantities of the samples available from ALD, the detection of these broad signals can be challenging. Further investigations with 29Si-enriched samples are conceivable to examine the reduction product

AFM as an analysis tool for high-capacity sulfur cathodes for Li–S batteries

• Renate Hiesgen,
• Seniz Sörgel,
• Rémi Costa,
• Linus Carlé,
• Ines Galm,
• Natalia Cañas,
• Brigitta Pascucci and
• K. Andreas Friedrich

Beilstein J. Nanotechnol. 2013, 4, 611–624, doi:10.3762/bjnano.4.68

• into the cathode structure. Therefore, Li+ ion diffusion is reduced and further electrochemical reactions are restricted. All of these phenomena result in degradation of the capacity. (3) Some of the high-order polysulfides migrate through to the anode side due to the shuttle mechanism and react with

• Li+ ions on the surface of the anode [31][32]. This time, low-order polysulfides form and settle down on the surface of the lithium anode. They cannot be oxidised back and therefore block the active sites of the anode surface [31]. As shown in Figure 2c and Figure 2d, the morphological changes upon

Large-scale atomistic and quantum-mechanical simulations of a Nafion membrane: Morphology, proton solvation and charge transport

• Pavel V. Komarov,
• Pavel G. Khalatur and
• Alexei R. Khokhlov

Beilstein J. Nanotechnol. 2013, 4, 567–587, doi:10.3762/bjnano.4.65

• positively charged hydrogen ions (protons) from the anode to the cathode; also, it serves as a barrier to fuel gas cross-leaks and electrical insulation between the electrodes. On the anode side, hydrogen fuel diffuses to the anode catalyst where it dissociates into electrons e– and protons H+: H2 ↔ 2H+ + 2e

• process of proton transfer from anode to cathode, which is responsible for overall FC efficiency [1]. The membranes are manufactured from special polymers containing both nonpolar atom groups and a relatively small number of polar groups that can dissociate in the water environment to give ions. Such

A nano-graphite cold cathode for an energy-efficient cathodoluminescent light source

• Alexander N. Obraztsov,
• Victor I. Kleshch and
• Elena A. Smolnikova

Beilstein J. Nanotechnol. 2013, 4, 493–500, doi:10.3762/bjnano.4.58

• the range of 2 to 5 kV, applied between the pencil core and the transparent anode. The anode was constructed of a glass plate with a conductive indium tin oxide (ITO) layer and covered by a CL phosphor. The bright spots in Figure 1B indicate the impingement of emitted electrons with the CL anode and

• were observed on the anode screen after these measurements. This demonstrates the process of the deposition of material from the pencil core, degraded under the action of the electric field. These results are quite similar to other materials with a graphitic type of atomic bonding: carbon fibers [9

• in CL lamps with a total anode area which is 10 to 100 times larger than the cathode emitting surface. A variant of such a kind of CL lamp has been disclosed in [21] and is presented by a photograph in Figure 5. The FE cathode of this lamp is made of a Ni cylindrical rod (1 mm diameter) with an NGF

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

• operated at a constant current density of 0.4 A·cm−2 for a 50 hour break-in. Pure hydrogen and air were supplied separately to the anode and cathode electrodes, respectively, without any humidification or excessive pressure. The gas flows were controlled by Bronkhorst El-Flow mass-flow controllers, which

• hydrogen crossover-current measurements, the cathode was fed with pure nitrogen, and pure hydrogen was supplied to the anode. The dry gases were supplied at an ambient pressure at flow rates of 50 mL·min−1. After several minutes the open-circuit voltage reached its steady-state value of about 120 mV. Then

Influence of diffusion on space-charge-limited current measurements in organic semiconductors

• Thomas Kirchartz

Beilstein J. Nanotechnol. 2013, 4, 180–188, doi:10.3762/bjnano.4.18

• simulations except for the one with Vbi = 1 V in Figure 2, where the contact barrier at the cathode (x = d) is 0.1 eV and the contact barrier at the anode (x = 0) is 1.1 eV. The relative permittivity used in all simulations is εr = 3.8 and the capture coefficient for the Gaussian defect is 10−10 cm3·s−1 for

Functionalization of vertically aligned carbon nanotubes

• Eloise Van Hooijdonk,
• Carla Bittencourt,
• Rony Snyders and
• Jean-François Colomer

Beilstein J. Nanotechnol. 2013, 4, 129–152, doi:10.3762/bjnano.4.14

• without a coaxial layer of vanadium oxide (V2O5) as cathode and anode, respectively. Due to their unique properties (e.g., large surface area, electrical conductivity, regular pore structure, electrolyte accessibility, charge transport), they are candidates for replacing traditional electrodes. Instead of

Characterization and properties of micro- and nanowires of controlled size, composition, and geometry fabricated by electrodeposition and ion-track technology

• Maria Eugenia Toimil-Molares

Beilstein J. Nanotechnol. 2012, 3, 860–883, doi:10.3762/bjnano.3.97

• other half-cell contains either water or an acidic stopping medium that neutralizes the etchant as soon as the pore opens. In both cases, further etching is extensively slowed down or entirely stopped (Figure 4c). In addition, by immersing the positive anode in the etching solution, the negative ions in

• monitored by chronoamperometric current–time (I–t) curves. In the two-electrode arrangement the potential Uc is applied between cathode and anode. In the three-electrode arrangement, reference electrodes such as saturated silver/silver chloride (Ag/AgCl/sat. KCl) and saturated calomel electrodes (SCE) are

• the deposition. Addition of sulphuric acid increases the conductivity of the solution and lowers the cathode overvoltage. Electrodeposition is typically performed potentiostatically in a two-electrode arrangement by using a copper anode, at temperatures between 25 and 70 °C. By applying low

Low-temperature synthesis of carbon nanotubes on indium tin oxide electrodes for organic solar cells

• Andrea Capasso,
• Luigi Salamandra,
• Aldo Di Carlo,
• John M. Bell and
• Nunzio Motta

Beilstein J. Nanotechnol. 2012, 3, 524–532, doi:10.3762/bjnano.3.60

• -modified ITO surfaces was measured by the Kelvin probe method to be 4.95 eV, resulting in an improved matching to the highest occupied molecular orbital level of the P3HT. This is in turn expected to increase the hole transport and collection at the anode, contributing to the significant increase of

• the fullerene derivative acts as an electron acceptor [6]. The holes move in the polymeric phase towards the anode, while the electrons hop along the fullerenes and eventually reach the cathode. Since the diffusion length of the exciton in the polymers is very low, recombination is highly probable

• the ITO–CNT electrode (as depicted in Figure 4). Nevertheless, this increase in WF is strongly beneficial because it brings the electrode WF closer to that of the photoactive blend. Thus we anticipate a reduction in the hole–injection barrier at the anode interface, as a result of the highest occupied

A facile approach to nanoarchitectured three-dimensional graphene-based Li–Mn–O composite as high-power cathodes for Li-ion batteries

• Wenyu Zhang,
• Yi Zeng,
• Chen Xu,
• Ni Xiao,
• Yiben Gao,
• Lain-Jong Li,
• Xiaodong Chen,
• Huey Hoon Hng and
• Qingyu Yan

Beilstein J. Nanotechnol. 2012, 3, 513–523, doi:10.3762/bjnano.3.59

• . As a material with high electrical conductivity and large surface area [19][20][21][22], graphene has attracted much attention for battery electrode applications. The hybrids of transition-metal-oxide nanocrystals attached onto graphene sheets have shown much improvement of LIB anode performance [23

• ][24][25][26], in which charge transfer is improved and the agglomeration of the metal oxide nanocrystals is prevented. Moreover, a recent report [27] indicated that by combining nanolayer carbon (e.g., graphene or nanoporous carbon) with sulfide anode may help to solve the issue of the dissolution of

Ultraviolet photodetection of flexible ZnO nanowire sheets in polydimethylsiloxane polymer

• Jinzhang Liu,
• Nunzio Motta and
• Soonil Lee

Beilstein J. Nanotechnol. 2012, 3, 353–359, doi:10.3762/bjnano.3.41

• suspension was vacuum filtered through a porous anode aluminum oxide (AAO) membrane, diameter of 4.3 cm and pore size of 200 nm, purchased from Whatman Co. Then the network film of ZnO nanowires on an AAO membrane was dried in air at 100 °C for 1 h. Finally, the thin sheet of ZnO nanowires was detached from

Parallel- and serial-contact electrochemical metallization of monolayer nanopatterns: A versatile synthetic tool en route to bottom-up assembly of electric nanocircuits

• Jonathan Berson,
• Assaf Zeira,
• Rivka Maoz and
• Jacob Sagiv

Beilstein J. Nanotechnol. 2012, 3, 134–143, doi:10.3762/bjnano.3.14

• electrooxidation of the target monolayer (CEP step), the target is biased positively (anode) with respect to the patterning electrode, whereas for metal transfer (CET step), the polarity of the applied bias voltage is reversed so that the stamp or the SFM probe now acts as the anode and the target monolayer as the

• lines surrounded by the unmodified OTS monolayer. As discussed in the following, the selectivity of silver deposition on the OTSeo lines follows from the fact that Ag+ ions generated electrochemically at the metal stamp (anode) are transported through the adsorbed water film, acting as an electrolyte

• electrochemical rather than adhesion-promoted [32][33][34][35], involving dissolution of stamp-metal grains (anode), ionic transport through an ultrathin water film adsorbed on the metal grains, and subsequent nucleation and growth of new metal grains at the target monolayer (cathode); (ii) metal grains can

Mesoporous MgTa₂O₆ thin films with enhanced photocatalytic activity: On the interplay between crystallinity and mesostructure

• Jin-Ming Wu,
• Igor Djerdj,
• Till von Graberg and
• Bernd M. Smarsly

Beilstein J. Nanotechnol. 2012, 3, 123–133, doi:10.3762/bjnano.3.13

• diffraction (XRD) measurements were performed in a Bruker D8 diffractometer with an accelerating voltage of 40 kV and a current of 40 mA, with Cu Kα radiation. The 2-D-SAXS measurements were carried out by using a Nonius rotating anode setup (Cu Kα radiation with λ = 0.154 nm) featuring a three-pinhole

Microfluidic anodization of aluminum films for the fabrication of nanoporous lipid bilayer support structures

• Jaydeep Bhattacharya,
• Alexandre Kisner,
• Andreas Offenhäusser and
• Bernhard Wolfrum

Beilstein J. Nanotechnol. 2011, 2, 104–109, doi:10.3762/bjnano.2.12

• aluminum was then anodized under constant voltage conditions. Thus, 40 V were applied between the aluminum and a platinum counter electrode, which was inserted in the flow cell, approximately 2 cm upstream of the substrate. The aluminum anode was directly contacted outside of the flow cell. Completion of

Low-temperature solution growth of ZnO nanotube arrays

• Ki-Woong Chae,
• Qifeng Zhang,
• Jeong Seog Kim,
• Yoon-Ha Jeong and
• Guozhong Cao

Beilstein J. Nanotechnol. 2010, 1, 128–134, doi:10.3762/bjnano.1.15

• V was applied to the ITO substrate as cathode and a platinum plate was used as the anode. The deposition time was about 5 min. The substrate was subsequently heat-treated at 500 °C for 30 min to improve the crystallinity of the film of ZnO nanocrystallites. For the growth of ZnO nanorods, the ZnO