Chemi- vs physisorption in the radical functionalization of single-walled carbon nanotubes under microwaves

• Victor Mamane,
• Guillaume Mercier,
• Junidah Abdul Shukor,
• Jérôme Gleize,
• Aziz Azizan,
• Yves Fort and
• Brigitte Vigolo

Beilstein J. Nanotechnol. 2014, 5, 537–545, doi:10.3762/bjnano.5.63

• functions from the SWNT surface. About 5 mg of raw or functionalized sample were placed in an alumina crucible in the TGA chamber, and the temperature was increased from room temperature up to 1000 °C under a helium Alphagaz 2 flux of 20 mL/min at a rate of 3 °C/min. Derivative data (dTG) were obtained by

A catechol biosensor based on electrospun carbon nanofibers

• Dawei Li,
• Zengyuan Pang,
• Xiaodong Chen,
• Lei Luo,
• Yibing Cai and
• Qufu Wei

Beilstein J. Nanotechnol. 2014, 5, 346–354, doi:10.3762/bjnano.5.39

• surface of a freshly polished glass carbon electrode. The glass carbon electrode was processed as follows: Firstly, it was polished with alumina. Following that, it was rinsed by water and ultrasonicated in ethanol and water. Finally, it was dried under a nitrogen atmosphere. The dried laccase–Nafion

3D-nanoarchitectured Pd/Ni catalysts prepared by atomic layer deposition for the electrooxidation of formic acid

• Loïc Assaud,
• Evans Monyoncho,
• Kristina Pitzschel,
• Anis Allagui,
• Matthieu Petit,
• Margrit Hanbücken,
• Elena A. Baranova and
• Lionel Santinacci

Beilstein J. Nanotechnol. 2014, 5, 162–172, doi:10.3762/bjnano.5.16

• , University of Ottawa, 161 Louis-Pasteur St., Ottawa, ON, K1N 6N5, Canada 10.3762/bjnano.5.16 Abstract Three-dimensionally (3D) nanoarchitectured palladium/nickel (Pd/Ni) catalysts, which were prepared by atomic layer deposition (ALD) on high-aspect-ratio nanoporous alumina templates are investigated with

• , has been used to grow well-ordered porous structures. Ni and Pd are then successively deposited into the templates by ALD. The alumina membranes are firstly coated by NiO that is reduced to metallic Ni by annealing under H2 atmosphere [29][30] (Figure 1f). The Pd clusters are then deposited directly

• microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), respectively. The electrocatalytic activity of the Pd/Ni systems, which were deposited on three-dimensional alumina membranes with various mass content ratios, for the electrooxidation of formic acid in acidic solution has

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

• ) reference electrode was used. Sample Preparation Catalyst spots Spots of ORR catalyst powders were prepared by using a catalyst suspension applied by means of a piezoceramic spotter (model SciFA DW with tip PDC 80 from Scienion; Dortmund, Germany) onto polished (0.3 µm alumina paste) glassy carbon plates

Adsorption of the ionic liquid [BMP][TFSA] on Au(111) and Ag(111): substrate effects on the structure formation investigated by STM

• Benedikt Uhl,
• Florian Buchner,
• Dorothea Alwast,
• Nadja Wagner and
• R. Jürgen Behm

Beilstein J. Nanotechnol. 2013, 4, 903–918, doi:10.3762/bjnano.4.102

• that the anion adsorbs in a cis-conformation, with the SO2-groups pointing to the surface and the CF3-groups pointing towards the vacuum. The same adsorption geometry for the anion was also proposed by Sobota et al. [29] for [BMIM][TFSA] (B = butyl) adsorbed on a thin alumina film grown on NiAl(110

Challenges in realizing ultraflat materials surfaces

• Takashi Yatsui,
• Wataru Nomura,
• Fabrice Stehlin,
• Olivier Soppera,
• Makoto Naruse and
• Motoichi Ohtsu

Beilstein J. Nanotechnol. 2013, 4, 875–885, doi:10.3762/bjnano.4.99

• ), because the land structures of 100 nm in height were etched by using this process. Dressed photon–phonon desorption A DPP desorption process has also been developed for smoothing the surfaces of transparent ceramics such as alumina (Al2O3), which is a hard polycrystalline ceramic [44]. Alumina can be used

• ]. In this study, radio frequency (RF) sputtering was used to deposit Al2O3 nanoparticles on an alumina substrate. In the case of conventional RF sputtering, the migration length of the Al2O3 nanoparticles on the substrate surface depends on the Schwöbel barrier [48] in the free energy profile. The

• on the etching time. Blue solid squares and red solid triangles are data for (c) and (d), blue open squares and red open triangles are for (f) and (g). AFM images of the alumina substrate surface after RF sputtering (a) without and (b) with visible light illumination (Reproduced with permission from

Template based precursor route for the synthesis of CuInSe₂ nanorod arrays for potential solar cell applications

• Mikhail Pashchanka,
• Jonas Bang,
• Niklas S. A. Gora,
• Ildiko Balog,
• Rudolf C. Hoffmann and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2013, 4, 868–874, doi:10.3762/bjnano.4.98

• electrodeposition into porous alumina templates [5][6]. The nanowires were composed of 5 nm grains and had a noticeable spread in diameter values (10–30 or 25–40 nm, depending on the pore size of the used template) and lengths (0.6–5 μm). Interestingly, authors reported a preferential growth in the [112] direction

• substrates, e.g., polycrystalline alumina, low-cost glass or even flexible polymeric films [18][19]. Experimental In- and Cu-oximato complexes were synthesised as reported earlier and were used as metal cation sources [20][21]. A solution of Cu-oximato and In-oximato precursors, and selenourea in 1:1:3 molar

Synthesis of boron nitride nanotubes from unprocessed colemanite

• Saban Kalay,
• Zehra Yilmaz and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2013, 4, 843–851, doi:10.3762/bjnano.4.95

• NH3, which is 450 °C. The decomposed NH3 has an important role in the synthesis of BNNT. It was observed that while the BNNTs were formed on top of the alumina boat, BNNT was not formed at the bottom of the reaction mixture (Figure 2f). TEM and HRTEM analysis The structure of BNNTs was further

• homogeneous mixture was transferred into an alumina boat. The water was evaporated with pre-heating at 180 °C for 15 min, and the alumina boat was placed into the center of the tubular furnace (Protherm, Furnaces PTF 14/50/450). The BNNT synthesis was performed under NH3 atmosphere. The furnace temperature

• was set to a heating rate of 8 °C/min until 1280 °C and then heated at this temperature for 3 hours. The furnace was left for cooling down to 520 °C, and the reaction boat was removed from the furnace. The BNNTs were collected from the top of alumina boat and kept in a dry environment at room

Surface passivation and optical characterization of Al₂O₃/a-SiC_x stacks on c-Si substrates

• Gema López,
• Pablo R. Ortega,
• Cristóbal Voz,
• Isidro Martín,
• Mónica Colina,
• Anna B. Morales,
• Albert Orpella and
• Ramón Alcubilla

Beilstein J. Nanotechnol. 2013, 4, 726–731, doi:10.3762/bjnano.4.82

• surface passivation is obtained after the annealing for the whole range of Al2O3 thicknesses. The field-effect passivation remains constant independently of the thickness of the alumina layer probably because fixed negative charges seem to be located at the interface between Al2O3 and c-Si [6]. Other

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

• pore walls of an anodic alumina template, followed by a thermal reduction with lithium vapor. This thermal reduction is quantitative, homogeneous over macroscopic samples, and it yields amorphous silicon and lithium oxide, at the exclusion of any lithium silicides. The reaction is characterized by

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

• /catalyst layer/alumina layer is used. During the CNT growth, the catalyst and alumina layers are lifted up and the CNTs grow vertically aligned, directly on the graphene layer. As a result of this strategy, no seam exists between the graphene and the nanotubes carpet. The introduction of the top alumina

• the template-synthesis method by using alumina membrane templates with a pore size of about 200–500 nm; the assembly is then immerged in an aqueous solution, in which the NPs production will occur. Depending on the conditions (metal salt concentration, exposure time), the shape and size of the NPs can

• be controlled. A subsequent dissolution of the alumina template in aqueous HF retrieves individual nanotubes for further manipulations. For instance, it is possible to obtain an asymmetric functionalization by attaching one kind of NPs on the inner wall of the CNTs and another kind of NPs on the

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

• in the channels or cavities of the given template. During growth, the nanostructures adopt the exact shape and size of the hosting channels [13]. The most commonly used templates are porous alumina [14], diblock-copolymers [15], and track-etched membranes. Electrochemical and electroless deposition

• -shaped (Figure 3c), are fabricated by applying adequate surfactants [46][49]. Before further processing, the template is rinsed in purified water. Compared to other available templates, such as di-block copolymer membranes or porous alumina, etched ion-track membranes offer the powerful possibility of

• deposited with reverse pulses exhibit a <100> texture and are polycrystalline with grain sizes of ca. 0.5 µm (Figure 9b). Bi nanowires with other preferred orientations have been synthesized by other techniques, such as low-temperature solvothermal process and high-pressure injection in alumina [89][90

Zeolites as nanoporous, gas-sensitive materials for in situ monitoring of DeNO_x-SCR

• Thomas Simons and
• Ulrich Simon

Beilstein J. Nanotechnol. 2012, 3, 667–673, doi:10.3762/bjnano.3.76

• screen-printed platinum electrodes on the front side of an alumina substrate with a width of 125 µm and a spacing of 150 µm. The whole electrode structure is about 8 mm in width and 9.5 mm in length. On the back side an integrated heating meander is applied (Figure 1; for electrode design see [24][35

Macromolecular shape and interactions in layer-by-layer assemblies within cylindrical nanopores

• Thomas D. Lazzara,
• K. H. Aaron Lau,
• Wolfgang Knoll,
• Andreas Janshoff and
• Claudia Steinem

Beilstein J. Nanotechnol. 2012, 3, 475–484, doi:10.3762/bjnano.3.54

• behavior, similar to that for a flat surface (Figure 1). Some deviations were observed for the initial deposition steps for the linear-PEs due to differences in the initial surface charge density, i.e., the number of positively charged silanes on alumina versus negatively charged thiols on gold [38]. Then

• , according to a previously reported technique [49]. Briefly, AAO membrane thin films were fabricated by electrochemical anodization of aluminum foils after electrochemical polishing. Polished aluminum foils were anodized for 2 h in 0.3 M oxalic acid, 1 °C at 40 V. The alumina was removed with H3PO4 (5 vol

• the coupling angle of a mode enables real-time, in situ monitoring of changes in the dielectric constant of the film, i.e., adsorption kinetics. The dielectric constant of AAO (εAAO) that is measured by OWS includes contributions from the alumina, the pore-filling medium (e.g., buffer), and any

Glassy carbon electrodes modified with multiwalled carbon nanotubes for the determination of ascorbic acid by square-wave voltammetry

• Sushil Kumar and
• Victoria Vicente-Beckett

Beilstein J. Nanotechnol. 2012, 3, 388–396, doi:10.3762/bjnano.3.45

• modification with MWCNTs, the working GCE was polished on a microcloth (Buehler, Lake Bluff, IL, USA) in a slurry of 0.05 µm alumina (Buehler, Lake Bluff, IL, USA) in Milli-Q water until the surface showed a mirror-like finish. The electrode was then rinsed with Milli-Q water, sonicated for 1 min to remove

• trace alumina particles from the electrode surface, and then air dried. This cleaning procedure was applied before all voltammetric measurements were carried out. The platinum-wire auxiliary electrode was typically polished with a CarbiMet fine-grit polishing disc (Buehler, Lake Bluff, IL, USA) to

Functionalised zinc oxide nanowire gas sensors: Enhanced NO₂ gas sensor response by chemical modification of nanowire surfaces

• Eric R. Waclawik,
• Jin Chang,
• Andrea Ponzoni,
• Isabella Concina,
• Dario Zappa,
• Elisabetta Comini,
• Nunzio Motta,
• Guido Faglia and
• Giorgio Sberveglieri

Beilstein J. Nanotechnol. 2012, 3, 368–377, doi:10.3762/bjnano.3.43

• were grown on alumina substrates for sensing tests (2 mm × 2 mm × 0.25 mm). The ZnO nanowires were grown from the vapour phase by using the evaporation–condensation technique. Pure Zn precursor powder was placed at the centre of an alumina tube and then the tube temperature was raised above the Zn

• decomposition temperature of 600 °C. A controlled flow of inert argon gas was maintained during the decomposition and the overall pressure was maintained at several hundreds of mbar. The temperature gradient downstream of the gas flow promoted condensation of metal cations on clean alumina substrates, which

Nano-FTIR chemical mapping of minerals in biological materials

• Sergiu Amarie,
• Paul Zaslansky,
• Yusuke Kajihara,
• Erika Griesshaber,
• Wolfgang W. Schmahl and
• Fritz Keilmann

Beilstein J. Nanotechnol. 2012, 3, 312–323, doi:10.3762/bjnano.3.35

• sides and etched for 45 s with a suspension of alumina nanoparticles (Struers OP-A), then cleaned and dried. Tooth samples were embedded in PMMA following dehydration by a graded ethanol and PMMA exchange solution; samples were cut perpendicularly to the tubules, serially ground and polished by using

Surface functionalization of aluminosilicate nanotubes with organic molecules

• Wei Ma,
• Weng On Yah,
• Hideyuki Otsuka and
• Atsushi Takahara

Beilstein J. Nanotechnol. 2012, 3, 82–100, doi:10.3762/bjnano.3.10

• water. However, if the pH is too low, the phosphate group may cause the dissolution of metal oxides. It was reported that PhPO(OH)2 can cause the release of aluminum cations from the alumina surface by cleavage of Al–O–Al bonds at pH 4 [54]. In this work, the acidity of the initial reaction mixture was

• controlled and set to be pH 5 in order to avoid a similar dissolution process of imogolite, whose external surface is similar to that of alumina. In our case, a pH 5 acetate buffer was employed. The adsorption of BMPOPO4 onto the imogolite surface was confirmed by FT-IR measurements and XPS analysis. FT-IR

• thought of as an insulator since imogolites consist of wide-bandgap alumina and silica. In fact, due to its unique tubular structure and high aspect ratio, imogolite can be used as an electron-emitting material and water sensor in nanoelectronic devices. The conductivities of the pure imogolite and of the

Self-assembled monolayers and titanium dioxide: From surface patterning to potential applications

• Yaron Paz

Beilstein J. Nanotechnol. 2011, 2, 845–861, doi:10.3762/bjnano.2.94

• to UV light. At the end of the process a negative image of the first-step surface was obtained, consisting of superhydrophilic TiO2 domains and superhydrophobic domains anchored to alumina. In that way, the restoration of hydrophilic contrast by exposure to UV was expected not to take its toll on the

• hydrophobic SAMs. With respect to remote degradation, the fact that the inert substrate here is alumina and not silica may assist to preserve the SAMs, as can be inferred from a comparison of the remote degradation effects of SAMs on silica to those of SAMs on alumina [51]. Remote degradation effects are not

Template-assisted formation of microsized nanocrystalline CeO₂ tubes and their catalytic performance in the carboxylation of methanol

• Jörg J. Schneider,
• Meike Naumann,
• Christian Schäfer,
• Armin Brandner,
• Heiko J. Hofmann and
• Peter Claus

Beilstein J. Nanotechnol. 2011, 2, 776–784, doi:10.3762/bjnano.2.86

• shown that this is due to ceria agglomeration and can be partially prevented by solid dilution of the active ceria catalyst with up to 20%, e.g., of alumina [34]. It would be interesting to find out whether a destructive agglomeration of the ceria catalyst could be diminished significantly by a nano

Micro- and mesoporous solids: From science to application

• Jörg J. Schneider

Beilstein J. Nanotechnol. 2011, 2, 774–775, doi:10.3762/bjnano.2.85

• experimental findings relating to mesoporous inorganic solids, covering aspects of synthesis as well as the functional properties of such materials in catalysis and sensing. Jörg J. Schneider Darmstadt, November 2011 Artificially colorized view of a hexagonally ordered cell structure of mesoporous alumina. The

• pores are shown in yellow and are ca. 40 nm in diameter. The red color grading represents the typically different densities of the alumina cells surrounding the pores, which is due to the synthesis process. As with other mesoporous materials, the inner surface of the pores can be chemically modified to

Generation and agglomeration behaviour of size-selected sub-nm iron clusters as catalysts for the growth of carbon nanotubes

• Ravi Joshi,
• Benjamin Waldschmidt,
• Jörg Engstler,
• Rolf Schäfer and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2011, 2, 734–739, doi:10.3762/bjnano.2.80

• °C), which prevents the iron particles from agglomeration and hence providing a good aluminium–iron interaction. Moreover, the deposited Al layer is also partially oxidized on top of the SiOx grid surface [12] and forms a stable alumina–catalyst interface, which stabilizes the deposited iron clusters

Ceria/silicon carbide core–shell materials prepared by miniemulsion technique

• Lars Borchardt,
• Martin Oschatz,
• Robert Frind,
• Emanuel Kockrick,
• Martin R. Lohe,
• Christoph P. Hauser,
• Clemens K. Weiss,
• Katharina Landfester,
• Bernd Büchner and
• Stefan Kaskel

Beilstein J. Nanotechnol. 2011, 2, 638–644, doi:10.3762/bjnano.2.67

• nanosized [26] silicon carbide are becoming increasingly interesting. There are several reports in literature showing that these materials are able to compete with supports such as alumina, silica or activated carbons, particularly in exothermic reactions [27][28][29][30]. In particular, the use of

Formation of precise 2D Au particle arrays via thermally induced dewetting on pre-patterned substrates

• Dong Wang,
• Ran Ji and
• Peter Schaaf

Beilstein J. Nanotechnol. 2011, 2, 318–326, doi:10.3762/bjnano.2.37

• annealing at 900 °C [11]. Elsewhere, a 2D ordered Au nanoparticle array was formed on a nano-hole patterned substrate via electron-beam-induced dewetting of the Au thin film [25]. Ripple patterned SiO2 substrates [35] and stepped alumina substrates [36] also led to the formation of metallic nanoparticle

Recrystallization of tubules from natural lotus (Nelumbo nucifera) wax on a Au(111) surface

• Sujit Kumar Dora and
• Klaus Wandelt

Beilstein J. Nanotechnol. 2011, 2, 261–267, doi:10.3762/bjnano.2.30

• HOPG (non-polar) to horizontally oriented tubules on polar substrates, e.g., silicon, alumina, or glass, they concluded that surface polarity is responsible for tubule orientation. They also demonstrated an increase in the hydrophobicity of the HOPG surface covered with tubules by measuring the contact

• parallel orientation of tubules on a number of different substrates, e.g., polyethylene, polypropylene, Teflon, alumina, mica, glass, etc. However, they applied a larger volume of solution of 50–250 µL (10 mg·mL−1) which effectively masks any effect of the substrate. A more recent study by Koch et al. [9

• ] demonstrated the effect of substrate polarity on the tubule growth by showing a vertical orientation on HOPG and a horizontal orientation on silicon and alumina. However, in our study by combining various properties (e.g., polarity, crystallinity) together at two different surfaces we have demonstrated that