Purification of ethanol for highly sensitive self-assembly experiments

• Kathrin Barbe,
• Martin Kind,
• Christian Pfeiffer and
• Andreas Terfort

Beilstein J. Nanotechnol. 2014, 5, 1254–1260, doi:10.3762/bjnano.5.139

• plates were immersed into ca. 0.1 mM solutions of Ellman's reagent in acetone and exposed to gaseous ammonia. Residual thiol molecules in the ethanolic solutions were indicated by formation of yellow spots. The highest dodecanethiol amount that did not lead to a color change of the TLC plates was assumed

Sublattice asymmetry of impurity doping in graphene: A review

• James A. Lawlor and
• Mauro S. Ferreira

Beilstein J. Nanotechnol. 2014, 5, 1210–1217, doi:10.3762/bjnano.5.133

• methods and techniques to achieve this have been developed to include chemical vapour deposition (CVD), using NH3 as a precursor, arc discharge [23], embedded nitrogen and carbon sources within a metal substrate [24], ion implantation [25][26], ammonia [27] or nitrogen plasma [28][29] treatments, and

• ]. They discovered that graphene grown via chemical vapour deposition (CVD) in the presence of ammonia (NH3) naturally incorporates nitrogen atoms as substitutional so-called ’graphitic’ dopants (see Figure 1A) into the crystal, and with a distinct sublattice segregation of dopants. Indeed further

• sublattice segregation, at least on local scales, was noted as a curiosity but was not discussed in depth. A key finding by the researchers was that by varying the ammonia precursor concentration they could adjust the resulting embedded dopant concentration. Further theoretical work confirmed that a tunable

Template-directed synthesis and characterization of microstructured ceramic Ce/ZrO₂@SiO₂ composite tubes

• Jörg J. Schneider and
• Meike Naumann

Beilstein J. Nanotechnol. 2014, 5, 1152–1159, doi:10.3762/bjnano.5.126

• mL of ethanol. 1mL distilled water, 1mL tetra-ethoxysilane (TEOS, TEOS, ABCR, 98%) and 2.5 mL of 25% ammonia solution were added one at a time. The obtained mixture was vigorously stirred for 6 h. The PS/silica composite fiber mats were washed with ethanol and dried at 80 °C for 12 h in an oven

Characterization and photocatalytic study of tantalum oxide nanoparticles prepared by the hydrolysis of tantalum oxo-ethoxide Ta₈(μ₃-O)₂(μ-O)₈(μ-OEt)₆(OEt)₁₄

• Subia Ambreen,
• N D Pandey,
• Peter Mayer and
• Ashutosh Pandey

Beilstein J. Nanotechnol. 2014, 5, 1082–1090, doi:10.3762/bjnano.5.121

• (μ-OEt)6(OEt)14 (1) was obtained by the controlled hydrolysis of tantalum ethoxide Ta(OEt)5 in the presence of ammonia. Compound 1 is considered as the intermediate building block in the sol–gel polymerization of Ta(OEt)5. Further hydrolysis of compound 1 yielded nanoparticles of Ta2O5, which were

• [16][17][18][19][20][21]. The present work deals with the study of the controlled hydrolysis of tantalum ethoxide in the presence of ammonia and to prepare tantalum pentaoxide nanoparticles. In this process the stable intermediate tantalum oxo-ethoxide with composition Ta8(μ3-O)2(μ-O)8(μ-OEt)6(OEt)14

• penta-ethoxide was dissolved in toluene and with the aim to examine the effect of hydrolysis in basic medium, wet ammonia gas was purged into it with continuous stirring. After 1 h at pH 8.0, a white solid was formed which was separated, re-dissolved in toluene and kept at low temperature for

Manipulation of isolated brain nerve terminals by an external magnetic field using D-mannose-coated γ-Fe₂O₃ nano-sized particles and assessment of their effects on glutamate transport

• Tatiana Borisova,
• Natalia Krisanova,
• Arsenii Borуsov,
• Roman Sivko,
• Ludmila Ostapchenko,
• Michal Babic and
• Daniel Horak

Beilstein J. Nanotechnol. 2014, 5, 778–788, doi:10.3762/bjnano.5.90

• of iron salts, namely FeCl2 and FeCl3, by rapid increase of pH by ammonia. Similarly as described in [12], this was followed by the oxidation of the resulting magnetite (Fe3O4) with sodium hypochlorite producing maghemite (γ-Fe2O3), which is chemically more stable than Fe3O4. This is in contrast to

A visible-light-driven composite photocatalyst of TiO₂ nanotube arrays and graphene quantum dots

• Donald K. L. Chan,
• Po Ling Cheung and
• Jimmy C. Yu

Beilstein J. Nanotechnol. 2014, 5, 689–695, doi:10.3762/bjnano.5.81

• for 1 h with a temperature increasing rate of 1 °C·min−1 in air was applied to improve crystallization. Synthesis of graphene quantum dots (GQDs): GQDs were synthesized from graphene oxide (GO) by heating with a solution of hydrogen peroxide and ammonia [44]. 20 mg of GO was dispersed into 5 mL of

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

• V or lower for all oxygen coverages studied, and it is thus possible to (re)activate (partially) oxidized nanoclusters for electrochemical ammonia production, e.g., using a dry proton conductor or an aqueous electrolyte. At lower oxygen coverages, nitrogen molecules can adsorb to the surface and

• electrochemical ammonia production via the associative mechanism is possible at potentials as low as −0.45 V to −0.7 V. Keywords: ammonia; density functional theory; electrocatalysis; nanoparticles; oxygen poisoning; Introduction Molybdenum nanoclusters have been identified as a prime candidate for

• electrochemical ammonia production with seemingly low Faradaic losses to hydrogen evolution [1][2]. To produce ammonia electrochemically, one can either use a liquid or a solid electrolyte, but these effectively require wet conditions to obtain sufficient protonic conduction [3][4]. The presence of water may give

Controlled synthesis and tunable properties of ultrathin silica nanotubes through spontaneous polycondensation on polyamine fibrils

• Jian-Jun Yuan,
• Pei-Xin Zhu,
• Daisuke Noda and
• Ren-Hua Jin

Beilstein J. Nanotechnol. 2013, 4, 793–804, doi:10.3762/bjnano.4.90

• formation induced by NaOH. Figure 7 shows the SEM images of silicas prepared by using ammonia solution (NH4OH) to induce self-assembly of LPEI with molar ratios [OH]/[EI] = 0.6, 0.8 and 3.2. We found that silica nanofilms were formed by using a molar ratio [OH]/[EI] = 0.6 (Figure 7A and Figure 7B), because

• the LPEI crystallization was delayed due to weak basicity of the ammonia solution and a low degree of deprotonation of LPEI–H+. This is consistent with the formation of silica nanofilms by using NaOH with low molar ratios [OH]/[EI]. Furthermore, when increasing the molar ratio [OH]/[EI] to 0.8, the

• similar to that synthesized by temperature-induced LPEI self-assembly (Figure 2). No peak value of the pore size distribution was observed (Figure S4 in Supporting Information File 1). To further confirm the effect of ammonia solution on the formation of silica nanostructure, the LPEI self-assembly was

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

Nanostructure-directed chemical sensing: The IHSAB principle and the dynamics of acid/base-interface interaction

• James L. Gole and
• William Laminack

Beilstein J. Nanotechnol. 2013, 4, 20–31, doi:10.3762/bjnano.4.3

• and the sensor response corresponds to a conductance decrease relative to the untreated interface. Note also that the in situ nitridation of TiO2 shifts the nature of this metal oxide nanostructure toward the soft acid side of Figure 2, closer to ammonia. The IHSAB principle dictates [3][6][7][8][24

• orbital makeup now becomes more closely aligned. The nitridation of NiO also leads to a decrease in response for NO; however, the reversible response resulting from the interaction with NH3 increases. Figure 4 presents comparable data as 1–10 ppm of ammonia interacts with a nitridated copper-oxide-treated

• oxinitride should simply increase the basicity of the nanostructure surface and thus should decrease the response to NH3. However, this does not occur. The nitridated copper oxide is shifted further to the soft-acid side of ammonia in Figure 2, dictating a greater molecular orbital mismatch. The IHSAB

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

• shows a significantly lower onset temperature, and time-dependent measurements suggest different SCR reaction mechanisms for the two catalysts tested. These results may help in the development of catalysts for the reduction of NOx emissions and ammonia consumption, and provide insight into the

• can be measured by different measuring techniques, such as infrared (IR) spectroscopy [2], NMR spectroscopy [3], thermal analysis [4][5][6] and indicator method [7], as well as the amine titration method [8] and temperature-programmed desorption of ammonia (NH3-TPD) [9][10][11]. H-form zeolites are

• onset temperature for the Fe-loaded material would be significantly lower than for the H-form, while the ammonia desorption temperature for both materials should occur at the same temperature. We thus demonstrate that in situ monitoring of DeNOx-SCR by IS provides insight into the elementary catalytic

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

• (THMA) and dodecanethiol (DT), was studied. The response towards ammonia, nitrous oxide and nitrogen dioxide was investigated for three sensor configurations, namely pure ZnO nanowires, organic-coated ZnO nanowires and ZnO nanowires covered with a sparse layer of organic-coated ZnO nanoparticles

• on the gas response. We investigated the chemiresistor response towards ammonia, nitrous oxide and nitrogen dioxide. Results and Discussion The morphology, surface roughness and evenness-of-coating of the ZnO nanowire sensors were examined by scanning electron microscopy. SEM images of each sensor

• ultrahigh vacuum rather than in dry air. Taking the TG results into account, a sensor operating temperature of 190 °C was chosen for all gas-response tests. Gas sensing measurements for the various ZnO samples with different morphologies and compositions were performed for the gases ammonia, nitrous oxide

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

• ammonium salt. The detailed assembly procedure is shown in Figure 4. The ammonium salt of dodecylphosphate (DDPO4(NH4)2) was precipitated from a 2-propanol solution of dodecylphosphoric acid (DDPO4H2) by the addition of ammonia. The outer surface of imogolite nanotubes is composed of aluminol groups, thus

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

• ammonia at 50 °C for half an hour, the sol was allowed to infiltrate into the electrospun polymer-template fibre mats upon application by a spray-coating technique [9][20][21]. The obtained PMMA/ceria composite samples were then plasma etched in 20 vol % oxygen atmosphere (air) for 16 h to remove the

• +%) was dissolved in 40 mL distilled water. 0.65 mL aqueous 25 wt % ammonia solution (Merck) was added and the solution was vigorously stirred for half an hour. 1 g Pluronic P123® (Sigma Aldrich) was added and dissolved at 50 °C. The sol was used immediately. The as-prepared cerium-containing sol was

Nanostructured, mesoporous Au/TiO₂ model catalysts – structure, stability and catalytic properties

• Matthias Roos,
• Dominique Böcking,
• Kwabena Offeh Gyimah,
• Gabriela Kucerova,
• Joachim Bansmann,
• Johannes Biskupek,
• Ute Kaiser,
• Nicola Hüsing and
• R. Jürgen Behm

Beilstein J. Nanotechnol. 2011, 2, 593–606, doi:10.3762/bjnano.2.63

• conditions, a classical example of this situation being the synthesis of ammonia [7]. Accordingly, the last two decades saw increasing efforts to bridge the gaps between reaction conditions, often known as the “pressure gap”, and between materials (the “materials gap”) [2][3][4][5][6]. On the one hand, this

Investigation on structural, thermal, optical and sensing properties of meta-stable hexagonal MoO₃ nanocrystals of one dimensional structure

• Angamuthuraj Chithambararaj and
• Arumugam Chandra Bose

Beilstein J. Nanotechnol. 2011, 2, 585–592, doi:10.3762/bjnano.2.62

• nitrates and ammonia compounds from the material. The same observation is made from the DTA curve, which exhibits two broad exothermic peaks well below 270 °C. After dehydration and removal of ammonia compounds, a sharp exothermic peak at 430 °C with weight loss of 1.35 wt % is attributed to liberation of

• coordinated water and ammonia molecules from the internal structure of the MoO3 material, which promotes an irreversible phase transformation from the hexagonal to the orthorhombic structure [14][16]. The powder subjected to TGA measurements was subjected to XRD analysis, and the result confirmed that above

Schottky junction/ohmic contact behavior of a nanoporous TiO₂ thin film photoanode in contact with redox electrolyte solutions

• Masao Kaneko,
• Hirohito Ueno and
• Junichi Nemoto

Beilstein J. Nanotechnol. 2011, 2, 127–134, doi:10.3762/bjnano.2.15

• ]. The present authors have reported a cell composed of a nanoporous semiconductor photoanode and an O2-reducing cathode that can efficiently photodecompose various bio-related compounds in water [11][12]. When ammonia was present in water in contact with a nanoporous TiO2 photoanode, the semiconductor

• formed a kind of Schottky junction, which induced efficient decomposition of ammonia with a high internal quantum efficiency (i.e., the number of decomposed molecules per photon activating an NH3 molecule) of over 100 (=104%) through auto-oxidative decomposition of the activated ammonia [12]. In

Magnetic nanoparticles for biomedical NMR-based diagnostics

• Huilin Shao,
• Tae-Jong Yoon,
• Monty Liong,
• Ralph Weissleder and
• Hakho Lee

Beilstein J. Nanotechnol. 2010, 1, 142–154, doi:10.3762/bjnano.1.17

• epichlorohydrin and activated by ammonia to provide primary amine group functionality. The amine groups can then be easily reacted with various agents containing anhydride, hydroxyl, carboxyl, thiol, or epoxide groups, to confer molecular specificity to the nanoparticle through bioconjugation [43]. Amine