Ammonia gas sensors based on In₂O₃/PANI hetero-nanofibers operating at room temperature

• Qingxin Nie,
• Zengyuan Pang,
• Hangyi Lu,
• Yibing Cai and
• Qufu Wei

Beilstein J. Nanotechnol. 2016, 7, 1312–1321, doi:10.3762/bjnano.7.122

• PANI influences the sensing performance of the In2O3/PANI composite nanofibers. In this paper, In2O3/PANI composite nanofibers with a mass ratio of 1:2 exhibited the highest response values, excellent selectivity, good repeatability and reversibility. Keywords: ammonia (NH3); electrospinning; gas

• pollution. Ammonia (NH3), as a highly toxic gas, can be emitted by natural and industrial sources and threaten human health [2][3][4]. NH3 at concentrations of 50 ppm may irritate the human respiratory system, skin and eyes [4]. Higher concentrations of NH3 will cause blindness, seizures, lung disease and

• even death [5][6][7]. So, there is an urgent need to develop a kind of gas sensor with high sensitivity and selectivity to detect NH3 at room temperature. Metal oxide semiconductors can be applied as sensing materials for monitoring NH3. Ammonia sensors based on In2O3 [8], TiO2 [9], SnO2 [10], ZnO [11

Mesoporous hollow carbon spheres for lithium–sulfur batteries: distribution of sulfur and electrochemical performance

• Anika C. Juhl,
• Artur Schneider,
• Boris Ufer,
• Torsten Brezesinski,
• Jürgen Janek and
• Michael Fröba

Beilstein J. Nanotechnol. 2016, 7, 1229–1240, doi:10.3762/bjnano.7.114

• methods in a two-step procedure [33][34]. For synthesis of the core, 536 mL of ethanol were mixed with 45 mL of aqueous ammonia (32%) and 6.8 mL of deionized water. After stirring for 30 min, 24 mL of tetraethyl orthosilicate (TEOS) were added and the mixture was stirred at room temperature for 18 h. The

Reasons and remedies for the agglomeration of multilayered graphene and carbon nanotubes in polymers

• Rasheed Atif and
• Fawad Inam

Beilstein J. Nanotechnol. 2016, 7, 1174–1196, doi:10.3762/bjnano.7.109

• introduction of heteroatoms in SWNTs can lead to novel properties. Heating may remove the attached functionalized groups. The functionalized SWNTs can be dissolved in organic solvents up to about 100 mg/L. The functionalization of SWNTs in liquid ammonia by reductive alkylation using lithium and alkyl halides

Phenalenyl-based mononuclear dysprosium complexes

• Yanhua Lan,
• Andrea Magri,
• Olaf Fuhr and
• Mario Ruben

Beilstein J. Nanotechnol. 2016, 7, 995–1009, doi:10.3762/bjnano.7.92

• ’ was characterized confirming its thermal stability. Results and Discussion Synthesis Van Deun et al. [23][24] synthesized 1:3 metal-to-ligand complexes using ammonia as a base and 1:4 metal-to-ligand complexes using the stronger base NaOH. In addition, phenalenyl-based europium and gadolinium

• nonanuclear complexes [26] were obtained by using (Et)3N as base in a 1:1.8 metal-to-ligand ratio. The synthetic procedures reported in our work are illustrated in Scheme 1. Instead of ammonia or NaOH as a base [23][24], we used NaH or diisopropyl amine to deprotonate the HPLN ligand. In order to obtain

Dielectrophoresis of gold nanoparticles conjugated to DNA origami structures

• Anja Henning-Knechtel,
• Matthew Wiens,
• Mathias Lakatos,
• Andreas Heerwig,
• Frieder Ostermaier,
• Nora Haufe and
• Michael Mertig

Beilstein J. Nanotechnol. 2016, 7, 948–956, doi:10.3762/bjnano.7.87

• peroxide (30 wt % in water; Merck), ammonia solution (25 wt % in water; Merck) and ddH2O in the ratio 1:1:5] and rinsed with ddH2O. Then, such a glass slide was placed in an inverted optical microscope (Axiovert 200M, Carl Zeiss MicroImaging) equipped with a 100×/1.45 numerical aperture oil immersion

Synthesis and applications of carbon nanomaterials for energy generation and storage

• Marco Notarianni,
• Jinzhang Liu,
• Kristy Vernon and
• Nunzio Motta

Beilstein J. Nanotechnol. 2016, 7, 149–196, doi:10.3762/bjnano.7.17

• can help to decrease the required annealing temperature to 450 °C and still give a high C/O ratio of ≈15, as was demonstrate by Wu et al. [120]. Li et al. [121] instead used a mixture of ammonia and argon (2 Torr, NH3/Ar (10% NH3), 500 °C) to produce good quality, doped rGO. The drawbacks of thermal

Evaluation of gas-sensing properties of ZnO nanostructures electrochemically doped with Au nanophases

• Elena Dilonardo,
• Michele Penza,
• Marco Alvisi,
• Cinzia Di Franco,
• Francesco Palmisano,
• Luisa Torsi and
• Nicola Cioffi

Beilstein J. Nanotechnol. 2016, 7, 22–31, doi:10.3762/bjnano.7.3

• Sol–gel synthesis of ZnO ZnO nanostructures were prepared through a sol–gel process. An aqueous solution of ZnCl2 (0.1 M) was heated to 60 °C for 1 h in a water-bath under continuous stirring. Ammonia solution (0.1 M) was then added drop-wise until a dense gel was formed at pH 9 [43]. The gel was

Sonochemical co-deposition of antibacterial nanoparticles and dyes on textiles

• Ilana Perelshtein,
• Anat Lipovsky,
• Nina Perkas,
• Tzanko Tzanov and
• Aharon Gedanken

Beilstein J. Nanotechnol. 2016, 7, 1–8, doi:10.3762/bjnano.7.1

• antibacterial CuO or ZnO nanoparticles (NPs) from an aqueous solution. The solution contains both the dye and the corresponding M(CH3COO)2 (M = Zn or Cu) precursor, which undergoes hydrolysis under alkaline conditions (ammonia) to form ZnO or CuO. The cotton was colored with the dye and showed good

• % amplitude of a 750 W booster sonicator (Sonics and Materials instrument, Ti-horn, 20 kHz). When the solution reached a temperature of 60 °C, 25% aqueous ammonia solution was added drop wise to adjust the pH to 8, and the sonochemical process was continued for another 60 min. The temperature of 30 °C was

• maintained constant during the sonochemical coating reaction by cooling the flask with cold water. The coated fabric was first washed thoroughly with water to remove traces of ammonia, then with ethanol, and dried under vacuum. A control experiment, in which only the dye (RO16 or RB5) was deposited

Green and energy-efficient methods for the production of metallic nanoparticles

• Mitra Naghdi,
• Mehrdad Taheran,
• Satinder K. Brar,
• M. Verma,
• R. Y. Surampalli and
• J. R. Valero

Beilstein J. Nanotechnol. 2015, 6, 2354–2376, doi:10.3762/bjnano.6.243

• 15 nm [21]. Kvitek et al. compared the performances of four different sugars including xylose, glucose, fructose and maltose in reduction of AgNO3 in the presence of ammonia and production of spherical Ag NPs in a single-step reduction process at 20 °C. They found that decreasing the ammonia content

• from 0.2 to 0.005 M can decrease the particle size from 380 down to 45 nm. For higher concentrations of ammonia (0.2 M) there are slight differences in the particle sizes of Ag NPs produced by the four sugars (352–380 nm). But at low ammonia concentrations (0.005 M), the average size of particles in

• the case of fructose (161 nm) are three times more than that in the case of other sugars (47–57 nm) [57]. In a similar study, they used galactose and lactose as reducing agents and achieved Ag NPs with the average particle size of 50 and 35 nm at 0.005 M ammonia concentrations [65]. In another work

Silica-coated upconversion lanthanide nanoparticles: The effect of crystal design on morphology, structure and optical properties

• Uliana Kostiv,
• Miroslav Šlouf,
• Hana Macková,
• Alexander Zhigunov,
• Hana Engstová,
• Katarína Smolková,
• Petr Ježek and
• Daniel Horák

Beilstein J. Nanotechnol. 2015, 6, 2290–2299, doi:10.3762/bjnano.6.235

• modifications. The OM–NaYF4:Yb3+/Er3+ nanoparticles (50 mg) were dispersed in cyclohexane (10 mL). Igepal CO-520 (0.5 mL) and 25% aqueous ammonia (0.08 mL) were added, and the suspension was mixed using a Sonopuls sonicator (Bandelin, Berlin, Germany) for 30 min, yielding a stable colloid. TMOS (0.04 mL) was

Influence of wide band gap oxide substrates on the photoelectrochemical properties and structural disorder of CdS nanoparticles grown by the successive ionic layer adsorption and reaction (SILAR) method

• Mikalai V. Malashchonak,
• Alexander V. Mazanik,
• Olga V. Korolik,
• Еugene А. Streltsov and
• Anatoly I. Kulak

Beilstein J. Nanotechnol. 2015, 6, 2252–2262, doi:10.3762/bjnano.6.231

• titanium, respectively. Mesoporous In2O3 films were prepared by spin coating of an indium hydroxide colloidal solution with subsequent heat treatment [36]. A stable indium hydroxide sol was prepared by hydrolysis of a 0.25 mol/L In(NO3)3 solution with aqueous ammonia (12%) under vigorous stirring at 0 °C

Electrochemical behavior of polypyrrol/AuNP composites deposited by different electrochemical methods: sensing properties towards catechol

• Celia García-Hernández,
• Cristina García-Cabezón,
• Cristina Medina-Plaza,
• Fernando Martín-Pedrosa,
• Yolanda Blanco,
• José Antonio de Saja and
• María Luz Rodríguez-Méndez

Beilstein J. Nanotechnol. 2015, 6, 2052–2061, doi:10.3762/bjnano.6.209

• [13], ammonia gas at room temperature [14], caffeine [15] or hydroxylamine [16] among others. Ppy/AuNP composites can be prepared by chemical and electrochemical polymerization. Electrochemical methods provide a better control of the structure and properties of the composite by controlling the

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

• graphene in ammonia gas [26]. However, few attempts have been made of directly growing nitrogen-doped graphene onto metal foils by CVD using N-containing precursors. On platinum surfaces, nitrogen-doped carbon films were grown below 500 °C with acetonitrile and below 700 °C with pyridine [27][28]. On

Thermal treatment of magnetite nanoparticles

• Beata Kalska-Szostko,
• Urszula Wykowska,
• Dariusz Satula and
• Per Nordblad

Beilstein J. Nanotechnol. 2015, 6, 1385–1396, doi:10.3762/bjnano.6.143

• in aqueous ammonia solution (MNP-1). This is a low temperature reaction that was conducted at 80 °C under Ar atmosphere. The procedure was adopted from the Massart method [7][22][23]. The second (MNP-2) and third (MNP-3) type of nanoparticles were based on the layer-by-layer synthetic procedure

Heterometal nanoparticles from Ru-based molecular clusters covalently anchored onto functionalized carbon nanotubes and nanofibers

• Deborah Vidick,
• Xiaoxing Ke,
• Michel Devillers,
• Claude Poleunis,
• Arnaud Delcorte,
• Pietro Moggi,
• Gustaaf Van Tendeloo and
• Sophie Hermans

Beilstein J. Nanotechnol. 2015, 6, 1287–1297, doi:10.3762/bjnano.6.133

• microscopy (HRTEM) and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) confirms their bimetal nature on the nanoscale. The obtained bimetal nanoparticles supported on nanocarbon were tested as catalysts in ammonia synthesis and are shown to be active at low temperature

• and atmospheric pressure with very low Ru loading. Keywords: ammonia synthesis; cluster; nanofibers; nanoparticles; nanotubes; Introduction Metal nanoparticles (NPs) supported on nanoscopic forms of carbon (nanotubes, nanofibers) are an important class of nanostructured materials that find

• agglomeration, and in particular, their characterization at atomic resolution to prove their bimetal nature within individual nanoparticles. In order to test their potential application in catalysis, the carbon-supported nanoparticles are evaluated in ammonia synthesis, as a reference reaction with mature

Electrocatalysis on the nm scale

• R. Jürgen Behm

Beilstein J. Nanotechnol. 2015, 6, 1008–1009, doi:10.3762/bjnano.6.103

• theoretical description of important electrocatalytic reactions, such as hydrogen evolution/water splitting [4][5] or electrocatalytic ammonia synthesis [6]. Additionally, mechanistic studies of electrocatalytic reactions, such as O2 reduction [7], CO oxidation [8] or the electrooxidation of small organic

Pt- and Pd-decorated MWCNTs for vapour and gas detection at room temperature

• Hamdi Baccar,
• Atef Thamri,
• Pierrick Clément,
• Eduard Llobet and
• Adnane Abdelghani

Beilstein J. Nanotechnol. 2015, 6, 919–927, doi:10.3762/bjnano.6.95

• known to weakly interact with VOCs in general and with aromatic VOCs in particular. Therefore, a functionalisation of the carbon nanotube sidewalls is essential to promote sensitivity. In previous works, we used oxygen-plasma-treated multiwalled carbon nanotubes for detecting nitrogen dioxide, ammonia

• , hydrogen sulphide, ammonia and hydrogen [28]. However, this technique leads to an inhomogeneous decoration of the carbon nanotubes with high irregularities in the shape and size of the metal nanoparticles, which eventually may result in poor sensor reproducibility. Espinosa and co-workers decorated plasma

A simple approach to the synthesis of Cu_1.8S dendrites with thiamine hydrochloride as a sulfur source and structure-directing agent

• Xiaoliang Yan,
• Sha Li,
• Yun-xiang Pan,
• Zhi Yang and
• Xuguang Liu

Beilstein J. Nanotechnol. 2015, 6, 881–885, doi:10.3762/bjnano.6.90

• temperature [4]. Polycrystalline Cu1.8S powder was prepared by mechanical alloying and subsequent spark plasma sintering and it exhibited excellent thermoelectric properties as a p-type sulfide [5]. An aqueous ammonia assisted approach was developed for the synthesis of Cu1.8S with triangular and rod-like

Transformation of hydrogen titanate nanoribbons to TiO₂ nanoribbons and the influence of the transformation strategies on the photocatalytic performance

• Melita Rutar,
• Nejc Rozman,
• Matej Pregelj,
• Carla Bittencourt,
• Romana Cerc Korošec,
• Andrijana Sever Škapin,
• Aleš Mrzel,
• Srečo D. Škapin and
• Polona Umek

Beilstein J. Nanotechnol. 2015, 6, 831–844, doi:10.3762/bjnano.6.86

• morphology or on the surface appearance of the nanoribbons. The transformations performed in the reductive atmosphere, an NH3(g)/Ar(g) flow, and in the ammonia solution led to nitrogen doping. The nitrogen content increased with an increasing calcination temperature, as was determined by X-ray photoelectron

• processing time required for complete conversion in the hydrothermal reactor, in deionized water at 160 °C (CH-W), was 10 h. In contrast, the transformation in 0.5 M NH3(aq) (CH-N) was only completed after 24 h. In addition, the experiments in ammonia solutions with higher molarities did not produce any TiO2

• suspensions decreases with the decreasing pH. This is in the agreement with our results since the transformation occurred only with 0.5 M NH3(aq) and not in ammonia solutions with larger molarities. Also the time needed for the complete transformation in the basic environment was significantly longer (24 h

Nanoparticle shapes by using Wulff constructions and first-principles calculations

• Georgios D. Barmparis,
• Zbigniew Lodziana,
• Nuria Lopez and
• Ioannis N. Remediakis

Beilstein J. Nanotechnol. 2015, 6, 361–368, doi:10.3762/bjnano.6.35

• ammonia-synthesis catalyst from first principles [47][48][49]. Density functional calculations were used to obtain accurate surface energies for several faces of hcp Ru. These values were used in a standard Wulff-construction software to create the polyhedron that corresponded to the equilibrium shape. In

• ). Microscopy and/or first-principles simulations are typically used to identify what the active sites for each catalytic reaction are. For example, B-type step atoms are the only active sites for ammonia synthesis on Ru-based catalysts [56]. Atomistic Wulff constructions can be then used to calculate the

Synthesis, characterization, monolayer assembly and 2D lanthanide coordination of a linear terphenyl-di(propiolonitrile) linker on Ag(111)

• Zhi Chen,
• Svetlana Klyatskaya,
• José I. Urgel,
• David Écija,
• Olaf Fuhr,
• Willi Auwärter,
• Johannes V. Barth and
• Mario Ruben

Beilstein J. Nanotechnol. 2015, 6, 327–335, doi:10.3762/bjnano.6.31

• of the resulting aldehydes with ammonia giving the final product 2 with a overall yield of 18% [45] (Scheme 1). Additionally, a small amount of a byproduct, identified as terphenyl-4-propiolonitrile (3) (Ph3–C≡C–C≡N), was separated and revealed to be a thus-far unreported decarboxylation reaction of

• (m/z): [M]+ calcd for C24H18O2, 338.1; found, 338.0. 3,3'-([1,1':4',1''-terphenyl]-4,4''-diyl)dipropiolonitrile (2) Following [45] a 2 M solution of ammonia in 2-propanol (1.8 mL, 3.2 mmol) and anhydrous magnesium sulfate (1.5 g, 12.8 mmol) were added to a stirred solution of compound 5 (203 mg, 0.6

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

• . The most commonly preferred chemical functionalization is through the –OH on B atoms and –NH2 groups at the edges and defects, as shown in Figure 3 [15][44][63][64][65]. In one study, BNNTs were functionalized with amine groups by ammonia plasma irradiation [63]. It was predicted that NH2∙ radicals

SERS and DFT study of copper surfaces coated with corrosion inhibitor

• Maurizio Muniz-Miranda,
• Francesco Muniz-Miranda and
• Stefano Caporali

Beilstein J. Nanotechnol. 2014, 5, 2489–2497, doi:10.3762/bjnano.5.258

• adsorbed species on the metal surface. In order to obtain a suitable surface roughness from a smooth copper substrate, etching in nitric acid was performed (as previously demonstrated [17]), followed by immersion in ammonia solution. The reducing environment limits the oxidation of the copper surface

• (which takes place very quickly) in order to preserve the metallic nanostructures necessary for the SERS activation by removing oxides by formation of water-soluble complexes with ammonia. Next, the copper plate was immersed in a solution of 1,2,4-triazole, which acts as a corrosion inhibitor by

• isolating the metallic surface from the oxidative action of the atmosphere. Conclusion An etching process was performed on smooth copper surfaces using nitric acid followed by immersion in an ammonia solution, resulting in SERS-active substrates. This activation was validated by the SEM and profilometry

Synthesis and characterization of fluorescence-labelled silica core-shell and noble metal-decorated ceria nanoparticles

• Rudolf Herrmann,
• Markus Rennhak and
• Armin Reller

Beilstein J. Nanotechnol. 2014, 5, 2413–2423, doi:10.3762/bjnano.5.251

• synthesis of ceria NP [38][39][40][41] and found the procedure with air oxidation of cerium(III) nitrate in ethanol/water mixtures in the presence of ammonia very convenient [42][43]. At 60–70 °C (open flask) one obtains small crystalline NP in ethanol/water 4:1 as solvent of almost spherical shape (average

Gas sensing properties of nanocrystalline diamond at room temperature

• Marina Davydova,
• Pavel Kulha,
• Alexandr Laposa,
• Karel Hruska,
• Pavel Demo and
• Alexander Kromka

Beilstein J. Nanotechnol. 2014, 5, 2339–2345, doi:10.3762/bjnano.5.243

• Figure 5, exposure of the sensor elements to 100 ppm of ammonia gas led to increased impedances from 4.4 to 5.4 MΩ and from 3.9 to 5.4 MΩ for the samples nucleated for 1 min and 5 min, respectively. It should be noted that a variation (shift) in the starting impedance value was observed. The starting

• ) for 15 min to stabilize the output characteristics. Subsequently, the specific testing gas (NH3) was injected into the chamber through the inlet port, and the change in the resistance of the sensors (dR/R) was investigated as a function of exposure time. Ammonia (NH3, quality N38, purity 99.98%) was