Graphene functionalised by laser-ablated V₂O₅ for a highly sensitive NH₃ sensor

• Margus Kodu,
• Artjom Berholts,
• Tauno Kahro,
• Mati Kook,
• Peeter Ritslaid,
• Helina Seemen,
• Tea Avarmaa,
• Harry Alles and
• Raivo Jaaniso

Beilstein J. Nanotechnol. 2017, 8, 571–578, doi:10.3762/bjnano.8.61

• on graphene with average thickness of ≈0.6 nm. From Raman spectroscopy, it was concluded that the PLD process also induced defects in graphene. Compared to unmodified graphene, the obtained chemiresistive sensor showed considerable improvement of sensing ammonia at room temperature. In addition, the

• between deposited V2O5 and graphene. Keywords: ammonia; electric conductivity; gas sensor; graphene; pulsed laser deposition; UV light activation; vanadium(V) oxide; Introduction Graphene, being a thin (semi)conducting material, is a promising gas sensing system. Highly sensitive response, down to

• gases, such as ammonia. Vanadium oxide based films and nanostructured layers have been previously synthesised for gas sensing applications by various methods [11], including pulsed laser deposition (PLD) [12]. PLD is a highly versatile method for relatively well-controlled preparation of thin films, and

Fiber optic sensors based on hybrid phenyl-silica xerogel films to detect n-hexane: determination of the isosteric enthalpy of adsorption

• Jesús C. Echeverría,
• Ignacio Calleja,
• Paula Moriones and
• Julián J. Garrido

Beilstein J. Nanotechnol. 2017, 8, 475–484, doi:10.3762/bjnano.8.51

• ammonia were supplied by Merck (Darmstadt, Germany). Silicon precursors with purity greater than 98% were obtained from Sigma-Aldrich (Steinheim, Germany). All chemicals were used without further purification. Water was deionized and purified with a Milli-Q system (model 185, Millipore, Mosheim, France

Tailoring bifunctional hybrid organic–inorganic nanoadsorbents by the choice of functional layer composition probed by adsorption of Cu²⁺ ions

• Veronika V. Tomina,
• Inna V. Melnyk,
• Yuriy L. Zub,
• Aivaras Kareiva,
• Miroslava Vaclavikova,
• Gulaim A. Seisenbaeva and
• Vadim G. Kessler

Beilstein J. Nanotechnol. 2017, 8, 334–347, doi:10.3762/bjnano.8.36

• into account the already developed principles of the production of APTES-derived materials [48][49]. The particles are generally smaller when higher TEOS/APTES ratios are applied [31]. They are less coalesced in the presence of higher ammonia content because of a stronger negative charging of the

• growing entities, which is especially important for highly hydrophobic materials that can otherwise form gels separating from solutions [50][51][52]. The most efficient way to keep the aminopropyl groups on the surface is to add TEOS after the APTES and, especially, to slightly increase the ammonia

• –ammonia complexes are well known. They also correlate well with the data obtained by some other physical methods (e.g., electron spectroscopy and EPR) as is traced in detail in [53]. Comparing the values of the sorption rate constants for monofunctional and amino/methyl samples, we can conclude, that the

Nitrogen-doped twisted graphene grown on copper by atmospheric pressure CVD from a decane precursor

• Ivan V. Komissarov,
• Nikolai G. Kovalchuk,
• Vladimir A. Labunov,
• Ksenia V. Girel,
• Olga V. Korolik,
• Mikhail S. Tivanov,
• Algirdas Lazauskas,
• Mindaugas Andrulevičius,
• Tomas Tamulevičius,
• Viktoras Grigaliūnas,
• Šarunas Meškinis,
• Sigitas Tamulevičius and
• Serghej L. Prischepa

Beilstein J. Nanotechnol. 2017, 8, 145–158, doi:10.3762/bjnano.8.15

• edges [13]. Finally, we turn to the problem of nitrogen incorporation into graphene. Nitrogen can be incorporated into graphene sheet (i) in situ, using ammonia as a component of the gas carrier mixture [43] or with nitrogen containing precursors [60][61] and (ii) by post-treatment, e.g., by treatment

• in ammonia plasma [62] or N-ion irradiation [63]. To the best of our knowledge, there is only one article where N2 gas was used as the nitrogen source during the CVD growth [64]. In our opinion, the main difficulties in using N2 gas as a nitrogen source arises from the fact that nitrogen molecule

From iron coordination compounds to metal oxide nanoparticles

• Mihail Iacob,
• Carmen Racles,
• Codrin Tugui,
• George Stiubianu,
• Adrian Bele,
• Liviu Sacarescu,
• Daniel Timpu and
• Maria Cazacu

Beilstein J. Nanotechnol. 2016, 7, 2074–2087, doi:10.3762/bjnano.7.198

• for NPM1 the pH of the reaction system was adjusted to 11. The sample NPM0 was obtained by adding ammonia water to the aqueous solution of FeAc2, without any additional operations (stirring, heating, etc.) and used as a control. The NPM1 and NPM2 samples were obtained by adding ammonia water to an

• , (0.5 g in each case) in a furnace up to 600 °C in air (heating rate 50 °C/min) and maintained at this temperature for 5 h. Preparation of iron oxide nanoparticles under microwave irradiation (NPM series). FeAc2 (0.3 mmol) was dissolved in 1 mL of distilled water, after which 2 mL of ammonia water (25

• ultrasonicated for 1 min at 100 °C, then 40 mL of ammonia water (25%) were added to the solution. The ultrasonication time was 10 min for sample NPU1, and 30 min for NPU2. TEM images and particle size distribution histograms of NPT1a (a,c) and NPT1b (b,d). The TEM images (a,c) and the histogram of the particle

Solvent-mediated conductance increase of dodecanethiol-stabilized gold nanoparticle monolayers

• Patrick A. Reissner,
• Jean-Nicolas Tisserant,
• Antoni Sánchez-Ferrer,
• Raffaele Mezzenga and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2016, 7, 2057–2064, doi:10.3762/bjnano.7.196

• nitrogen prior to immersion. For OPE/THF and TPT/EtOH immersion the molecular concentration was 1 mM. In the case of OPE, the acetyl protecting group was removed by addition of 20 µL ammonia (30%) in 3 mL solution while bubbling with nitrogen. The samples were immersed upside down. After immersion the

A dioxaborine cyanine dye as a photoluminescence probe for sensing carbon nanotubes

• Mohammed Al Araimi,
• Petro Lutsyk,
• Anatoly Verbitsky,
• Yuri Piryatinski,
• Mykola Shandura and
• Aleksey Rozhin

Beilstein J. Nanotechnol. 2016, 7, 1991–1999, doi:10.3762/bjnano.7.190

• probes for amines and ammonia [14][15][16]. Optical properties (absorption and PL) of monomeric and dimeric forms of DOB-719 were reported in [16] showing that there is a weak interaction of SWNTs with DOB-719. The novelty of the present study is an elucidation of the interaction of the dye with the

Facile fabrication of luminescent organic dots by thermolysis of citric acid in urea melt, and their use for cell staining and polyelectrolyte microcapsule labelling

• Nadezhda M. Zholobak,
• Anton L. Popov,
• Alexander B. Shcherbakov,
• Nelly R. Popova,
• Mykhailo M. Guzyk,
• Valeriy P. Antonovich,
• Alla V. Yegorova,
• Yuliya V. Scrypynets,
• Inna I. Leonenko,
• Alexander Ye. Baranchikov and
• Vladimir K. Ivanov

Beilstein J. Nanotechnol. 2016, 7, 1905–1917, doi:10.3762/bjnano.7.182

• spectral properties Citric acid reacts with ammonia in a molar ratio of 1:3 to form triammonium citrate, and with urea in a molar ratio of 1:1 [37] to form urea citrate. Thermolysis of ammonium citrate or urea citrate leads to formation of the luminescent O-dots, proceeding readily and at moderate

• non-linear (Figure 2, right). More details on the absorption, excitation and emission spectra of the samples are presented in Supporting Information File 1, Figures S5–S10. Upon heating, decomposition and release of gaseous products such as water, ammonia, carbon dioxide took place. Useful indicators

• acid and ammonia [41][42] released in the course of urea decomposition. It was found that the heating of pure ammonium citrazinate at 160 °C for 120 min did not affect its absorption and emission spectra. Conversely, heating ammonium citrazinate in the urea melt led to O-dots formation (Supporting

Role of RGO support and irradiation source on the photocatalytic activity of CdS–ZnO semiconductor nanostructures

• Suneel Kumar,
• Rahul Sharma,
• Vipul Sharma,
• Gurunarayanan Harith,
• Vaidyanathan Sivakumar and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2016, 7, 1684–1697, doi:10.3762/bjnano.7.161

• permanganate (KMnO4) and hydrogen peroxide (H2O2) were purchased from Merck. Zinc chloride (ZnCl2), sodium hydroxide (NaOH), cadmium acetate dihydrate (Cd(OOCCH3)2·2H2O), sodium sulfide (Na2S), ammonia solution and methyl orange were also supplied by Merck. Polyvinyl pyrrolidone (PVP) used in synthesis was

• adding ammonia solution. The resultant solution was refluxed for about 1 h at 70 °C. Upon completion of the reaction, the product was washed with deionized water and ethanol thrice and finally yellow colored CdS NP were formed after drying in an oven at 80 °C for 2 h. Synthesis of CdS–ZnO binary

• nanocomposite CdS–ZnO binary nanocomposite was prepared by employing a reported hydrothermal strategy [39]. In short, 0.2 M ZnCl2 was dispersed in 40 mL deionized water, followed by the addition of 0.5 M NaOH solution dropwise with continuous stirring. Aqueous ammonia was added to maintain the pH value around 8

Graphene-enhanced plasmonic nanohole arrays for environmental sensing in aqueous samples

• Christa Genslein,
• Peter Hausler,
• Eva-Maria Kirchner,
• Rudolf Bierl,
• Antje J. Baeumner and
• Thomas Hirsch

Beilstein J. Nanotechnol. 2016, 7, 1564–1573, doi:10.3762/bjnano.7.150

• . Experimental Nanohole array fabrication All substrates are based on glass slides (20 × 20 mm2) of F1-Type with a refractive index of 1.61 (Mivitec GmbH, Sinzing, Germany). All glass slides were cleaned in piranha solution for 90 min and in a mixture of water, ammonia and hydrogen peroxide at a 5:1:1 (v/v/v

Viability and proliferation of endothelial cells upon exposure to GaN nanoparticles

• Tudor Braniste,
• Ion Tiginyanu,
• Tibor Horvath,
• Simion Raevschi,
• Serghei Cebotari,
• Marco Lux,
• Axel Haverich and
• Andres Hilfiker

Beilstein J. Nanotechnol. 2016, 7, 1330–1337, doi:10.3762/bjnano.7.124

• epitaxy (HVPE) in two stages, as previously described [29]. Metallic gallium, ammonia (NH3) gas, hydrogen chloride (HCl) gas, and hydrogen (H2) were used as source materials and carrier gases. In the source zone, GaCl was formed as a result of chemical reactions between gaseous HCl and liquid Ga. GaCl and

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