Growth and characterization of CNT–TiO₂ heterostructures

• Yucheng Zhang,
• Ivo Utke,
• Johann Michler,
• Gabriele Ilari,
• Marta D. Rossell and
• Rolf Erni

Beilstein J. Nanotechnol. 2014, 5, 946–955, doi:10.3762/bjnano.5.108

• deposition [32]. Non-covalent surface functionalization leaves the pristine CNTs sp2 structure and carbon atom conjugation intact. Examples include in-situ NO2 physisorption which permitted the uniform growth of Al2O3 on SW-CNT [33], MW-CNT [34] and graphene [35], as well as the physisorption of ethanol and

Gas sensing with gold-decorated vertically aligned carbon nanotubes

• Prasantha R. Mudimela,
• Mattia Scardamaglia,
• Oriol González-León,
• Nicolas Reckinger,
• Rony Snyders,
• Eduard Llobet,
• Carla Bittencourt and
• Jean-François Colomer

Beilstein J. Nanotechnol. 2014, 5, 910–918, doi:10.3762/bjnano.5.104

• decorated with gold nanoparticles were investigated as gas sensitive materials for detecting nitrogen dioxide (NO2) at room temperature. Gold nanoparticles of about 6 nm in diameter were sputtered on the top surface of the carbon nanotube forests to enhance the sensitivity to the pollutant gas. We showed

• that the sensing response to nitrogen dioxide depends on the nanotube length. The optimum was found to be 300 µm for getting the higher response. When the background humidity level was changed from dry to 50% relative humidity, an increase in the response to NO2 was observed for all the sensors

• increasing impact in our environment of human activities. The detection of typical pollutants such as nitrogen dioxide (NO2) generated by industrial combustions or by car emissions is critical because of both environmental problems and health consequences for humans. In the last few years, new technologies

An analytical approach to evaluate the performance of graphene and carbon nanotubes for NH₃ gas sensor applications

• Elnaz Akbari,
• Vijay K. Arora,
• Aria Enzevaee,
• Mohamad. T. Ahmadi,
• Mehdi Saeidmanesh,
• Mohsen Khaledian,
• Hediyeh Karimi and
• Rubiyah Yusof

Beilstein J. Nanotechnol. 2014, 5, 726–734, doi:10.3762/bjnano.5.85

• theoretical studies on gas molecular adsorption on CNT/graphene have been reported for NO2, H2O, NH3, CO, and NO molecules that are physically adsorbed on pristine CNT/graphene [31][32]. Figure 3 illustrates a schematic representation of CNTs when electron-donating NH3 gas molecules are in the atmosphere

Synthesis and electrochemical performance of Li₂Co_1−xM_xPO₄F (M = Fe, Mn) cathode materials

• Nellie R. Khasanova,
• Oleg A. Drozhzhin,
• Stanislav S. Fedotov,
• Darya A. Storozhilova,
• Rodion V. Panin and
• Evgeny V. Antipov

Beilstein J. Nanotechnol. 2013, 4, 860–867, doi:10.3762/bjnano.4.97

• NO2 evolved by nitrates) and, at the same time, did not reduce Co2+ to metallic Co. The Mn-substituted olivine precursors, LiCo1−xMnxPO4, were prepared through the freeze spraying technique. The initial reagents LiCH3COO (99%), NH4H2PO4, Co(NO3)2·6H2O and Mn(CH3COO)2·3.2H2O were dissolved in distilled

Optimization of solution-processed oligothiophene:fullerene based organic solar cells by using solvent additives

• Gisela L. Schulz,
• Marta Urdanpilleta,
• Roland Fitzner,
• Eduard Brier,
• Elena Mena-Osteritz,
• Egon Reinold and
• Peter Bäuerle

Beilstein J. Nanotechnol. 2013, 4, 680–689, doi:10.3762/bjnano.4.77

• 60, mesh 0.063–0.2 μm, were used for column chromatography. High performance liquid chromatography was performed on a Hitachi instrument equipped with a UV–vis detector L-7420, columns (Nucleosil 100-5 NO2 with a pore size of 100 Å) from Machery-Nagel using a dichlormethane/n-hexane mixture (40:60

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

• by using the recently developed IHSAB model. The optical pumping of a TiO2 and TiO2−xNx decorated interface demonstrates a significant enhancement in the ability to sense NH3 and NO2. Comparisons to traditional metal-oxide sensors are also discussed. Keywords: chemical sensors; gas interface

• decreasing resistance. While the response to NH3 is rapid [1][3][8][11] in this unsaturated mode, the system recovery is slowed as NH3, a sticky gas, results in a drift in baseline (see Experimental section). NO2, as a moderate acid, is found to extract electrons from a PS interface [7][29] increasing

• majority carrier “holes”, and treatment with moderate concentrations of TiO2 enhances the response to NO2. However, Figure 6 demonstrates that UV light now reverses this process as the optically pumped TiO2 treated interface becomes more acidic and begins to extract electrons from the moderately acidic NO2

Structural and electronic properties of oligo- and polythiophenes modified by substituents

• Simon P. Rittmeyer and
• Axel Groß

Beilstein J. Nanotechnol. 2012, 3, 909–919, doi:10.3762/bjnano.3.101

• properties of oligothiophenes and whether the underlying effects can be transferred to the respective polymers. First, we took into account classical substituents, namely methyl (CH3), amino (NH2) and nitro groups (NO2) and the chlorine atom (Cl). We chose these substituents, because they exemplify the basic

Plasmonics-based detection of H₂ and CO: discrimination between reducing gases facilitated by material control

• Gnanaprakash Dharmalingam,
• Nicholas A. Joy,
• Benjamin Grisafe and
• Michael A. Carpenter

Beilstein J. Nanotechnol. 2012, 3, 712–721, doi:10.3762/bjnano.3.81

• -temperature-combustion applications is very important for regulating the discharge of gases such as NO2 and CO as well as unburnt fuel into the environment. This work reports the detection of H2 and CO gases by employing a metal–metal oxide nanocomposite (gold–yttria stabilized zirconia (Au–YSZ)) film

• films to the gases at temperatures of 500 °C in a background of dry air. Characterization of the samples by XRD and SEM enabled the correlation of material properties with the differences in the CO- and H2-induced LSPR peak shifts, including the relative desensitization towards NO2. Sensing

• temperature of 300 °C [15]. For consistent and sensitive detection of H2, CO and NO2, Rogers et al. and Sirinakis et al. used Au–yttria stabilized zirconia (Au–YSZ) films and reported sensing observations through hundreds of hours of laboratory testing between 500 and 800 °C [16][17][18]. While detection of

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

• this purpose, the zeolite-mediated DeNOx-SCR (selective catalytic reduction of NOx with NH3) may serve as a model reaction, and is of great relevance in the after treatment of diesel exhaust gas as well as in NOx-emitting technical plants. It relies on the conversion of NH3 with NO/NO2 and is catalysed

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

• . Exposure of the nanowire sensors to the oxidising gas NO2 produced a significant and reproducible response. ZnO and THMA-coated ZnO nanowire sensors both readily detected NO2 down to a concentration in the very low ppm range. Notably, the THMA-coated nanowires consistently displayed a small, enhanced

• response to NO2 compared to uncoated ZnO nanowire sensors. At the lower concentration levels tested, ZnO nanowire sensors that were coated with THMA-capped ZnO nanoparticles were found to exhibit the greatest enhanced response. ΔR/R was two times greater than that for the as-prepared ZnO nanowire sensors

• . It is proposed that the ΔR/R enhancement in this case originates from the changes induced in the depletion-layer width of the ZnO nanoparticles that bridge ZnO nanowires resulting from THMA ligand binding to the surface of the particle coating. The heightened response and selectivity to the NO2

Twofold role of calcined hydrotalcites in the degradation of methyl parathion pesticide

• Alvaro Sampieri,
• Geolar Fetter,
• María Elena Villafuerte-Castrejon,
• Adriana Tejeda-Cruz and
• Pedro Bosch

Beilstein J. Nanotechnol. 2011, 2, 99–103, doi:10.3762/bjnano.2.11

• may be reduced directly to p-NP (degradation) or via an intermediate molecule (isomerization). At pH 9 or 10, the second mechanism is favored (65%) due to the basic catalytic features of the clay hydroxyl ions (OH). Although MP can decompose to give simple molecules, such as SO2, CO2, CO and NO2