Gas sensing properties of individual SnO₂ nanowires and SnO₂ sol–gel nanocomposites

• Alexey V. Shaposhnik,
• Dmitry A. Shaposhnik,
• Sergey Yu. Turishchev,
• Olga A. Chuvenkova,
• Stanislav V. Ryabtsev,
• Alexey A. Vasiliev,
• Xavier Vilanova,
• Francisco Hernandez-Ramirez and
• Joan R. Morante

Beilstein J. Nanotechnol. 2019, 10, 1380–1390, doi:10.3762/bjnano.10.136

• seem to be approaching their limit. Because of this, there is increasing interest in the fabrication of functional materials based on nanowires, i.e., quasi-one-dimensional objects. In this work, nanocrystalline tin dioxide samples with different morphology were synthesized. The gas-transport method

• ; gas transport method; nanowires; quasi-one-dimensional materials; sol–gel synthesis; tin dioxide; X-ray absorption near edge structure (XANES); X-ray photoelectron spectroscopy (XPS); Introduction Semiconductor sensor functionality relies on heterogeneous catalytic chemical processes, which makes the

• characterization SnO2 nanowire synthesis The gas transport method based on the vapor–liquid–solid (VLS) mechanism was used for the synthesis of SnO2 nanowires. Argon saturated with water vapor served as the transport medium. Water was used as a mild oxidant of metallic tin in the following reaction: The formation

Wafer-scale bioactive substrate patterning by chemical lift-off lithography

• Chong-You Chen,
• Chang-Ming Wang,
• Hsiang-Hua Li,
• Hong-Hseng Chan and
• Wei-Ssu Liao

Beilstein J. Nanotechnol. 2018, 9, 311–320, doi:10.3762/bjnano.9.31

• therefore be fulfilled with different molecules, e.g., ligands, and the substrate is active for biological responses. Comparing to conventional lithographic stamping processes which use mobile inks, this approach solves the problems of molecular lateral diffusion and gas transport obstacles. The fabricated

Diffusion of dilute gas in arrays of randomly distributed, vertically aligned, high-aspect-ratio cylinders

• Wojciech Szmyt,
• Carlos Guerra and
• Ivo Utke

Beilstein J. Nanotechnol. 2017, 8, 64–73, doi:10.3762/bjnano.8.7

• molecular regime of gas transport. It can be specifically shown that the gas diffusion coefficient inside such arrays is inversely proportional to the areal density of cylinders and their mean diameter. An example calculation of a diffusion coefficient is delivered for a system of titanium isopropoxide

• nanocylinder arrays in solar cells and energy storage applications. Furthermore, gas sensing devices with high-aspect-ratio nanocylinder arrays and the growth of vertically aligned carbon nanotubes need the fundamental understanding and precise modelling of gas transport to optimise such processes. Keywords

• : dilute gas; gas transport; molecular diffusion; nanocylinders; random walk; Introduction Arrays of vertically aligned nanowires and nanotubes with high-aspect ratio composed of various materials have been widely used in science and industry. Arrays of silicon nanowires [1][2] and carbon nanotubes [3

From lithium to sodium: cell chemistry of room temperature sodium–air and sodium–sulfur batteries

• Philipp Adelhelm,
• Pascal Hartmann,
• Conrad L. Bender,
• Martin Busche,
• Christine Eufinger and
• Juergen Janek

Beilstein J. Nanotechnol. 2015, 6, 1016–1055, doi:10.3762/bjnano.6.105

• , CO2, and also H2O for the case of non-aqueous systems) and to protect the metal electrode from oxygen exposure. At the same time, drying out of the cell due to solvent evaporation must be avoided. (2) The gas transport must be fast enough to enable sufficiently fast discharging and charging. (3) The

Multiscale modeling of lithium ion batteries: thermal aspects

• Arnulf Latz and
• Jochen Zausch

Beilstein J. Nanotechnol. 2015, 6, 987–1007, doi:10.3762/bjnano.6.102

• conditions, mass convection can be excluded as transport mechanism, but will always be a possibility in a systematic theory. Especially, if there are side reactions leading to film growth or convective gas transport after electrolyte degradation, convective transport might be initiated as a consequence. In

Low-cost formation of bulk and localized polymer-derived carbon nanodomains from polydimethylsiloxane

• Juan Carlos Castro Alcántara,
• Mariana Cerda Zorrilla,
• Lucia Cabriales,
• Luis Manuel León Rossano and
• Mathieu Hautefeuille

Beilstein J. Nanotechnol. 2015, 6, 744–748, doi:10.3762/bjnano.6.76

• a muffle (Lindberg 51894), sealed by a two-hole rubber stopper that allows for gas transport both inwards and outwards. Residual gases expulsion is verified by their bubbling in a water container placed outside the chamber. The reagent used in this work for nanodomains production was a solution of

Plasma-assisted synthesis and high-resolution characterization of anisotropic elemental and bimetallic core–shell magnetic nanoparticles

• M. Hennes,
• A. Lotnyk and
• S. G. Mayr

Beilstein J. Nanotechnol. 2014, 5, 466–475, doi:10.3762/bjnano.5.54

• order of magnitude as the initial concentration in the evacuated vessels. Ar flow into A is controlled manually by a leak valve v1 (Balzers 135) while an additional valve v2 (MKS 248) regulates the stream into vessel B. The pressure in these two chambers can therefore be adjusted separately. The gas

• transport is maintained by differential pumping using two turbo molecular pumps (Varian TV 301) with a pumping capacity of 300 L/s. Two gate valves are employed to switch between gas flow configurations that enable pumping towards base pressures p ≈ 10−7 mbar (v3 and pv1 open, pv2 closed) and particle

Modeling and optimization of atomic layer deposition processes on vertically aligned carbon nanotubes

• Nuri Yazdani,
• Vipin Chawla,
• Eve Edwards,
• Vanessa Wood,
• Hyung Gyu Park and
• Ivo Utke

Beilstein J. Nanotechnol. 2014, 5, 234–244, doi:10.3762/bjnano.5.25

• typical ALD processes, gas phase collisions among the precursor molecules in the pores of VACNT structure are far less frequent than collisions between a precursor molecule and a CNT surface. This corresponds to the free molecular regime of gas transport (i.e., Knudsen diffusion) [28][29]. Furthermore

• than the average distance between the CNTs of the vertical array, which is typically smaller than 10−5 cm. The gas transport of this system is thus in the regime of free molecular flow, in which the effective diffusion coefficient for this porous medium is described by Knudsen diffusivity, where dpore