High-temperature resistive gas sensors based on ZnO/SiC nanocomposites

• Vadim B. Platonov,
• Marina N. Rumyantseva,
• Alexander S. Frolov,
• Alexey D. Yapryntsev and
• Alexander M. Gaskov

Beilstein J. Nanotechnol. 2019, 10, 1537–1547, doi:10.3762/bjnano.10.151

• °C. The ZnO/SiC nanocomposites were characterized by a higher concentration of chemisorbed oxygen, higher activation energy of conductivity, and higher sensor response towards CO and NH3 as compared with ZnO nanofibers. The obtained experimental results were interpreted in terms of the formation of

• material conductance, kB is the Boltzmann constant, the values of the activation energy Ea were calculated. For ZnO nanofibers, Ea = 0.40 ± 0.04 eV. This value lies within the error with the potential barrier at the grain boundaries eVs (the surface potential barrier energy between particles of

• nanocrystalline zinc oxide) determined by the method of temperature-stimulated conductance measurements [29][30] as eVs = 0.44 eV at T = 500 °C [31]. The creation of ZnO/SiC nanocomposites leads to an increase in the activation energy of conductivity up to 0.71–0.78 eV, and the value of Еa does not depend on the

Review of time-resolved non-contact electrostatic force microscopy techniques with applications to ionic transport measurements

• Aaron Mascaro,
• Yoichi Miyahara,
• Tyler Enright,
• Omur E. Dagdeviren and
• Peter Grütter

Beilstein J. Nanotechnol. 2019, 10, 617–633, doi:10.3762/bjnano.10.62

• a phase-locked loop (PLL). This was first performed by Bennewitz et al. to measure the mobility of F− vacancies in a CaF2 crystal [27]. Schirmeisen et al. later improved the technique by performing the measurements at various temperatures to extract the activation energy for ionic transport in Li

A novel polyhedral oligomeric silsesquioxane-modified layered double hydroxide: preparation, characterization and properties

• Xianwei Zhang,
• Zhongzhu Ma,
• Hong Fan,
• Carla Bittencourt,
• Jintao Wan and
• Philippe Dubois

Beilstein J. Nanotechnol. 2018, 9, 3053–3068, doi:10.3762/bjnano.9.284

• slopes of these lines using the following expression: The fitting results and Eα data are summarized in Table 4. Results show that the apparent activation energy increases as a whole with increasing conversion. Combined with the TGA data and the data of α as a function of T, the Eα values of NLDH can be

Site-controlled formation of single Si nanocrystals in a buried SiO₂ matrix using ion beam mixing

• Xiaomo Xu,
• Thomas Prüfer,
• Daniel Wolf,
• Hans-Jürgen Engelmann,
• Lothar Bischoff,
• René Hübner,
• Karl-Heinz Heinig,
• Wolfhard Möller,
• Stefan Facsko,
• Johannes von Borany and
• Gregor Hlawacek

Beilstein J. Nanotechnol. 2018, 9, 2883–2892, doi:10.3762/bjnano.9.267

• the activation energy and the diffusion constant for the dominant diffusion process (SiO diffusion in SiO2) Ea = 6.2 eV and D0 = 4 × 104 cm2/s, respectively, [30] and the Boltzmann constant, kB. The effect of different thermal budgets, TB, can be seen from Figure 3c and Figure 3d. Using identical ion

Electrospun one-dimensional nanostructures: a new horizon for gas sensing materials

• Muhammad Imran,
• Nunzio Motta and
• Mahnaz Shafiei

Beilstein J. Nanotechnol. 2018, 9, 2128–2170, doi:10.3762/bjnano.9.202

• ] have been extensively applied for sensing of acetone, ethanol, toluene, formaldehyde and volatile organic compounds (VOCs). WO3 NFs functionalized by Au NPs exhibit improved VOC sensing properties. Noble metals onto metal oxide NFs reduce the activation energy, thus increasing their efficiency [109

Formation and development of nanometer-sized cybotactic clusters in bent-core nematic liquid crystalline compounds

• Yuri P. Panarin,
• Sithara P. Sreenilayam,
• Jagdish K. Vij,
• Anne Lehmann and
• Carsten Tschierske

Beilstein J. Nanotechnol. 2018, 9, 1288–1296, doi:10.3762/bjnano.9.121

• director. The temperature dependence of the relaxation frequencies f1 and f2 obey the Arrhenius mechanism. The activation energy corresponding to the processes P1 and P2 was found to be 2.55 eV and 1.93 eV, respectively. A higher value of the activation energy for the cluster compared to that of the

• fits to the Arrhenius equation, f(T) = f0 exp(−EA / kBT), where EA is the activation energy. Temperature dependent cluster size (i.e., an average number of molecules involved in a cluster) (open red triangles), ratio of the dielectric strength, Δε1/Δε2 (open blue cirecles), the volume fraction of

Understanding the performance and mechanism of Mg-containing oxides as support catalysts in the thermal dry reforming of methane

• Nor Fazila Khairudin,
• Mohd Farid Fahmi Sukri,
• Mehrnoush Khavarian and
• Abdul Rahman Mohamed

Beilstein J. Nanotechnol. 2018, 9, 1162–1183, doi:10.3762/bjnano.9.108

• various catalysts for DRM [3]. The CO2 activation energy in this study recorded a lower value, which is 48.1 kJ/mol compared to that of CH4 and CO2 of previous studies. This is might be due to the existence of Mg, which is known to be a strong Lewis base, making it easier for CO2 to activate on the Ni–Co

• and CH4 partial pressure due to the simultaneously occurrence of DRM and RWGS reactions. Figure 8a,b displays the effect of reactant partial pressure on H2 formation rates. Table 2 outlines the values of activation energy for CO2, CH4, H2 and CO2 for various catalysts. The authors highlighted that the

• lowest activation energies were recorded by CO2. This is probably due to the existence of MgO, which is a strong Lewis base that acts as a support in this study, and can also activate CO2. The activation energy of H2 is greater than CO because of the occurrence of the RWGS reaction. Development of Mg

Comparative study of sculptured metallic thin films deposited by oblique angle deposition at different temperatures

• Susann Liedtke,
• Christoph Grüner,
• Jürgen W. Gerlach and
• Bernd Rauschenbach

Beilstein J. Nanotechnol. 2018, 9, 954–962, doi:10.3762/bjnano.9.89

• . Thus, surface diffusion would be frozen until the homologous temperature exceeds TH > 0.15 providing enough activation energy. As a consequence, Mo columns deposited at TH = 0.03 and at TH = 0.10 would have similar tilt angles, whereas for TH > 0.15 a significant change in the tilt angles is expected

• (hopping or exchange) [22][23][24]. A comparison between these reported data for Al and Mo shows that Al is expected to have smaller activation energies than Mo. This smaller activation energy corresponds to an enlarged surface self-diffusion so that the Al adatoms are also able to move in the shadowed

• regions. This reduces the shadowing effect as well as the influence of the incidence angle on the tilt angle (compare Figure 5a). Moreover, this smaller activation energy and in turn larger surface self-diffusion can also be a reason why the tilt angles are enlarged by approximately 15° if deposited at

Dynamics and fragmentation mechanism of (C₅H₄CH₃)Pt(CH₃)₃ on SiO₂ surfaces

• Kaliappan Muthukumar,
• Harald O. Jeschke and
• Roser Valentí

Beilstein J. Nanotechnol. 2018, 9, 711–720, doi:10.3762/bjnano.9.66

• methylcyclopentadienyl ring. Removal of the methylcyclopentadienyl ring from (C5H4CH3)Pt(CH3)3 has an activation energy of +0.771 eV, which leaves the Pt(CH3)3 part of the precursor bound to the substrate. The formation of Pt(CH3)3 in vacuum is observed in our molecular dynamics simulations. However, neither its

•  1. From Pt(CH3)3, the release of one methyl group (P1TS1) forming Pt(CH3)2 has an activation energy of about +1.073 eV compared to +1.617 eV for the release of ethane (P2TS1). The O2 -assisted elimination of the first methyl group (P3TS1) from Pt(CH3)3 has a barrier of +3.699 eV. Therefore, the

Kinetics of solvent supported tubule formation of Lotus (Nelumbo nucifera) wax on highly oriented pyrolytic graphite (HOPG) investigated by atomic force microscopy

• Sujit Kumar Dora,
• Kerstin Koch,
• Wilhelm Barthlott and
• Klaus Wandelt

Beilstein J. Nanotechnol. 2018, 9, 468–481, doi:10.3762/bjnano.9.45

• start to evaporate thereby decreasing the rate of diffusion of wax molecules. Within the tubules, their growth is further hindered by the fact that incorporation of molecules above or below the tubules needs considerable activation energy which leads to a substantial decrease in their growth rate

Review: Electrostatically actuated nanobeam-based nanoelectromechanical switches – materials solutions and operational conditions

• Liga Jasulaneca,
• Jelena Kosmaca,
• Raimonds Meija,
• Jana Andzane and
• Donats Erts

Beilstein J. Nanotechnol. 2018, 9, 271–300, doi:10.3762/bjnano.9.29

BN/Ag hybrid nanomaterials with petal-like surfaces as catalysts and antibacterial agents

• Konstantin L. Firestein,
• Denis V. Leybo,
• Alexander E. Steinman,
• Andrey M. Kovalskii,
• Andrei T. Matveev,
• Anton M. Manakhov,
• Irina V. Sukhorukova,
• Pavel V. Slukin,
• Nadezda K. Fursova,
• Sergey G. Ignatov,
• Dmitri V. Golberg and
• Dmitry V. Shtansky

Beilstein J. Nanotechnol. 2018, 9, 250–261, doi:10.3762/bjnano.9.27

• . The activation energy for surface diffusion of Ag was shown to depend on the type of a substrate (67 kJ/mol (Ni), 73 kJ/mol (Cu), and 100–155 kJ/mol (TiCaPCON film)), but was always lower than the activation energy for bulk self-diffusion in Ag (191 kJ/mol) [28]. A significant increase in the

Dielectric properties of a bisimidazolium salt with dodecyl sulfate anion doped with carbon nanotubes

• Doina Manaila Maximean,
• Viorel Cîrcu and
• Constantin Paul Ganea

Beilstein J. Nanotechnol. 2018, 9, 164–174, doi:10.3762/bjnano.9.19

• nanotubes (CNT) were recorded over a wide frequency and temperature range of 10−1 to 107 Hz and 293–338 K, respectively. The values of the activation energy were found in the range of 0.46–0.61 eV; the characteristic time was obtained by fitting the spectra of the dielectric loss with the Havriliak–Negami

• low frequencies confirm the presence of EP. Keywords: activation energy; carbon nanotubes; dielectric spectroscopy; ionic liquid crystal; relaxation time; Introduction Ionic liquid crystals (ILCs) represent a very appealing class of materials that has found various recent applications in dye

• dielectric studies. The activation energy was calculated by employing the Vogel–Fulcher–Tammann law while the characteristic time was obtained by fitting the spectra of the dielectric loss with the Havriliak–Negami functions. Results and Discussion Synthesis of the bisimidazolium salt The preparation of new

Electrical properties of a liquid crystal dispersed in an electrospun cellulose acetate network

• Doina Manaila Maximean,
• Octavian Danila,
• Pedro L. Almeida and
• Constantin Paul Ganea

Beilstein J. Nanotechnol. 2018, 9, 155–163, doi:10.3762/bjnano.9.18

• techniques, such as polarized optical microscopy, dielectric spectroscopy and impedance measurements. Dielectric constant and electric energy loss were studied as a function of frequency and temperature. The activation energy was evaluated and the relaxation time was obtained by fitting the spectra of the

• investigations of the electrical properties of an electrospun CA network with dispersed liquid crystals. Dielectric spectroscopy (DS) was performed over wide ranges of frequency and temperature to determine physical properties such as activation energy and characteristic time. The experimental results of DS were

• the activation energy were determined, and found to be in good agreement with previously obtained data. The relaxation time was obtained by fitting the spectra of the dielectric loss with the Havriliak–Negami function. Impedance measurements were evaluated using Cole–Cole diagrams and the three

Impact of titanium dioxide nanoparticles on purification and contamination of nematic liquid crystals

• Dmitrii Pavlovich Shcherbinin and
• Elena A. Konshina

Beilstein J. Nanotechnol. 2017, 8, 2766–2770, doi:10.3762/bjnano.8.275

• of the activation energy that affected the diffusion coefficients [32]. To conclude, we would like mention other factors that influence the ionic conductivity of the LC composites. As it was mentioned above, a high density of unoccupied adsorbing states is desirable. Size, aggregation, local fields

Synthesis of [{AgO₂CCH₂OMe(PPh₃)}_n] and theoretical study of its use in focused electron beam induced deposition

• Jelena Tamuliene,
• Julian Noll,
• Peter Frenzel,
• Tobias Rüffer,
• Alexander Jakob,
• Bernhard Walfort and
• Heinrich Lang

Beilstein J. Nanotechnol. 2017, 8, 2615–2624, doi:10.3762/bjnano.8.262

• the sum of the total energies of the fragments predicted. The calculations for the final states of the compounds are presented for the case of dissociation without taking into account the activation energy of the reverse reaction (Еr). The total number of the decomposition reactions investigated was

• energy of all fragments produced during dissociation). However, this calculation does not take the activation energy of the molecular ion fragmentation into account. Subsequently, only the most favorable fragmentation routes according to the lowest energy pathways are considered, which are pathways A–C

Adsorption of iron tetraphenylporphyrin on (111) surfaces of coinage metals: a density functional theory study

• Hao Tang,
• Nathalie Tarrat,
• Véronique Langlais and
• Yongfeng Wang

Beilstein J. Nanotechnol. 2017, 8, 2484–2491, doi:10.3762/bjnano.8.248

• activation barrier of the free molecule between HS and IS states of this conformation, the energy of a series of intermediate images has been calculated (Figure 4). From these calculations, the activation energy from IS to HS (respectively, from HS to IS) was found to be 0.02 eV (respectively, 0.07 eV) with

• deformation creates a square-based pyramid environment for the coordination sphere around the Fe atom, which also favours the HS state. The activation energy between the HS and IS states of FeTPP adsorbed on Au(111) has been evaluated. To do so, the NEB method was employed for FeTPP adsorbed on fcc site from

• HS (S = 2) to IS (S = 1) (Figure 6). While the activation energy from HS to IS (energy difference) is found to be 0.08 eV, no energy barrier was found to pass from IS to HS, indicating that the IS state is unstable when the molecule is adsorbed on Au(111). The fact that IS state was obtained during

Ester formation at the liquid–solid interface

• Nguyen T. N. Ha,
• Thiruvancheril G. Gopakumar,
• Nguyen D. C. Yen,
• Carola Mende,
• Lars Smykalla,
• Maik Schlesinger,
• Roy Buschbeck,
• Tobias Rüffer,
• Heinrich Lang,
• Michael Mehring and
• Michael Hietschold

Beilstein J. Nanotechnol. 2017, 8, 2139–2150, doi:10.3762/bjnano.8.213

• theory. The higher the molecular concentration, the more collisions of suitable pairs of molecules can take place. The successful collisions should have also sufficient activation energy transferred at the moment of impact to break the existing bonds and to form new ones, resulting in the reaction

Substrate and Mg doping effects in GaAs nanowires

• Perumal Kannappan,
• Nabiha Ben Sedrine,
• Jennifer P. Teixeira,
• Maria R. Soares,
• Bruno P. Falcão,
• Maria R. Correia,
• Nestor Cifuentes,
• Emilson R. Viana,
• Marcus V. B. Moreira,
• Geraldo M. Ribeiro,
• Alfredo G. de Oliveira,
• Juan C. González and
• Joaquim P. Leitão

Beilstein J. Nanotechnol. 2017, 8, 2126–2138, doi:10.3762/bjnano.8.212

• the GaAs nanowires on their electronic structure; ii) a considerable reduction of the density of vertical nanowires, which is almost null for growth on Si(111); iii) the occurrence of a higher WZ phase fraction, in particular for growth on Si(111); iv) an increase of the activation energy to release

• quenching of the PL. The resulting fitting parameters are listed in Table 2. We have found that for all components of sample A the model is the same and comprises two non-radiative de-excitation channels: one involving a discrete level (with activation energy E1), and one involving a band (with activation

• , the estimated activation energy (Ex) for the release of the less bound charge carrier in the radiative state is far from the ionization energy (28 meV) reported for Mg in the literature [41]. On the other hand, in the case of the growth on Si(111), and for the transition at 1.442 eV, the ionization

Process-specific mechanisms of vertically oriented graphene growth in plasmas

• Subrata Ghosh,
• Shyamal R. Polaki,
• Niranjan Kumar,
• Sankarakumar Amirthapandian,
• Mohamed Kamruddin and
• Kostya (Ken) Ostrikov

Beilstein J. Nanotechnol. 2017, 8, 1658–1670, doi:10.3762/bjnano.8.166

• the temperature-dependent growth rates where the activation energy is found to be as low as 0.57 eV. It is shown that the growth rate and the structural quality of the films could be enhanced by (a) increasing the substrate temperature, (b) decreasing the distance between the microwave plasma source

• , catalysis and energy storage. Keywords: activation energy; plasmas; residual stress; vertical graphene nanosheets; wettability; Introduction Vertical graphene nanosheets (VGNs) consist of interconnected 3D porous networks of vertically oriented graphitic sheets, which are aligned perpendicularly to the

• quantify the vertical growth, the growth rate is plotted as a function of the temperature in Figure 1i. This dependence can be described by the Arrhenius equation. The activation energy is calculated from this plot. The activation energy for the vertical growth is found to be 0.57 eV. Faster nucleation and

Two-dimensional carbon-based nanocomposites for photocatalytic energy generation and environmental remediation applications

• Suneel Kumar,
• Ashish Kumar,
• Ashish Bahuguna,
• Vipul Sharma and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2017, 8, 1571–1600, doi:10.3762/bjnano.8.159

• photocatalysts to produce more reactive sites and to reduce the activation energy for H2 and O2 gas evolution. Cocatalysts also enhances the charge separation in photocatalytic materials because of their high work function. This high work function of noble metals and some metal oxides accelerates the transfer of

Low-temperature CO oxidation over Cu/Pt co-doped ZrO₂ nanoparticles synthesized by solution combustion

• Amit Singhania and
• Shipra Mital Gupta

Beilstein J. Nanotechnol. 2017, 8, 1546–1552, doi:10.3762/bjnano.8.156

• ). This is due to combined effect of smaller particle size, large oxygen vacancies, high specific surface area and better thermal stability of the Cu/Pt co-doped ZrO2 nanoparticles. The apparent activation energy for CO oxidation is found to be 45.6 kJ·mol−1. The CO conversion decreases with increase in

Charge transport in organic nanocrystal diodes based on rolled-up robust nanomembrane contacts

• Vineeth Kumar Bandari,
• Lakshmi Varadharajan,
• Longqian Xu,
• Abdur Rehman Jalil,
• Mirunalini Devarajulu,
• Pablo F. Siles,
• Feng Zhu and
• Oliver G. Schmidt

Beilstein J. Nanotechnol. 2017, 8, 1277–1282, doi:10.3762/bjnano.8.129

• -described by the classical Arrhenius relation. where Ea is the activation energy, kB the Boltzmann’s constant, A1 the pre-exponential factor, and S the estimated contact area. The occurrence of two thermally activated regions can be explained as the following: for lower temperature, the CT effect between

• by the hopping mobility. For higher temperature and lower bias, the ohmic current is dominated by the temperature dependent carrier density which is provided by the CT between VOPc and F16CuPc. In the left part of the curves which are subject to higher activation energy, the activation energy Ea is

• density is subject to thermal activation. The activation energy Ea is almost constant with decreasing voltage, and calculated to be about 0.41 eV for the voltages below 0.7 V, which is regarded as the CT energy between VOPc and F16CuPc. Region C under high bias conditions corresponds to the complete SCL

Fully scalable one-pot method for the production of phosphonic graphene derivatives

• Kamila Żelechowska,
• Marta Prześniak-Welenc,
• Marcin Łapiński,
• Izabela Kondratowicz and
• Tadeusz Miruszewski

Beilstein J. Nanotechnol. 2017, 8, 1094–1103, doi:10.3762/bjnano.8.111

• to obtain the graphene-type material with comparable electrical properties without additional reduction processes, such as thermal reduction. Moreover, the activation energy calculated from the slope of the plotted line in Figure 10 is equal to 0.014 eV. The reported values for different graphene

• characterized by using spectroscopic methods along with thermal analysis. The morphology of the samples was examined by electron microscopy. The electrical studies revealed that the functionalized graphene derivative behaves in a way similar to chemically or thermally reduced graphene oxide, with an activation

• energy of 0.014 eV. Keywords: functionalized graphene; graphene oxide; one-pot synthesis; phosphonic derivatives; reduced graphene oxide; Introduction Graphene oxide (GO) with its multifunctionality attracts interest in different fields of science. The chemical nature and reactivity of GO have been

CVD transfer-free graphene for sensing applications

• Chiara Schiattarella,
• Sten Vollebregt,
• Tiziana Polichetti,
• Brigida Alfano,
• Ettore Massera,
• Maria Lucia Miglietta,
• Girolamo Di Francia and
• Pasqualina Maria Sarro

Beilstein J. Nanotechnol. 2017, 8, 1015–1022, doi:10.3762/bjnano.8.102

• of the electronic properties of the material due to the analyte adsorption. Similarly to Arrhenius' concept of activation energy, this approach still includes the fundamental assumption of the validity of Maxwell–Boltzmann statistics. The absolute number of analyte molecules approaching the devices