Search results

Search for "vacancies" in Full Text gives 228 result(s) in Beilstein Journal of Nanotechnology. Showing first 200.

Atomic layer deposition and properties of ZrO2/Fe2O3 thin films

  • Kristjan Kalam,
  • Helina Seemen,
  • Peeter Ritslaid,
  • Mihkel Rähn,
  • Aile Tamm,
  • Kaupo Kukli,
  • Aarne Kasikov,
  • Joosep Link,
  • Raivo Stern,
  • Salvador Dueñas,
  • Helena Castán and
  • Héctor García

Beilstein J. Nanotechnol. 2018, 9, 119–128, doi:10.3762/bjnano.9.14

Graphical Abstract
  • reactive DC magnetron sputtering [7], also exhibited ferromagnetic properties. The undoped ZrO2 exhibited ferromagnetic properties mainly driven by oxygen vacancies. Monoclinic and tetragonal phases with similar amounts of oxygen vacancies were compared and ferromagnetism was only observed in the case of
  • iron and zirconium oxides, the amount of defects (in particular oxygen vacancies) is increased due to the substitutive exchange between metal ions of different valence, resulting in an increase also in the leakage currents. Pure ZrO2 exhibited the lowest leakage current (Figure 7) and did not show any
PDF
Album
Full Research Paper
Published 10 Jan 2018

Facile synthesis of silver/silver thiocyanate (Ag@AgSCN) plasmonic nanostructures with enhanced photocatalytic performance

  • Xinfu Zhao,
  • Dairong Chen,
  • Abdul Qayum,
  • Bo Chen and
  • Xiuling Jiao

Beilstein J. Nanotechnol. 2017, 8, 2781–2789, doi:10.3762/bjnano.8.277

Graphical Abstract
  • nm. The absorption peak of silver nanoparticles becomes gradually stronger as the content of Ag increases, indicating that the sunlight utilization efficiency increases steadily. During UV irradiation, many defects are formed in AgSCN, including different interstitial sites and vacancies [29]. The
  • the metal from the Fermi level directly transfer to the conduction band of AgSCN, and the vacancies remain on the surface of the Ag particles. A dipole-based resonance energy can directly excite semiconductors to produce photogenerated electron–hole pairs that can improve the visible-light catalytic
  • vacancies were left on the surface of the Ag particles. The dipole-based resonance energy can directly excite semiconductors to produce photogenerated electron–hole pairs. The presence of Ag nanoparticles can not only improve the photocatalytic efficiency, but also can trap photogenerated electrons, slow
PDF
Album
Supp Info
Full Research Paper
Published 22 Dec 2017

Patterning of supported gold monolayers via chemical lift-off lithography

  • Liane S. Slaughter,
  • Kevin M. Cheung,
  • Sami Kaappa,
  • Huan H. Cao,
  • Qing Yang,
  • Thomas D. Young,
  • Andrew C. Serino,
  • Sami Malola,
  • Jana M. Olson,
  • Stephan Link,
  • Hannu Häkkinen,
  • Anne M. Andrews and
  • Paul S. Weiss

Beilstein J. Nanotechnol. 2017, 8, 2648–2661, doi:10.3762/bjnano.8.265

Graphical Abstract
  • . The values for Ha and 95% confidence intervals (95% CI) are shown below each graph. Two configurations calculated by molecular dynamics simulations of lift-off of a butanethiolate SAM on Au{111}. (A) Initially, densely packed RS–Au–SR (R = butyl) units occur on Au{111} having surface vacancies. The
  • number of vacancies equals the number of RS–Au–SR units. (B) Initially, a dense packing of individual butane thiolates occurs at the face-centered cubic sites of a defect-free Au{111} surface. The dashed vertical lines define the borders of each computational unit cell, i.e., in the figure there are two
PDF
Album
Supp Info
Full Research Paper
Published 08 Dec 2017

Fabrication of CeO2–MOx (M = Cu, Co, Ni) composite yolk–shell nanospheres with enhanced catalytic properties for CO oxidation

  • Ling Liu,
  • Jingjing Shi,
  • Hongxia Cao,
  • Ruiyu Wang and
  • Ziwu Liu

Beilstein J. Nanotechnol. 2017, 8, 2425–2437, doi:10.3762/bjnano.8.241

Graphical Abstract
  • independent forms. The formation of highly-dispersed copper species promotes the adsorption of CO molecules, while the presence of oxygen vacancies provided by CeO2 can in turn create active oxygen in the oxidation reactions [12][13]. Therefore, the creation of two-phase interfaces as numerous as possible and
  • /and hierarchical architecture, which possess excellent redox properties and abundant oxygen vacancies, will be favorable for the enhancement of catalytic activity toward CO oxidation. CeO2-based hybrid oxides with hollow structure can be synthesized by a sacrificial-template method based on
  • on various parameters, including the crystal defects, oxygen vacancies, phonon confinement, and inhomogeneous strain related to the reduced ceria [31][32]. Herein, the shift can be related to the interaction between the MOx species and CeO2 surface, which leads to lengthening and weakening of the M–O
PDF
Album
Full Research Paper
Published 16 Nov 2017

Ta2N3 nanocrystals grown in Al2O3 thin layers

  • Krešimir Salamon,
  • Maja Buljan,
  • Iva Šarić,
  • Mladen Petravić and
  • Sigrid Bernstorff

Beilstein J. Nanotechnol. 2017, 8, 2162–2170, doi:10.3762/bjnano.8.215

Graphical Abstract
  • these materials are non-stoichiometric materials (metal or N vacancies) the properties of which can be tuned by using different preparation parameters [15][16]. Along with the choice of material, the LSPR efficiency very much depends on the NP morphology [2][4][17]. For example, TiN nanoparticles can
PDF
Album
Supp Info
Full Research Paper
Published 16 Oct 2017

Intercalation of Si between MoS2 layers

  • Rik van Bremen,
  • Qirong Yao,
  • Soumya Banerjee,
  • Deniz Cakir,
  • Nuri Oncel and
  • Harold J. W. Zandvliet

Beilstein J. Nanotechnol. 2017, 8, 1952–1960, doi:10.3762/bjnano.8.196

Graphical Abstract
  • intrinsic defects, which are visible as dark depressions as indicated by the arrow in Figure 1a. These defects are most probably caused by vacancies or interstitials and have been found to exhibit a metal-like behavior [42][43]. Upon the deposition of 0.2 monolayers of Si, the surface morphology converts to
PDF
Album
Supp Info
Full Research Paper
Published 19 Sep 2017

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

Graphical Abstract
  • spectra exhibit D + D″ (ca. 2450 cm−1), G′ (ca. 2705 cm−1), D + D′ (ca. 2948 cm−1) and 2D′ (ca. 3244 cm−1) peaks. The defect-related peaks (D, D′, D″ and the overtones) are attributed to high edge density, structural defects and disorder such as vacancies and strained hexagonal/non-hexagonal (pentagon or
PDF
Album
Full Research Paper
Published 10 Aug 2017

Uptake and intracellular accumulation of diamond nanoparticles – a metabolic and cytotoxic study

  • Antonín Brož,
  • Lucie Bačáková,
  • Pavla Štenclová,
  • Alexander Kromka and
  • Štěpán Potocký

Beilstein J. Nanotechnol. 2017, 8, 1649–1657, doi:10.3762/bjnano.8.165

Graphical Abstract
  • influencing the bulk of the NDs (formation of vacancies, and N-V sites supported by high-temperature annealing in vacuum) [39]. This was confirmed by the fact that there was no obvious difference in the FTIR spectra between the MR-18 sample and the AR-40 sample. The zeta potential of MR-type NDs were negative
PDF
Album
Supp Info
Full Research Paper
Published 10 Aug 2017

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

Graphical Abstract
  • reactions but mainly hydrogen evolution reactions [67]. The lattice structure of g-C3N4 is composed of C–N with short interlayer distances and amino functional groups with larger periodic vacancies [67]. In addition to this, g-C3N4 possesses excellent chemical and thermal stability, unique surface
PDF
Album
Review
Published 03 Aug 2017

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

Graphical Abstract
  • dissolve into the ZrO2 lattice and thus creates oxygen vacancies due to lattice distortion and charge imbalance. High-resolution transmission electron microscopy (HRTEM) results showed Cu/Pt co-doped ZrO2 nanoparticles with a size of ca. 10 nm. X-ray diffraction (XRD) and Raman spectra confirmed cubic
  • structure and larger oxygen vacancies. The nanoparticles showed excellent activity for CO oxidation. The temperature T50 (the temperature at which 50% of CO are converted) was lowered by 175 °C in comparison to bare ZrO2. Further, they exhibited very high stability for CO reaction (time-on-stream ≈ 70 h
  • ). 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
PDF
Album
Full Research Paper
Published 31 Jul 2017

Formation of ferromagnetic molecular thin films from blends by annealing

  • Peter Robaschik,
  • Ye Ma,
  • Salahud Din and
  • Sandrine Heutz

Beilstein J. Nanotechnol. 2017, 8, 1469–1475, doi:10.3762/bjnano.8.146

Graphical Abstract
  • vacancies in the mixed films generate sufficient free volume around the MnPc molecules for a rearrangement to the thermodynamically stable β-phase (Figure 1c), which normally forms above 300 °C [7][8]. Film morphology, structure and composition Optical micrographs in Figure 2 reveal the surface morphology
PDF
Album
Full Research Paper
Published 14 Jul 2017

Fabrication of hierarchically porous TiO2 nanofibers by microemulsion electrospinning and their application as anode material for lithium-ion batteries

  • Jin Zhang,
  • Yibing Cai,
  • Xuebin Hou,
  • Xiaofei Song,
  • Pengfei Lv,
  • Huimin Zhou and
  • Qufu Wei

Beilstein J. Nanotechnol. 2017, 8, 1297–1306, doi:10.3762/bjnano.8.131

Graphical Abstract
  • diameters of tens of nanometers. It meant that the axially aligned pores were the vacancies of paraffin oil. Thermogravimetry (TG) and differential thermogravimetry (DTG) curves of as-spun sample A1 are shown in Figure 2a. It can be seen that the total weight loss was approximately 35%, and whole
  • the number of channels in each nanofiber decreased as the content of paraffin oil increased. This is because the pores stemmed from the vacancies of oil droplets after calcination, and a larger oil droplets were formed when more paraffin oil was added into the microemulsion [31]. The SEM image of
PDF
Album
Supp Info
Full Research Paper
Published 22 Jun 2017

Metal oxide nanostructures: preparation, characterization and functional applications as chemical sensors

  • Dario Zappa,
  • Angela Bertuna,
  • Elisabetta Comini,
  • Navpreet Kaur,
  • Nicola Poli,
  • Veronica Sberveglieri and
  • Giorgio Sberveglieri

Beilstein J. Nanotechnol. 2017, 8, 1205–1217, doi:10.3762/bjnano.8.122

Graphical Abstract
  • NO2. At lower temperatures (100 °C), NiO devices are too resistive to be measured in our test chamber. NiO has hardly been studied as a material for chemical sensors. Hence, there are only few reports about a tentative NO2 sensing mechanism. Zhang et. al. [24] pointed out that nickel vacancies could
PDF
Album
Full Research Paper
Published 06 Jun 2017

Stable Au–C bonds to the substrate for fullerene-based nanostructures

  • Taras Chutora,
  • Jesús Redondo,
  • Bruno de la Torre,
  • Martin Švec,
  • Pavel Jelínek and
  • Héctor Vázquez

Beilstein J. Nanotechnol. 2017, 8, 1073–1079, doi:10.3762/bjnano.8.109

Graphical Abstract
  • tunneling microscope. These features are stable at room temperature against diffusion on the surface. We carry out DFT calculations of fullerene molecules having one missing carbon atom to simulate the vacancies in the molecules resulting from the sputtering process. These modified fullerenes have an
  • vacancies. This provides a pathway for the formation of fullerene-based nanostructures on Au at room temperature. Keywords: Au–C bonds; density functional theory (DFT); fullerenes; scanning tunneling microscopy (STM); sputtering; Introduction In single-molecule electronics, the active element in an
  • observed, which we show to be adsorbed fullerenes with defects created by the sputtering process. The sputtering process is expected to result in the formation of vacancies in the fullerene molecules, where C atoms are knocked out. A series of fullerene fragments can be formed in the collision with high
PDF
Album
Full Research Paper
Published 17 May 2017

Structural properties and thermal stability of cobalt- and chromium-doped α-MnO2 nanorods

  • Romana Cerc Korošec,
  • Polona Umek,
  • Alexandre Gloter,
  • Jana Padežnik Gomilšek and
  • Peter Bukovec

Beilstein J. Nanotechnol. 2017, 8, 1032–1042, doi:10.3762/bjnano.8.104

Graphical Abstract
  • , causing no structural distortion. The latter would lead to lower symmetry, from tetragonal to monoclinic, which means also a lower thermal stability. (II) Dopant ions of lower valence lead to the formation of octahedral vacancies to maintain the charge balance, with or without the additional incorporation
  • of K+ into tunnels. Vacancies cause structural distortion and lower the thermal stability. When ions of higher valence are incorporated, the content of K+ ions is reduced or more Mn4+ ions are transformed to Mn3+ [14]. Recently, a few different strategies of doping of different MnO2 structures with
PDF
Album
Full Research Paper
Published 10 May 2017

Study of the correlation between sensing performance and surface morphology of inkjet-printed aqueous graphene-based chemiresistors for NO2 detection

  • F. Villani,
  • C. Schiattarella,
  • T. Polichetti,
  • R. Di Capua,
  • F. Loffredo,
  • B. Alfano,
  • M. L. Miglietta,
  • E. Massera,
  • L. Verdoliva and
  • G. Di Francia

Beilstein J. Nanotechnol. 2017, 8, 1023–1031, doi:10.3762/bjnano.8.103

Graphical Abstract
  • the case of graphene the active sites are represented by sp2 carbon atoms (low interaction energy) and defects such as vacancies, dangling bonds, coordination defects and functionalizations (high interaction energy). In the specific case of our LPE graphene, defects are mostly ascribed to edge defects
PDF
Album
Supp Info
Full Research Paper
Published 09 May 2017

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

Graphical Abstract
  • , namely I(D)/I(D′), can be related to the preponderant typology of defects in the different graphene samples [25]. In particular, the I(D)/I(D′) ratio exhibits its maximum value, around 13, for sp3-like defects, it decreases down to about 7 in the case of vacancies and it is minimum for edge defects (ca
PDF
Album
Full Research Paper
Published 08 May 2017

Synthesis of graphene–transition metal oxide hybrid nanoparticles and their application in various fields

  • Arpita Jana,
  • Elke Scheer and
  • Sebastian Polarz

Beilstein J. Nanotechnol. 2017, 8, 688–714, doi:10.3762/bjnano.8.74

Graphical Abstract
  • photoluminescence (PL) band at 373 nm, which is due to the exciton recombination corresponding to the band edge emission, and a green emission peak is most commonly observed that arises from the defect of ZnO NPs such as oxygen vacancies, zinc vacancies, oxygen interstitials, and zinc interstitials [241]. Graphene
PDF
Album
Review
Published 24 Mar 2017

Diffusion and surface alloying of gradient nanostructured metals

  • Zhenbo Wang and
  • Ke Lu

Beilstein J. Nanotechnol. 2017, 8, 547–560, doi:10.3762/bjnano.8.59

Graphical Abstract
  • higher binding energy between Mn and vacancies, of which the concentration was much larger in the GNS sample than in the CG sample, also contributed to the quicker formation of Mn-enriched oxide scale [45][96][97]. Conclusion Due to the importance of understanding the diffusion and surface alloying
PDF
Album
Review
Published 03 Mar 2017
Graphical Abstract
  • to its high and variable electrical conductivity in the range of 100 Ω−1·cm−1 to 102 Ω−1·cm−1 due to the existence of free electrons in oxygen vacancies. This effect has been widely applied for the construction of prototypical gas sensors devices with both thick and thin films [3][4][5][6][7][8]. The
PDF
Album
Full Research Paper
Published 27 Feb 2017

Nanocrystalline ZrO2 and Pt-doped ZrO2 catalysts for low-temperature CO oxidation

  • Amit Singhania and
  • Shipra Mital Gupta

Beilstein J. Nanotechnol. 2017, 8, 264–271, doi:10.3762/bjnano.8.29

Graphical Abstract
  • conversion at 240 °C, which is the highest conversion rate reported for ZrO2 in literature to date. It is found that through solution combustion, Pt2+ ions replace Zr4+ ions in the ZrO2 lattice and because of this, oxygen vacancies are formed due to charge imbalance and lattice distortion in ZrO2. 1% Pt was
  • oxygen mobility and oxygen vacancies and improves the activity and stability of the catalyst. The effects of gas hourly space velocity (GHSV) and initial CO concentration on the CO oxidation over Pt(1%)-ZrO2 were studied. Keywords: CO oxidation; nanomaterials; platinum; solution combustion method
  • CO oxidation by different researchers [13][14][15][16]. The addition of precious metals such as Pd, Pt and Rh increased the reactivity of the support by increasing its oxygen mobility and number of oxygen vacancies (the source of oxygen in CO oxidation) [10][11][12]. In recent years, ZrO2 has been
PDF
Album
Full Research Paper
Published 26 Jan 2017

Nanocrystalline TiO2/SnO2 heterostructures for gas sensing

  • Barbara Lyson-Sypien,
  • Anna Kusior,
  • Mieczylaw Rekas,
  • Jan Zukrowski,
  • Marta Gajewska,
  • Katarzyna Michalow-Mauke,
  • Thomas Graule,
  • Marta Radecka and
  • Katarzyna Zakrzewska

Beilstein J. Nanotechnol. 2017, 8, 108–122, doi:10.3762/bjnano.8.12

Graphical Abstract
  • which the semiconducting behavior begins to prevail over water desorption/oxygen adsorption depends on the TiO2–SnO2 composition. The higher Tmax for TiO2-rich heterostructures can be explained on the basis of the higher ionic defect concentration (mainly oxygen vacancies) at the surface of TiO2. It is
  • well known that oxygen vacancies act as water adsorption centers. Moreover, in the case of SnO2 water adsorption takes place because of the formation of weak van der Waals bonds between water dipoles and lattice ions (Sn4+ and O2−) [19]. This facilitates water desorption from the surface of SnO2-rich
  • of oxygen vacancies VO, the following reaction could be proposed: The condition of lattice electroneutrality requires that: where k = 1 or 2 corresponds to singly or doubly ionized defects, respectively. Applying the law of mass action to Equation 11 (with k = 1 or 2) gives power-law coefficients of
PDF
Album
Full Research Paper
Published 12 Jan 2017

Ordering of Zn-centered porphyrin and phthalocyanine on TiO2(011): STM studies

  • Piotr Olszowski,
  • Lukasz Zajac,
  • Szymon Godlewski,
  • Bartosz Such,
  • Rémy Pawlak,
  • Antoine Hinaut,
  • Res Jöhr,
  • Thilo Glatzel,
  • Ernst Meyer and
  • Marek Szymonski

Beilstein J. Nanotechnol. 2017, 8, 99–107, doi:10.3762/bjnano.8.11

Graphical Abstract
  • investigation of molecular adsorption is titanium dioxide [11][12]. The most stable and the most studied face of TiO2 is the rutile (110) surface. In the context of adsorption studies, it is important to note that the (110) face of rutile usually contains numerous oxygen vacancies, often filled with hydroxy
PDF
Album
Full Research Paper
Published 11 Jan 2017

Obtaining and doping of InAs-QD/GaAs(001) nanostructures by ion beam sputtering

  • Sergei N. Chebotarev,
  • Alexander S. Pashchenko,
  • Leonid S. Lunin,
  • Elena N. Zhivotova,
  • Georgy A. Erimeev and
  • Marina L. Lunina

Beilstein J. Nanotechnol. 2017, 8, 12–20, doi:10.3762/bjnano.8.2

Graphical Abstract
  • occupy Ga vacancies in the course of GaAs layer growth and behave as an acceptor-type impurity partially compensating the concentration of Te+ donors. The formation of neutral SnTe complexes results in a decrease in electrically active donors Sn+ + Te+ incorporated in the GaAs layer. We consider that
PDF
Album
Full Research Paper
Published 03 Jan 2017

Annealing-induced recovery of indents in thin Au(Fe) bilayer films

  • Anna Kosinova,
  • Ruth Schwaiger,
  • Leonid Klinger and
  • Eugen Rabkin

Beilstein J. Nanotechnol. 2016, 7, 2088–2099, doi:10.3762/bjnano.7.199

Graphical Abstract
  • dislocation loops is non-conservative, it generates a flux of excess vacancies. The vacancies can reach the film-substrate interface and the nearby grain boundary, which both can serve as vacancy sinks. The annihilation of vacancies at the film-substrate interface leads to the slight decrease of the film
  • thickness [21], whereas annihilation of vacancies at the grain boundaries helps to relax compressive stresses in the film formed during heating due to the mismatch of thermal expansion coefficients between the film and the substrate. The rim-less shape of the dewetting holes observed far from the indented
  • region (see Figure 6) confirms that the film-substrate interface is indeed a potent sink and source of vacancies; the vacancies that originated at the interface are consumed by the expanding hole. Some fraction of the vacancy flux generated by annihilating dislocation loops may lead to the nucleation of
PDF
Album
Full Research Paper
Published 28 Dec 2016
Other Beilstein-Institut Open Science Activities