The Kirkendall effect and nanoscience: hollow nanospheres and nanotubes

• Abdel-Aziz El Mel,
• Ryusuke Nakamura and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2015, 6, 1348–1361, doi:10.3762/bjnano.6.139

• Co nanocrystals. They demonstrated that both the annealing temperature and the annealing time have a direct impact on the transformation kinetics of the nanoparticles from solid Co into hollow CoS. In this same study, the authors show that a similar effect occurs during oxidation or selenization of

• Co nanocrystals. Since this first report, the nanoscale Kirkendall effect has become very popular and been adopted by many research groups for the synthesis of hollow nanoparticles covering a wide range of materials including sulfides [8][26][27][28][29][30], oxides [9][10][11][30][31][32][33][34][35

• , they applied their novel approach to synthesize ZnAl2O4 nanotubes containing ZnO nanocrystals. First, rippled ZnO nanowires coated with a 12 nm thick Al2O3 layer were synthesized (Figure 13a) and then annealed at 700 °C for 5 h (Figure 13b). The annealing process results in the transformation of the

Addition of Zn during the phosphine-based synthesis of indium phospide quantum dots: doping and surface passivation

• Natalia E. Mordvinova,
• Alexander A. Vinokurov,
• Oleg I. Lebedev,
• Tatiana A. Kuznetsova and
• Sergey G. Dorofeev

Beilstein J. Nanotechnol. 2015, 6, 1237–1246, doi:10.3762/bjnano.6.127

• luminescence quantum yield through the reduction of phosphorous dangling bonds. A scenario for the growth of the colloidal InP(Zn) QDs was proposed and discussed. Keywords: core–shell nanoparticles; doped semiconductor nanocrystals; InP(Zn) quantum dots; luminescence; zinc; Introduction Colloidal quantum

• excess myristic acid is lower. Moreover, the excess myristic acid contaminates the samples and rendering them too viscous and difficult to purify. Figure 2 shows the powder XRD patterns of the InP nanocrystals with different Zn amounts added during the synthesis. The XRD pattern show a clear zinc blende

• nanocrystals solution dispersed in hexane was mixed with THF and a certain amount of myristic acid was added. The mixture was loaded into a perfluoroethylene vessel and a certain amount of etching mixture (HF in THF 1:10) was added under stirring. Characterization The UV–vis absorption spectra were measured at

Nano-contact microscopy of supracrystals

• Adam Sweetman,
• Nicolas Goubet,
• Ioannis Lekkas,
• Marie Paule Pileni and
• Philip Moriarty

Beilstein J. Nanotechnol. 2015, 6, 1229–1236, doi:10.3762/bjnano.6.126

• , France CEA/IRAMIS, CEA Saclay, 91191, Gif-sur-Yvette, France 10.3762/bjnano.6.126 Abstract Background: Highly ordered three-dimensional colloidal crystals (supracrystals) comprised of 7.4 nm diameter Au nanocrystals (with a 5% size dispersion) have been imaged and analysed using a combination of

• tunnelling microscopy and spectroscopy. Keywords: dynamic force microscopy; nanoparticle; non-contact atomic force microscopy; point contact imaging; scanning probe microscopy; supracrystal; Introduction Artificial solids comprising extended assemblies of nanocrystals with a narrow size distribution

• polyhedral supracrystals arising from precipitation in the colloidal suspension. There is a significant body of work that focuses on elucidating the electronic properties of nanocrystals and their associated 1D, 2D, and 3D assemblies. Building on the conceptual and theoretical framework put forward by

The convenient preparation of stable aryl-coated zerovalent iron nanoparticles

• Olga A. Guselnikova,
• Andrey I. Galanov,
• Anton K. Gutakovskii and
• Pavel S. Postnikov

Beilstein J. Nanotechnol. 2015, 6, 1192–1198, doi:10.3762/bjnano.6.121

• ). In the darkfield image, the nanocrystals are indicated by bright areas. In the high-resolution transmission electron microscopy (HRTEM) image, the atomic planes of the iron crystal lattice are clearly visualized. The NPs are mostly uniform in size with an average core particle diameter of 21 nm with

Tattoo ink nanoparticles in skin tissue and fibroblasts

• Colin A. Grant,
• Peter C. Twigg,
• Richard Baker and
• Desmond J. Tobin

Beilstein J. Nanotechnol. 2015, 6, 1183–1191, doi:10.3762/bjnano.6.120

• quantum dots and nanocrystals to target specific tumour antigens [6]. Other medical research on nanoparticles includes the formation of a network of nanoparticles with an insulin core that can regulate and control normal blood sugar level [7]. However, despite considerable progress in nanoscience, it is

Electronic interaction in composites of a conjugated polymer and carbon nanotubes: first-principles calculation and photophysical approaches

• Florian Massuyeau,
• Jany Wéry,
• Jean-Luc Duvail,
• Serge Lefrant,
• Abu Yaya,
• Chris Ewels and
• Eric Faulques

Beilstein J. Nanotechnol. 2015, 6, 1138–1144, doi:10.3762/bjnano.6.115

• molecules, and semiconducting nanocrystals have been extensively studied, in order to understand the photophysical changes observed on varying the particles concentration [8][9][10][11]. Notably, polymer-composite materials with different electron affinity have been used to enhance charge separation upon

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

• the functionality and the necessity of heterogeneous catalysts in Li/O2 cells remain unsolved, the search for improved heterogeneous catalysts for improved cyclability is still the subject of many new articles on Li/O2 batteries. The most promising catalyst material, ruthenium nanocrystals, was

Observing the morphology of single-layered embedded silicon nanocrystals by using temperature-stable TEM membranes

• Sebastian Gutsch,
• Daniel Hiller,
• Jan Laube,
• Margit Zacharias and
• Christian Kübel

Beilstein J. Nanotechnol. 2015, 6, 964–970, doi:10.3762/bjnano.6.99

• -von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany 10.3762/bjnano.6.99 Abstract We use high-temperature-stable silicon nitride membranes to investigate single layers of silicon nanocrystal ensembles by energy filtered transmission electron microscopy. The silicon nanocrystals are prepared

• thickness and stoichiometry are below a critical value. Keywords: electron irradiation damage; energy-filtered transmission electron microscopy; membrane; plane view; silicon nanocrystals; size control; size distribution; Introduction Si nanocrystals (Si NC) are interesting for applications in third

Nanostructuring of GeTiO amorphous films by pulsed laser irradiation

• Valentin S. Teodorescu,
• Cornel Ghica,
• Adrian V. Maraloiu,
• Mihai Vlaicu,
• Andrei Kuncser,
• Magdalena L. Ciurea,
• Ionel Stavarache,
• Ana M. Lepadatu,
• Nicu D. Scarisoreanu,
• Andreea Andrei,
• Valentin Ion and
• Maria Dinescu

Beilstein J. Nanotechnol. 2015, 6, 893–900, doi:10.3762/bjnano.6.92

• matrix was also evidenced in amorphous GeTiO films annealed in a conventional furnace [23]. The annealing at about 600 °C leads to the formation of Ge nanocrystals in the film matrix, which is formed by a crystallized mixture of two phases, the Ge in TiO2 anatase phase and the rutile phase (Ti in GeO2

Microwave assisted synthesis and characterisation of a zinc oxide/tobacco mosaic virus hybrid material. An active hybrid semiconductor in a field-effect transistor device

• Shawn Sanctis,
• Rudolf C. Hoffmann,
• Sabine Eiben and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2015, 6, 785–791, doi:10.3762/bjnano.6.81

• HRTEM investigations of the as-synthesized particles formed from the precursor solution, which yield stable zinc oxide nanoparticles (Figure 2a). TEM also indicates the successful formation of ZnO nanocrystals in solution after the completion of the microwave irradiation process. Grazing incidence X-ray

Combination of surface- and interference-enhanced Raman scattering by CuS nanocrystals on nanopatterned Au structures

• Alexander G. Milekhin,
• Nikolay A. Yeryukov,
• Larisa L. Sveshnikova,
• Tatyana A. Duda,
• Ekaterina E. Rodyakina,
• Victor A. Gridchin,
• Evgeniya S. Sheremet and
• Dietrich R. T. Zahn

Beilstein J. Nanotechnol. 2015, 6, 749–754, doi:10.3762/bjnano.6.77

• nanocrystals (NCs) with a low areal density fabricated through the Langmuir–Blodgett technology on nanopatterned Au nanocluster arrays using a combination of surface- and interference-enhanced Raman scattering (SERS and IERS, respectively). Micro-Raman spectra of one monolayer of CuS NCs deposited on a bare Si

• advantages of SERS and IERS and demonstrate stronger SERS enhancement allowing for the observation of Raman signals from CuS NCs with an ultra-low areal density. Keywords: copper sulfide (CuS) nanocrystals; interference-enhanced Raman spectroscopy; phonons; surface-enhanced Raman spectroscopy; Introduction

• Investigations of Raman scattering in nanostuctures such as nanocrystals (NCs) are limited by a low Raman cross-section because of the very low scattering volume of the nanostructures. Surface-enhanced Raman spectroscopy (SERS) taking advantage of plasmonics leads to a remarkable increase of the Raman

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

• processes presented shiny and dark residual materials after the polymer combustion and according to micro-Raman spectroscopy of the domains, graphitic nanocrystals and carbon nanotubes have successfully been produced by the combustion of polydimethylsiloxane layers. The fabrication processes and

• characterization of the byproduct materials are reported. We demonstrate that CVD led to bulk production of graphitic nanocrystals and single-walled carbon nanotubes while direct laser ablation may be employed for the formation of localized fluorescent nanodots. In the latter case, graphitic nanodomains and multi

• nanocrystals (GNC) are composing the shiny layers, whereas dark parts consist mainly of single-walled carbon nanotubes (SWCNT) [14]. Selective laser ablation Selective and localized laser pyrolysis has also been tested to study the formation of nanodomains from PDMS in a controlled fashion, using a low-cost

Tm-doped TiO₂ and Tm₂Ti₂O₇ pyrochlore nanoparticles: enhancing the photocatalytic activity of rutile with a pyrochlore phase

• Desiré M. De los Santos,
• Javier Navas,
• Teresa Aguilar,
• Antonio Sánchez-Coronilla,
• Concha Fernández-Lorenzo,
• Rodrigo Alcántara,
• Jose Carlos Piñero,
• Ginesa Blanco and
• Joaquín Martín-Calleja

Beilstein J. Nanotechnol. 2015, 6, 605–616, doi:10.3762/bjnano.6.62

• . Moreover, for both phases, the higher the annealing temperature, the higher the t, due to the sintering of the nanocrystals. Generally, t decreases with an increased dopant concentration. The introduction of a Tm3+ ion into the structure can create structural distortions that break the crystal continuity

Silica micro/nanospheres for theranostics: from bimodal MRI and fluorescent imaging probes to cancer therapy

• Shanka Walia and
• Amitabha Acharya

Beilstein J. Nanotechnol. 2015, 6, 546–558, doi:10.3762/bjnano.6.57

• fluorophores presently available, QDs have received much interest because of their ability to resist photobleaching. These nanocrystals were found to be brighter, more stable and to exhibit a narrower spectral distribution than organic dyes. Gerion et al. [19] reported a procedure for the synthesis of silica

• -shell-encapsulated hybrid nanomaterials consisting of paramagnetic Gd3+ ions and QDs or Au nanocrystals. The citric-acid-capped gold colloids and CdSe/ZnS QDs were silanized by using mercaptopropyltrimethoxysilane (MPS) as surfactant. Further, a Gd3+-DOTA (tetraazacyclododecanetetraacetic acid) complex

Nanoparticle shapes by using Wulff constructions and first-principles calculations

• Georgios D. Barmparis,
• Zbigniew Lodziana,
• Nuria Lopez and
• Ioannis N. Remediakis

Beilstein J. Nanotechnol. 2015, 6, 361–368, doi:10.3762/bjnano.6.35

• with surfactants Metal-only nanoparticles or metal-adsorbate interactions have been the leading force that has helped the evolution of the presented methodology for the shape of nanocrystals. However, recent developments to design colloidal suspensions of nanoparticles with interesting physical and

Carrier multiplication in silicon nanocrystals: ab initio results

• Ivan Marri,
• Marco Govoni and
• Stefano Ossicini

Beilstein J. Nanotechnol. 2015, 6, 343–352, doi:10.3762/bjnano.6.33

• of carrier multiplication decay dynamics by analyzing systems of isolated and coupled silicon nanocrystals. The effects on carrier multiplication dynamics by energy and charge transfer processes are also discussed. Keywords: carrier multiplication; nanocrystals; silicon; solar cells; Introduction

• Trinh et al. [36] in order to explain results obtained in photoluminescence (PL) and induced absorption (IA) experiments conducted on dense arrays of silicon nanocrystals (Si-NCs, NC–NC separation ≤ 1 nm). In the first set of experiments, the authors proved that although the excitation cross-section is

Nanoporous Ge thin film production combining Ge sputtering and dopant implantation

• Jacques Perrin Toinin,
• Alain Portavoce,
• Khalid Hoummada,
• Michaël Texier,
• Maxime Bertoglio,
• Sandrine Bernardini,
• Marco Abbarchi and
• Lee Chow

Beilstein J. Nanotechnol. 2015, 6, 336–342, doi:10.3762/bjnano.6.32

• island formation or agglomeration at a temperature below the melting temperature of the film material. This phenomenon is generally undesirable in the field of micro- or nano-technology [34] yet has been reported to be interesting for the fabrication of nanocrystals. A wide range of materials can be used

• for the fabrication of nanocrystals by dewetting, such as metals or semiconductors. In addition, the structure of the dewetted layers can be controlled using several techniques such as pulsed laser annealing [35][36] or a substrate patterned by focused ion beam. The study of Ge dewetting on SiO2 [37

Tunable white light emission by variation of composition and defects of electrospun Al₂O₃–SiO₂ nanofibers

• Jinyuan Zhou,
• Gengzhi Sun,
• Hao Zhao,
• Xiaojun Pan,
• Zhenxing Zhang,
• Yujun Fu,
• Yanzhe Mao and
• Erqing Xie

Beilstein J. Nanotechnol. 2015, 6, 313–320, doi:10.3762/bjnano.6.29

• preparation processes, which can be effectively tuned and controlled by doping [1][2][3][4]. Thus far, in order to achieve enhanced and stable light emission, various materials have been incorporated into a SiO2 matrix, such as Si nanocrystals, carbon nanocomposites, ZnO, Al2O3, SnO2, and various rare-earth

• )–O–C∙=O) formed on the pore surface [16]. Mir et al. incorporated 30 nm, Al2O3 nanocrystals into silica aerogels, followed by calcination at 1150 °C in air for 2 h. The resulting 1Al2O3–3SiO2 composites exhibited strong, visible PL bands ranging from 400 to 600 nm centered at ≈500 nm, which were

• . Moreover, from the enlarged SEM image shown in the inset of Figure 2b, some black spots were formed on the surface of fibers. This may be due to the precipitation of mullite nanocrystals from the inside to the surface of the Al2O3 during the calcination [18]. When the concentration of SiO2 is further

Comparative evaluation of the impact on endothelial cells induced by different nanoparticle structures and functionalization

• Lisa Landgraf,
• Ines Müller,
• Peter Ernst,
• Miriam Schäfer,
• Christina Rosman,
• Isabel Schick,
• Oskar Köhler,
• Hartmut Oehring,
• Vladimir V. Breus,
• Thomas Basché,
• Carsten Sönnichsen,
• Wolfgang Tremel and
• Ingrid Hilger

Beilstein J. Nanotechnol. 2015, 6, 300–312, doi:10.3762/bjnano.6.28

• . Colloidal semiconductor nanocrystals or quantum dots (QDs) with their outstanding fluorescence properties also play a distinct role in life science. QDs exhibit high stability against photo bleaching and they are easily tunable in color. Several studies demonstrated their feasibility for detection of

The effect of surface charge on nonspecific uptake and cytotoxicity of CdSe/ZnS core/shell quantum dots

• Vladimir V. Breus,
• Anna Pietuch,
• Marco Tarantola,
• Thomas Basché and
• Andreas Janshoff

Beilstein J. Nanotechnol. 2015, 6, 281–292, doi:10.3762/bjnano.6.26

• resulting from CdSe and CdTe QD exposure to cultured cells was attributed to the presence of Cd2+ ions during the initial stages of synthesis or during in situ release, resulting in mitochondrial damage and oxidative stress [8][9]. The isolation of toxic core contents by coating the CdSe nanocrystals with a

• of Se solution. The nanocrystals were left to grow for 6 minutes at 200 °C, then the heating was removed and the flask was cooled down to ≈80 °C by compressed air flow before the addition of 40 mL of ethanol. The sample was centrifuged at 4000 rpm for 5 minutes; the resulting pellet containing CdSe

Tailoring the ligand shell for the control of cellular uptake and optical properties of nanocrystals

• Johannes Ostermann,
• Christian Schmidtke,
• Christopher Wolter,
• Jan-Philip Merkl,
• Hauke Kloust and
• Horst Weller

Beilstein J. Nanotechnol. 2015, 6, 232–242, doi:10.3762/bjnano.6.22

Tunable light filtering by a Bragg mirror/heavily doped semiconducting nanocrystal composite

• Ilka Kriegel and
• Francesco Scotognella

Beilstein J. Nanotechnol. 2015, 6, 193–200, doi:10.3762/bjnano.6.18

• good candidates. However, their optical characteristics are determined during the fabrication stage. Heavily doped semiconductor nanocrystals (NCs), on the other hand, deliver a high degree of optical tunability through the active modulation of their carrier density, ultimately influencing their

The distribution and degradation of radiolabeled superparamagnetic iron oxide nanoparticles and quantum dots in mice

• Denise Bargheer,
• Artur Giemsa,
• Barbara Freund,
• Markus Heine,
• Christian Waurisch,
• Gordon M. Stachowski,
• Stephen G. Hickey,
• Alexander Eychmüller,
• Jörg Heeren and
• Peter Nielsen

Beilstein J. Nanotechnol. 2015, 6, 111–123, doi:10.3762/bjnano.6.11

• /CdS/ZnS-Qdots in the liver. Keywords: biodistribution; chromium(III); 51Cr; quantum dots; SPIOs; zinc metabolism; 65Zn; Introduction Quantum dots (Qdots) are semiconductor nanocrystals (2–100 nm in diameter) that combine a strong, size-tunable photoluminescence with robust photostability, which

• the form of Qdots is stored in these organs, and the particles are thus not fully degraded. Otherwise, 65Zn released by degradation of the nanocrystals was distributed between all organs in a manner comparable to that of the ionic 65ZnCl2. In contrast to the chromium results discussed above, 65Zn from

Manganese oxide phases and morphologies: A study on calcination temperature and atmospheric dependence

• Matthias Augustin,
• Daniela Fenske,
• Ingo Bardenhagen,
• Anne Westphal,
• Martin Knipper,
• Thorsten Plaggenborg,
• Joanna Kolny-Olesiak and
• Jürgen Parisi

Beilstein J. Nanotechnol. 2015, 6, 47–59, doi:10.3762/bjnano.6.6

• applying milder reaction conditions (i.e., decreasing the synthesis temperature and increasing the reaction time), we obtained homogeneous, rectangular Mn(II) glycolate nanocrystals with diameters less than 25 nm. The preparation of nanoscale precursor particles with uniform morphology is advantageous for

Bright photoluminescence from ordered arrays of SiGe nanowires grown on Si(111)

• D. J. Lockwood,
• N. L. Rowell,
• A. Benkouider,
• A. Ronda,
• L. Favre and
• I. Berbezier

Beilstein J. Nanotechnol. 2014, 5, 2498–2504, doi:10.3762/bjnano.5.259

• . The latter step, called galvanic deposition, is based on the spontaneous oxido-reduction reactions between the semiconductor surface (the substrate) and the metallic ions in the solution. Upon contact with the Si surface, the solution spontaneously reduces and precipitates into Au nanocrystals

• Au0.18Si0.82 catalysts. The main advantage of this growth method is the control of the NW position (related to site selectivity) and its size; a homogeneous size is obtained due to the regular network of Au nanocrystals (see Figure 2). Also, SiGe NWs can be grown and then transformed in a second step into core