A visible-light-driven composite photocatalyst of TiO₂ nanotube arrays and graphene quantum dots

• Donald K. L. Chan,
• Po Ling Cheung and
• Jimmy C. Yu

Beilstein J. Nanotechnol. 2014, 5, 689–695, doi:10.3762/bjnano.5.81

• for 1 h with a temperature increasing rate of 1 °C·min−1 in air was applied to improve crystallization. Synthesis of graphene quantum dots (GQDs): GQDs were synthesized from graphene oxide (GO) by heating with a solution of hydrogen peroxide and ammonia [44]. 20 mg of GO was dispersed into 5 mL of

Fabrication of carbon nanomembranes by helium ion beam lithography

• Xianghui Zhang,
• Henning Vieker,
• André Beyer and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2014, 5, 188–194, doi:10.3762/bjnano.5.20

• been transferred onto a SiO2/Si substrate. Interestingly, the first step is the formation of circular shaped nuclei, which is analogous to the nucleation for thin films or polymer crystallization [23]. After a dose of 176 µC/cm2 (Figure 3a), the average diameter of the nuclei is 9.0 ± 1.7 nm, which

Controlled synthesis and tunable properties of ultrathin silica nanotubes through spontaneous polycondensation on polyamine fibrils

• Jian-Jun Yuan,
• Pei-Xin Zhu,
• Daisuke Noda and
• Ren-Hua Jin

Beilstein J. Nanotechnol. 2013, 4, 793–804, doi:10.3762/bjnano.4.90

• chemistry is highly desirable. We are interested in the programmable construction of biomimetic silica nanomaterials by exploiting the crystallization-driven self-assembly of a simple synthetic polyamine, namely linear polyethyleneimine (LPEI) [31][32][33]. In contrast to branched PEI, LPEI is composed only

• crystallization. In contrast, the alkali-induced self-assembly of LPEI occurred rapidly because the deprotonation reaction is a fast process. Comparatively, the LPEI fibrils from rapid crystallization-driven self-assembly serve as templates that allow for a well-controlled silicification. The surface areas and

• formation from a higher molar ratio of [OH]/[EI] (0.8, Figure 1A–C), the decreased molar ratio of [OH]/[EI] induced the formation of nanofilms. This could be attributed to a slower crystallization rate of LPEI, because of insufficient neutralization of the protonated LPEI. On the other hand, when the molar

Controlling the near-field excitation of nano-antennas with phase-change materials

• Tsung Sheng Kao,
• Yi Guo Chen and
• Ming Hui Hong

Beilstein J. Nanotechnol. 2013, 4, 632–637, doi:10.3762/bjnano.4.70

• conducted to estimate the amount of crystallized phase-change molecules. Since GST is known as a nucleation-dominated material, many small crystalline nuclei were formed first when the local temperature reaches the crystallization point of constituent phase-change molecules. Then numerous randomly

• sputtered GST phase-change thin film was performed by a homogeneous heating on a hot-plate with a crystallization temperature of 135 °C. This constant temperature was set to provide a slow phase transition rate, which facilitated a finer control of the crystalline proportions of samples. As the heating time

• spectra measurements (solid lines) and the simulated far-field transmission spectra (dashed lines) of a GST thin film switched at different intermediate phases. A good agreement in both spectral results suggests that a phase-change GST thin film can be well controlled at different crystallization levels

Photocatalytic antibacterial performance of TiO₂ and Ag-doped TiO₂ against S. aureus. P. aeruginosa and E. coli

• Kiran Gupta,
• R. P. Singh,
• Ashutosh Pandey and
• Anjana Pandey

Beilstein J. Nanotechnol. 2013, 4, 345–351, doi:10.3762/bjnano.4.40

• investigated against Gram-positive Staphylococcus aureus (S. aureus), and Gram-negative Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli) bacteria under visible light. Results and Discussion XRD of TiO2 and Ag-doped TiO2 The samples were annealed at 450 °C to achieve crystallization in TiO2

Nanoscopic surfactant behavior of the porin MspA in aqueous media

• Ayomi S. Perera,
• Hongwang Wang,
• Tej B. Shrestha,
• Deryl L. Troyer and
• Stefan H. Bossmann

Beilstein J. Nanotechnol. 2013, 4, 278–284, doi:10.3762/bjnano.4.30

• hydrophilic vestibule (the “head” of the surfactant) can potentially be deformed when single MspA proteins aggregate. Protein deformation is often observed during crystallization [26]. The formation of a bilayer is evidence for attractive interactions between MspA units. Predicting the geometry of

Electrospinning preparation and electrical and biological properties of ferrocene/poly(vinylpyrrolidone) composite nanofibers

• Ji-Hong Chai and
• Qing-Sheng Wu

Beilstein J. Nanotechnol. 2013, 4, 189–197, doi:10.3762/bjnano.4.19

• , the degree of crystallization of Fc in the composite fibers is not good. This is because the solidification of fibers is a very fast process with the volatilization of the solvents and the time is too short for Fc to fully crystallize during the electrospinning process. The results indicate that the

• Fc in the PVP polymer is in the amorphous form with a poor degree of crystallization. The degradation process of products was investigated using thermogravimetric analysis (TGA) from 20 to 600 °C in nitrogen gas. Figure 3a represents the TG curve of the pure Fc. It was found that the TGA data of Fc

Low-dose patterning of platinum nanoclusters on carbon nanotubes by focused-electron-beam-induced deposition as studied by TEM

• Xiaoxing Ke,
• Carla Bittencourt,
• Sara Bals and
• Gustaaf Van Tendeloo

Beilstein J. Nanotechnol. 2013, 4, 77–86, doi:10.3762/bjnano.4.9

• of nanoparticles, which can be difficult to monitor and control. Our post-growth experiment through electron irradiation has shown that the crystallization of amorphous carbon can be performed in a controllable manner, where the growth of nanoparticles is seen to increase along with the electron dose

• reducing amorphous carbon using in-situ electron-beam irradiation in TEM at low kilovolt potentials (80 kV), where a simultaneous growth of a thin graphitic layer and Pt nanoclusters is achieved. The controllable crystallization of amorphous carboneous and Pt nanoclusters could be interesting for contact

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

• envision their crystallization during the short deposition and subsequent surface cleaning process. After deposition, the decorated surfaces are cleaned for 120 s in DI and 120 s in methanol. Basic character is introduced to the nanostructured metal oxides by direct in situ treatment with triethylamine

Highly ordered ultralong magnetic nanowires wrapped in stacked graphene layers

• Abdel-Aziz El Mel,
• Jean-Luc Duvail,
• Eric Gautron,
• Wei Xu,
• Chang-Hwan Choi,
• Benoit Angleraud,
• Agnès Granier and
• Pierre-Yves Tessier

Beilstein J. Nanotechnol. 2012, 3, 846–851, doi:10.3762/bjnano.3.95

• (also known as metal-filled carbon nanotubes). Carbon-containing nickel nanowires are first grown on a nanograted surface by magnetron sputtering. Then, a post-annealing treatment favors the metal-catalyzed crystallization of carbon into stacked graphene layers rolled around the nickel cores. The

• the nickel-catalyzed crystallization of carbon by thermal annealing. During the post-annealing stage of the carbon-containing nickel nanowires, the carbon atoms diffuse and homogenously dissolve in the nickel phase [31][32]. As the limit of the solid solubility of carbon in the nickel phase is reached

• . Moreover, the metal-catalyzed crystallization of carbon by thermal annealing, which is the mechanism employed in this work, allows the synthesis of graphene sheets of a few layers with low defects [31][32][33]. Therefore, after an optimization of the materials and the processing conditions of the technique

Focused electron beam induced deposition: A perspective

• Michael Huth,
• Fabrizio Porrati,
• Christian Schwalb,
• Marcel Winhold,
• Roland Sachser,
• Maja Dukic,
• Jonathan Adams and
• Georg Fantner

Beilstein J. Nanotechnol. 2012, 3, 597–619, doi:10.3762/bjnano.3.70

• special microstructural feature, such as re-entrant crystallization of the granules, has been observed. It thus remains an unresolved issue, whether the granular electronic density of states is indeed indicative of the formation of an amorphous precursor of the metastable, hexagonal and superconducting

• bias current. Future research will have to show whether this is the result of local crystallization towards the Pt2Si3-phase caused by the high dissipation levels under large current bias. For details concerning the electronic transport properties of nanogranular FEBID structures the reader is referred

Forming nanoparticles of water-soluble ionic molecules and embedding them into polymer and glass substrates

• Stella Kiel,
• Olga Grinberg,
• Nina Perkas,
• Jerome Charmet,
• Herbert Kepner and
• Aharon Gedanken

Beilstein J. Nanotechnol. 2012, 3, 267–276, doi:10.3762/bjnano.3.30

• inorganic salt are produced as a result of the influence of localized higher temperatures and pressures. According to Kordylla et al. [21] the nucleation work needed for crystallization is strongly reduced by the presence of a liquid–gas interface (the bubble surface), therefore the presence of the bubble

Mesoporous MgTa₂O₆ thin films with enhanced photocatalytic activity: On the interplay between crystallinity and mesostructure

• Jin-Ming Wu,
• Igor Djerdj,
• Till von Graberg and
• Bernd M. Smarsly

Beilstein J. Nanotechnol. 2012, 3, 123–133, doi:10.3762/bjnano.3.13

• (poly(ethylene-co-butylene)-b-poly(ethylene oxide)) and PIB6000 (CH3C(CH3)2(CH2C(CH3)2)107CH2C(CH3)2C6H4O(CH2CH2O)100H), was the key to achieving a stable ordered mesoporous structure even upon crystallization of MgTa2O6 within the mesopore walls. The effect of the calcination temperature on the ability

• photocatalyst access to the target molecules and also possess a high specific surface area. Unfortunately, because of the high crystallization temperature and low decomposition temperature of most commercially available templates, the fabrication of ordered mesoporous MgTa2O6 thin films with crystallized walls

• -developed mesostructure. It has been often stated that the performance of mesoporous metal oxides requires both features to be optimized at the same time, but to the best of our knowledge no systematic study has been performed in the field of photocatalysis. Various oxides with high crystallization

Synthesis and catalytic applications of combined zeolitic/mesoporous materials

• Jarian Vernimmen,
• Vera Meynen and
• Pegie Cool

Beilstein J. Nanotechnol. 2011, 2, 785–801, doi:10.3762/bjnano.2.87

• precursors and the organosilane surfactant avoids the expelling of the surfactant-based mesostructure out of the crystallization of the zeolite phase during the synthesis (Figure 6). The number of publications on these tailor-made surfactants keeps on rising [60][142][143][144][145][146]. Recently, Ryoo and

Approaches to nanostructure control and functionalizations of polymer@silica hybrid nanograss generated by biomimetic silica mineralization on a self-assembled polyamine layer

• Jian-Jun Yuan and
• Ren-Hua Jin

Beilstein J. Nanotechnol. 2011, 2, 760–773, doi:10.3762/bjnano.2.84

• [30], where methanol addition was found to induce the formation of a ribbon structure. The addition of LPEI-dissolving methanol delays the crystallization process and this slow crystallization is beneficial for the formation of crystals with increased size. Moreover, we also developed a methanol

• would induce a relatively faster crystallization of LPEI in the thin film, leading to the formation of crystalline LPEI aggregates with decreased size and networklike structure between the nanounits. This room-temperature process for both LPEI matrix formation and silica deposition is important, because

Lifetime analysis of individual-atom contacts and crossover to geometric-shell structures in unstrained silver nanowires

• Christian Obermair,
• Holger Kuhn and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2011, 2, 740–745, doi:10.3762/bjnano.2.81

• contacts are formed, corresponding to only one or two atoms in their cross-sectional area. With increasing contact radius the conductance is dominated by the building of electronic shells, and finally the bulk crystallization leads to the dominance of geometric shells. Our experimental data are in

Nanostructured, mesoporous Au/TiO₂ model catalysts – structure, stability and catalytic properties

• Matthias Roos,
• Dominique Böcking,
• Kwabena Offeh Gyimah,
• Gabriela Kucerova,
• Joachim Bansmann,
• Johannes Biskupek,
• Ute Kaiser,
• Nicola Hüsing and
• R. Jürgen Behm

Beilstein J. Nanotechnol. 2011, 2, 593–606, doi:10.3762/bjnano.2.63

• maximum at 2Θ = 1.35, indicating repeating unit distances of 6.54 nm (data not shown). Upon calcination, the material crystallized and anatase nanocrystallites formed at temperatures above 350 °C; crystallization was completed with increasing temperature (600 °C). Further heat treatment resulted in the

• formation of the thermodynamically stable polymorph rutile, with complete transformation from anatase to rutile at about 1000 °C (cf. Figure 3). Concomitantly with crystallization, the organized mesopore system collapsed during the heat treatment as expected when structure-directing agents, such as Pluronic

Plasmonic nanostructures fabricated using nanosphere-lithography, soft-lithography and plasma etching

• Manuel R. Gonçalves,
• Taron Makaryan,
• Fabian Enderle,
• Stefan Wiedemann,
• Alfred Plettl,
• Othmar Marti and
• Paul Ziemann

Beilstein J. Nanotechnol. 2011, 2, 448–458, doi:10.3762/bjnano.2.49

• an acrylic glass container of 1.25 cm3 volume. The cold sides of two Peltier elements were attached to the upper and lower sides of the sample container. By applying adequate currents the rate of evaporation was reduced and the crystallization of the beads occurred, mostly forming monolayers with

• areal extents up to 1 cm2. The number of vacancies and dislocations of the colloidal crystal increased as the size of the beads decreased. For beads of 3 μm size, single crystals of several mm2 were usually obtained. The evaporation of the water and full crystallization takes up to 6 h. Epoxy resin

Recrystallization of tubules from natural lotus (Nelumbo nucifera) wax on a Au(111) surface

• Sujit Kumar Dora and
• Klaus Wandelt

Beilstein J. Nanotechnol. 2011, 2, 261–267, doi:10.3762/bjnano.2.30

• similar surface properties. Results Figure 1 shows a series of AFM images of wax growth on the Au(111) surface. A video sequence of all the images taken during scanning, which demonstrates the representative wax crystallization process on Au(111), is available in Supporting Information File 1. As for

• we would also like to refer to the orientation of wax tubules found in previous studies of the self-assembly of natural nonacosan-10-ol wax on different substrates. Jetter and co-workers [2] showed that substrate polarity and roughness play no role in tubule crystallization by demonstrating a

• applied onto the central part of both the Au(111) and a HOPG surface. The total area of wax crystallization was about 20 mm2 for both substrates. The chloroform took ca. 30 seconds to evaporate from the surface leaving the wax molecules on the substrate. The substrates were then fixed to the AFM stainless

Hierarchically structured superhydrophobic flowers with low hysteresis of the wild pansy (Viola tricolor) – new design principles for biomimetic materials

• Anna J. Schulte,
• Damian M. Droste,
• Kerstin Koch and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2011, 2, 228–236, doi:10.3762/bjnano.2.27

• ], was used. In this method a sample–droplet (glycerol–water mixture of 1:3) complex was frozen with liquid nitrogen. A water–glycerol mixture was used as the liquid to prevent crystallization patterns on the droplet surface, which occur on pure water droplets. After this the sample was separated from

Detection of interaction between biomineralising proteins and calcium carbonate microcrystals

• Hanna Rademaker and
• Malte Launspach

Beilstein J. Nanotechnol. 2011, 2, 222–227, doi:10.3762/bjnano.2.26

• %. Thus, the protocol used for crystallization produced different polymorphs with reasonable purities. Determination of the specific surface area of aragonite and calcite by evaluation of light microscopy images and gas adsorption (BET method, see, e.g., [4]) both showed a roughly ten times larger

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

• patterns with marked differences (Supporting Information File 2 for XRD diffractograms). This process leads to the formation of mixed oxides whose crystallite size depends on their crystallization rate [9][10][11][12][27][28]. For instance, NiO and MgO oxides, from Mg–Al and Ni–Al calcined HTs, have a

Synthesis of LiNbO₃ nanoparticles in a mesoporous matrix

• Anett Grigas and
• Stefan Kaskel

Beilstein J. Nanotechnol. 2011, 2, 28–33, doi:10.3762/bjnano.2.3

• present work, we investigated a rapid and efficient one-step route for the direct IR-accelerated synthesis of LiNbO3 nanopowders using an ordered mesoporous silica SBA-15 as the template, in combination with an IR furnace for the crystallization. The matrix stabilizes the nanoparticles against sintering

• while the heat treatment promotes crystallization. For material tailoring purposes the factors influencing the particle size under the reaction conditions on the size of the nanoparticles were considered. The IR furnace uses a lamp for indirect heat treatment and the wavelength can be tuned with the

• located close to the sample. Results and Discussion In general for the preparation of LiNbO3, SBA-15 was impregnated with a solution containing LiNO3 and NH4NbO(C2O4)2·xH2O. Crystallization was carried out in air using an IR furnace IRF 10 (Behr) in the temperature range 750–1000 °C (see Experimental

Single-pass Kelvin force microscopy and dC/dZ measurements in the intermittent contact: applications to polymer materials

• Sergei Magonov and
• John Alexander

Beilstein J. Nanotechnol. 2011, 2, 15–27, doi:10.3762/bjnano.2.2

• evaporation of the solvent and crystallization of PVDF. Therefore, dendritic structures observed on film surface represent crystalline PVDF. The dark surface potential contrast of the structures is consistent with the presence of a molecular dipole (~2.1 V) in this polymer and the preferential orientation of

Enhanced visible light photocatalysis through fast crystallization of zinc oxide nanorods

• Sunandan Baruah,
• Mohammad Abbas Mahmood,
• Myo Tay Zar Myint,
• Tanujjal Bora and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2010, 1, 14–20, doi:10.3762/bjnano.1.3

• observed with engineered defects in ZnO crystals achieved by fast crystallization during synthesis of the nanoparticles [20]. Results from photocatalysis experiments carried out using ZnO nanoparticles prepared through a slow growth process (3 h hydrolysis at 60 °C) and rapid crystallization (7 min under

• microwave irradiation) have already been reported in a previous publication [20]. A higher optical absorption in the visible region was observed in this case. The faster degradation of methylene blue (MB) in the presence of nonstoichiometric crystallites of ZnO prepared through fast crystallization can be

• crystallization temperatures, homogenous nucleation and fast supersaturation by rapid dissolution [22][23][24][25][26][27]. In this work a study is conducted on the improvement of visible light photocatalytic degradation of a model organic dye, methylene blue, with ZnO nanorods grown by a rapid growth process