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

• range order in LiBH4 confined in 2–4 nm pores in nanoporous carbon is connected to the reduction of the barriers for the rotational motion of BH4− anions and the high- temperature behavior even at temperatures well below the bulk Tc [63]. The experimental insight to the properties of nano-confined LiBH4

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

• , 13397 Marseille, France Department of Physics, University of Central Florida, Orlando, FL 32816, USA 10.3762/bjnano.6.32 Abstract In this work a novel process allowing for the production of nanoporous Ge thin films is presented. This process uses the combination of two techniques: Ge sputtering on SiO2

• different nature in the material (vacancy, dislocation, amorphization, etc.). High-dose implantations in Ge (>1015 atoms/cm2) have been reported to induce the formation of nanoporous structures [16][17][18][19][20][21][22][23][24][25]. Thus, ion implantation may be a simple way to produce a nanoporous

• ), (ii) holes with an average lateral size of ≈100 nm, and (iii) a nanoporous structure exhibiting pores with an average lateral size of ≈35 nm. The same three types of defects are observed in all the three sets of samples. The average size and the density of these defects are reported in Table 1. An

Poly(styrene)/oligo(fluorene)-intercalated fluoromica hybrids: synthesis, characterization and self-assembly

• Giuseppe Leone,
• Francesco Galeotti,
• William Porzio,
• Guido Scavia,
• Luisa Barba,
• Gianmichele Arrighetti,
• Giovanni Ricci,
• Chiara Botta and
• Umberto Giovanella

Beilstein J. Nanotechnol. 2014, 5, 2450–2458, doi:10.3762/bjnano.5.254

• of the keto-defects green emission band, peaked at around 530 nm, at the expense of the initial blue emission. In the flat PT15 film the contribution of keto-defects emission is almost suppressed and the decrease of PL intensity is slower (Figure 6c) with respect to neat TF film. In the nanoporous

Synthesis and characterization of fluorescence-labelled silica core-shell and noble metal-decorated ceria nanoparticles

• Rudolf Herrmann,
• Markus Rennhak and
• Armin Reller

Beilstein J. Nanotechnol. 2014, 5, 2413–2423, doi:10.3762/bjnano.5.251

• metallic catalysts. For automobile catalytic converters meso- or nanoporous ceria or alumina is used as washcoat (on which the noble metal catalysts are deposited) for cordierite, the latter supplying the required mechanical strength. Here the oxygen storage capacity of CeO2 improves the performance of the

Biopolymer colloids for controlling and templating inorganic synthesis

• Laura C. Preiss,
• Katharina Landfester and
• Rafael Muñoz-Espí

Beilstein J. Nanotechnol. 2014, 5, 2129–2138, doi:10.3762/bjnano.5.222

• . Reprinted with permission from [87]. Copyright 2008 John Wiley & Sons. Schematic representation of aerogel preparation. A nanoporous cellulose gel is impregnated with the silica precursor TEOS (a). Afterwards, the silica formation takes place by sol–gel process (hydrolysis and condensation), yielding a

Liquid fuel cells

• Grigorii L. Soloveichik

Beilstein J. Nanotechnol. 2014, 5, 1399–1418, doi:10.3762/bjnano.5.153

• is a four-electron process, which corresponds to the formation of glycolic acid, a major product determined by chromatography (GCMS) [100]. An acidic EG fuel cell using a 100 µm nanoporous proton-conducting membrane and a Pt–Ru anode catalyst demonstrated a peak power density of 300 mW/cm2 for the

• high OCV (1.75) V and showed a very high peak power density (1.02 W/cm2 at 80 °C) [161]. A higher temperature improves the performance of the cathode but has little effect on the anode [161]. An electrocatalyst consisting of dealloyed nanoporous gold leaves demonstrated activities toward both hydrazine

• towards hydrolysis turned out to be more efficient catalysts than platinum. Thiourea, a known hydrogen evolution inhibitor, was also used as an additive to increase the coulombic efficiency [181]. Nanoporous gold electrodes prepared by extracting Ag from an AgAu alloy catalyze the oxidation of AB at a

Nanoporous composites prepared by a combination of SBA-15 with Mg–Al mixed oxides. Water vapor sorption properties

• Amaury Pérez-Verdejo,
• Alvaro Sampieri,
• Heriberto Pfeiffer,
• Mayra Ruiz-Reyes,
• Juana-Deisy Santamaría and
• Geolar Fetter

Beilstein J. Nanotechnol. 2014, 5, 1226–1234, doi:10.3762/bjnano.5.136

• -synthesis method, produces a composite material with Mg–Al mixed oxides homogeneously dispersed on the SBA-15 nanoporous surface. The resulting composites present textural properties similar to the SBA-15. On the other hand, with the second procedure (in situ method), Mg and Al mixed oxides occur on the

• might be utilized as as acid-base catalysts, adsorbents, sensors or storage nanomaterials. Keywords: calcined Mg–Al hydrotalcite; nanoporous composites; SBA-15; vapor sorption; Introduction Multifunctional nanomaterials are designed to satisfy specific ranged sets of performance requirements. The

• 40 °C to 55 °C (equilibrium temperature). Therefore, the smaller pore size causes slow water diffusion. Conclusion Nanoporous composites were obtained from combinations of Mg–Al precursors of a hydrotalcite with SBA-15. The post-synthesis method is a simple and effective way to prepare composites

Organic and inorganic–organic thin film structures by molecular layer deposition: A review

• Pia Sundberg and
• Maarit Karppinen

Beilstein J. Nanotechnol. 2014, 5, 1104–1136, doi:10.3762/bjnano.5.123

Functionalized nanostructures for enhanced photocatalytic performance under solar light

• Liejin Guo,
• Dengwei Jing,
• Maochang Liu,
• Yubin Chen,
• Shaohua Shen,
• Jinwen Shi and
• Kai Zhang

Beilstein J. Nanotechnol. 2014, 5, 994–1004, doi:10.3762/bjnano.5.113

• hydrogen production. Both CuGa2In3S8 (1.91 eV) and AgGa2In3S8 (2.27 eV) showed a quite high photocatalytic activity [62]. Chen and co-workers synthesized hierarchical ZnS–In2S3–CuS nanospheres with a nanoporous structure. A high QE of 22.6% at 420 nm is achieved without loading cocatalysts due to their

Nanostructure sensitization of transition metal oxides for visible-light photocatalysis

• Hongjun Chen and
• Lianzhou Wang

Beilstein J. Nanotechnol. 2014, 5, 696–710, doi:10.3762/bjnano.5.82

• photosensitization of nanoporous titanium dioxide, zinc oxide, tin dioxide, niobium oxide, and tantalum oxide by quantum-sized cadmium sulfide, lead sulfide, silver sulfide, antimony sulfide, and bismuth sulfide. They found that the photocurrent quantum yields of these photosensitized transition metal oxides can be

• [59][60][61][62][63], photocatalytic water splitting [64][65] photoelectrochemical water splitting [66][67][68][69][70][71][72], photocatalytic conversion of CO2 with H2O to hydrocarbon fuels [73], and degradation of organic molecules [74]. In 2004, Tatsuma et al. reported that nanoporous TiO2 films

Nanoscale patterning of a self-assembled monolayer by modification of the molecule–substrate bond

• Cai Shen and
• Manfred Buck

Beilstein J. Nanotechnol. 2014, 5, 258–267, doi:10.3762/bjnano.5.28

• reductive desorption of the less tightly bound thiol molecules in the UPD-free Au areas to yield either nanoporous SAMs or binary SAMs in the case of backfilling with a second type of thiol [11]. So far, however, this approach has been lacking control as UPD is mediated by random defects [24][26][27] which

• selective removal of thiols from UPD-free Au areas has been exploited for the generation of nanoporous SAMs [11], the process lacked control as UPD occurred at defects present in the native monolayer. The approach based on the SAMs used here, which perfectly block UPD, allows for the exploitation of this

Atomic layer deposition, a unique method for the preparation of energy conversion devices

• Julien Bachmann

Beilstein J. Nanotechnol. 2014, 5, 245–248, doi:10.3762/bjnano.5.26

• the interface causes transport to become limiting. For this reason, nanostructured interfaces with elongated folds or tubes can result in optimized devices (Figure 2). In this context, any method capable of depositing thin functional layers onto structured substrates, and especially into nanoporous

3D-nanoarchitectured Pd/Ni catalysts prepared by atomic layer deposition for the electrooxidation of formic acid

• Loïc Assaud,
• Evans Monyoncho,
• Kristina Pitzschel,
• Anis Allagui,
• Matthieu Petit,
• Margrit Hanbücken,
• Elena A. Baranova and
• Lionel Santinacci

Beilstein J. Nanotechnol. 2014, 5, 162–172, doi:10.3762/bjnano.5.16

• , University of Ottawa, 161 Louis-Pasteur St., Ottawa, ON, K1N 6N5, Canada 10.3762/bjnano.5.16 Abstract Three-dimensionally (3D) nanoarchitectured palladium/nickel (Pd/Ni) catalysts, which were prepared by atomic layer deposition (ALD) on high-aspect-ratio nanoporous alumina templates are investigated with

• the catalyst, and it provides a high coverage of high aspect ratio nanostructures [21][22][23]. It is therefore possible to precisely design catalysts onto nanoarchitectured supports that exhibit enhanced abilities for fuel cell applications [24][25]. As previously proposed [26], nanoporous anodic

• have been investigated for the electrooxidation of formic acid in 0.5 M H2SO4. The deposition of nickel oxide from NiCp2 and O3 precursors on high aspect ratio nanoporous Al2O3 has been demonstrated. Although the chemical composition analysis of the NiO layers has not shown that the reductive treatment

Constant-distance mode SECM as a tool to visualize local electrocatalytic activity of oxygen reduction catalysts

• Michaela Nebel,
• Thomas Erichsen and
• Wolfgang Schuhmann

Beilstein J. Nanotechnol. 2014, 5, 141–151, doi:10.3762/bjnano.5.14

• , Germany) as background electrolyte. As a model catalyst a commercial nanoporous ORR catalyst from ETEK (Natick, USA) with 20 wt % Pt on Vulcan XC72 was used. An air saturated 0.1 M sodium phosphate buffer (pH 7, VWR International, Darmstadt, Germany) was used for all investigations of the catalytic

Advances in nanomaterials

• Herbert Gleiter,
• Horst Hahn and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2013, 4, 805–806, doi:10.3762/bjnano.4.91

• these contributions is found in this Thematic Series in the form of original research articles reflecting recent advances in nanomaterials. The articles in this Thematic Series highlight recent developments, from nanoporous polymers to graphene quantum dots, from concepts for designing magnetic

Preparation of electrochemically active silicon nanotubes in highly ordered arrays

• Tobias Grünzel,
• Young Joo Lee,
• Karsten Kuepper and
• Julien Bachmann

Beilstein J. Nanotechnol. 2013, 4, 655–664, doi:10.3762/bjnano.4.73

• spectroscopic ellipsometry for thin silica films, and by nuclear magnetic resonance and X-ray photoelectron spectroscopy for nanoporous samples. After removal of the lithium oxide byproduct, the silicon nanotubes can be contacted electrically. In a lithium ion electrolyte, they then display the electrochemical

• waves also observed for other bulk or nanostructured silicon systems. The method established here paves the way for systematic investigations of how the electrochemical properties (capacity, charge/discharge rates, cyclability) of nanoporous silicon negative lithium ion battery electrode materials

• -standing nanoporous oxide membrane. Its mechanical stability is only sufficient for practical purposes if its thickness is beyond 100 µm. Because of the very large aspect ratio of the pores, the ALD SiO2 coating does not reach their lower extremity: in our experimental conditions, the continuous, conformal

Nanoglasses: a new kind of noncrystalline materials

• Herbert Gleiter

Beilstein J. Nanotechnol. 2013, 4, 517–533, doi:10.3762/bjnano.4.61

• surface region of the metal due to an electrochemical double layer at the interface between the electrolyte and the nanoporous metallic material. By means of this induced electric charge, all properties of the nanoporous metal that depend on its electronic structure may be tuned. As multiphase nanoglasses

• –Sc–Cu although these elements are practically immiscible in the crystalline state. Generation of an electrically charged surface in a nanoporous metal (e.g., Au) if it is immersed into a suitable electrolyte (here KOH) and if a voltage is applied between the metal and the electrolyte so that a double

• -layer is formed at the surface of the nanoporous metal [85][86][87]. Reproduced with permission from [86]. Acknowledgements The author gratefully acknowledges the numerous contributions from his colleagues all over the world, in particular from Professors/Drs. Albe, Birringer, Hahn, Fang, Feng, Jiang

Kelvin probe force microscopy of nanocrystalline TiO₂ photoelectrodes

• Alex Henning,
• Gino Günzburger,
• Res Jöhr,
• Yossi Rosenwaks,
• Biljana Bozic-Weber,
• Catherine E. Housecroft,
• Edwin C. Constable,
• Ernst Meyer and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2013, 4, 418–428, doi:10.3762/bjnano.4.49

• ); surface photovoltage (SPV); titanium dioxide (TiO2); Introduction Dye-sensitized solar cells (DSCs) provide a promising low-cost, high-efficiency third-generation photovoltaic concept based on the spectral sensitization of a nanoporous wide bandgap semiconductor [1][2]. In the past two decades DSCs have

• the incident light since the nanoporous TiO2, deposited on top of the FTO-layer, is only about 10 μm thin and transparent to visible light (Eg = 3.2 eV). Due to the high n-dopant density of SnO2:F (ND ~ 1020), it can be approximated to being nearly metallic. Generally, the SnO2:F contact is regarded

• diffusion through the network) is slow (seconds to minutes). A slow response time has also been reported for nanoporous TiO2 [56][57] and for porous Si, which exhibited recombination times of up to 1 h [58]. Microscopic surface-dipole variations By averaging the work function values over several images on

In situ monitoring magnetism and resistance of nanophase platinum upon electrochemical oxidation

• Eva-Maria Steyskal,
• Stefan Topolovec,
• Stephan Landgraf,
• Heinz Krenn and
• Roland Würschum

Beilstein J. Nanotechnol. 2013, 4, 394–399, doi:10.3762/bjnano.4.46

• –electrolyte interface of nanophase materials, the physical material properties may also be changed by electrochemical surface reactions, as for instance documented for nanoporous Au [6]. Based on tunability studies of the electrical resistance of porous nanocrystalline Pt [5] or nanoporous Pt [7] and of the

• charge coefficient in this regime (Figure 4b). It is worth mentioning that, compared to the present case of cluster-assembled porous Pt, the charge-induced resistance variation of nanoporous Pt prepared by electrochemical dealloying in addition showed a sign inversion at high potentials [7]. This

• ], strongly differing surface states may respond rather differently with respect to charging. Regarding dealloyed nanoporous Pt, the sign-inversion of the charge-induced resistance variation was associated with the semiconducting behavior of the partially oxidized surface [7]. The electrochemical tunability

Porous polymer coatings as substrates for the formation of high-fidelity micropatterns by quill-like pens

• Michael Hirtz,
• Marcus Lyon,
• Wenqian Feng,
• Andrea E. Holmes,
• Harald Fuchs and
• Pavel A. Levkin

Beilstein J. Nanotechnol. 2013, 4, 377–384, doi:10.3762/bjnano.4.44

• feature sizes below 50 μm. We showed that the narrow pore size distribution as well as the small average pore size is crucial for achieving high pattern fidelity and reproducibility. Additionally, the three-dimensional morphology in nanoporous substrates like the HEMA polymer films presents a higher

Functionalization of vertically aligned carbon nanotubes

• Eloise Van Hooijdonk,
• Carla Bittencourt,
• Rony Snyders and
• Jean-François Colomer

Beilstein J. Nanotechnol. 2013, 4, 129–152, doi:10.3762/bjnano.4.14

• for the catalysts, which are then deposited by dip or spin coating or, alternatively, are filled into nanoporous architectures serving as templates for the CNT growth. Plasma vapor deposition is an efficient method for the preparation of thin films of metal catalysts with well-defined thicknesses. The

• deposited within the pores of nanoporous templates (for example, anodic aluminum oxide (AAO) membranes) allows design of a wide range of nanostructures with particular geometries, including aligned and monodispersed CNTs [40]. After the catalyst preparation, the next step is the synthesis of the VA-CNTs

• 20 kHz). The peculiarity of this treatment is the extremely brief treatment time (1, 2 or 5 min). Many transport applications (e.g., controlled drug delivery or molecular sensing [92]) require nanoporous membranes with a precise pore diameter, a perfect vertical orientation of the pores and a high

Catalytic activity of nanostructured Au: Scale effects versus bimetallic/bifunctional effects in low-temperature CO oxidation on nanoporous Au

• Lu-Cun Wang,
• Yi Zhong,
• Haijun Jin,
• Daniel Widmann,
• Jörg Weissmüller and
• R. Jürgen Behm

Beilstein J. Nanotechnol. 2013, 4, 111–128, doi:10.3762/bjnano.4.13

• oxidation as a test reaction. In order to distinguish between structural effects (structure–activity correlations) and bimetallic/bifunctional effects, unsupported nanoporous gold (NPG) samples prepared from different Au alloys (AuAg, AuCu) by selective leaching of a less noble metal (Ag, Cu) were employed

• are discussed. Keywords: AuAg alloy; AuCu alloy; CO oxidation; dynamic studies; kinetics; nanoporous Au (NPG) catalyst; oxygen storage capacity (OSC); temporal analysis of products (TAP); Introduction Porous metallic materials with well-controlled morphologies and surface properties have attracted

• considerable attention in both fundamental research and technological applications owing to their unique physical and chemical properties, for applications, e.g., in optics, catalysis or as sensors [1][2]. Among these materials, monolithic gold with nanoporous structures as well as high surface areas is of

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

• approach to enable the selection of device materials and a general framework for the design of advanced sensor platforms. The sensor interface Micro/nanoporous semiconductor surface The design of the semiconductor interfaces that have been used thus far in sensor experiments is illustrated by the porous

• nanoporous coating (green in Figure 1). A hybrid etch procedure is used to create this desired interfacial support structure. It is possible to replace the porous silicon (PS) structure that has been etched into a silicon wafer with any alternate extrinsic III–V (GaP or InP) or II–VI semiconductor (CdTe or

• extrinsic semiconductors, which can be of p, p+, or n-type. The nanopore covered microporous structure is created specifically to facilitate efficient gaseous diffusion (Fickian) [6] to the highly active nanostructure-modified nanoporous coating, that acts to provide a phase matching for the subsequent

Zeolites as nanoporous, gas-sensitive materials for in situ monitoring of DeNO_x-SCR

• Thomas Simons and
• Ulrich Simon

Beilstein J. Nanotechnol. 2012, 3, 667–673, doi:10.3762/bjnano.3.76

• elementary catalytic process promoting a full description of the NH3-SCR reaction system. Keywords: DeNOx-SCR; gas sensing; in situ; impedance spectroscopy; zeolite; Introduction Zeolites are crystalline, nanoporous aluminosilicates composed of [TO4] tetrahedra (T = Si, Al). In H-form zeolites protons

Ordered arrays of nanoporous gold nanoparticles

• Dong Wang,
• Ran Ji,
• Arne Albrecht and
• Peter Schaaf

Beilstein J. Nanotechnol. 2012, 3, 651–657, doi:10.3762/bjnano.3.74

• ) enables fabrication of perfectly ordered 2-dimensional arrays of nanoporous gold nanoparticles. The dewetting of Au/Ag bilayers on the periodically prepatterned substrates leads to the interdiffusion of Au and Ag and the formation of an array of Au–Ag alloy nanoparticles. The array of alloy nanoparticles

• is transformed into an array of nanoporous gold nanoparticles by a following dealloying step. Large areas of this new type of material arrangement can be realized with this technique. In addition, this technique allows for the control of particle size, particle spacing, and ligament size (or pore

• size) by varying the period of the structure, total metal layer thickness, and the thickness ratio of the as-deposited bilayers. Keywords: dealloying; dewetting; nanoimprint lithography; nanoparticles; nanoporous gold; ordered arrays; Introduction Metallic nanoparticle arrays are attracting more and