Mesoporous cerium oxide nanospheres for the visible-light driven photocatalytic degradation of dyes

• Subas K. Muduli,
• Songling Wang,
• Shi Chen,
• Chin Fan Ng,
• Cheng Hon Alfred Huan,
• Tze Chien Sum and
• Han Sen Soo

Beilstein J. Nanotechnol. 2014, 5, 517–523, doi:10.3762/bjnano.5.60

• , Singapore 138632 Energy Research Institute @ NTU (ERI@N), 1 CleanTech Loop, Singapore 637141 Singapore-Berkeley Research Initiative for Sustainable Energy (SinBeRISE), 1 Create Way, Singapore 138602 10.3762/bjnano.5.60 Abstract A facile, solvothermal synthesis of mesoporous cerium oxide nanospheres is

• photoelectron and UV–vis spectroscopy, and transmission electron microscopy. Together with N2 sorption experiments, the data confirms that the new cerium oxide material is mesoporous and absorbs visible light. The photocatalytic degradation of rhodamin B is investigated with a series of radical scavengers

• , suggesting that the mechanism of photocatalytic activity under visible-light irradiation involves predominantly hydroxyl radicals as the active species. Keywords: cerium oxide; dye degradation; mesoporous; photocatalysis; visible light; Introduction The degradation of organic pollutants by affordable and

A catechol biosensor based on electrospun carbon nanofibers

• Dawei Li,
• Zengyuan Pang,
• Xiaodong Chen,
• Lei Luo,
• Yibing Cai and
• Qufu Wei

Beilstein J. Nanotechnol. 2014, 5, 346–354, doi:10.3762/bjnano.5.39

• water samples. Keywords: biosensor; carbon nanofibers; catechol; electrospinning; laccase; Introduction Nowadays, carbon nanomaterials attract a great deal of attention due to their high surface area, excellent electronic conduction and biocompatibility. Among these, mesoporous carbon [1][2][3][4][5

Thermal stability and reduction of iron oxide nanowires at moderate temperatures

• Annalisa Paolone,
• Marco Angelucci,
• Stefania Panero,
• Maria Grazia Betti and
• Carlo Mariani

Beilstein J. Nanotechnol. 2014, 5, 323–328, doi:10.3762/bjnano.5.36

• mesoporous silica (SBA-15) synthesized through the sol–gel method. In order to embed the iron oxide nanowires, 0.01 M Fe(NO3)3·9H2O was dissolved in 50 mL of ethanol and added to 1 g of SBA-15. This solution was mixed at room temperature, dried at 310 K for 1 week, and the resulting powder was sintered at

Modeling and optimization of atomic layer deposition processes on vertically aligned carbon nanotubes

• Nuri Yazdani,
• Vipin Chawla,
• Eve Edwards,
• Vanessa Wood,
• Hyung Gyu Park and
• Ivo Utke

Beilstein J. Nanotechnol. 2014, 5, 234–244, doi:10.3762/bjnano.5.25

• guidelines; titania, TiO2; Introduction Recent advances in the synthesis and processing of carbon nanotubes (CNTs) have enabled the prospect of their integration into existing technologies that exploit the high surface area of mesoporous ceramic films [1]. Over the last 10 years, ceramic coated CNTs have

Study of mesoporous CdS-quantum-dot-sensitized TiO₂ films by using X-ray photoelectron spectroscopy and AFM

• Mohamed N. Ghazzal,
• Robert Wojcieszak,
• Gijo Raj and
• Eric M. Gaigneaux

Beilstein J. Nanotechnol. 2014, 5, 68–76, doi:10.3762/bjnano.5.6

• Bruxelles 61 - 5000 Namur, Belgique Institute of Chemistry, University of Sao Paulo, USP, São Paulo, 05508-000, SP, Brazil 10.3762/bjnano.5.6 Abstract CdS quantum dots were grown on mesoporous TiO2 films by successive ionic layer adsorption and reaction processes in order to obtain CdS particles of various

• effects [9][11][12][13]. In this study, X-ray photoelectron spectroscopy (XPS) was used for the first time, to the best of our knowledge, to estimate the particle size of QDs-CdS grown on a mesoporous TiO2 film. The successive ionic layer adsorption and reaction processes, which are defined as deposition

• preparation Mesoporous TiO2 films were prepared following the procedure reported elsewhere [14]. An adequate amount of titanium(IV) tetraethoxide (TEOT, Ti(OC2H5)4, 95% Aldrich) was dissolved under vigourous stirring (20 min) in concentrated hydrochloric acid (37%) at room temperature. In parallel, the hybrid

Design criteria for stable Pt/C fuel cell catalysts

• Josef C. Meier,
• Carolina Galeano,
• Ioannis Katsounaros,
• Jonathon Witte,
• Hans J. Bongard,
• Angel A. Topalov,
• Claudio Baldizzone,
• Stefano Mezzavilla,
• Ferdi Schüth and
• Karl J. J. Mayrhofer

Beilstein J. Nanotechnol. 2014, 5, 44–67, doi:10.3762/bjnano.5.5

• ], nanohorns [29], ordered mesoporous carbons (OMCs) [30][31], carbon aerogels [32], carbon shells [33][34][35][36], colloid-imprinted carbon supports (CIC) [37] and even boron-doped diamond structures [38][39]. Alternatively, certain non-carbon materials (e.g., oxides, carbides and nitrides of metals such as

• and support structure on the underlying degradation mechanisms. The hollow graphitic spheres (HGS) provide a mesoporous, three-dimensional interconnected support structure with a high degree of graphitization and a high BET surface area (ca. 1200 m2·g−1) at the same time. The synthesis was described

• 360 nm with an average shell thickness of approximately 50 nm. The mesoporous network is intended to provide a good separation and encapsulation of the particles without losing accessibility to the Pt particles. The access is also facilitated by the short diffusion pathways through the shell, 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

• , which are indicative of the mesoporous nature of nanotubes and nanoribbons. The BET specific surface areas of the silica nanotubes and nanoribbons were calculated to be 307 m2/g (run 1 in Table 1) and 404 m2/g (run 2 in Table 1), respectively. Barrett–Joyner–Halenda (BJH) calculations derived from the

• 3.5 nm, which corresponds to the hollow inner of nanotube (Figure 2B) [38][39], which is in good agreement with the TEM observations (Figure 1C). This BET result indicates that our silica nanotubes have an excellent thermal stability compared to the conventional mesoporous silica (i.e., M41S), which

A facile synthesis of a carbon-encapsulated Fe₃O₄ nanocomposite and its performance as anode in lithium-ion batteries

• Raju Prakash,
• Katharina Fanselau,
• Shuhua Ren,
• Tapan Kumar Mandal,
• Christian Kübel,
• Horst Hahn and
• Maximilian Fichtner

Beilstein J. Nanotechnol. 2013, 4, 699–704, doi:10.3762/bjnano.4.79

• an H3-type hysteresis loop (Figure 3), which indicates a mesoporous (pore width < 50 nm) nature of the material [21]. In addition, a sharp increase of the adsorbed gas at very low relative-pressures suggesting the presence of micropores (pore width < 2 nm). The micro- and mesoporous volumes were

Site-selective growth of surface-anchored metal-organic frameworks on self-assembled monolayer patterns prepared by AFM nanografting

• Tatjana Ladnorg,
• Alexander Welle,
• Stefan Heißler,
• Christof Wöll and
• Hartmut Gliemann

Beilstein J. Nanotechnol. 2013, 4, 638–648, doi:10.3762/bjnano.4.71

• -dimensional micro- and mesoporous materials that consist of metal ions or metal-oxo units (serving as nodes) interconnected by organic linkers. In conventional synthesis the MOFs are formed in a solvothermal process, and the reaction products precipitate in the form of crystalline powders [1][2]. One of the

AFM as an analysis tool for high-capacity sulfur cathodes for Li–S batteries

• Renate Hiesgen,
• Seniz Sörgel,
• Rémi Costa,
• Linus Carlé,
• Ines Galm,
• Natalia Cañas,
• Brigitta Pascucci and
• K. Andreas Friedrich

Beilstein J. Nanotechnol. 2013, 4, 611–624, doi:10.3762/bjnano.4.68

• use of highly ordered mesoporous carbon with a bimodal pore structure with a high specific area and a large pore volume is beneficial. It traps a part of the polysulfides for a certain time before release, thereby reduces the electrochemical irreversibility and can lead to a very high and stable

A nano-graphite cold cathode for an energy-efficient cathodoluminescent light source

• Alexander N. Obraztsov,
• Victor I. Kleshch and
• Elena A. Smolnikova

Beilstein J. Nanotechnol. 2013, 4, 493–500, doi:10.3762/bjnano.4.58

• stability of the FE process is stems from the weak interaction between these atomic layers, which lead to their splitting and detachment under the action of the strong electric field. This problem is essentially eliminated in mesoporous nano-graphite film (NGF) material obtained by chemical vapor deposition

• lamps were manufactured by using cold nano-graphite cathodes. NGF films produced by plasma enhanced CVD consist of a mesoporous graphite flaky material. Each flake is a well ordered graphite crystallite of nanometer thickness, composed of graphene atomic layers, oriented predominantly in the direction

• tip. Typical SEM images of NGF material taken with different magnifications: overview of the mesoporous structure of the film (A) and a fragment of a flake transparent for secondary electrons taken with a higher resolution (B). HRTEM image of the top-edge fragment of the graphite flake extracted from

Photoelectrochemical and Raman characterization of In₂O₃ mesoporous films sensitized by CdS nanoparticles

• Mikalai V. Malashchonak,
• Sergey K. Poznyak,
• Eugene A. Streltsov,
• Anatoly I. Kulak,
• Olga V. Korolik and
• Alexander V. Mazanik

Beilstein J. Nanotechnol. 2013, 4, 255–261, doi:10.3762/bjnano.4.27

• , Minsk 220072, Belarus 10.3762/bjnano.4.27 Abstract The method of successive ion layer adsorption and reaction was applied for the deposition of CdS nanoparticles onto a mesoporous In2O3 substrate. The filling of the nanopores in In2O3 films with CdS particles mainly occurs during the first 30 cycles of

• , Ag2S, Bi2S3 and others) immobilized onto the surface of mesoporous films of wide-bandgap oxides (TiO2, ZnO, SnO2, Nb2O5, Ta2O5, WO3, In2O3) are used as the sensitizing components [2][3][4][5]. It is considered that the best technique for the in situ deposition of such nanoparticles is the successive

• -induced charge-carriers at the sensitizer, (b) a wide-bandgap oxide interface that is mainly determined by the difference ELUMO − Ec, as well as (c) on the further transport of the charge carriers through the mesoporous oxide matrix to the substrate. Previous investigations have demonstrated that, in

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

• aligned CNTs from acetylene chemical vapor deposition (CVD) catalyzed by iron nanoparticles embedded in mesoporous silica. In that work, the growth direction of not very straight, entangled-CNTs was related to the direction of the pores in the silica substrate, being perpendicular to the substrate surface

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

• with earlier proposals for Ag-contaminated submicron-size Au nanoparticles [34] and highly active mesoporous oxide-supported AuAg catalysts [35][36]. From calculations based on density functional theory, Moskaleva et al. found a significant reduction of the barrier for O2 dissociation in the vicinity

Physics, chemistry and biology of functional nanostructures

• Paul Ziemann and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2012, 3, 843–845, doi:10.3762/bjnano.3.94

• , in turn, stands alongside previous series. Of special interest appear those reports dealing with self-assembly on solid surfaces, micro- and mesoporous solids, electrical transport through nanostructures, nanooptical aspects, organic–inorganic hybrids and properties of magnetic nanoparticles. A much

A facile approach to nanoarchitectured three-dimensional graphene-based Li–Mn–O composite as high-power cathodes for Li-ion batteries

• Wenyu Zhang,
• Yi Zeng,
• Chen Xu,
• Ni Xiao,
• Yiben Gao,
• Lain-Jong Li,
• Xiaodong Chen,
• Huey Hoon Hng and
• Qingyu Yan

Beilstein J. Nanotechnol. 2012, 3, 513–523, doi:10.3762/bjnano.3.59

• the practical capacity of the material. On the other hand, promising progress in the modification of micro/nanostructures of LMO has been made [10][11][12][13]. Ordered mesoporous LMO, created by using silica templates, favors rapid kinetics for both lithium ions and electron transport, which show

FTIR nanobiosensors for Escherichia coli detection

• Stefania Mura,
• Gianfranco Greppi,
• Maria Laura Marongiu,
• Pier Paolo Roggero,
• Sandeep P. Ravindranath,
• Lisa J. Mauer,
• Nicoletta Schibeci,
• Francesco Perria,
• Massimo Piccinini,
• Plinio Innocenzi and
• Joseph Irudayaraj

Beilstein J. Nanotechnol. 2012, 3, 485–492, doi:10.3762/bjnano.3.55

• necessary to improve the safety of our food supply chain. In this work we report on mesoporous titania thin-film substrates as sensors to detect E. coli O157:H7. Titania films treated with APTES ((3-aminopropyl)triethoxysilane) and GA (glutaraldehyde) were functionalized with specific antibodies and the

• −1. The final calcination process to remove the organic template of these stabilized coatings was conducted at 350 °C for 3.5 h in air under static conditions at a heating rate of 10 °C·min−1. In this way mesoporous titania thin films were obtained and characterized as described in a previous work of

• films were collected. Some tests with E. coli K12 were carried out to monitor the selectivity of the device. Film characterization Mesoporous titania thin films were characterized with a Nicolet Nexus FTIR spectrophotometer equipped with a KBr–DTGS detector and a KBr beam splitter. The measurements were

Distribution of functional groups in periodic mesoporous organosilica materials studied by small-angle neutron scattering with in situ adsorption of nitrogen

• Monir Sharifi,
• Dirk Wallacher and
• Michael Wark

Beilstein J. Nanotechnol. 2012, 3, 428–437, doi:10.3762/bjnano.3.49

• Center (BENSC), Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany 10.3762/bjnano.3.49 Abstract Periodic mesoporous materials of the type (R′O)3Si-R-Si(OR′)3 with benzene as an organic bridge and a crystal-like periodicity within the pore walls were

• employed, from the loss of the mesoporous structure due to a lack of optimum micelle formation with the increase in the organic/functional loadings [4]. In addition the wide application of grafting for the modification of Si-MCM-41 materials is hindered due to the lack of reactive centers apart from the OH

• -groups (silanol groups) present on the inner surface [3]. Therefore periodic mesoporous organosilicas (PMOs) have attracted much attention in scientific and technological research since their discovery in 1999 by three independent groups [5][6][7]. PMO materials directly form hybrid organic–inorganic

Reduced electron recombination of dye-sensitized solar cells based on TiO₂ spheres consisting of ultrathin nanosheets with [001] facet exposed

• Hongxia Wang,
• Meinan Liu,
• Cheng Yan and
• John Bell

Beilstein J. Nanotechnol. 2012, 3, 378–387, doi:10.3762/bjnano.3.44

• mesoporous structure. The average thickness of the TiO2 film was 13 μm. TiCl4 post-treatment of the TiO2 film was carried out by immersing the sintered film in TiCl4 aqueous solution (40 mM) at 70 °C for 30 min. The film was washed with distilled water thoroughly and blow dried with N2 gas. The film was then

• process between electrons at the Pt electrode and I3− ions of the electrolyte, RPt. Zw is the Warburg resistance arising from the ion transport in the electrolyte and Ztl is a distribution line describing the electron transport and recombination in the mesoporous TiO2 film [13][16]. A typical EIS spectrum

• ]. The charge distribution, g(E), in a mesoporous TiO2 film is described by [18][19]: where nEF is the quasi Fermi level of TiO2, Ec the conduction band of TiO2, EF,redox the potential energy of the redox couple, Nt,0 the total density of the trapped electrons, kB is the Boltzmann constant and T0 the

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

• -35392 Giessen, Germany 10.3762/bjnano.3.13 Abstract Ordered mesoporous, crystalline MgTa2O6 thin films with a mesoscopic nanoarchitecture were synthesized by evaporation-induced self-assembly (EISA) in combination with a sol–gel procedure. Utilization of novel templates, namely the block copolymers KLE

• (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

• of the mesoporous films to assist the photodegradation of rhodamine B in water was studied. As a result, two maxima in the photocatalytic activity were identified in the calcination temperature range of 550–850 °C, peaking at 700 °C and 790 °C, and the origin of this was investigated by using

Self-assembled monolayers and titanium dioxide: From surface patterning to potential applications

• Yaron Paz

Beilstein J. Nanotechnol. 2011, 2, 845–861, doi:10.3762/bjnano.2.94

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

• mesoporous materials with intrinsic zeolitic features. These materials are thought to be superior, because they are able to combine (i) the enhanced diffusion and accessibility for larger molecules and viscous fluids typical of mesoporous materials with (ii) the remarkable stability, catalytic activity and

• selectivity of zeolites. This review gives an overview of the state of the art concerning combined zeolitic/mesoporous materials. Focus is put on the synthesis and the applications of the combined zeolitic/mesoporous materials. The different synthesis approaches and formation mechanisms leading to these

• materials are comprehensively discussed and compared. Moreover, Ti-containing nanoporous materials as redox catalysts are discussed to illustrate a potential implementation of combined zeolitic/mesoporous materials. Keywords: catalysis; characterization; combined zeolitic/mesoporous materials; synthesis

Micro- and mesoporous solids: From science to application

• Jörg J. Schneider

Beilstein J. Nanotechnol. 2011, 2, 774–775, doi:10.3762/bjnano.2.85

• decades especially, mesoporous materials having pore dimensions between 2 and approximately 50 nm have emerged, and this group has established itself as an important class of solid-state materials with a huge and still constantly growing number of new congeners with pores on the nano- to mesoscale. These

• can be broadly classified into inorganic, organic and metal–organic types. Nevertheless, hybrids of these compositions have even been realized, extending the diversity in the chemical composition of such mesoporous solids further still. Besides their different chemical composition, the pore morphology

• , geometry and pore dimensions make these materials outstanding with respect to, e.g., catalytic reaction processes, in the area of sensorics, photonics and gas storage (Figure 1). In the realm of gas storage, mesoporous metal–organic frameworks (MOFs) appeared on the scene a couple of years ago and have

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

• model catalysts consisting of a thin mesoporous TiO2 film of 200–400 nm thickness with Au nanoparticles, with a mean particle size of ~2 nm diameter, homogeneously distributed therein. The systems were prepared by spin-coating of a mesoporous TiO2 film from solutions of ethanolic titanium

• and catalytic properties of ultra-thin Au/TiO2 catalyst films, which were prepared by spin-coating a thin film of mesoporous TiO2 of 200–400 nm thickness on a flat Si(100) substrate and subsequent loading with Au nanoparticles. After describing the experimental procedures, we first present

• catalysts based on highly dispersed mesoporous TiO2 supports [33]. From the ICP–OES analysis of the Au/TiO2 catalyst material (cast in the Petri dishes) we derived a Au content of 2.7 wt %. This is in the range of Au contents typical for realistic supported Au catalysts [25][34]. XPS measurements of the

Inorganic–organic hybrid materials through post-synthesis modification: Impact of the treatment with azides on the mesopore structure

• Miriam Keppeler,
• Jürgen Holzbock,
• Johanna Akbarzadeh,
• Herwig Peterlik and
• Nicola Hüsing

Beilstein J. Nanotechnol. 2011, 2, 486–498, doi:10.3762/bjnano.2.52

• strong influence on the structure in the mesoporous regime, with changes such as an increase of mesopore diameter, pore volume and lattice constants, as well as a concomitant decrease of the pore wall thickness, as confirmed by small angle X-ray scattering, transmission electron microscopy, and nitrogen

• solvent (N,N-dimethylformamide, 1,1,3,3-tetramethylurea, 1,3-dimethyl-2-imidazolidinone) or a protic solvent that can form hydrogen bonds, such as water, was used. Keywords: inorganic–organic hybrid materials; mesoporous materials; nucleophilic substitution; silica; sol–gel chemistry; Introduction

• with selectivity provided by meso- or micropores. This is especially true for materials with uniform pore size distributions in the mesoporous (2–50 nm) and/or macroporous regime (>50 nm) [1][2][3]. A powerful tool in the preparation of stable, mesoscopically organized materials that are characterized