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

• coupling with semiconductor materials such as TiO2 [73], ZnO [74], CdS [75], SnO2 [76], CeO2 [77], WO3 [78], Fe2O3 [79], Ag3PO4 [80], Ag3VO4 [81], ZnWO4 [82], SrTiO3 [83], BiVO4 [84], Bi2WO6 [85], BiOX [86][87], etc. These heterojunction formations have proved to be an effective method to improve the

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

• , different types of catalysts including monometallic (e.g., Pt, Pd, Rh, Au, Ni, Co and Sn), bimetallic (e.g., Pd–Au, Pd–Rh, Pt–Co, Cu–Rh, Au–Cu and Au–Ag) along with various types of supports (e.g., CeO2, SiO2, Al2O3, Co3O4, Fe2O3, activated carbon (AC), carbon nanotubes (CNTs) and ZrO2) have been reported

Needs and challenges for assessing the environmental impacts of engineered nanomaterials (ENMs)

• Michelle Romero-Franco,
• Hilary A. Godwin,
• Muhammad Bilal and
• Yoram Cohen

Beilstein J. Nanotechnol. 2017, 8, 989–1014, doi:10.3762/bjnano.8.101

Synthesis of coaxial nanotubes of polyaniline and poly(hydroxyethyl methacrylate) by oxidative/initiated chemical vapor deposition

• Alper Balkan,
• Efe Armagan and
• Gozde Ozaydin Ince

Beilstein J. Nanotechnol. 2017, 8, 872–882, doi:10.3762/bjnano.8.89

• parabolic behavior with the same resistance readings for two different humidity levels is problematic for sensor applications, making the sensor unreliable. In order to modify this parabolic behavior, Parvatikar et al. [34] fabricated PANI/CeO2 composites, whose resistance values decreased linearly as

• humidity increased due to charge transfer between CeO2 and PANI. However, incorporating CeO2 in the polymer decreases flexibility and increases the overall electrical resistance, which may limit the range of applications. Lin et al. [35] fabricated electrospun PANI nanofibers and introduced hydrophilic

Surface improvement of organic photoresists using a near-field-dependent etching method

• Felix J. Brandenburg,
• Tomohiro Okamoto,
• Hiroshi Saito,
• Benjamin Leuschel,
• Olivier Soppera and
• Takashi Yatsui

Beilstein J. Nanotechnol. 2017, 8, 784–788, doi:10.3762/bjnano.8.81

• , there have been efforts to reduce the usage of the rare-earth material CeO2 used in the chemical slurry of CMP [8]. So in order to achieve SR reduction without the use of CMP methods, a novel approach, called near-field etching, has been introduced. This fine-tuning technique has previously proven to be

Investigation of the photocatalytic efficiency of tantalum alkoxy carboxylate-derived Ta₂O₅ nanoparticles in rhodamine B removal

• Subia Ambreen,
• Mohammad Danish,
• Narendra D. Pandey and
• Ashutosh Pandey

Beilstein J. Nanotechnol. 2017, 8, 604–613, doi:10.3762/bjnano.8.65

• and CeO2, serve as potential photocatalysts [1][2][3][4]. The properties of the metal oxide nanoparticles (surface area, band gap, porosity) determine its photocatalytic activity for the degradation of organic pollutants from water. Because of properties such as high refractive index and large band

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

• anthropogenic activities. The catalytic CO oxidation is a very well established and exploited process. So far, noble metals such as Pt, Pd, Rh and Au dominated as catalysts for CO oxidation [10][11][12]. Various supports such as Al2O3, TiO2, SiO2, CeO2, Fe2O3 and carbon nanotubes (CNTs) have also been used for

In situ formation of reduced graphene oxide structures in ceria by combined sol–gel and solvothermal processing

• Jingxia Yang,
• Johannes Ofner,
• Bernhard Lendl and
• Ulrich Schubert

Beilstein J. Nanotechnol. 2016, 7, 1815–1821, doi:10.3762/bjnano.7.174

• –gel processing, by which the rGO structures and the catalytic activity were enhanced. Keywords: ceria; CO oxidation; graphene oxide; sol–gel processing; Introduction Ceria (CeO2) has been widely studied as catalyst or catalyst support for redox reactions owing to its high oxygen storage and release

• capacity. It is mostly used together with other components, such as noble metals or transition metal oxides, such as NiO or Co3O4, because synergistic effects improve the catalytic properties. Graphene-modified CeO2 greatly enhances the performance in electrochemical devices (supercapacitors, fuel cells or

• batteries) [1][2][3][4][5][6][7] or (photo-)catalysts [8][9][10][11][12][13][14][15][16]. The property enhancements are mainly due to the charge transfer between graphene and CeO2. For the preparation of graphene–CeO2 composites external graphene oxide (GO) is usually added to the ceria precursor or pre

High performance Ce-doped ZnO nanorods for sunlight-driven photocatalysis

• Bilel Chouchene,
• Tahar Ben Chaabane,
• Lavinia Balan,
• Emilien Girot,
• Kevin Mozet,
• Ghouti Medjahdi and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2016, 7, 1338–1349, doi:10.3762/bjnano.7.125

• ) crystal planes of wurtzite ZnO (JCPDS No 36-1451). It should also be mentioned that for the highest degrees of doping (5, 7 and 10% in Ce doping), an additional and weak signal corresponding to the (111) diffraction plane of cubic CeO2 could be observed at 2θ = 28.3° (JCPDS No 34-0394), thus indicating

• the partial oxidation of Ce3+ into Ce4+ during the synthesis and the formation of CeO2. To demonstrate the incorporation of Ce3+ or Ce4+ in Zn2+ sites or interstitial sites in the ZnO lattice, the angle shift of the (100), (002) and (101) peaks as a function of doping percentage has been studied. As

• formation of CeO2 was further confirmed by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis. Figure 2 shows the Raman spectra of undoped and Ce-doped ZnO rods excited by the 532 nm line of a YAG laser. The peaks located at 332, 379, and 437 cm−1 can be assigned to 2E2, A1(To), and E2

NanoE-Tox: New and in-depth database concerning ecotoxicity of nanomaterials

• Katre Juganson,
• Angela Ivask,
• Irina Blinova,
• Monika Mortimer and
• Anne Kahru

Beilstein J. Nanotechnol. 2015, 6, 1788–1804, doi:10.3762/bjnano.6.183

• database NanoE-Tox that is available as Supporting Information File 2. The database is based on existing literature on ecotoxicology of eight ENMs with different chemical composition: carbon nanotubes (CNTs), fullerenes, silver (Ag), titanium dioxide (TiO2), zinc oxide (ZnO), cerium dioxide (CeO2), copper

• uptake of ENMs in the organisms. 35% of the data in NanoE-Tox concerns ecotoxicity of Ag NPs, followed by TiO2 (22%), CeO2 (13%), and ZnO (10%). Most of the data originates from studies with crustaceans (26%), bacteria (17%), fish (13%), and algae (11%). Based on the median toxicity values of the most

• sensitive organism (data derived from three or more articles) the toxicity order was as follows: Ag > ZnO > CuO > CeO2 > CNTs > TiO2 > FeOx. We believe NanoE-Tox database contains valuable information for ENM environmental hazard estimation and development of models for predicting toxic potential of ENMs

Simulation tool for assessing the release and environmental distribution of nanomaterials

• Haoyang Haven Liu,
• Muhammad Bilal,
• Anastasiya Lazareva,
• Arturo Keller and
• Yoram Cohen

Beilstein J. Nanotechnol. 2015, 6, 938–951, doi:10.3762/bjnano.6.97

• environmental distributions of TiO2, CeO2, SiO2, and CNT in selected regions. The multimedia distribution of ENMs (use case #1) and the dynamic response of an environmental system to temporal variations of ENM release rate (use case #2) are illustrated for TiO2 in Los Angeles. Due to a lack of transfer

• , Figure S5), indicating that rain scavenging has a more significant impact on the environmental ENM distribution relative to dry deposition. A comparative analysis of the potential environmental ENM concentrations in various countries (use case #4) is given using the example of CeO2 ENMs, whereby release

• rates were estimated via LearNano for 12 selected countries. These countries were selected to represent the high ENM producing (and high emission) regions. The estimated CeO2 release rates (high estimate) for the 12 countries span over the range of 7.2–486 T yr−1 for Chile and China (Figure 12). The

A surface acoustic wave-driven micropump for particle uptake investigation under physiological flow conditions in very small volumes

• Florian G. Strobl,
• Dominik Breyer,
• Phillip Link,
• Adriano A. Torrano,
• Christoph Bräuchle,
• Matthias F. Schneider and
• Achim Wixforth

Beilstein J. Nanotechnol. 2015, 6, 414–419, doi:10.3762/bjnano.6.41

• rates over the whole physiological range in sample volumes as small as 200 μL can be achieved. A precise characterization method for the induced flow profile is presented and the influence of flow on the uptake of Pt-decorated CeO2 particles by endothelial cells (HMEC-1) is demonstrated. Under

• under flow In order to show the relevance of physiological shear conditions for the uptake of nanoparticles in cells and to prove the applicability of our system, we examined the uptake of Pt-decorated CeO2 particles (d = 50 nm) by HMEC-1 cells. The cells were incubated with cell medium containing the

• randomly chosen cells were analyzed at every ROI. Before starting the measurement, the culture medium was exchanged by medium containing Pt-decorated CeO2 particles with a concentration of 100 μg/mL. Cells and particles were then imaged with a spinning disc fluorescence microscope. Finally, the amount of

Morphology, structural properties and reducibility of size-selected CeO_2−x nanoparticle films

• Maria Chiara Spadaro,
• Sergio D’Addato,
• Gabriele Gasperi,
• Francesco Benedetti,
• Paola Luches,
• Vincenzo Grillo,
• Giovanni Bertoni and
• Sergio Valeri

Beilstein J. Nanotechnol. 2015, 6, 60–67, doi:10.3762/bjnano.6.7

• : CeO2 ultra-thin films; ceria nanoparticles; magnetron sputtering; reduction and oxidation; size-dependent properties; size-selected nanoparticles; X-ray photoelectron spectroscopy; Introduction The main property of cerium oxide that attracts scientific attention is its ability to store and release

• in CeO2−x NPs the lattice parameter increases when the particle size is decreased. Tsunekawa et al. [6], analyzing NPs with diameter between 2 nm and 4 nm, suggested that the reduction of the Ce ion charge from 4+ to 3+ leads to an increase of the lattice parameter because of the decrease in the

• due to the presence of Ce3+ ions. Non-stoichiometric NPs grown in this way exhibit a higher catalytic activity than stoichiometric material, mainly because of surface defects and chemisorbed oxygen [13][14]. A new interpretation for the redox activity of CeO2−x NPs has been recently proposed, based on

The fate of a designed protein corona on nanoparticles in vitro and in vivo

• Denise Bargheer,
• Julius Nielsen,
• Gabriella Gébel,
• Markus Heine,
• Sunhild C. Salmen,
• Roland Stauber,
• Horst Weller,
• Joerg Heeren and
• Peter Nielsen

Beilstein J. Nanotechnol. 2015, 6, 36–46, doi:10.3762/bjnano.6.5

• nm) is much smaller than the adsorbent. If the nanoparticle and protein are in the same size, the Langmuir adsorption formalism seems not to be valid. This was discussed by Liu et al. using small CeO2-particles and bovine serum albumin with similar size of 7 nm [36]. The smaller surface free energy

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

• media not exceeding one weak of duration. At 120 °C at ceria NP the dye is completely destroyed within 90 min, the typical conditions for sterilization prior to biological experiments. Oxidic nanoparticles like SiO2, TiO2, CeO2, ZnO and Al2O3 generally contain hydroxy groups at their surface to saturate

• removal of the fluorescence label from the NP [13]. However, we could detect detached dye only after storage of several months in water. There is no change at all on storage in ethanol. Labelling by the APS-derived perylene dyes is possible directly during the synthesis process (for SiO2, CeO2, and ZnO

• groups. A common feature of all dyes which failed is their cationic nature. We therefore think that they have difficulties to pass through the membrane of the micelles formed from (easily deprotonated) 4-dodecylbenzenesulfonic acid. Ceria nanoparticles Ceria (CeO2) NP do not occur in nature but are man

Biocompatibility of cerium dioxide and silicon dioxide nanoparticles with endothelial cells

• Claudia Strobel,
• Martin Förster and
• Ingrid Hilger

Beilstein J. Nanotechnol. 2014, 5, 1795–1807, doi:10.3762/bjnano.5.190

• Medicine and Allergy/Immunology, Jena University Hospital – Friedrich Schiller University Jena, Erlanger Allee 101, 07747 Jena, Germany 10.3762/bjnano.5.190 Abstract Cerium dioxide (CeO2) and silicon dioxide (SiO2) nanoparticles are of widespread use in modern life. This means that human beings are

• markedly exposed to them in their everyday life. Once passing biological barriers, these nanoparticles are expected to interact with endothelial cells, leading to systemic alterations with distinct influences on human health. In the present study we observed the metabolic impact of differently sized CeO2

• (8 nm; 35 nm) and SiO2 nanoparticles (117 nm; 315 nm) on immortalized human microvascular (HMEC-1) and primary macrovascular endothelial cells (HUVEC), with particular focus on the CeO2 nanoparticles. The characterization of the CeO2 nanoparticles in cell culture media with varying serum content

Precise quantification of silica and ceria nanoparticle uptake revealed by 3D fluorescence microscopy

• Adriano A. Torrano and
• Christoph Bräuchle

Beilstein J. Nanotechnol. 2014, 5, 1616–1624, doi:10.3762/bjnano.5.173

• significantly alter the cytotoxicity of these particles on HMEC-1 cells. The primary size of the two nanoparticles was determined through TEM. One particle type has a diameter of 8 nm and is spherical (CeO2-8nm), while the other particle type has a diameter of roughly 30 nm (CeO2-30nm) (ellipsoid of 27 nm × 30

• nm). It has been shown that the smaller the nanoparticles, the stronger the agglomeration [40]. This has been confirmed in the determination of the hydrodynamic diameter of these particles. DLS measurements were carried out and the size of CeO2-8nm increased up to 417 nm in cell medium. In the case

• of the CeO2-30nm particles, the diameter in cell medium was determined to be 316 nm. The zeta potential was also assessed in cell medium: −11.3 mV for the 8 nm particles and −12.3 mV for the 30 nm particles. The same procedure described for the silica nanoparticles in the previous section was used to

Template-directed synthesis and characterization of microstructured ceramic Ce/ZrO₂@SiO₂ composite tubes

• Jörg J. Schneider and
• Meike Naumann

Beilstein J. Nanotechnol. 2014, 5, 1152–1159, doi:10.3762/bjnano.5.126

• deposited onto structured one-dimensional objects is presented. In particular, CeO2/ZrO2@SiO2 composite tubes were synthesized in a two-step procedure by using electrospun polystyrene fibers as fiber template. First, a sol–gel approach based on an exo-templating technique was employed to obtain polystyrene

• (PS)/SiO2 composite fibers. These composite fibers were subsequently covered by spray-coating with ceria and zirconia sol solutions. After drying and final calcination of the green body composites, the PS polymer template was removed, and composite tubes of the composition CeO2/ZrO2@SiO2 were obtained

• . The SiO2/ZrO2/CeO2 microtubes, which consist of interconnected silica particles, are held together by ceria and zirconia deposits formed during the thermal treatment process. These microtubes are mainly located in the pendentive connecting the individual spherical silica particles and glue them

Antimicrobial properties of CuO nanorods and multi-armed nanoparticles against B. anthracis vegetative cells and endospores

• Pratibha Pandey,
• Merwyn S. Packiyaraj,
• Himangini Nigam,
• Gauri S. Agarwal,
• Beer Singh and
• Manoj K. Patra

Beilstein J. Nanotechnol. 2014, 5, 789–800, doi:10.3762/bjnano.5.91

• from 10 to 100 mg per 2000 cells. Haggstrom et al. [14] have reported sporicidal activity of corrosive halogen adducts of nanometer-scaled active metal oxides Al2O3, TiO2 and CeO2 in a solid based interaction on microfiltration membranes. The ratio of bacterial agents to metal oxide is not clear from

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

• semiconductors have been explored for the visible-light driven photocatalytic degradation of pollutants and microbes, such as bismuth oxides [5][6] and cerium oxides [12][13]. CeO2 specifically has been applied in a number of sustainable energy applications lately, including oxidative catalysis, hydrogen storage

• nanospheres, which is a mixed phase of Ce7O12 and CeO2, and can absorb visible light to photocatalytically degrade dyes such as rhodamine B (RhB). The materials characterization of the cerium oxide nanospheres and some mechanistic insights into the photocatalytic process are presented. Findings

• Polycrystalline Ce7O12 samples have been previously synthesized, but harsh conditions (up to 1030 °C) by reduction of CeO2 with CO were employed [25][26]. Instead, mild, surfactant-free solvothermal conditions were used to prepare mesoporous cerium oxide with oxygen vacancies. A solution of ceric ammonium nitrate

Challenges in realizing ultraflat materials surfaces

• Takashi Yatsui,
• Wataru Nomura,
• Fabrice Stehlin,
• Olivier Soppera,
• Makoto Naruse and
• Motoichi Ohtsu

Beilstein J. Nanotechnol. 2013, 4, 875–885, doi:10.3762/bjnano.4.99

• be as small as 100 nm. The slurries that are used for chemical–mechanical polishing (CMP) [7] consist of a large amount of the rare-earth material CeO2, which chemically polishes the substrate. Owing to issues of cost and material availability, there has recently been an effort to reduce the usage of

• such rare-earth materials [8]. To reduce the usage of the CeO2, many groups have attempted to develop alternative polishing pads [9] and slurries [10]. Watanabe et al. developed a surface treatment for SiC and diamond that uses a photocatalytic effect [11]. To induce this photocatalytic effect, they

• use a light source of shorter wavelengths to excite the carriers in TiO2, so that the generated electrons and holes induce a photocatalytic effect and etch the substrate [12]. Those techniques resulted in ultraflat surfaces with Ra values as small as 2 Å. Although CeO2 is not required in this

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

• [14], aerobic oxidation of alcohols [15], and oxidation of organosilanols [16]. Until recently, high activities for the CO oxidation over Au catalysts were only reported for gold nanoparticles of a few nanometers in diameter, which are supported on reducible metal oxides such as TiO2, CeO2 and Fe2O3

Template-assisted formation of microsized nanocrystalline CeO₂ tubes and their catalytic performance in the carboxylation of methanol

• Jörg J. Schneider,
• Meike Naumann,
• Christian Schäfer,
• Armin Brandner,
• Heiko J. Hofmann and
• Peter Claus

Beilstein J. Nanotechnol. 2011, 2, 776–784, doi:10.3762/bjnano.2.86

• to yield microstructured ceria tubes, which are composed of nanocrystalline ceria particles. The PMMA template is removed from the organic/inorganic hybrid material by radio frequency (rf) plasma etching followed by calcination of the ceramic green-body fibres. Microsized ceria (CeO2) tubes, with a

• additive. Keywords: activation of CO2; ceria; electrospinning; exotemplating; nanotubes; Introduction Ceria, CeO2, is known as a semiconducting ceramic material with unique electronic properties, exhibiting a broad range of functional properties with potential for application in various areas [1][2][3

• dehydrogenation of ethylbenzene to styrene. With respect to catalysis, CeO2 is a valuable support material for the low-temperature water–gas shift reaction and preferential oxidation of CO in hydrogen-enriched atmospheres. Herein, we will focus our attention on the direct carboxylation of methanol to dimethyl

Ceria/silicon carbide core–shell materials prepared by miniemulsion technique

• Lars Borchardt,
• Martin Oschatz,
• Robert Frind,
• Emanuel Kockrick,
• Martin R. Lohe,
• Christoph P. Hauser,
• Clemens K. Weiss,
• Katharina Landfester,
• Bernd Büchner and
• Stefan Kaskel

Beilstein J. Nanotechnol. 2011, 2, 638–644, doi:10.3762/bjnano.2.67

• State and Materials Research Dresden (IFW Dresden), Institute for Solid State Research, Helmholtzstrasse 20, 01069 Dresden, Germany Max Planck Institut für Polymerforschung, Ackermannweg 10, D-55128 Mainz, Germany 10.3762/bjnano.2.67 Abstract For the first time we present the synthesis of CeO2/Si(O)C

• reaction [34][35]. Thus, we report for the first time a CeO2/SiC core–shell system with tunable particle sizes through a miniemulsion technique, and demonstrate its use as a catalyst for the oxidation of methane. Results and Discussion Polycarbosilane (PCS) nanospheres were synthesized from a miniemulsion

• functionalized polymer spheres coated with hydroxyapatite. Accordingly, we used the surface functionalized PCS/acrylic acid spheres for the growth of a CeO2 shell. Additionally, dip coating of the unfunctionalized PCS spheres in an ethanolic Ce(NO3)3 solution was investigated. Functionalized as well as