Analysis of catalyst surface wetting: the early stage of epitaxial germanium nanowire growth

• Owen C. Ernst,
• Felix Lange,
• David Uebel,
• Thomas Teubner and
• Torsten Boeck

Beilstein J. Nanotechnol. 2020, 11, 1371–1380, doi:10.3762/bjnano.11.121

Role of redox-active axial ligands of metal porphyrins adsorbed at solid–liquid interfaces in a liquid-STM setup

• Thomas Habets,
• Sylvia Speller and
• Johannes A. A. W. Elemans

Beilstein J. Nanotechnol. 2020, 11, 1264–1271, doi:10.3762/bjnano.11.110

• at room temperature. We found that while the porphyrin catalyst MnTUPCl (tetrakis-meso-undecylporphyrin manganese(III) chloride, Figure 1a) is fully inert in n-tetradecane solution, it becomes catalytically active in the epoxidation of alkenes when it is adsorbed at the interface of a Au(111

• added salts, allows us to pinpoint the behavior of the axial ligand of our catalyst in the non-polar liquid in which also our catalysis studies were carried out. Still, our system shows several of the characteristics of a conventional electrochemical cell. Apart from the bias dependency of the reaction

Revealing the local crystallinity of single silicon core–shell nanowires using tip-enhanced Raman spectroscopy

• Marius van den Berg,
• Ardeshir Moeinian,
• Arne Kobald,
• Yu-Ting Chen,
• Anke Horneber,
• Steffen Strehle,
• Alfred J. Meixner and
• Dai Zhang

Beilstein J. Nanotechnol. 2020, 11, 1147–1156, doi:10.3762/bjnano.11.99

• polarizations of Raman scattering and the photoluminescence from the tip–sample nanogap. Results and Discussion Silicon nanowire core–shell morphology In accordance with the VLS synthesis method (see Experimental section), the utilized Pt catalyst, or finally PtxSiy, remains at the tip of the nanowire during

• grains with different orientation. Furthermore, catalyst migration along the SiNW backbone was observed in some cases (Figure 1c). Although the SiNWs grown by the VLS mechanism possess are crystalline, the silicon shells deposited onto the nanowires by thermal CVD (here using a temperature of 520 °C) can

• of the nanowire exhibits an amorphous morphology. Confocal optical microscopy of silicon nanowires As the first step, core–shell SiNWs grown with a platinum catalyst [29] are characterized using a custom-built confocal optical microscope. Figure 2a shows the representative geometry of these SiNWs

Gas-sensing features of nanostructured tellurium thin films

• Dumitru Tsiulyanu

Beilstein J. Nanotechnol. 2020, 11, 1010–1018, doi:10.3762/bjnano.11.85

• sensing parameters did not differ much from the similar parameters obtained earlier for microcrystalline Te films. Further investigations have been extended to Te nanotubes grown on quartz or Si(111) substrates through a catalyst-free growing process in a furnace filled with argon [21]. Another study used

Atomic layer deposition for efficient oxygen evolution reaction at Pt/Ir catalyst layers

• Stefanie Schlicht,
• Korcan Percin,
• Stefanie Kriescher,
• André Hofer,
• Claudia Weidlich,
• Matthias Wessling and
• Julien Bachmann

Beilstein J. Nanotechnol. 2020, 11, 952–959, doi:10.3762/bjnano.11.79

• well documented in the literature, and this paper provides a direct comparison under identical experimental conditions of electrochemical measurements and in identical units. In the first method, based on classical engineering, the bimetallic catalyst is deposited by dip-coating in a precursor solution

• different types are not possible. The goal of the present paper is to provide such a direct comparison between two very distinct preparation methods of bimetallic Pt/Ir electrocatalysts. For both catalyst types, we will consider one electrode substrate (titanium felt) [15], one electrolyte (0.5 M H2SO4 at

• consider here two distinct catalyst preparation methods. As a standard method used in the engineering context, we perform an acid etch of the titanium fibers (to generate surface roughness and thereby increase the specific surface area), followed by dip-coating of a noble metal salt precursor solution on

Transition from freestanding SnO₂ nanowires to laterally aligned nanowires with a simulation-based experimental design

• Jasmin-Clara Bürger,
• Sebastian Gutsch and
• Margit Zacharias

Beilstein J. Nanotechnol. 2020, 11, 843–853, doi:10.3762/bjnano.11.69

• substrates were prepared by two different preparation methods for the catalyst seeds, which are required for the VLS process. As a catalyst material, gold was chosen. First, a-plane sapphire substrates with structured gold thin films (thickness 5 nm) by metal evaporation, and second, a-plane sapphire

• controllers for individual adjustment of the introduced volumetric flow of the carrier gas, Ar, and the process gas, O2. The gas outlet is connected to a pumping system for base pressure evacuation and process pressure control. The samples, which were previously covered with catalyst, were arranged in the

• ]. The droplets compete for the tin atoms and oxygen molecules [30]. This results in a locally reduced material concentration in the surrounding area of the catalyst-decorated samples. As seen from the simulations of the volumetric flow (Figure 2), an increased volumetric flow will result in a reduced

Nickel nanoparticles supported on a covalent triazine framework as electrocatalyst for oxygen evolution reaction and oxygen reduction reactions

• Secil Öztürk,
• Yu-Xuan Xiao,
• Dennis Dietrich,
• Beatriz Giesen,
• Juri Barthel,
• Jie Ying,
• Xiao-Yu Yang and
• Christoph Janiak

Beilstein J. Nanotechnol. 2020, 11, 770–781, doi:10.3762/bjnano.11.62

• method. CTF-1-600 and Ni/CTF-1-600 show high catalytic activity towards OER and a clear activity for the electrochemical oxygen reduction reaction (ORR). Ni/CTF-1-600 requires 374 mV overpotential in OER to reach 10 mA/cm2, which outperforms the benchmark RuO2 catalyst, which requires 403 mV under the

• developed. Noble metals (Ir, Ru) and their oxides are the current commercial electrocatalysts for the OER, whereas Pt metal is the benchmark catalyst for the ORR [4][5]. Yet, all these catalysts have drawbacks such as scarcity and high cost, which are disadvantageous for their large-scale production and

• nitrogen-containing aromatic polymer frameworks with triazine rings, which exhibit high surface area, porosity, and thermal and chemical stability [21][22]. CTFs are promising materials for applications such as catalysts or catalyst support [23][24][25] and for energy storage and conversion [26][27][28

Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

• Stefania Castelletto,
• Faraz A. Inam,
• Shin-ichiro Sato and
• Alberto Boretti

Beilstein J. Nanotechnol. 2020, 11, 740–769, doi:10.3762/bjnano.11.61

• , it can be considered a hybrid 1D and 2D material. In [116], commercially available BNNTs were fabricated using a catalyst-free high-temperature pressure method, and the laser heating method was studied in terms of SPEs. Non-treated BNNTs provided photostable SPEs down to the single nanotube, either

Effect of Ag loading position on the photocatalytic performance of TiO₂ nanocolumn arrays

• Jinghan Xu,
• Yanqi Liu and
• Yan Zhao

Beilstein J. Nanotechnol. 2020, 11, 717–728, doi:10.3762/bjnano.11.59

• of the 1D TiO2–Ag nanostructures prepared to date are Ag-nanoparticle-coated TiO2 (ACT), in which the catalytic efficiency of the catalyst is greatly decreased when the Ag loading is increased to a certain extent. Wang et al. [29] used the hydrothermal method to prepare an array of TiO2 nanocolumns

• the catalyst, so the catalyst needs to have a certain adsorption capacity for dye molecules. Due to the presence of oxygen vacancies, the surface of TiO2 is usually negatively charged and has a good adsorption capacity for cationic dye molecules [36]. Commonly used cationic dyes are rhodamine, methyl

Adsorptive removal of bulky dye molecules from water with mesoporous polyaniline-derived carbon

• Hyung Jun An,
• Jong Min Park,
• Nazmul Abedin Khan and
• Sung Hwa Jhung

Beilstein J. Nanotechnol. 2020, 11, 597–605, doi:10.3762/bjnano.11.47

• regarded to be very effective and attractive because of its operation under mild conditions and no need of oxidant, active catalyst, and irradiation [8][9]. Therefore, adsorption with carbon nanotubes, activated carbon (AC), biomass, and metallic–organic frameworks (MOFs) has been actively studied for the

Identification of physicochemical properties that modulate nanoparticle aggregation in blood

• Ludovica Soddu,
• Duong N. Trinh,
• Eimear Dunne,
• Dermot Kenny,
• Giorgia Bernardini,
• Ida Kokalari,
• Arianna Marucco,
• Marco P. Monopoli and
• Ivana Fenoglio

Beilstein J. Nanotechnol. 2020, 11, 550–567, doi:10.3762/bjnano.11.44

• ) for the medium and small carbon nanoparticles (CNP-M and CNP-S, respectively). Synthesis of silica nanoparticles Silica nanoparticles (SNPs) were prepared by hydrolysis and condensation of TEOS in the presence of ammonia as a catalyst following the Stöber process [25]. Briefly, a defined amount of

Multilayer capsules made of weak polyelectrolytes: a review on the preparation, functionalization and applications in drug delivery

• Varsha Sharma and
• Anandhakumar Sundaramurthy

Beilstein J. Nanotechnol. 2020, 11, 508–532, doi:10.3762/bjnano.11.41

• ), is a reversible reaction between different types of diene and dienophile resulting in thermo-responsive products. A fourth type, the thiol-ene reaction, is a reaction between thiol and alkene groups in the presence of a radical source as catalyst. The radicals can be generated through light, thermal

• . Other click chemistries like thiol-ene have also been reported because of their light-initiated and metal-catalyst-free approach. PVP along with PMA functionalized by thiol (PMAThiol) and ene (PMAEne) groups were used to fabricate hydrogen bonded hollow capsules via UV crosslinking [100]. It was further

Electrochemically derived functionalized graphene for bulk production of hydrogen peroxide

• Munaiah Yeddala,
• Pallavi Thakur,
• Anugraha A and
• Tharangattu N. Narayanan

Beilstein J. Nanotechnol. 2020, 11, 432–442, doi:10.3762/bjnano.11.34

• produced through the complex and energy-intensive anthraquinone method [4], and although it is popular, it has drawbacks such as side reactions, which consume the catalyst leading to the regeneration and hydrogenation of the catalyst [4]. Alternative routes for peroxide generation include direct

• presence of a catalyst [15] is one of the possible routes having high yield, while the direct mixing of H2 and O2 can be explosive in nature [16], and hence requires a large quantity of another gas such as N2 and CO2 to dilute the reactant gases [17]. Electrochemical synthesis methods such as the PEM fuel

• (Se) edge functionalized graphene (reduced graphene oxide (rGO)) was found to undergo a direct four-electron path ORR process in alkaline medium, where rGO undergoes a two-electron path peroxide route ORR [35]. In this process, Se acts as a single atom site catalyst. In a nutshell, depending on the

Using gold nanoparticles to detect single-nucleotide polymorphisms: toward liquid biopsy

• María Sanromán Iglesias and
• Marek Grzelczak

Beilstein J. Nanotechnol. 2020, 11, 263–284, doi:10.3762/bjnano.11.20

• formation of DNA circuits and include hybridization chain reaction (HCR), catalytic hairpin assembly (CHA) and entropy-driven catalysis [64]. These mechanisms have shown a great potential for developing biosensors of high sensitivity and high selectivity since the target DNA itself is used as a catalyst to

• reaction was initialized by a catalyst (X) binding to the γ domain of S. Thus, releasing a by-product, an intermediate species was produced, which had a single-stranded region complementary to the DNA sequence of the fuel. In the next step, the fuel displaced the catalyst X, resulting in the cross-linking

• aggregation of the two DNA–AuNP complexes. The catalyst was released back into the solution. The authors observed that the aggregation of nanoparticles was slower by a factor of 10 when the sequence of the catalyst contained single-base mismatches (spurious catalyst). This colorimetric bioassay could detect

Fabrication of Ag-modified hollow titania spheres via controlled silver diffusion in Ag–TiO₂ core–shell nanostructures

• Bartosz Bartosewicz,
• Malwina Liszewska,
• Bogusław Budner,
• Marta Michalska-Domańska,
• Krzysztof Kopczyński and
• Bartłomiej J. Jankiewicz

Beilstein J. Nanotechnol. 2020, 11, 141–146, doi:10.3762/bjnano.11.12

• obtained composite catalyst exhibits a synergistic effect between the anatase crystalline shell and the AuNPs as well as superb thermal and mechanical stability of the highly dispersed AuNPs. TiO2 HSs decorated with ultrasmall Ag nanocrystallites and exhibiting excellent photocatalytic properties were

Simple synthesis of nanosheets of rGO and nitrogenated rGO

• Pallellappa Chithaiah,
• Madhan Mohan Raju,
• Giridhar U. Kulkarni and
• C. N. R. Rao

Beilstein J. Nanotechnol. 2020, 11, 68–75, doi:10.3762/bjnano.11.7

• °C·min−1 using a Mettler-Toledo-TG-850 apparatus. AFM measurements were performed using a CP2 atomic force microscope. Electrode preparation and electrochemical characterization The catalyst inks of as-synthesized rGO and reduced graphene oxide H-rGO were prepared by ultrasonication separately. A mixture

• of 4.0 mg rGO and 0.025 wt % (5 μL) of Nafion in 0.4 mL of dimethylformamide (DMF) was sonicated until a homogeneous dispersion was obtained. 3 μL catalyst ink was taken and drop-cast onto a glassy carbon electrode, which was allowed to dry at room temperature. A similar procedure was followed to

Synthesis of amorphous and graphitized porous nitrogen-doped carbon spheres as oxygen reduction reaction catalysts

• Maximilian Wassner,
• Markus Eckardt,
• Andreas Reyer,
• Thomas Diemant,
• Michael S. Elsaesser,
• R. Jürgen Behm and
• Nicola Hüsing

Beilstein J. Nanotechnol. 2020, 11, 1–15, doi:10.3762/bjnano.11.1

• correlations between structural properties and electrochemical performance. In the following we will first give a detailed structural and chemical analysis of the resulting materials (section 1 in “Results and Discussion”), followed by a discussion of their performance as ORR catalyst in electrocatalytic

• 150 °C). The as-synthesized carbon particles show a well-defined spherical shape with diameters of 330 ± 50 nm and a smooth surface (see also the scanning electron microscopy (SEM) image in Figure 2a). Fe2O3 particles, as graphitization catalyst, are loaded successfully on pre-carbonized carbon

• spheres; yet there are domains of higher or lower loadings. After nitriding with ammonia, g-NCS-550, g-NCS-700 and all samples of the NCS series still show a spherical shape with a smooth surface (Figure 2b and Figure 2c show, respectively, NCS-550 and NCS-1000 as examples). No remaining catalyst

Evaluation of click chemistry microarrays for immunosensing of alpha-fetoprotein (AFP)

• Seyed Mohammad Mahdi Dadfar,
• Sylwia Sekula-Neuner,
• Vanessa Trouillet,
• Hui-Yu Liu,
• Ravi Kumar,
• Annie K. Powell and
• Michael Hirtz

Beilstein J. Nanotechnol. 2019, 10, 2505–2515, doi:10.3762/bjnano.10.241

• of biotin–amine (Mw = 595 g/mol, 1190 μg/mL) and biotin–thiol (Mw = 2000 g/mol, 4000 μg/mL), respectively. For the reaction between epoxy and amine, 1 mol % Bi(OTf)3 to biotin–amine was added as a catalyst to the biotin–amine solution. The reaction between epoxy and thiol was catalyzed by 10 mol

Air oxidation of sulfur mustard gas simulants using a pyrene-based metal–organic framework photocatalyst

• Ghada Ayoub,
• Mihails Arhangelskis,
• Xuan Zhang,
• Florencia Son,
• Timur Islamoglu,
• Tomislav Friščić and
• Omar K. Farha

Beilstein J. Nanotechnol. 2019, 10, 2422–2427, doi:10.3762/bjnano.10.232

• quantum yields and whose absorption wavelengths span the ultraviolet–visible spectrum. Moreover, singlet oxygen could be generated from homogenous [23] or heterogeneous catalysts, the latter of which will allow for the ease of separation at the end of the reaction, recyclability of the catalyst, wide

• of producing singlet oxygen upon exposure to UV light [44][45], we anticipated that a MOF with isolated pyrene linkers would be a good candidate catalyst for the photocatalytic oxidation of sulfur mustard. The NU-400 material (Figure 1) was synthesized from the pyrene-2,7-dicarboxylic acid (Py-DCA

• (Figure 2). Achieving complete oxidation of CEES without the O2 saturation represents a milestone for the potential deployment of MOFs as an active detoxification catalyst and, consequently, we focused on detailed exploration of the activity of NU-400 in air, without oxygen purging. Given that NU-400 is

Coating of upconversion nanoparticles with silica nanoshells of 5–250 nm thickness

• Cynthia Kembuan,
• Maysoon Saleh,
• Bastian Rühle,
• Ute Resch-Genger and
• Christina Graf

Beilstein J. Nanotechnol. 2019, 10, 2410–2421, doi:10.3762/bjnano.10.231

• name Igepal® CO-520) and distributed in the continuous nonpolar phase [44]. The ratio between the aqueous components and the surfactant determines the size of these droplets [30], which act as nanoreactors. For the polycondensation of precursors such as TEOS, ammonia usually acts as a catalyst [43

• growth of a silica layer in a single step without producing UCNP-free silica particles as side products, a thin silica layer was grown first onto the particles via a reverse microemulsion process in cyclohexane with Igepal CO-520 as surfactant and ammonia as a catalyst. In such a reverse microemulsion

Design and facile synthesis of defect-rich C-MoS₂/rGO nanosheets for enhanced lithium–sulfur battery performance

• Chengxiang Tian,
• Juwei Wu,
• Zheng Ma,
• Bo Li,
• Pengcheng Li,
• Xiaotao Zu and
• Xia Xiang

Beilstein J. Nanotechnol. 2019, 10, 2251–2260, doi:10.3762/bjnano.10.217

• subsequently disperses. Consequently, the reutilization of Li2Sn will become very hard due to the repulsion between the nonpolar conductive surface and the polar reactants [17]. Two-dimensional layered transition metal dichalcogenides (TMDs), strong candidates in the search for energy storage and catalyst

Mannosylated brush copolymers based on poly(ethylene glycol) and poly(ε-caprolactone) as multivalent lectin-binding nanomaterials

• Stefania Ordanini,
• Wanda Celentano,
• Anna Bernardi and
• Francesco Cellesi

Beilstein J. Nanotechnol. 2019, 10, 2192–2206, doi:10.3762/bjnano.10.212

• -hexamethyltriethylenetetramine (HMTETA) catalyst [27]. Ethyl α-bromoisobutyrate (1) and pentaerythritol tetrakis(2-bromoisobutyrate) (2) were chosen as the initiators for linear and four-arm polymers, respectively (Scheme 1, step c). A DP value of 10 (for the linear polymers and for each branch of the four-arm ones) was

• alumina pad to remove the copper catalyst, followed by precipitation in diethyl ether. Synthesis of the mannosylated polymers The sugar functionalization of the polymeric backbone was performed through CuAAC click reaction (Scheme 1, step d), by combining the triple bonds with 2-azidoethyl α-ᴅ

• the synthesis of PEGx-PCLy. THF (inhibitor-free) was degassed under nitrogen for 10 min. Pg-PCL-MA (y equiv) and poly(ethylene glycol) methyl ether methacrylate (Mn = 500 Da, x equiv) were added in a Schlenk tube and three cycles of vacuum–nitrogen were performed. The catalyst solution was prepared as

Improved adsorption and degradation performance by S-doping of (001)-TiO₂

• Xiao-Yu Sun,
• Xian Zhang,
• Xiao Sun,
• Ni-Xian Qian,
• Min Wang and
• Yong-Qing Ma

Beilstein J. Nanotechnol. 2019, 10, 2116–2127, doi:10.3762/bjnano.10.206

• photocatalytic activity was tested by the degradation of methylene blue (MB). For this, the samples were placed 20 cm away from a xenon lamp (300 W, 16 A). The experimental process was as follows: 50 mg of catalyst was added into a 100 mL MB solution with a concentration of 10 mg/L, and the samples were kept in

Synthesis of highly active ETS-10-based titanosilicate for heterogeneously catalyzed transesterification of triglycerides

• Muhammad A. Zaheer,
• David Poppitz,
• Khavar Feyzullayeva,
• Marianne Wenzel,
• Jörg Matysik,
• Radomir Ljupkovic,
• Aleksandra Zarubica,
• Alexander A. Karavaev,
• Andreas Pöppl,
• Roger Gläser and
• Muslim Dvoyashkin

Beilstein J. Nanotechnol. 2019, 10, 2039–2061, doi:10.3762/bjnano.10.200

• accessible for triolein and enhancing the rate of transesterification. The resulting catalyst exhibits a comparable triolein conversion (≈73%) after 4 h of reaction to CaO (≈76%), which is reportedly known to be highly active in the transesterification of triglycerides. In addition, while CaO showed a

• maximum conversion of 83% after 24 h, the ETS-10-based catalyst reached 100% after 8 h, revealing its higher stability compared to CaO. The following characteristics of the catalysts were experimentally addressed – crystal structure (X-ray diffraction, transmission electron microscopy), crystal shape and

• efficient catalyst for initiation of the transesterification process that converts triglycerides into FAMEs. Other methods that do not require a catalyst, such as pyrolysis and utilization of supercritical fluid technology, are considered to be highly energy-intensive, inhibiting their practical

Review of advanced sensor devices employing nanoarchitectonics concepts

• Katsuhiko Ariga,
• Tatsuyuki Makita,
• Masato Ito,
• Taizo Mori,
• Shun Watanabe and
• Jun Takeya

Beilstein J. Nanotechnol. 2019, 10, 2014–2030, doi:10.3762/bjnano.10.198

• processes, such as catalytic reactions and fluorescence quenching, often improves sensor capabilities through component nanoarchitectonics. Imanaka and co-workers used a combustion process induced by a precious-metal-free CeO2–ZrO2–ZnO catalyst for CO gas detection [87]. The semiconducting (p-type) La2CuO4

• -loaded CeO2–ZrO2–ZnO catalyst has a small heat capacity and dramatically increases the temperature of the Pt coil, resulting in a highly sensitive sensor signal. On the other hand, the n-type Sm2CuO4-loaded CeO2–ZrO2–ZnO catalyst is advantageous when rapid response and low temperature operation are