Carbon nano-onions (multi-layer fullerenes): chemistry and applications

• Juergen Bartelmess and
• Silvia Giordani

Beilstein J. Nanotechnol. 2014, 5, 1980–1998, doi:10.3762/bjnano.5.207

• the pure CNO material) to 334 F·g−1 (for the RuO2·H2O–CNO composite material). Another strategy to increase the CNO capacitance is the activation of the CNO surface by treatment with 6 M KOH, creating porosity in the outer shells of the CNOs (Figure 8) [60]. The activated CNOs show largely improved

• permission from [40] and [41]. Copyright 2014 The Royal Society of Chemistry. (a) A schematic showing the chemical activation of CNOs in KOH. TEM images of pristine CNO (b), ACNO-4M (c), ACNO-6M (d), and ACNO-7M (e). ‘‘ACNO-nM’’ denotes the activated CNO prepared using n mol·L−1 KOH solution. Reprinted with

Liquid fuel cells

• Grigorii L. Soloveichik

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

• GE and used composite electrodes (a Pt black mixed with Teflon) and an AEM impregnated with 30% KOH [10]. An advantage of AEM fuel cells is that it is possible to use non-PGM electrocatalysts while classic PGM-oxide catalysts are less corrosion stable [11]. In general, AEMs have a lower conductivity

• formed at a Pd catalyst with very high faradaic efficiency while ethylacetate is the only product at a Ag catalyst [74]. The addition of a base (NaOH or KOH) in the concentration of at least 1 M to ethanol solutions is necessary to provide good conductivity. It was found that for 2 M fuel and 3 M KOH the

• current density was similar for methanol or ethanol but the ethanol cell exhibited a slightly higher voltage [75]. A cell with a non-platinum HYPERMECTM (Acta) anode and cathode catalyst and Tokuyama® AEM using 3 M EtOH and 5 M KOH showed an OCV of about 900 mV and a peak power density of 60 mW/cm2 [76

Review of nanostructured devices for thermoelectric applications

• Giovanni Pennelli

Beilstein J. Nanotechnol. 2014, 5, 1268–1284, doi:10.3762/bjnano.5.141

• . Plasma etching/ reactive ion etching (RIE), which is a standard process in integrated circuit fabrication, can be used. However, a simple and more convenient technique is the wet silicon anisotropic etching in alkaline solutions [98][99], typically based on potassium hydroxide (KOH) or

• tetramethylammonium hydroxide (TMAH). As for example, the silicon top layer can be etched in KOH 35% in volume at 43°C for 5–7 min: The etching time is not very critical, because the etching stops (it is very low) on the buried oxide layer, and on {111} silicon crystalline planes. At the end of the etching process

Purification of ethanol for highly sensitive self-assembly experiments

• Kathrin Barbe,
• Martin Kind,
• Christian Pfeiffer and
• Andreas Terfort

Beilstein J. Nanotechnol. 2014, 5, 1254–1260, doi:10.3762/bjnano.5.139

• maintained at 293.1 ± 0.1 K by means of a FP 40 thermostat (Julabo). To avoid contamination by the glassware, it was cleaned by 10% KOH/H2O containing H2O2 (ca. 10 mM), followed by rinsing with hot water, deionized water and ultrapure water (Millipore, 18.2 MΩ cm) before each experiment. Top: Picture of

Enhanced photocatalytic activity of Ag–ZnO hybrid plasmonic nanostructures prepared by a facile wet chemical method

• Sini Kuriakose,
• Vandana Choudhary,
• Biswarup Satpati and
• Satyabrata Mohapatra

Beilstein J. Nanotechnol. 2014, 5, 639–650, doi:10.3762/bjnano.5.75

• aqueous solutions of zinc nitrate and KOH involves the following reactions [37]: The concentration of KOH is an important factor in deciding the morphology of the ZnO nanostructures that are formed. The addition of aqueous KOH into Zn salt solution leads to formation of white precipitates of Zn(OH)2

• , which decompose to form ZnO nuclei. Depending on the Zn2+ concentration and synthesis conditions, ZnO nuclei grow into nanoparticles. In the presence of excess OH− ions (because of a higher KOH concentration) [Zn(OH)4]2− ions form, which help in formation of aggregates of ZnO nanoparticles. As seen from

• decoration with Ag nanoparticles, which suppress the recombination of photodegenerated electrons and holes and improve sun-light utilization due to plasmonic response of Ag nanoparticles. Experimental Materials Zinc nitrate hexahydrate (Zn(NO3)·6H2O, Merck, Germany) and potassium hydroxide (KOH, SRL, India

Preparation of poly(N-vinylpyrrolidone)-stabilized ZnO colloid nanoparticles

• Tatyana Gutul,
• Emil Rusu,
• Nadejda Condur,
• Veaceslav Ursaki,
• Evgenii Goncearenco and
• Paulina Vlazan

Beilstein J. Nanotechnol. 2014, 5, 402–406, doi:10.3762/bjnano.5.47

• with PVP as stabilizer. Experimental Synthesis of colloidal ZnO solutions and nanocomposites The following chemical were used in the synthesis processes: zinc acetate Zn(Ac)2·H2O (Aldrich, 99%); KOH (Aldrich, 99.0%); poly(N-vinylpyrrolidone) PVP10, MS = 10,000 (Aldrich, 99%); methanol 99.9%; ethanol

• anhydrous (Sigma Aldrich); hexane (Aldrich, 99%); acetone (Sigma 99%). We have modified the typical synthesis of ZnO colloidal solutions [13]. Zinc acetate dihydrate (Zn(OAc)2·2H2O) powder (0.439 g) was added to a KOH solution (0.02–0.04 M). Poly(N-vinylpyrrolidone) PVP was dissolved in methanol under

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

• characterisation and patterning was done with a PicoPlus microscope (Molecular Imaging) including a bipotentiostat and PicoLITH software. The tips were fabricated by chemically etching a Pt/Ir (80:20, GoodFellow) wire in a 2 M KSCN/0.5 M KOH mixture applying an AC current. Subsequently, they were coated with

• referenced to Cu2+/Cu. Before filling in the electrolyte, the sample potential was set to +0.4 V. UPD was performed at potentials in the range of 0–300 mV, depending on the desired deposition rate. Generation of binary SAM. The exchange of BP2 by AdSH was done in a 0.1 M KOH ethanol solution containing 1 mM

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

• electrocatalytic activity of Pd/Ni system is observed. Indeed, the stability of Ni in H2SO4 is not as good as in KOH, however in the potential region of interest no Pd/Ni deactivation due to Ni dissolution has been observed. The third cycle is shown because after three cycles a stable and reproducible behavior of

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

• alkali Et4NOH (Figure S5A–C). In contrast, the utilization of relatively strong alkalies (KOH and LiOH) for the LPEI self-assembly produced the silica nanotube structures (Figure S5D–I). However, it should be noted that well-defined thin films of silica nanotubes could be synthesized even by using

• Chemical Co., Japan and was used as received. Other chemicals were used as received. Deionized water was used in all experiments. Synthesis of silica nanostructure by templating alkali-induced LPEI aggregates. LPEI self-assembly were simply induced by dropping alkali (NaOH, NH4OH, KOH, LiOH or Et4NOH) into

Structural, optical and photocatalytic properties of flower-like ZnO nanostructures prepared by a facile wet chemical method

• Sini Kuriakose,
• Neha Bhardwaj,
• Jaspal Singh,
• Biswarup Satpati and
• Satyabrata Mohapatra

Beilstein J. Nanotechnol. 2013, 4, 763–770, doi:10.3762/bjnano.4.87

• uses zinc acetate and KOH as precursors mixed in a ratio of 1:10 under stirring at 60 °C. It is well known that the formation of ZnO nanoparticles in aqueous solutions from Zn(CH3COO)2 and KOH under alkaline conditions and heating involves the following reactions [39][40]: Firstly, the addition of KOH

• − ions (in our case a much higher KOH concentration), the formation of [Zn(OH)4]2− ions is preferred (Equation 3). Dehydration of [Zn(OH)4]2− due to heating leads to nucleation and growth of ZnO nanoparticles (Equation 4). The [Zn(OH)4]2− complexes preferentially adsorb onto the surface of the ZnO

• that Zn(OH)2 surface passivating layer leads to a drastic reduction in the efficiency of flower-like ZnO structures for sunlight induced photocatalytic degradation of MB dye. Experimental Materials Zinc acetate dihydrate (Zn(CH3COO)2·2H2O) and potassium hydroxide (KOH) were used as the starting

Nanoglasses: a new kind of noncrystalline materials

• Herbert Gleiter

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

• –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

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

• , applying an electrical contact (further referred to as sample PtSQUID). All measurements were carried out at ambient temperature in a 1 molar aqueous solution of KOH. Resistance measurements were performed in a standard electrochemical cell with a PGZ-100 potentiostat (Radiometer Analytical). The PtER

• nanocrystalline Pt (sample PtER) measured at a scan rate of v = 0.5 mV/s in different potential ranges from −1050 mV to +600 mV (gray), −465 mV to −35 mV (green, red), −135 mV to −35 mV (yellow), 0 mV to +500 mV (blue) in 1 M KOH. Relative variation of resistance (ΔR/R0, b) and magnetic moment (Δm/m0, c) of

• porous nanocrystalline Pt upon electrochemical CV-cycling in 1 M KOH between −465 mV and −35 mV. (a) CV measured for sample PtER. Measurements of m were performed at 5 kOe. Anodic scan indicated by green dashed line and green open symbols. Cathodic scan indicated by red solid line and red full symbols

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

• illumination of the mesoporous In2O3 electrodes annealed at 200 °C (1) and 400 °C (2). Electrolyte: 0.1 M KOH solution. Photocurrent versus electrode potential curves recorded under visible-light illumination of the In2O3 (1, 2) and In2O3/CdS electrodes (3–5). The In2O3 films were annealed at 200 (1, 3) and

Calculation of the effect of tip geometry on noncontact atomic force microscopy using a qPlus sensor

• Julian Stirling and
• Gordon A. Shaw

Beilstein J. Nanotechnol. 2013, 4, 10–19, doi:10.3762/bjnano.4.2

• control over the quantity of material removed from the tip [18]. The sensor was positioned with a micromanipulator such that the 1 M KOH electrolyte contacted only the tungsten probe tip, then a potential of 0.3 V versus SCE was applied until the desired charge was accumulated from the Faradaic etch

Pinch-off mechanism in double-lateral-gate junctionless transistors fabricated by scanning probe microscope based lithography

• Farhad Larki,
• Arash Dehzangi,
• Alam Abedini,
• Ahmad Makarimi Abdullah,
• Elias Saion,
• Sabar D. Hutagalung,
• Mohd N. Hamidon and
• Jumiah Hassan

Beilstein J. Nanotechnol. 2012, 3, 817–823, doi:10.3762/bjnano.3.91

• wt % potassium hydroxide (KOH) saturated with 10 vol % isopropyl alcohol (IPA) at 63 °C for 20 s, in order to remove the unmasked Si layer. IPA was used as an initiator to improve the cleaning process: it reduces the etch rate, improves the surface roughness and makes the etching process more

• (Vth) between the simulation and experimental curves can be illustrated by the presence of fixed interface charge, work function differences, or both [20]. It should be mentioned that, during the KOH anisotropic etching process, very complicated three-dimensional structures based on the etchant

Dimer/tetramer motifs determine amphiphilic hydrazine fibril structures on graphite

• Loji K. Thomas,
• Nadine Diek,
• Uwe Beginn and
• Michael Reichling

Beilstein J. Nanotechnol. 2012, 3, 658–666, doi:10.3762/bjnano.3.75

• ), 7.71 (d,1H, aromatic). Synthesis of 3,4-bis(decyloxy)benzoic acid (4): Compound 3 (8.0014 g; 17.8 mmol) was dissolved in 350 mL boiling EtOH, and a solution of 11.2 g (200 mmol) KOH in 25 mL water was added and heated under reflux for 4 h. The reaction mixture was poured into 1 L distilled water

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

• schematically presented in Figure 1. The surface of a Si(100) wafer was patterned into a periodic array of pyramidal pits (Figure S1, Supporting Information File 1) by using SCIL, reactive ion etching (RIE), and KOH etching. The spatial period of these pits is 520 nm. A 200 nm layer of SiO2 was thermally grown

• acted as a mask during the anisotropic etching of Si in a KOH solution, and the Si surface was patterned into a periodic array of pyramidal pits. After removal of the SiO2 mask, about 20 nm of SiO2 was then again thermally grown on the structured Si surface to avoid a reaction between the subsequently

• spatial period. However, the pits were fabricated by KOH etching in this study and have a depth of about 360 nm, whereas the pits in the previous work were fabricated by reactive ion etching and have a depth of 150 nm. This means that a larger optimized thickness is required for the formation of an

Effect of deposition temperature on the structural and optical properties of chemically prepared nanocrystalline lead selenide thin films

• Anayara Begum,
• Amir Hussain and
• Atowar Rahman

Beilstein J. Nanotechnol. 2012, 3, 438–443, doi:10.3762/bjnano.3.50

• solution was adjusted to 10.80 by drop-wise addition of KOH. Finally, Na2SeSO3 was added and the pH of the final deposition bath was adjusted to 11. The glass substrates were vertically immersed in the deposition bath at the desired temperature. After a deposition period of 2 h, the substrates were taken

Glassy carbon electrodes modified with multiwalled carbon nanotubes for the determination of ascorbic acid by square-wave voltammetry

• Sushil Kumar and
• Victoria Vicente-Beckett

Beilstein J. Nanotechnol. 2012, 3, 388–396, doi:10.3762/bjnano.3.45

• : 6–13 nm, length: 2.5–20 μm, purity > 99.8%) and Nafion (5% (w/v) in a mixture of lower aliphatic alcohols) were purchased from Sigma Aldrich (St. Louis, MO, USA). L-ascorbic acid was obtained from BDH Chemicals (Port Fairy, VIC, Australia). All other chemicals (HCOOH, K2HPO4, KH2PO4, KOH, CH3COOH

Substrate-mediated effects in photothermal patterning of alkanethiol self-assembled monolayers with microfocused continuous-wave lasers

• Anja Schröter,
• Mark Kalus and
• Nils Hartmann

Beilstein J. Nanotechnol. 2012, 3, 65–74, doi:10.3762/bjnano.3.8

• of 0.1 M K2S2O3 (>98%, Fluka), 1.0 M KOH (p.a., Merck), 0.01 M K3Fe(CN)6 (99%, Sigma Aldrich), and 0.001 M K4Fe(CN)6 (purum, 99%, Riedel de Haën) at room temperature. For each substrate type, the immersion time was adjusted in order to completely dissolve the Au film in the laser-depleted surface

Highly efficient ZnO/Au Schottky barrier dye-sensitized solar cells: Role of gold nanoparticles on the charge-transfer process

• Tanujjal Bora,
• Htet H. Kyaw,
• Soumik Sarkar,
• Samir K. Pal and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2011, 2, 681–690, doi:10.3762/bjnano.2.73

• ZnO/Au-nanocomposite DSSCs, measured at 1 sun, AM 1.5 G illumination, (b) short-circuit photocurrent density of the bare ZnO-nanorod and ZnO/Au-nanocomposite DSSCs measured at different incident wavelengths and (c) optical absorptions of dye N719 in 0.1 mM KOH aqueous solution for bare ZnO-nanorod and

• ZnO/Au-nanocomposite photoelectrodes. The optical absorption was measured by removing the dye molecules from the respective photoelectrodes (size = 1 cm2) by dipping them in a 0.1 mM KOH aqueous solution (2 mL) for 5 min. Energy-band diagram depicting the possible electron-transfer path in the ZnO/Au