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

• /CTF-1-400-20, whereas 7 atom % N is involved in bonding to Ni for Ni/CTF-1-600-22. Electrochemical catalysis In order to investigate the activity of the synthesized materials in the OER, rotating disc electrode (RDE) experiments were conducted in 1 mol/L KOH solution in a three-electrode cell. Figure

• electrocatalytic ORR activity of the materials, polarization curves were collected in O2-saturated 1 mol/L KOH solution with a sweep rate of 10 mV/s at room temperature. The half-wave potentials are shown in Figure 8a. CTF-1-400, Ni/CTF-1-400-20 and Ni/CTF-1-400-35 show similar ORR polarization curves and their

• electrode. The loading amount of all catalysts was 0.255 mg/cm2. The OER measurements were carried out in 1 mol/L KOH using the glassy-carbon RDE at a rotation rate of 1600 rpm with a 5 mV/s sweep rate. The accelerated durability tests (ADTs) for OER were performed in 1 mol/L KOH solution with cyclic

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

• ) 8.1 times that of commercial, activated carbon for AR1. The remarkable adsorption of AR1 and JGB over KOH-900 could be explained by the combined mechanisms of hydrophobic, π–π, electrostatic and van der Waals interactions. Keywords: acid red 1; adsorption; bulky dye molecules; Janus green B

• -presence of activating agents such as KOH, H3PO4 or ZnCl2 [39]. Even though PANI-derived carbon (PDC) was used in gas-phase adsorption [40][41], it has been scarcely applied in liquid phase adsorption. Only recently we applied PDC for the possible purification of water contaminated with organics and fuel

• ). Importantly, the pore size distribution patterns presented in Figure 1b show that the pore size of PDC increased with increasing pyrolysis temperature; and KOH-900, a PDC material that was obtained via pyrolysis of PANI at 900 °C, has an average pore size of ≈3 nm, which is very effective in adsorption of

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

• equilibrium). This indicates the presence of C=O groups and their role in electrochemical processes. The ORR activity of different EEG samples is estimated using a conventional three-electrode system. The CV profiles of EEG-modified GCE in 0.1 M KOH electrolyte saturated with N2 and O2 gas are displayed in

• performance in 0.1 M KOH solution, and the data is given in Figure 5. In Figure 5a, the Raman spectra of EEG before and after 3 h of chronoamperometry are shown, which show no appreciable change in either the peak position or peak intensity. This indicates that no additional defects are created during the

• functional groups during the chronoamperometry, which is suggests that most of the C=O functional groups are converted into –C–OH during the reaction. To study the effect of the change in the functionalization on ORR, we recorded the CV of ORR in 0.1 M KOH solution before and after chronoamperometry. Such

An advanced structural characterization of templated meso-macroporous carbon monoliths by small- and wide-angle scattering techniques

• Felix M. Badaczewski,
• Marc O. Loeh,
• Torben Pfaff,
• Dirk Wallacher,
• Daniel Clemens and
• Bernd M. Smarsly

Beilstein J. Nanotechnol. 2020, 11, 310–322, doi:10.3762/bjnano.11.23

• microporosity additional approaches are necessary to further introduce mesoporosity or macroporosity and to tune the pore system. Chemical and physical activation, using reactive agents such as bases (KOH) or gases (CO2), are only capable to enhance the microporosity by etching the carbon skeleton [33][34]. To

High-performance asymmetric supercapacitor made of NiMoO₄ nanorods@Co₃O₄ on a cellulose-based carbon aerogel

• Meixia Wang,
• Jing Zhang,
• Xibin Yi,
• Benxue Liu,
• Xinfu Zhao and
• Xiaochan Liu

Beilstein J. Nanotechnol. 2020, 11, 240–251, doi:10.3762/bjnano.11.18

• of the NiMoO4@Co3O4/CA electrode in a potential supercapacitor. The synthesized samples were used as working electrodes for electrochemical analysis. The electrochemical experiments were conducted by using a three-electrode testing system in a 2.0 M KOH solution. The reference electrode and the

• KOH aqueous solution. The working electrode materials were prepared by mixing the obtained sample, carbon black, acetylene black and polytetrafluoroethylene (PTEF) emulsions at a mass ratio of 80:7.5:7.5:5.0. The homogeneous slurry was coated on Ni foam substrates (1 cm × 1 cm) and dried at 80 °C for

Influence of the epitaxial composition on N-face GaN KOH etch kinetics determined by ICP-OES

• Markus Tautz,
• Maren T. Kuchenbrod,
• Joachim Hertkorn,
• Robert Weinberger,
• Martin Welzel,
• Arno Pfitzner and
• David Díaz Díaz

Beilstein J. Nanotechnol. 2020, 11, 41–50, doi:10.3762/bjnano.11.4

• diffraction (XRD). Thin-film processing including laser lift off (LLO) was applied. The influence of epitaxial changes on the N-face etch kinetics was determined in aqueous KOH solution at elevated temperature. Inductively-coupled plasma optical emission spectroscopy (ICP-OES) was used to measure the etch

• progress in small time increments with high precision. Thereby, the disadvantages of other techniques such as determination of weight loss or height difference were overcome, achieving high accuracy and reproducibility. Keywords: etching; GaN; ICP-OES; KOH; LED; Introduction The light emitting diode (LED

• , surface roughening is an integral part of flip-chip processing. The two approaches towards surface roughening are wet- and dry-chemical etching [11][12]. During wet etching, aqueous KOH and other alkaline or acidic solutions are commonly used to remove GaN from the N-polar surface in an anisotropic manner

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

• prepared by depositing and drying 20 μL of an aqueous catalyst suspension on a silicon wafer, which was pre-cleaned by sequential rinsing in ultrapure water (MilliQ), 1 M KOH solution, and conc. H2SO4. By using silicon wafers instead of a carbon-containing support, we minimized contributions from the

Antimony deposition onto Au(111) and insertion of Mg

• Lingxing Zan,
• Da Xing,
• Abdelaziz Ali Abd-El-Latif and
• Helmut Baltruschat

Beilstein J. Nanotechnol. 2019, 10, 2541–2552, doi:10.3762/bjnano.10.245

• small compartment filled with the same electrolyte and separated from main compartment by a capillary. Pt/Ir (90:10) STM tips with a diameter of 0.25 cm were prepared by etching in a 2 M KOH/4 M KSCN bath and coated with hot-melt glue containing different types of polymer (provided by Steinel) to

pH-Controlled fluorescence switching in water-dispersed polymer brushes grafted to modified boron nitride nanotubes for cellular imaging

• Saban Kalay,
• Yurij Stetsyshyn,
• Volodymyr Donchak,
• Khrystyna Harhay,
• Ostap Lishchynskyi,
• Halyna Ohar,
• Yuriy Panchenko,
• Stanislav Voronov and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2019, 10, 2428–2439, doi:10.3762/bjnano.10.233

• number AN = 1373 mg KOH/g (theoretical value is 1368 mg KOH/g). Synthesis of oligoperoxide with residual acid chloride groups As described in [12], 4.6 g (0.014 mol) of pyromellitic acid chloride was dissolved in 15 mL of anhydrous dichloroethane, placed in a three-necked flask equipped with a stirrer

• distilled out and the pellet was dried in vacuum (100–200 Pa) at 40 °C for 3 h, yielding 8.2 g (81%) of oligoperoxide. Its characteristics are summarized as follows: content of active oxygen – 1.9% (calc. 2.2%); content of active chlorine – 5.4% (calc. 4.9%); AN = 163.1 mg KOH/g (calc. 155.3 mg KOH/g

Integration of sharp silicon nitride tips into high-speed SU8 cantilevers in a batch fabrication process

• Nahid Hosseini,
• Matthias Neuenschwander,
• Oliver Peric,
• Santiago H. Andany,
• Jonathan D. Adams and
• Georg E. Fantner

Beilstein J. Nanotechnol. 2019, 10, 2357–2363, doi:10.3762/bjnano.10.226

• by low-pressure chemical vapor deposition. Circular openings (20 µm diameter) are then cut into the layer by electron-beam lithography. The LSNT mask is dry-etched before the moulds are structured by anisotropic KOH (40% at 60 °C) etching. The formation of {111} facets results in four-sided pyramidal

• (f0) and the spring constant (k). (vi) The process is designed for top release, so the wafer is treated with DRIE to create a freestanding SU8 beam with the embedded silicon nitride tip encased in a protective oxide. (vii) The release process is finalized by placing the wafer in KOH (23% at 90 °C) to

Adsorption and desorption of self-assembled L-cysteine monolayers on nanoporous gold monitored by in situ resistometry

• Elisabeth Hengge,
• Eva-Maria Steyskal,
• Rupert Bachler,
• Alexander Dennig,
• Bernd Nidetzky and
• Roland Würschum

Beilstein J. Nanotechnol. 2019, 10, 2275–2279, doi:10.3762/bjnano.10.219

• double-layer capacitance of the substrate [14], Figure 2 compares CVs in 1 M KOH of sample A under cysteine-free conditions (before SAM assembly) and after different treatments. The SAMs can be considered stable between −400 mV (SAM desorption) and −50 mV (cysteine oxidation). At −300 mV, a double-layer

• ]. The blue solid curve was recorded after the dashed curves. All CVs were conducted in 1 M KOH at a scan rate of 1 mV/s. Please note the change in x-axis scale between (a) and (b). Cyclic voltammetry of sample B modified with cysteine (a) and concomitantly measured change in relative electrical

• resistance (b). The potential was varied between −900 and −50 mV with a scan rate of 1 mV/s in 1 M KOH. Acknowledgements The authors thank Nadiia Mameka (Helmholtz-Zentrum Geesthacht) and Egbert Zojer (Institute of Solid State Physics, University of Technology Graz) for the fruitful discussion. The work was

Ultrathin Ni_1−xCo_xS₂ nanoflakes as high energy density electrode materials for asymmetric supercapacitors

• Xiaoxiang Wang,
• Teng Wang,
• Rusen Zhou,
• Lijuan Fan,
• Shengli Zhang,
• Feng Yu,
• Tuquabo Tesfamichael,
• Liwei Su and
• Hongxia Wang

Beilstein J. Nanotechnol. 2019, 10, 2207–2216, doi:10.3762/bjnano.10.213

• corresponding nickel–cobalt oxides with the same material morphology. The assembled ASC also exhibits a superior energy density and high rate capability in a 2 M KOH aqueous electrolyte, making it a promising electrode for SCs. Experimental Materials Nickel nitrate hexahydrate (Ni(NO3)2·6H2O), cobalt nitrate

• and Hg/HgO electrode were used as a counter and a reference electrode, respectively. The electrolyte was a 2 M aqueous KOH solution. Cyclic voltammetry (CV) curves of Ni1−xCoxS2 at scan rates from 2 to 100 mV·s−1 are shown in Figure 3a. As expected, redox peaks observed within the potential window

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

• homogenous transesterification of triglycerides with methanol in the presence of sodium hydroxide (NaOH) or potassium hydroxide (KOH), which is still in use on an industrial scale. Along with the obvious advantages of being highly active and relatively inexpensive (depending however on the number of washing

• diffusion limitations for reaching effectiveness factors close to unity, iv) leaching resistance, v) activity at moderate temperatures (e.g., at the boiling point of methanol) being ideally comparable to KOH/NaOH catalysts and vi) stability for multiple reuse. Our approach to address this challenge is based

Porous silver-coated pNIPAM-co-AAc hydrogel nanocapsules

• William W. Bryan,
• Riddhiman Medhi,
• Maria D. Marquez,
• Supparesk Rittikulsittichai,
• Michael Tran and
• T. Randall Lee

Beilstein J. Nanotechnol. 2019, 10, 1973–1982, doi:10.3762/bjnano.10.194

• glassware and equipment used were first cleaned using aqua regia (3:1, HCl/HNO3), then cleaned in a base bath (saturated KOH in isopropyl alcohol) and lastly, rinsed with Milli-Q water prior to use. Preparation of pNIPAM-co-AAc hydrogel particles. Colloidal pNIPAM-co-AAc hydrogel particles were prepared

Facile synthesis of carbon nanotube-supported NiO//Fe₂O₃ for all-solid-state supercapacitors

• Shengming Zhang,
• Xuhui Wang,
• Yan Li,
• Xuemei Mu,
• Yaxiong Zhang,
• Jingwei Du,
• Guo Liu,
• Xiaohui Hua,
• Yingzhuo Sheng,
• Erqing Xie and
• Zhenxing Zhang

Beilstein J. Nanotechnol. 2019, 10, 1923–1932, doi:10.3762/bjnano.10.188

• as a reference electrode, CC-CNT@Fe2O3 as the binder-free working electrode and 2 M KOH as the electrolyte. Figure 4a shows cyclic voltammetry (CV) curves of the CC-CNT@Fe2O3 electrode at scan rates of 2, 5, 10, 20, 50 and 100 mV·s−1, from which visible redox peaks can be seen. The reduction peak at

• . All-solid-state asymmetric supercapacitor An all-solid-state asymmetric supercapacitor (ASC) was constructed with CC-CNT@Fe2O3 as the negative electrode, CC-CNT@NiO as the positive electrode, potassium hydroxide/polyvinyl alcohol gel (KOH/PVA, 1:1 mass ratio) as the electrolyte, and a cellulose

• experimental current. Since the conductivity of PVA-KOH is not as high as the aqueous electrolyte, the resistance could be rather high. IR drop is 0.038 V at 2 A·g−1, and due to that it intends to increase with current, thus is pretty high at 20 A·g−1 [38]. The specific capacitance is calculated to be 178, 136

Fabrication of phase masks from amorphous carbon thin films for electron-beam shaping

• Lukas Grünewald,
• Dagmar Gerthsen and
• Simon Hettler

Beilstein J. Nanotechnol. 2019, 10, 1290–1302, doi:10.3762/bjnano.10.128

• ). Pyramid-shaped trenches are generated beneath the thin films by anisotropic wet-etching of Si in a heated KOH solution (KOH + H2O in a ratio of 2:3, 80 °C, Figure 1a,c). The lithography mask was designed such that a 3 × 3 array of square-shaped SixNy thin films was produced on a single wafer (Figure 1b,c

Glucose-derived carbon materials with tailored properties as electrocatalysts for the oxygen reduction reaction

• Rafael Gomes Morais,
• Natalia Rey-Raap,
• José Luís Figueiredo and
• Manuel Fernando Ribeiro Pereira

Beilstein J. Nanotechnol. 2019, 10, 1089–1102, doi:10.3762/bjnano.10.109

• speed controller allowed the rotation of the working electrode to be adjusted according to the assessments being done. The experiments were carried out at room temperature in a 0.1 mol L−1 KOH solution saturated with N2 or O2 for 30 min before the cyclic voltammetry (CV) and linear sweep voltammetry

• performed in the same type of cell, with N2-saturated electrolyte (KOH 0.1 mol L−1) and with no rotation. The current density at the disk can be expressed by the Koutecký–Levich equation: where j is the measured current density (mA·cm−2), jL is the O2 diffusion-limited current density (mA cm-2), jk is the

• ) of the activated carbons. Linear sweep voltammetry recorded in an O2-saturated 0.1 mol L−1 KOH electrolyte at 1600 rpm (a) and Nyquist plot obtained from electrochemical impedance spectroscopy (b). Relationship between BET surface area and the limiting current density of the activated samples

A Ni(OH)₂ nanopetals network for high-performance supercapacitors synthesized by immersing Ni nanofoam in water

• Donghui Zheng,
• Man Li,
• Yongyan Li,
• Chunling Qin,
• Yichao Wang and
• Zhifeng Wang

Beilstein J. Nanotechnol. 2019, 10, 281–293, doi:10.3762/bjnano.10.27

• , China) in 1 M KOH aqueous solution at 298 K. The CV curves were examined in the voltage window of 0 to 0.5 V (vs Ag/AgCl) at scan rates of 2.5, 5, 10, 20, 50, 100 mV/s, and the GCD curves were collected at current densities of 0.5, 1, 2, 4, 8,12 A/cm3. The volumetric capacitance, based on the whole

• amplitude within a frequency range of 0.01 to 1000 kHz under open-circuit potential conditions. Assembly of symmetrical energy storage devices The SC devices were assembled in a commercial 2032 button-cell shell, using Ni(OH)2/Ni-NF/MG-7 as active material, non-woven fabrics as separator and 1 M KOH as

• -electrode cell in 1 M KOH aqueous solution at 298 K (Figure 5). The CV curves of the Ni(OH)2/Ni-NF/MG-2, Ni(OH)2/Ni-NF/MG-5, and Ni(OH)2/Ni-NF/MG-7 electrodes at the scan rate of 2.5 mV/s with the potential window from 0 to 0.5 V are shown in Figure 5a. A set of strong redox peaks can be clearly detected

Site-specific growth of oriented ZnO nanocrystal arrays

• Rekha Bai,
• Dinesh K. Pandya,
• Sujeet Chaudhary,
• Veer Dhaka,
• Vladislav Khayrudinov,
• Jori Lemettinen,
• Christoffer Kauppinen and
• Harri Lipsanen

Beilstein J. Nanotechnol. 2019, 10, 274–280, doi:10.3762/bjnano.10.26

• of precursors and the growth is controlled by some additional reactants during the chemical reaction such as KOH, LiOH and NaOH [21][22]. These additional reactants are employed to reduce the growth rate as well as growth temperature. But, even for a very small concentration of additional reactant

Amorphous Ni_xCo_yP-supported TiO₂ nanotube arrays as an efficient hydrogen evolution reaction electrocatalyst in acidic solution

• Yong Li,
• Peng Yang,
• Bin Wang and
• Zhongqing Liu

Beilstein J. Nanotechnol. 2019, 10, 62–70, doi:10.3762/bjnano.10.6

• obtain current densities of 10 mA cm−2 and 100 mA cm−2 in alkaline electrolyte for HER, respectively [21]. However, the preparation procedure is more complicated and not environmentally friendly and includes a hydrothermal reaction, phosphorization step and KOH activation. This brings some difficulties

Bidirectional biomimetic flow sensing with antiparallel and curved artificial hair sensors

• Claudio Abels,
• Antonio Qualtieri,
• Toni Lober,
• Alessandro Mariotti,
• Lily D. Chambers,
• Massimo De Vittorio,
• William M. Megill and
• Francesco Rizzi

Beilstein J. Nanotechnol. 2019, 10, 32–46, doi:10.3762/bjnano.10.4

• the cantilever beams (300 nm etching depth). Subsequently, anisotropic back side wet etching with a potassium hydroxide (KOH) 28% solution at 85 °C creates two cavities underneath the cantilever beams (400 μm etching depth). The SiO2 insulating layer acts as an etching barrier. Next, a hydrofluoric

• acid (HF) back side wet etching step removes the SiO2 layer (2 μm etching depth). By performing a last KOH top side wet etching, the exposed (U-shaped) silicon device layer around the cantilevers is removed (2 μm etching depth). Due to the residual stress in the material, the released SiN/Si bilayer

Hydrogen-induced plasticity in nanoporous palladium

• Markus Gößler,
• Eva-Maria Steyskal,
• Markus Stütz,
• Norbert Enzinger and
• Roland Würschum

Beilstein J. Nanotechnol. 2018, 9, 3013–3024, doi:10.3762/bjnano.9.280

• (CV) in 1 M KOH (see Figure 1). A CV probes the current as a function of the potential, which is varied up and down triangularly at a certain scan rate, which represents the slope of this potential variation. Potentiostatic hydrogen sorption The CV (black) in Figure 1 is typical for palladium and has

• vs Ag/AgCl in 1 M KOH) was determined. Experimental Alloy fabrication A Co75Pd25 master alloy was prepared from Pd granules (AlfaAesar, 99.95%) and Co slug (AlfaAesar, 99.95%) via electron-beam melting. The sample was melted multiple times to ensure complete intermixing in the liquid state and

• KOH aqueous solution. For electrochemical characterisation a porous carbon cloth was used as counter electrode. In order to assure measurement stability a pre-treatment consisting of five voltammetric cycles was applied at a scan rate of 0.1 mV·s−1 in a potential window between −1 V and 0.4 V. All

Thickness-dependent photoelectrochemical properties of a semitransparent Co₃O₄ photocathode

• Malkeshkumar Patel and
• Joondong Kim

Beilstein J. Nanotechnol. 2018, 9, 2432–2442, doi:10.3762/bjnano.9.228

• electrodes with a potential of 1.65 V vs a Co3O4 electrode in 400 mL of an alkaline bath (1 M KOH). The measured current value is presented in Figure 6b for a current density of 25 mA·cm−2 that is stable over a period of 24 h. In order to see the morphological changes after 24 h, the Co3O4 electrodes were

• splitting (Co3O4||Pt electrodes) in our previous report [20]. In order to verify the PEC performance, a PEC cell with dual Co3O4 electrodes was set up for volumetric measurements. The Co3O4 electrodes were loaded into two seperated vials (15 mL, Figure 7) and placed into the 1 M KOH electrolyte bath as

• as a function of the time. The Co3O4 electrode was biased at 1.75 V in 1 M KOH electrolyte. Inset shows the photograph of gas evolution by time. (b) Photographs of the gas evolution at t = 0 and t = 23 min. (c) The hydrogen and oxygen gas evolution as a function of the time. Summarized properties of

ZnO-nanostructure-based electrochemical sensor: Effect of nanostructure morphology on the sensing of heavy metal ions

• Marina Krasovska,
• Vjaceslavs Gerbreders,
• Irena Mihailova,
• Andrejs Ogurcovs,
• Eriks Sledevskis,
• Andrejs Gerbreders and
• Pavels Sarajevs

Beilstein J. Nanotechnol. 2018, 9, 2421–2431, doi:10.3762/bjnano.9.227

• -dimensional ZnO nanostructures were selected for the experiment: nanorods, nanoneedles and nanotubes. The samples were prepared according to the following description. Glass slides (76 × 26 × 1 mm) were precleaned via ultrasonication in aqueous solutions of KOH and H2SO4, followed by several rinses with

Performance analysis of rigorous coupled-wave analysis and its integration in a coupled modeling approach for optical simulation of complete heterojunction silicon solar cells

• Ziga Lokar,
• Benjamin Lipovsek,
• Marko Topic and
• Janez Krc

Beilstein J. Nanotechnol. 2018, 9, 2315–2329, doi:10.3762/bjnano.9.216

• solar cells and can be obtained by wet etching with KOH [36]. In Figure 4 simulated top views and cross-sectional profiles of the two textures are presented, in this case applied to the front part of the analyzed solar cell. The corresponding front thin layers are indicated by different colors. In