Optimization and performance of nitrogen-doped carbon dots as a color conversion layer for white-LED applications

• Tugrul Guner,
• Hurriyet Yuce,
• Didem Tascioglu,
• Eren Simsek,
• Umut Savaci,
• Aziz Genc,
• Servet Turan and
• Mustafa M. Demir

Beilstein J. Nanotechnol. 2019, 10, 2004–2013, doi:10.3762/bjnano.10.197

• using glucose and polyethylene glycol 200. It is reported that the WLED showed a superior performance indicated by Commission Internationale de l'Éclairage (CIE) coordinates of (0.32, 0.37) and a CCT of 5584 K. In another study, Joseph et al. reported the synthesis of CDots by the electrochemical

• coordinates of (0.35, 0.37), a CRI of 88 and a CCT of 4802 K. Furthermore, Xie et al. fabricated WLEDs using polymerizable silane‒prefunctionalized carbon dots (Si-CDots) [48]. These green low-cost polymerizable Si-CDots produced by a one-pot electrochemical synthesis have emission peaks located around 541

Nanostructured and oriented metal–organic framework films enabling extreme surface wetting properties

• Andre Mähringer,
• Julian M. Rotter and
• Dana D. Medina

Beilstein J. Nanotechnol. 2019, 10, 1994–2003, doi:10.3762/bjnano.10.196

• example, sol–gel synthesis, electrochemical deposition, anodization, electrochemical polymerization, electrospinning, plasma treatment, chemical or hydrothermal methods, vapor deposition, layer-by-layer assembly or laser ablation [19][27][28][29][30][31][32][33][34][35][36][37][38][39]. However, the

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

• a diameter of about 20 nm (Supporting Information File 1, Figure S1). The high conductivity of the CNTs will help charge transfer during the electrochemical process. As shown in Supporting Information File 1, Figure S2, the pure CC with a size of 1 × 1 cm2 is grey, it becomes black after CNT growth

• 530.13 eV, corresponding to C–O, Fe–O–C, and Fe–O, respectively [30]. The XPS results strongly support the XRD and Raman results and confirm Fe2O3 on the CC-CNT. A three-electrode system was used to examine the electrochemical characteristics of the CC-CNT@Fe2O3 with Pt foil as a counter electrode, SCE

• the CC-CNT@Fe2O3 electrode. Electrochemical impedance spectroscopy (EIS) was carried out to explore the resistance of the electrode (Figure 4d). The measured curve can be well fitted by equivalent circuits, and the insert is an enlarged view in the high-frequency area. All fitted values are shown in

High-tolerance crystalline hydrogels formed from self-assembling cyclic dipeptide

• Yongcai You,
• Ruirui Xing,
• Qianli Zou,
• Feng Shi and
• Xuehai Yan

Beilstein J. Nanotechnol. 2019, 10, 1894–1901, doi:10.3762/bjnano.10.184

• -assembly of cyclic dipeptides results in highly robust hydrogels which can be applied for electrochemical applications such as electrochemical supercapacitors. Keywords: crystalline hydrogel; cyclic dipeptide; electrochemical supercapacitors; nanoarchitectonics; self-assembly; Introduction On account of

• (ALG), hyaluronic acid (HA)), extreme acid/base environments, and thermal conditions. Owing to the robustness of the hydrogel, the material also showed excellent performance as an electrochemical supercapacitor. Hence, self-assembled CDP hydrogels are promising for applications in complex and harsh

• applications in harsh environments, such as those of electrochemical supercapacitors. Application in electrochemical supercapacitors Inspired by the high stability in harsh environments, we next investigated the application of the C-WY hydrogel as a candidate material for electrochemical supercapacitors

Charge-transfer interactions between fullerenes and a mesoporous tetrathiafulvalene-based metal–organic framework

• Manuel Souto,
• Joaquín Calbo,
• Samuel Mañas-Valero,
• Aron Walsh and
• Guillermo Mínguez Espallargas

Beilstein J. Nanotechnol. 2019, 10, 1883–1893, doi:10.3762/bjnano.10.183

• electrical conductivity and porosity at the same time. Fullerenes (C60) [25] have found numerous applications in different fields, ranging from molecular electronics and nanotechnology to biomedical applications, due to their exceptional electrochemical and photophysical properties [26][27]. In particular

• electrochemical properties [53][54]. In view of the remarkable electron-donor character of the TTF-based ligands, herein we present the encapsulation of C60 in MUV-2 (C60@MUV-2) (Figure 1). A detailed study on the CT interactions between the electron-donor TTF ligands from the framework and the electron-acceptor

• intermolecular CT excitation between the C60 and TTF ligands, as supported by theoretical calculations (see below). The experimental optical bandgap calculated from the onset is near 1.4 eV (885 nm), which is in agreement with the calculated electrochemical bandgap (1.43 eV) since the redox potential of TTF

Processing nanoporous organic polymers in liquid amines

• Jeehye Byun,
• Damien Thirion and
• Cafer T. Yavuz

Beilstein J. Nanotechnol. 2019, 10, 1844–1850, doi:10.3762/bjnano.10.179

• polymerization [14], ionic complexation [15], and electrochemical polymerization [16], which require sophisticated techniques. There are only a few reports that show the processing of nanoporous polymers into the desired morphologies, for instance, the nanoporous polymers were directly processed into

TiO₂/GO-coated functional separator to suppress polysulfide migration in lithium–sulfur batteries

• Ning Liu,
• Lu Wang,
• Taizhe Tan,
• Yan Zhao and
• Yongguang Zhang

Beilstein J. Nanotechnol. 2019, 10, 1726–1736, doi:10.3762/bjnano.10.168

• electrochemical performance of Li/S batteries. The interlayer can capture the polysulfides due to the presence of oxygen functional groups and formation of chemical bonds. The hierarchically porous TiO2 nanoparticles are tightly wrapped in GO sheets and facilitate the polysulfide storage and chemical absorption

• ]. However, the development and widespread utilization of Li/S batteries is hindered by (i) the poor electronic/ionic conductivity of sulfur, causing a low reaction rate and electrochemical polarization, (ii) dissolution and the shuttle effect of intermediate polysulfides, resulting in the deposition of Li2S

• intermediate layer and plays an important role in enhancing the electrochemical performance of Li/S batteries. It has been demonstrated that the polysulfide shuttle can be effectively suppressed by modifying the separator or incorporating an interlayer at the cathode/separator interface [21][22]. For instance

Tuning the performance of vanadium redox flow batteries by modifying the structural defects of the carbon felt electrode

• Ditty Dixon,
• Deepu Joseph Babu,
• Aiswarya Bhaskar,
• Hans-Michael Bruns,
• Joerg J. Schneider,
• Frieder Scheiba and
• Helmut Ehrenberg

Beilstein J. Nanotechnol. 2019, 10, 1698–1706, doi:10.3762/bjnano.10.165

• Ditty Dixon Deepu Joseph Babu Aiswarya Bhaskar Hans-Michael Bruns Joerg J. Schneider Frieder Scheiba Helmut Ehrenberg Central Electrochemical Research Institute (CSIR-CECRI), Karaikudi, 630003, India Fachbereich Chemie, Eduard-Zintl Institut für Anorganische und Physikalische Chemie, Technische

• oxygen functional groups on the N2-plasma-treated sample was very low, the felt showed enhanced electrochemical performance for both V3+/V2+ as well as V5+/V4+ redox reactions. The result is highly significant as the pristine electrode with the same amount of oxygen functional groups showed significantly

• configuration, showed poor electrochemical performance for the positive (V5+/V4+) redox reaction. Taking into account that the negative redox reaction is the limiting reaction in VRFB, the overall enhancement in the full cell performance was purely attributed to enhancement in the V3+/V2+ redox kinetics due to

Layered double hydroxide/sepiolite hybrid nanoarchitectures for the controlled release of herbicides

• Ediana Paula Rebitski,
• Margarita Darder and
• Pilar Aranda

Beilstein J. Nanotechnol. 2019, 10, 1679–1690, doi:10.3762/bjnano.10.163

• components in diverse electrochemical devices (such as supercapacitors, sensors, and biosensors), in drug delivery and controlled-release formulations, or in non-viral gene transfection [21][22][23][24][25][26]. The fact that the stability of LDH varies with the pH value has proved advantageous in some of

Upcycling of polyurethane waste by mechanochemistry: synthesis of N-doped porous carbon materials for supercapacitor applications

• Christina Schneidermann,
• Pascal Otto,
• Desirée Leistenschneider,
• Sven Grätz,
• Claudia Eßbach and
• Lars Borchardt

Beilstein J. Nanotechnol. 2019, 10, 1618–1627, doi:10.3762/bjnano.10.157

• applications in catalysis [24][25][26], gas sorption/separation [27][28][29] and electrochemical energy storage/conversion. For the latter, porous carbon materials are established as electrode materials in fuel cells [30][31][32][33], Li–S cells [34][35][36][37], and supercapacitors [38]. In addition, these

• -3, exhibiting a lower nitrogen content, absorbed the water after 20 s. Thus, the higher nitrogen content benefits the wettability of the carbon surface. Electrochemical characterization The produced carbon materials differ in terms of specific surface area, pore sizes, and nitrogen content

• . Therefore, we selected three carbon materials that represent a wide range of structure characteristics for electrochemical characterization: PUPC-800-3, PUUPC-800-1, and PUUPC-800-2. First, we determined the powder resistance of the carbon materials. Two general trends are observable. Firstly, the

Kelvin probe force microscopy work function characterization of transition metal oxide crystals under ongoing reduction and oxidation

• Dominik Wrana,
• Karol Cieślik,
• Wojciech Belza,
• Christian Rodenbücher,
• Krzysztof Szot and
• Franciszek Krok

Beilstein J. Nanotechnol. 2019, 10, 1596–1607, doi:10.3762/bjnano.10.155

• understanding of the operation of nanostructure electrochemical sensors [48]. Thus, we have focused on the systematic approach of the influence of ambient air on the work function of TiO and SrTiO3(100). Figure 6a shows the topography and work function of representative TiO nanowire networks before and after

• catalytic activity of the TiO surface, which was previously postulated in the case of TiO/TiO2 nanoparticles [44]. Reduced titania TiO1.23 proves also to be a promising candidate for electrochemical water splitting [50]. As the catalytic activity of a crystalline rock-salt TiO phase has yet to be studied

Materials nanoarchitectonics at two-dimensional liquid interfaces

• Katsuhiko Ariga,
• Michio Matsumoto,
• Taizo Mori and
• Lok Kumar Shrestha

Beilstein J. Nanotechnol. 2019, 10, 1559–1587, doi:10.3762/bjnano.10.153

• because of their superior electric/electrochemical properties that make them suitable for energy and electrochemical applications [56][57][58][59][60]. The works include the use of two-dimensional metal oxide nanosheets for artificial photosynthesis systems, i.e., photocatalytic water splitting and

• reported. Jayavel, Shrestha, and co-workers demonstrated the enhanced performance of electrochemical supercapacitors using composites of cobalt oxide nanoparticles and reduced graphene oxide, which are zero-dimensional and two-dimensional nanomaterials, respectively [86]. Leong and co-workers reported a

• through electrochemical processes. The interfacial formation of COFs at the liquid–liquid interfaces is more complicated because of the necessity of water-soluble COF precursors. Sahabudeen et al. have overcome this issue by using a hydrophilic dialdehyde monomer, 2,5-dihydroxyterephthalaldehyde (DHTPA

Synthesis of P- and N-doped carbon catalysts for the oxygen reduction reaction via controlled phosphoric acid treatment of folic acid

• Rieko Kobayashi,
• Takafumi Ishii,
• Yasuo Imashiro and
• Jun-ichi Ozaki

Beilstein J. Nanotechnol. 2019, 10, 1497–1510, doi:10.3762/bjnano.10.148

• ) (PFA). Two types of PFA-based carbon materials were prepared by using hydrochloric acid or phosphoric acid as polymerization initiators (non-doped and P-doped PFA carbon materials, respectively). Electrochemical methods The ORR activity of carbon materials was probed by rotating disk electrode

Flexible freestanding MoS₂-based composite paper for energy conversion and storage

• Florian Zoller,
• Jan Luxa,
• Thomas Bein,
• Dina Fattakhova-Rohlfing,
• Daniel Bouša and
• Zdeněk Sofer

Beilstein J. Nanotechnol. 2019, 10, 1488–1496, doi:10.3762/bjnano.10.147

• -1) Materials Synthesis and Processing, Wilhelm-Johnen-Straße, 52425 Jülich, Germany 10.3762/bjnano.10.147 Abstract The construction of flexible electrochemical devices for energy storage and generation is of utmost importance in modern society. In this article, we report on the synthesis of

• and delivers specific capacity of 740 mA·h·g−1 at a current density of 0.1 A·g−1. After 40 cycles at this current density the material still reached a capacity retention of 91%. Our findings show that this composite material could find application in electrochemical energy storage and generation

• active material and the current collector upon bending deformation [10]. However, there are promising reports on freestanding MoS2/carbonaceous composite electrodes which have demonstrated attractive electrochemical performance [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. Beside

Hierarchically structured 3D carbon nanotube electrodes for electrocatalytic applications

• Pei Wang,
• Katarzyna Kulp and
• Michael Bron

Beilstein J. Nanotechnol. 2019, 10, 1475–1487, doi:10.3762/bjnano.10.146

• , Figure S8). Electrochemical Investigations Cyclic voltammetry A basic electrochemical characterization of the prepared electrodes was carried out using cyclic voltammetry (CV). CVs of GC before and after oxidation in HNO3 as well as after growth of the primary CNTs and additional secondary CNTs are

• transfer resistance with respect to the primary CNTs as determined by electrochemical impedance spectroscopy. Thus, we speculate that the improvement in Pt dispersion is due to a better conductivity within the 3D network and a facilitated electron transfer, which may facilitate Pt nucleation at the CNT

• cycle of each measurements is represented in Figure 10. The current response for electrochemical activity towards MOR was quantified to the Pt mass and the Pt ECSA in Figure 10a and Figure 10b, respectively, where the Pt ESCA was calculated from the COad stripping voltammograms. Figure 10 represents the

BiOCl/TiO₂/diatomite composites with enhanced visible-light photocatalytic activity for the degradation of rhodamine B

• Minlin Ao,
• Kun Liu,
• Xuekun Tang,
• Zishun Li,
• Qian Peng and
• Jing Huang

Beilstein J. Nanotechnol. 2019, 10, 1412–1422, doi:10.3762/bjnano.10.139

• a Micromeritics ASAP 2020 surface area and porosity measurement system. A Unico UV-2600 spectrophotometer was used to analyze the concentration of RhB in the photocatalytic process. The photoelectrochemical properties were analyzed using electrochemical workstations (Gamry interface 1010 and Chenhua

• good cyclic ability and stability. Photocatalytic mechanism analysis In order to reveal the photocatalytic mechanism, we observe the optical, photochemical and electrochemical properties to study the energy band structure and carrier migration pathway of BTD. Figure 8a presents the UV–vis diffuse

• efficiency of the samples, photoluminescence spectroscopy, photocurrent and electrochemical impedance spectroscopy were tested. The recombination rate of photogenerated carriers (electrons and holes) in photocatalysts was characterized by photoluminescence spectra. Generally, the lower the spectral intensity

Warped graphitic layers generated by oxidation of fullerene extraction residue and its oxygen reduction catalytic activity

• Machiko Takigami,
• Rieko Kobayashi,
• Takafumi Ishii,
• Yasuo Imashiro and
• Jun-ichi Ozaki

Beilstein J. Nanotechnol. 2019, 10, 1391–1400, doi:10.3762/bjnano.10.137

• the amount of surface functional groups. The details of this technique are described elsewhere [45][46]. Electrochemical techniques Cyclic voltammetry was used to evaluate the heterogeneous electron transfer rate of the carbons in an aqueous solution consisting of 6 × 10−3 mol/L K3[Fe(CN)6] and 1 mol

• was subtracted from a voltammogram in an O2-saturated electrolyte giving a net ORR voltammogram. The electrochemical system consisted of a rotation apparatus (RRDE-3A, BAS Japan) and a potentiostat (ALS700 series, BAS Japan). The potential sweep was started from 1 V to 0 V vs RHE, at a potential sweep

Construction of a 0D/1D composite based on Au nanoparticles/CuBi₂O₄ microrods for efficient visible-light-driven photocatalytic activity

• Weilong Shi,
• Mingyang Li,
• Hongji Ren,
• Feng Guo,
• Xiliu Huang,
• Yu Shi and
• Yubin Tang

Beilstein J. Nanotechnol. 2019, 10, 1360–1367, doi:10.3762/bjnano.10.134

• photocatalytic activity after three cycles. This decrease of photocatalytic performance is mainly due to the mass of catalysts being inevitably lost in the recycling process [39]. Photocurrent response and electrochemical impedance spectroscopy (EIS) measurements were carried out to obtain some insights into the

Multicomponent bionanocomposites based on clay nanoarchitectures for electrochemical devices

• Giulia Lo Dico,
• Bernd Wicklein,
• Lorenzo Lisuzzo,
• Giuseppe Lazzara,
• Pilar Aranda and
• Eduardo Ruiz-Hitzky

Beilstein J. Nanotechnol. 2019, 10, 1303–1315, doi:10.3762/bjnano.10.129

• biocomposite: HNTs act as nanocontainers for bioactive species, GNPs provide electrical conductivity (enhanced by doping with MWCNTs) and, the CHI polymer matrix introduces mechanical and membrane properties that are of key significance for the development of electrochemical devices. The resulting

• characteristics allow for a possible application of these active elements as integrated multicomponent materials for advanced electrochemical devices such as biosensors and enzymatic biofuel cells. This strategy can be regarded as an “a la carte” menu, where the selection of the nanocomponents exhibiting

• different properties will determine a functional set of predetermined utility with SEP maintaining stable colloidal dispersions of different nanoparticles and polymers in water. Keywords: bionanocomposites; carbon nanostructures; electrochemical devices; halloysite nanotubes; sepiolite; Introduction In

Alloyed Pt₃M (M = Co, Ni) nanoparticles supported on S- and N-doped carbon nanotubes for the oxygen reduction reaction

• Stéphane Louisia,
• Yohann R. J. Thomas,
• Pierre Lecante,
• Marie Heitzmann,
• M. Rosa Axet,
• Pierre-André Jacques and
• Philippe Serp

Beilstein J. Nanotechnol. 2019, 10, 1251–1269, doi:10.3762/bjnano.10.125

• ) alloyed nanoparticles that have a very homogeneous size distribution (in spite of the high metal loading of ≈40 wt % Pt), using an ionic liquid as a stabilizer. The electrochemical surface area, the activity for the oxygen reduction reaction and the amount of H2O2 generated during the oxygen reduction

• reaction (ORR) have been evaluated in a rotating ring disk electrode experiment. The Pt3M/N-CNT catalysts revealed excellent electrochemical properties compared to a commercial Pt3Co/Vulcan XC-72 catalyst. The nature of the carbon support plays a key role in determining the properties of the metal

• from thermochemical instability and corrosion in fuel cell applications. In the cathodic layer, the oxidizing, wet and acidic environment, the high electrochemical potential, and the high platinum loading all lead to the oxidation of the carbon surface, and occasionally to the formation of CO2 [9

Porous N- and S-doped carbon–carbon composite electrodes by soft-templating for redox flow batteries

• Maike Schnucklake,
• László Eifert,
• Jonathan Schneider,
• Roswitha Zeis and
• Christina Roth

Beilstein J. Nanotechnol. 2019, 10, 1131–1139, doi:10.3762/bjnano.10.113

• obtained inside the macroporous carbon felt. For the investigation of electrode structure and porosity X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and nitrogen sorption (BET) were used. The electrochemical performance of the carbon felts was evaluated by cyclic voltammetry

• (CV) and electrochemical impedance spectroscopy (EIS). The N- and S-doped carbon electrodes show promising activity for the positive side reaction and could be seen as a significant advance in the design of carbon felt electrodes for use in redox flow batteries. Keywords: N- and S-doped carbon

• energy is stored in the form of vanadium containing electrolytes, which consist of V2+/3+ at the negative and V4+/5+ at the positive side. These are flowed through carbon materials, which are usually porous felts or carbon paper electrodes [4]. Carbon electrodes exhibit good stability and electrochemical

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

• -doped biomass-derived carbon materials were prepared by hydrothermal carbonization of glucose, and their textural and chemical properties were subsequently tailored to achieve materials with enhanced electrochemical performance towards the oxygen reduction reaction. Carbonization and physical activation

• materials [3][4] have been widely studied as electrocatalysts in ORR due to their attractive physical and electrochemical properties. Among these materials, metal-free carbon materials have received tremendous attention due to their versatility and lower price in comparison with metal-based materials [2

• basic electrolyte at 1600 rpm and the Nyquist plot obtained from electrochemical impedance spectroscopy measurements are shown in Figure 2a and 2b, respectively. To evaluate the performance of the prepared electrocatalysts, cyclic voltammetry (CV) and linear sweep voltammetry (LSV) were performed. LSV

Correlation of surface-enhanced Raman scattering (SERS) with the surface density of gold nanoparticles: evaluation of the critical number of SERS tags for a detectable signal

• Vincenzo Amendola

Beilstein J. Nanotechnol. 2019, 10, 1016–1023, doi:10.3762/bjnano.10.102

• plasmonic nanoparticles dispersed on a substrate [38], inside microcavities [39], or even while monitoring electrochemical reactions [40]. This work reports on the study of SERS tags obtained by laser ablation synthesis in liquid solution (LASiS) of gold (Au) nanoparticles, their coating with three

Concurrent nanoscale surface etching and SnO₂ loading of carbon fibers for vanadium ion redox enhancement

• Jun Maruyama,
• Shohei Maruyama,
• Tomoko Fukuhara,
• Toru Nagaoka and
• Kei Hanafusa

Beilstein J. Nanotechnol. 2019, 10, 985–992, doi:10.3762/bjnano.10.99

• demonstration of this surface-structure change is difficult through FESEM observation only, Raman spectroscopy and electrochemical measurements can show clear differences as described below. The degree of the surface etching depends on the temperature of the thermal oxidation (Figure 1e and Figure S2

• exposure to air after the CSnPc deposition. The graphitic surface is much less susceptible to the oxidation [27]. Thus, the oxygen surface concentration decreases from TGP-CSnPc to TGP-CSnPc-550Air also suggested the removal of the CSnPc coating. Electrochemical behavior without vanadium ions The cyclic

• voltammograms (CVs) obtained in an acidic electrolyte without vanadium ions are shown in Figure 4. The current in the voltammogram is composed from three components, i.e., the electrochemical double-layer charging current at the carbon–electrolyte interface, and the faradaic currents due to the redox reactions

Structural and optical properties of penicillamine-protected gold nanocluster fractions separated by sequential size-selective fractionation

• Xiupei Yang,
• Zhengli Yang,
• Fenglin Tang,
• Jing Xu,
• Maoxue Zhang and
• Martin M. F. Choi

Beilstein J. Nanotechnol. 2019, 10, 955–966, doi:10.3762/bjnano.10.96

• common method that has been used to the size fraction nanomaterial dispersions such as CdS and CdSe. However, this method has been mainly carried out to separate water-insoluble nanoparticles from organic solvents. On the other hand, it is also understood that the photophysical, electrochemical and other