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

• exfoliation of graphite [47]. The obtained CDots showed a broad band emission due to their heterogeneity in particle size and surface-functional groups. The authors explored the potential of CDots as UV-to-visible color converters using a 365 nm UV chip and could generate white light with CIE color

• nanoparticles instead of power spectra, which show diffraction spots generated by only one plane. Figure 2c shows the HRTEM micrograph of a ≈10 nm diameter nanoparticle. This nanoparticle is identified as being composed of a graphite phase based on the observation of the 0.34 nm lattice spacing values

• this lattice spacing as the {1120} lattice plane of graphene [55][56]. It should be noted here that when it comes to CDots, it is common to assign them as graphene rather than graphite, since typically, stacking of a few layers of graphene forms the CDots. The HRTEM micrographs obtained from a ≈9 nm

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

• , both electrode surfaces tend to oxidize with the additional formation of oxygen functional groups [9][10]. Excess oxidation of the carbon felt can also introduce nonselective functional groups such as –C–O and –C=O and reduces the sp2 carbon content or the graphite content of the felt. The formation of

• nonselective functional groups can impede the redox reaction. For example, Estevez et al. showed that the presence of –O–C=O groups increases the performance of the VRFB whereas the presence of –C–O and –C=O degrades it [11]. In the long run, reduction in the graphite or sp2 carbon content of the felt reduces

• graphitic nature as functionalization proceeds by breaking of the C6 rings, and in many cases, with the formation of a sp3 hybridized carbon atoms (out of plane with the graphene layer). Moreover, most of these functional groups will be predominantly formed at graphite edge sites which are much more active

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

• STO materials enabled a low sample bias of +1 mV for the LC-AFM measurements to be used. Real work function values were calculated from recorded CPD maps after calibration against a material of known work function, here highly oriented pyrolytic graphite (HOPG), which was annealed in situ up to 300 °C

Graphynes: an alternative lightweight solution for shock protection

• Kang Xia,
• Haifei Zhan,
• Aimin Ji,
• Jianli Shao,
• Yuantong Gu and
• Zhiyong Li

Beilstein J. Nanotechnol. 2019, 10, 1588–1595, doi:10.3762/bjnano.10.154

• : graphyne; in silico studies; stress wave propagation; supersonic-velocity impact; Introduction Owing to its versatile flexibility, carbon is able to form three different hybridization states namely sp, sp2 and sp3, which yields many kinds of carbon allotropes. Graphite and diamond are the two common

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

• /pyridone-type, quaternary, and oxygen-bonded (oxidized) N, respectively (Table 2). Thus, P-700 contained quaternary N incorporated into graphite layers, as exemplified by the corresponding peaks at 401–400.7 eV. The peak of pyridinic N (398.5 eV), clearly observed for H-series precursors, was less

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

• extend their application to large energy storage systems or to the electromobility sector, an improvement in the energy storage capacity is necessary. Layered dichalcogenide materials such as molybdenum sulfide (MoS2) are promising candidates for the replacement of the commercial anode material graphite

• graphite (372 mA·h·g−1) [6]. However, poor electrical conductivity, capacity fading and large volume changes upon charge and discharge make the commercialization of MoS2 in LIBs problematic [6][7]. In order to address this issue, the fabrication of MoS2 composites and carbonaceous support materials (such

Kelvin probe force microscopy of the nanoscale electrical surface potential barrier of metal/semiconductor interfaces in ambient atmosphere

• Petr Knotek,
• Tomáš Plecháček,
• Jan Smolík,
• Petr Kutálek,
• Filip Dvořák,
• Milan Vlček,
• Jiří Navrátil and
• Čestmír Drašar

Beilstein J. Nanotechnol. 2019, 10, 1401–1411, doi:10.3762/bjnano.10.138

• material because of its well-defined layered structure with sub-nanometer roughness similar to mica or highly oriented pyrolytic graphite (HOPG). The electrical conductivity and mechanical stiffness of Bi2Se3 allow for the measurement with high-intensity electrical fields (10 V/30 nm) without damaging the

Nanoscale spatial mapping of mechanical properties through dynamic atomic force microscopy

• Zahra Abooalizadeh,
• Leszek Josef Sudak and
• Philip Egberts

Beilstein J. Nanotechnol. 2019, 10, 1332–1347, doi:10.3762/bjnano.10.132

• modulus of highly oriented pyrolytic graphite (HOPG), specifically by using force modulation microscopy (FMM) and contact resonance (CR) AFM. In both of these techniques, a variation in the amplitude signal was observed when scanning over an uncovered step edge of HOPG. In comparison, no variation in the

• (CR) AFM; elastic modulus mapping; force modulation microscopy (FMM); highly oriented pyrolytic graphite (HOPG); mechanical properties; surface science; surface steps; Introduction In recent years, the study of the size-dependent properties of materials, and in particular those at the nanometer scale

• vacuum (UHV) AFM, which can increase the spatial resolution of the measured mechanical properties as well as the reliability of the measurements made. In this work, both FMM and CR modes have been employed to examine surfaces of highly oriented pyrolytic graphite (HOPG) under UHV conditions in order to

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

• by coupling the bioactive foam, as anode, to a Pt wire as cathode in a one-pot cell working in 0.1 M of glucose and 0.1 M PBS, at two different pH values (7 and 5.5) and saturated with air. The foam was connected to the potentiostat with a copper wire, glued with colloidal graphite and covered by an

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

• obtained with XRD are presented in Table 1. All the values are larger than that of graphite (3.334 Å), and the smallest value is obtained for N-CNTHT, indicating a higher level of graphitization for this sample. The elemental composition as well as the surface chemistry is also affected by heteroatom

• performed on a diffractometer dedicated to pair distribution function (PDF) analyses: graphite-monochromatized molybdenum radiation (0.07169 nm), solid state detection and low background setup. The samples were sealed in Lindemann glass capillaries (diameter 1.5 mm). The MEA cross-sections were prepared by

Tailoring the magnetic properties of cobalt ferrite nanoparticles using the polyol process

• Malek Bibani,
• Romain Breitwieser,
• Alex Aubert,
• Vincent Loyau,
• Silvana Mercone,
• Souad Ammar and
• Fayna Mammeri

Beilstein J. Nanotechnol. 2019, 10, 1166–1176, doi:10.3762/bjnano.10.116

• °C in a graphite die (more details are given in [35]). Then, a resistive strain gauge (EA-06-062TT-120, Micro-Measurements) was glued (with epoxy resin) on the top face of each polished pellet, to perform extensometry measurements in presence of a longitudinally applied magnetic field H (Figure 8b

In situ AFM visualization of Li–O₂ battery discharge products during redox cycling in an atmospherically controlled sample cell

• Kumar Virwani,
• Younes Ansari,
• Khanh Nguyen,
• Francisco José Alía Moreno-Ortiz,
• Jangwoo Kim,
• Maxwell J. Giammona,
• Ho-Cheol Kim and
• Young-Hye La

Beilstein J. Nanotechnol. 2019, 10, 930–940, doi:10.3762/bjnano.10.94

• Li/O2 reactions. Wen et al. [23] performed in situ AFM imaging of the Li/O2 electrochemical reaction on highly oriented pyrolytic graphite (HOPG). In their work, the imaging during the electrochemical reaction was performed using contact mode and upon completion of the electrochemical reaction, the

Synthesis of novel C-doped g-C₃N₄ nanosheets coupled with CdIn₂S₄ for enhanced photocatalytic hydrogen evolution

• Jingshuai Chen,
• Chang-Jie Mao,
• Helin Niu and
• Ji-Ming Song

Beilstein J. Nanotechnol. 2019, 10, 912–921, doi:10.3762/bjnano.10.92

• /CCN (CISCCN) composite products were characterized by X-ray diffraction (XRD). As shown in Figure 2, the (100) peak located at 13.1° displayed in pure g-C3N4 is attributed to the in-planar stacking of tris-triazine units [35]. The characteristic graphite-like nanosheet structure of g-C3N4 is

The systemic effect of PEG-nGO-induced oxidative stress in vivo in a rodent model

• Qura Tul Ain,
• Samina Hyder Haq,
• Abeer Alshammari,
• Moudhi Abdullah Al-Mutlaq and
• Muhammad Naeem Anjum

Beilstein J. Nanotechnol. 2019, 10, 901–911, doi:10.3762/bjnano.10.91

• graphite, a strong XRD peak at 2θ = 26.5° and a slight peak at 2θ = 54.5° were observed specific to the (002) and (004) planes with d-spacing of 3.5 Å and 1.9 Å, respectively. The XRD pattern of graphene oxide shows a peak at 2θ = 9.9° (d-spacing of 8.9 Å), the (100) diffraction peak at 2θ = 42.0

• of PEGylated nano-graphene oxide (PEG-nGO), and examined the recovery of the organ from the stress after specific intervals of time. For this purpose, we oxidized sheets of graphite with an improved Hummer's method [3]. Afterward, GO sheets were cracked into nGO by a previously adopted method by

• accompanied by reduced activity levels of antioxidant enzymes directly indicated that all organs were in oxidative stress after the intraperitoneal administration of PEG-nGO. These studies further reiterated the cytotoxicity of graphite oxide in vivo. Further safety evaluation and research must be undertaken

Synthesis of MnO₂–CuO–Fe₂O₃/CNTs catalysts: low-temperature SCR activity and formation mechanism

• Yanbing Zhang,
• Lihua Liu,
• Yingzan Chen,
• Xianglong Cheng,
• Chengjian Song,
• Mingjie Ding and
• Haipeng Zhao

Beilstein J. Nanotechnol. 2019, 10, 848–855, doi:10.3762/bjnano.10.85

• diffraction measurements Figure 2 shows the XRD patterns of the acid-treated CNTs and the as-synthesized catalysts. All samples present the characteristic diffraction peaks at 26.3°, 42.6° and 53.7°, corresponding to the (002), (100), and (004) planes of graphite, respectively [18]. For MnO2–CuO–Fe2O3/CNTs

• the results of NO conversion. Besides, the intensities of the graphite peaks declines with increased loading, which is due to the interaction between the metal oxide catalysts and CNTs [21][22][23][24][25]. Transmission electron microscopy and energy dispersive X-ray spectrometry The morphologies of

Capillary force-induced superlattice variation atop a nanometer-wide graphene flake and its moiré origin studied by STM

• Loji K. Thomas and
• Michael Reichling

Beilstein J. Nanotechnol. 2019, 10, 804–810, doi:10.3762/bjnano.10.80

• superlattices on graphite by imaging a live transition from one superlattice to another with concurrent and direct measurement of the orientation angle before and after rotation using scanning tunneling microscopy (STM). This has been possible due to a fortuitous observation of a superlattice on a nanometer

• sufficient to account for the total expenditure of energy involved in the process. Keywords: capillary force; graphene; graphite; HOPG; moiré; solid–liquid interface; STM; superlattice; Introduction Graphite is a layered material with graphene sheets arranged in ABAB stacking. HOPG is an ordered form of

• pyrolytic graphite with a high degree of crystallographic orientation of the c-axis. Polycrystalline HOPG consists of micrometer-sized grains and has been widely used as a substrate in STM studies [1][2][3] due to its high conductivity, atomic flatness and chemical inertness [4]. The surface also contains

An efficient electrode material for high performance solid-state hybrid supercapacitors based on a Cu/CuO/porous carbon nanofiber/TiO₂ hybrid composite

• Mamta Sham Lal,
• Thirugnanam Lavanya and
• Sundara Ramaprabhu

Beilstein J. Nanotechnol. 2019, 10, 781–793, doi:10.3762/bjnano.10.78

• assigned to the highly ordered graphite structure which arises due to stretching of carbon atoms bonded with sp2 bonds. TiO2 nanoparticles in the low frequency region were assigned to the E1g (148.5 cm−1), B1g (400 cm−1), A1g (517 cm−1) and Eg (638 cm−1) modes of the anatase phase respectively [26]. A

Self-assembly and wetting properties of gold nanorod–CTAB molecules on HOPG

• Imtiaz Ahmad,
• Floor Derkink,
• Tim Boulogne,
• Pantelis Bampoulis,
• Harold J. W. Zandvliet,
• Hidayat Ullah Khan,
• Rahim Jan and
• E. Stefan Kooij

Beilstein J. Nanotechnol. 2019, 10, 696–705, doi:10.3762/bjnano.10.69

• drying on a nonwetting highly ordered pyrolytic graphite (HOPG) surface have been investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Although SEM did not reveal coverage of CTAB layers, AFM showed not only CTAB assembly, but also the dynamics of the process on the

• that CTAB surfactant molecules can self-assemble on a highly ordered pyrolytic graphite (HOPG) surface in the form of hemi-cylindrical micelles [43][44][45]. The surface of HOPG is hydrophobic [46][47], while the CTAB molecules have a hydrophilic end group and a hydrophobic tail [48]. Therefore, to

Mechanical and thermodynamic properties of Aβ₄₂, Aβ₄₀, and α-synuclein fibrils: a coarse-grained method to complement experimental studies

• Adolfo B. Poma,
• Horacio V. Guzman,
• Mai Suan Li and
• Panagiotis E. Theodorakis

Beilstein J. Nanotechnol. 2019, 10, 500–513, doi:10.3762/bjnano.10.51

• , such as highly oriented pyrolytic graphite (HOPG), silica, and other “clean” surfaces, which are, however, very far away from biological systems. Moreover, by considering the indenter as a sphere, the anisotropies in the deformed material can be screened, since the measured deformation depends on the

Polymorphic self-assembly of pyrazine-based tectons at the solution–solid interface

• Achintya Jana,
• Puneet Mishra and
• Neeladri Das

Beilstein J. Nanotechnol. 2019, 10, 494–499, doi:10.3762/bjnano.10.50

• the observed polymorphs. Such weak hydrogen bonding interactions are highly desirable for the formation of modular supramolecular architectures since they can provide sufficiently robust molecular structures and also facilitate error correction. Keywords: highly oriented pyrolytic graphite (HOPG

Improving control of carbide-derived carbon microstructure by immobilization of a transition-metal catalyst within the shell of carbide/carbon core–shell structures

• Teguh Ariyanto,
• Jan Glaesel,
• Andreas Kern,
• Gui-Rong Zhang and
• Bastian J. M. Etzold

Beilstein J. Nanotechnol. 2019, 10, 419–427, doi:10.3762/bjnano.10.41

• 5 s per step. The XRD diffractograms were deconvoluted to evaluate the properties of graphitic reflexes (see exemplary deconvolution in Figure 7). The graphite dimension (La of the in-plane and Lc of the cross section size) was evaluated by the Scherrer equation shown in Equation 2 [34]. where λ is

Sub-wavelength waveguide properties of 1D and surface-functionalized SnO₂ nanostructures of various morphologies

• Venkataramana Bonu,
• Binaya Kumar Sahu,
• Arindam Das,
• Sankarakumar Amirthapandian,
• Sandip Dhara and
• Harish C. Barshilia

Beilstein J. Nanotechnol. 2019, 10, 379–388, doi:10.3762/bjnano.10.37

• of SnO2 QDs was discussed in our earlier report [18]. In the case of VLS growth, a mixture of SnO2 QDs of diameter 2.4 nm and graphite powder (Alfa Aesar, 99.9995%) in a 3:1 weight ratio was placed in a high purity Al2O3 (99.99 %) boat. Au-coated Si (100) was used as the substrate. A Au film of 3 nm

• one case the growth temperature was 950 °C and in the other case it was 1000 °C (Figure S1a). In the case of VS growth, a mixture of SnO2 QDs of size 2.4 nm and graphite powder (Alfa Aesar, 99.9995%) in a 3:1 weight ratio was placed in a high purity Al2O3 crucible (99.99%). The NWs were grown in the

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

• nickel hydroxide without binders has become a hot topic in recent years. For instance, Ni(OH)2 active materials have been loaded on stainless steel [21], carbon foam [22] and three-dimensional (3D) graphite foam [23]. Furthermore, 3D porous nickel materials have been used extensively as conductive

Graphene–graphite hybrid epoxy composites with controllable workability for thermal management

• Idan Levy,
• Eyal Merary Wormser,
• Maxim Varenik,
• Matat Buzaglo,
• Roey Nadiv and
• Oren Regev

Beilstein J. Nanotechnol. 2019, 10, 95–104, doi:10.3762/bjnano.10.9

• comprising a combination of two different carbon-based fillers, graphene nanoplatelets (GNPs) and graphite. By adjusting the GNP:graphite concentration ratio and the total concentration of the fillers, we were able to fine tune the thermal conductivity and the workability of the hybrid polymer composite. To

• graphene, a two-dimensional sheet of sp2-hybridized carbons, with a much lower filler-to-filler resistance than that of the CNTs [11][24][25]. In recent years, extensive studies have been conducted on graphite and graphene nanoplatelets (GNPs, composed of several graphene layers, with thickness of up to

• surfaces [40]. It is, therefore, important to tailor the rheological properties of the TIM to the specific application, while still striving to maintain a high TC in the bulk material. In a previous study [41] we have demonstrated that by loading a polymer matrix with two fillers, namely, GNP and graphite

Threshold voltage decrease in a thermotropic nematic liquid crystal doped with graphene oxide flakes

• Mateusz Mrukiewicz,
• Krystian Kowiorski,
• Paweł Perkowski,
• Rafał Mazur and
• Małgorzata Djas

Beilstein J. Nanotechnol. 2019, 10, 71–78, doi:10.3762/bjnano.10.7

• K11, electric anisotropy Δε, switch-on τON and switch-off τOFF times and their dependence on the concentration of the GO flakes. Materials and Methods Graphene oxide (GO) flakes dispersed in water were obtained from natural graphite by the modified Hummers’ method [29][30] in the Department of