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

• surface. The emission corresponding to such a structure is considered to originate from the conjugated sp2-domains [16][17] and can be adjusted either by modulating the dimension of these sp2-domains [18] or through surface modifications [19][20]. For instance, doping of the CDots with heteroatoms such as

• nitrogen-doped CDots (N-CDots). The doping with nitrogen enables us to tune the resulting emission color of the CDots from blue to green. In order to obtain color conversion layers with these N-CDots, a mixture of water-based polyvinylpyrrolidone (PVP) and N-CDots were prepared and subsequently processed

Prestress-loading effect on the current–voltage characteristics of a piezoelectric p–n junction together with the corresponding mechanical tuning laws

• Wanli Yang,
• Shuaiqi Fan,
• Yuxing Liang and
• Yuantai Hu

Beilstein J. Nanotechnol. 2019, 10, 1833–1843, doi:10.3762/bjnano.10.178

• on how much influence of the deformation-induced electric field can reach the SCZ. Furthermore, it is also found that the deformation-induced electric field becomes weak with increasing doping because the higher doping is corresponding to the stronger electric leakage. Thus, the higher mechanical

• ZnO nanowire based on the linear phenomenological theory of piezoelectric semiconductors. In their studies, the electric leakage of a bent ZnO nanowire is connected to the semiconductor properties and concluded that a lower doping concentration is more suitable for a bent ZnO nanowire to harvest

• –n junction can be written as where (p(n0,p0)(x), n(n0,p0)(x)) and (NA, ND) are carrier concentrations and doping concentrations, respectively. The subscripts “p” and “n” represent p-zone and n-zone, respectively. q = 1.602 × 10−19 C is the electronic charge. For a piezoelectric p–n junction exposed

Growth dynamics and light scattering of gold nanoparticles in situ synthesized at high concentration in thin polymer films

• Corentin Guyot,
• Philippe Vandestrick,
• Ingrid Marenne,
• Olivier Deparis and
• Michel Voué

Beilstein J. Nanotechnol. 2019, 10, 1768–1777, doi:10.3762/bjnano.10.172

• in the composite less than 1%, the effect of doping is usually not detected experimentally using MG-EMA when the optical measurements are carried out out-of-resonance. This effect has been modeled in Supporting Information File Supporting Information File 1. Moreover, going from standard ellipsometry

• the sample temperature reaches Tg, the glass transition temperature of the polymer. For bulk PVA, Tg equals 85 °C [32]. As already reported for other polymers, Tg is also a function of the film thickness and differs from the bulk value of Tg [33]. It can also be modified by doping. Since the

• neglectable. Theoretical calculations were made using the Maxwell–Garnett effective medium approximation (MG-EMA) for spherical nanoparticles (Figure S3, Supporting Information File Supporting Information File 1). They showed that, at the operating wavelength of the ellipsometer and at the doping levels

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

• )-based carbon felt was subjected to N2-plasma treatment to increase the heteroatom defects and reactive edge sites as a method to increase the performance in vanadium redox flow batteries (VRFBs). N-doping in the felt was mainly in the form of pyrrolic and pyridinic nitrogen. Even though the amount of

• and edge sites. Thus, from the present study, it can be concluded that an alternate way to increase the performance of the VRFBs is to introduce specific defects such as N-doping/substitution or to increase the edge sites. In other words, defects induced in the carbon felt such as heteroatom doping

• reaction site or catalytic center in graphite is by doping it with heteroatoms such as B, N, or P. The heteroatom perturbs the electronic structure of the graphite layer subjected to doping, leading to enhanced polarization [14]. N-doped carbon-based electrodes have been successfully tested in VRFBs. For

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

• increased with increasing nitrogen content. Thus, nitrogen-doping has no beneficial influence on the conductivity of the electrodes in contrast to expectations. The materials have been processed to free-standing electrodes and characterized as symmetrical supercapacitors in three different electrolytes: 1 M

• setup. By using different amounts of activation and doping reagents, we obtained optimized carbon materials offering excellent properties such as a high specific surface area of 2150 m2·g−1, and a total pore volume of 0.9 cm3·g−1 (PUUPC-800-1). These N-doped carbon materials performed similarly well as

• the activation and doping reagents, the mixture was then milled in the same ball mill and vessel for 30 min and at a rotation speed of 800 rpm. The resulting polymer was pyrolyzed for one hour in argon at 800 °C with a heating rate of 150 °C·h−1 and afterwards purified with diluted HCl and water

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

• uniform two-dimensional nanocarbon films, so-called carbon nanosheets, with ca. 10 nm thickness with dispersed nanopore structural motifs. The electrical conductivity of the transferred film was significantly increased after the thermal carbonization process. Nitrogen-doping was carried out simply by

Rapid thermal annealing for high-quality ITO thin films deposited by radio-frequency magnetron sputtering

• Petronela Prepelita,
• Ionel Stavarache,
• Doina Craciun,
• Florin Garoi,
• Catalin Negrila,
• Beatrice Gabriela Sbarcea and
• Valentin Craciun

Beilstein J. Nanotechnol. 2019, 10, 1511–1522, doi:10.3762/bjnano.10.149

• near the valence band (such as oxygen interstitials and indium vacancies) and the number of states increases with increasing oxygen flow. A poor crystalline quality with abundant structural defects leads to effective compensation of doping [33][48]. The metallic nature of the highly conductive ITO

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

• oxygen reduction reaction (ORR) at the cathode of a fuel cell. Precursors obtained by heating FA in the presence of phosphoric acid at temperatures of 400–1000 °C were further annealed at 1000 °C to afford PN-doped carbon materials. The extent of precursor P doping was maximized at 700 °C, and the use of

• employed as a single-cell cathode [17]. The ORR activity of carbon-based catalysts can be substantially improved by their simultaneous doping with N and other elements. In 2007, we reported that carbon prepared by carbonization of a N- and B-doped furan resin exhibited an increased ORR activity in sulfuric

• acid solution [11], and since then, much attention has been directed at the activation of carbon catalysts through co-doping [18]. The concept of co-doping has been even extended to three-component catalysts, as exemplified by studies on N, P, S-doped and N, P, F-doped carbon materials [19][20

Direct observation of oxygen-vacancy formation and structural changes in Bi₂WO₆ nanoflakes induced by electron irradiation

• Hong-long Shi,
• Bin Zou,
• Zi-an Li,
• Min-ting Luo and
• Wen-zhong Wang

Beilstein J. Nanotechnol. 2019, 10, 1434–1442, doi:10.3762/bjnano.10.141

• be induced by chemical doping [18][19], hydrogen reduction [16] or ultra-thinning [14][20]. Surface oxygen vacancies can efficiently separate photogenerated electron–hole pairs, resulting in enhanced photocatalytic activity. Bismuth defects or dangling bonds of bismuth atoms resulting from oxygen

Selective gas detection using Mn₃O₄/WO₃ composites as a sensing layer

• Yongjiao Sun,
• Zhichao Yu,
• Wenda Wang,
• Pengwei Li,
• Gang Li,
• Wendong Zhang,
• Lin Chen,
• Serge Zhuivkov and
• Jie Hu

Beilstein J. Nanotechnol. 2019, 10, 1423–1433, doi:10.3762/bjnano.10.140

• based on Mn3O4/WO3 composites presented outstanding selectivity to H2S, NH3 and CO at the working temperatures of 90 °C, 150 °C and 210 °C, respectively. Furthermore, we also found that 3 atom % is the optimal doping amount of Mn3O4 for the composite as sensor, which exhibits the highest response and

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

• such as doping [21], sensitization [22], modification [23], coupled and supported semiconductors [24]. As an important bismuth oxyhalide semiconductor material, bismuth oxychloride (BiOCl) has gained extensive attention in photocatalysis [25][26]. BiOCl has a band gap of 3.05–3.55 eV [27], which allows

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

• (NIs/NPs) into the bulk semiconducting matrices has been proposed [4][5][6] and supported in theoretical works [7][8][9]. Such NIs or NPs are able to enhance ZT via a reduction of the thermal conductivity by phonon scattering [10][11][12][13][14], by modulated carrier doping or by the carrier energy

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

• = Fe, Co) and its analog on carbon substrates [5][6][7][8]; (2) change in the electronic distribution by doping with nitrogen and other elements [9][10][11][12][13][14][15][16][17][18][19][20][21][22]; and (3) activation of the carbon surface by encapsulated metal particles [23][24][25][26][27][28

The effect of magneto-crystalline anisotropy on the properties of hard and soft magnetic ferrite nanoparticles

• Hajar Jalili,
• Bagher Aslibeiki,
• Ali Ghotbi Varzaneh and
• Volodymyr A. Chernenko

Beilstein J. Nanotechnol. 2019, 10, 1348–1359, doi:10.3762/bjnano.10.133

• doping on structure, morphology and magnetic properties of CoxFe3−xO4 samples was investigated. In particular, we examined the interparticle interactions in the samples by δm graphs and Henkel plots that have not been reported before in literature. Finally, we studied the hyperthermia properties and

• anisotropy and magnetic interactions on properties of magnetic nanoparticles, in this work, a series of CoxFe3−xO4 (0 ≤ x ≤ 1) NPs was synthesized using a co-precipitation method. The effect of Co doping on the structural, magnetic and hyperthermia properties of CoxFe3−xO4 nanoparticles has been studied. We

• Co doping on the average crystallite size was studied using the Scherrer equation: where ⟨D⟩XRD is the average crystallite size, K ≈ 0.9 is the Scherrer constant and β is the full width at half-maximum (FWHM) of the XRD peaks. Table 1 shows that the crystallite size increases with increasing cobalt

A biomimetic nanofluidic diode based on surface-modified polymeric carbon nitride nanotubes

• Kai Xiao,
• Baris Kumru,
• Lu Chen,
• Lei Jiang,
• Bernhard V. K. J. Schmidt and
• Markus Antonietti

Beilstein J. Nanotechnol. 2019, 10, 1316–1323, doi:10.3762/bjnano.10.130

• and Discussion Fabrication of carbon nitride nanotube membrane Graphitic carbon nitride (g-CN) was chosen as it is formed from tri-s-triazine moieties interconnected via tertiary amines in a well-defined way without doping or modification, composed of only the two earth-abundant elements carbon and

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

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

• doping. Elemental and X-ray photoelectron spectroscopy (XPS) analysis results are shown in Table 1. The elemental analysis confirmed the efficiency of the doping, and showed that S-CNT contains a significant amount of residual catalyst (iron, encapsulated in the structure of the tubes). An effect of heat

• correspond to the oxidation of the sulfur species introduced during the doping during the purification step in H2SO4. As the S 2p peaks are typically presented in spin–orbit doublets of S 2p3/2 and S 2p1/2 (splitting magnitude ≈1.18 eV), four S 2p3/2 peaks representing sulfur bonding of FeS2 (≈162.5 eV), H–S

• –C (≈163.5 eV), R–S–C (≈164.5 eV), and S–O (≈168.0 eV) were observed (Supporting Information File 1, Figure S3) [42][43]. The intense peak at 163.5 eV indicated the doping of CNTs with mainly thiol surface groups (Table 2). The peak at 164.5 eV could arise from the presence of sulfur in the carbon

Luminescence of Tb₃Al₅O₁₂ phosphors co-doped with Ce³⁺/Gd³⁺ for white light-emitting diodes

• Yu-Guo Yang,
• Lei Wei,
• Jian-Hua Xu,
• Hua-Jian Yu,
• Yan-Yan Hu,
• Hua-Di Zhang,
• Xu-Ping Wang,
• Bing Liu,
• Cong Zhang and
• Qing-Gang Li

Beilstein J. Nanotechnol. 2019, 10, 1237–1242, doi:10.3762/bjnano.10.123

• wavelength at about 554 nm. After co-doping Gd3+ into Tb2.96Ce0.04Al5O12, the peak wavelength of the Ce3+ emission band shifts to longer wavelengths, which is induced by the increasing crystal field splitting. However, the Ce3+ emission intensity also decreases because the substitution of Tb3+ with Gd3

• that Tb3Al5O12 is also a good host for various ions and the luminescent properties could be tuned by co-doping different ions into the Tb3Al5O12 host. The Tb3Al5O12:Ce3+ phosphor also shows a yellow emission band. But the emission wavelength is longer than that of the Y3Al5O12:Ce3+ phosphor because Tb3

• longer than 611 nm [9]. We aimed to shift the emission wavelength of Tb3Al5O12:Ce3+ to a longer wavelength that is, however, still shorter than 611 nm. In this work, we report the synthesis and luminescence of a series of Ce3+/Gd3+-co-doped Tb3Al5O12 phosphors. The effect of co-doping Gd3+ on the

Green fabrication of lanthanide-doped hydroxide-based phosphors: Y(OH)₃:Eu³⁺ nanoparticles for white light generation

• Tugrul Guner,
• Anilcan Kus,
• Mehmet Ozcan,
• Aziz Genc,
• Hasan Sahin and
• Mustafa M. Demir

Beilstein J. Nanotechnol. 2019, 10, 1200–1210, doi:10.3762/bjnano.10.119

• -micrometer-sized Y(OH)3:Eu3+ particles (as red phosphor) were synthesized in water at ambient conditions in ≤60 min reaction time. The doping ratio was controlled from 2.5–20 mol %. Additionally, first principle calculations were performed on Y(OH)3:Eu3+ to understand the preferable doping scenario and its

• method. The doping process and complete crystallization were achieved in 60 min. State-of-the-art first-principle calculations were performed on Y(OH)3:Eu3+ to investigate its crystallographic structure and resulting electronic and optical properties. In summary, a novel water-based, rapid, and simple

• other possible ions and can therefore lead to an increase in the formation of defects to make the doping process more favorable (as previously mentioned at the end of the Introduction section). The solutions were mixed and sonicated for 5 min. After the sonication process, the reaction was maintained

A highly efficient porous rod-like Ce-doped ZnO photocatalyst for the degradation of dye contaminants in water

• Binjing Hu,
• Qiang Sun,
• Chengyi Zuo,
• Yunxin Pei,
• Siwei Yang,
• Hui Zheng and
• Fangming Liu

Beilstein J. Nanotechnol. 2019, 10, 1157–1165, doi:10.3762/bjnano.10.115

• –hole pairs are easy to recombine. The photocatalytic performance can be greatly affected by the particle size, morphology and concentration [8][9]. As such, it is possible to modify these ZnO properties to enhance its photocatalytic efficiency. Doping ZnO with rare-earth ions is an attractive strategy

• to improve its photocatalytic activity by modifying its surface morphology [10][11]. Wang et al. [12] prepared Ce-doped ZnO with different doping levels by using a one-step solution method, using methylene blue as the target pollutant for photodegradation. After exposure to light for 200 minutes, the

• pure ZnO achieved a degradation rate of 48.36% whereas 1% Ce/ZnO exhibited the best activity among the as-synthesized products (96.11%). It was found that a moderate amount of cerium doping can significantly improve the photocatalytic activity of ZnO. It was hypothesized that when cerium is mixed with

Photoactive nanoarchitectures based on clays incorporating TiO₂ and ZnO nanoparticles

• Eduardo Ruiz-Hitzky,
• Pilar Aranda,
• Marwa Akkari,
• Nithima Khaorapapong and
• Makoto Ogawa

Beilstein J. Nanotechnol. 2019, 10, 1140–1156, doi:10.3762/bjnano.10.114

• compared to TiO2, particularly in acidic solution, which can be a drawback for practical applications [46][47]. By changing morphology, doping, and conformation, i.e. as films, of the nanoparticles the intrinsic opto-electronic properties of the semiconductor as well as its chemical stability and surface

• semiconducting NPs on inert porous solids of large specific surface area is considered to be beneficial for the photocatalytic activity. Recently, strategies have been reported to improve the performance of photocatalysts via doping, or the introduction of semiconductor heterojunctions by combining them with

• transition metals or with other semiconductors. Among them, semiconductor heterojunctions have attracted great attention [139]. The doping of TiO2 and ZnO NPs with the aim to conveniently tuning the bandgap energy values can be a suitable option. In this context, it has been verified for both types of NPs, a

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

• works described heteroatom doping that should provide more active centres for the vanadium redox reactions, and hence lead to a higher electrochemical activity [14][15][16][17]. But still details of the mechanism are lacking and contradictory suggestions can be found in the literature, as to which

• functionality. Results and Discussion For the synthesis of nitrogen-doped carbon composite electrodes phloroglucinol was suggested as a carbon source whereas pyrrole-2-carboxaldehyde was utilized as a nitrogen source and the block copolymer Pluronic® F-127 was used as porogen. In the co-doping process

• can be observed. While the fibers of the co-doped composite electrode are covered completely and the space between fibers is filled up almost completely, the N-doped felt exhibits only partial coverage. It seems as if the carbon coating sticks more readily to the fibers after co-doping. But so far, we

Synthesis and characterization of quaternary La(Sr)S–TaS₂ misfit-layered nanotubes

• Marco Serra,
• Erumpukuthickal Ashokkumar Anumol,
• Dalit Stolovas,
• Iddo Pinkas,
• Ernesto Joselevich,
• Reshef Tenne,
• Andrey Enyashin and
• Francis Leonard Deepak

Beilstein J. Nanotechnol. 2019, 10, 1112–1124, doi:10.3762/bjnano.10.111

• a non-monotonic behavior upon Sr doping of the LaS part. In fact, the charge transfer per TaS2-unit, Q, first slightly increases in absolute value with increasing Sr content in the rock-salt lattice from 0.14 to 0.16 e− per TaS2 unit and then reaches a minimum (maximum in absolute value) at 20 atom

• , progressive Sr doping should disqualify the necessity of nanotubular morphology. Not surprisingly, the interlayer distance (c-axis) and the overall diameter of the SrxLa1−xS–TaS2 misfit nanotubes increases with higher Sr content in the lattice. Conclusion In conclusion, new alloys of misfit-layered compounds

CuInSe₂ quantum dots grown by molecular beam epitaxy on amorphous SiO₂ surfaces

• Henrique Limborço,
• Pedro M.P. Salomé,
• Rodrigo Ribeiro-Andrade,
• Jennifer P. Teixeira,
• Nicoleta Nicoara,
• Kamal Abderrafi,
• Joaquim P. Leitão,
• Juan C. Gonzalez and
• Sascha Sadewasser

Beilstein J. Nanotechnol. 2019, 10, 1103–1111, doi:10.3762/bjnano.10.110

• performance of vacuum-prepared materials and non-vacuum-prepared materials is usually attributed to the sensitivity of the chalcopyrite semiconductor to external contaminants [29], to the dependency of its properties on the preparation method [30], and to the self-doping characteristics of the chalcopyrite

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

• were applied to modify the textural properties, while nitrogen functionalities were incorporated via different N-doping methodologies (ball milling and conventional methods) using melamine. A direct relationship between the microporosity of the activated carbons and the limiting current density was

• found, with the increase of microporosity leading to interesting improvements of the limiting current density. Regardless of the doping method used, similar amounts of nitrogen were incorporated into the carbon structures. However, significant differences were observed in the nitrogen functionalities

• according to the doping method applied: ball milling appeared to originate preferentially quaternary and oxidized nitrogen groups, while the formation of pyridinic and pyrrolic groups was favoured by conventional doping. The onset potential was improved and the two-electron mechanism of the original