Light–matter interactions in two-dimensional layered WSe₂ for gauging evolution of phonon dynamics

• Avra S. Bandyopadhyay,
• Chandan Biswas and
• Anupama B. Kaul

Beilstein J. Nanotechnol. 2020, 11, 782–797, doi:10.3762/bjnano.11.63

• , ML and bulk samples, were mechanically exfoliated on top of SiO2/Si substrates (SiO2 thickness = 270 nm) using the scotch tape method [1][30][31]. The mechanical exfoliation process used in this study is similar to the one reported in our earlier work [30]. Prior to the exfoliation procedure, the

• sapphire substrate is used compared to SiO2/Si substrates [24]. As the SiO2/Si susbstrate and the preparation method (mechanical exfoliation) remained the same for 1L and bulk WSe2 used in our study, this may be the reason why the intensity of the Raman mode remained unchanged even in bulk WSe2. Moreover

Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

• Stefania Castelletto,
• Faraz A. Inam,
• Shin-ichiro Sato and
• Alberto Boretti

Beilstein J. Nanotechnol. 2020, 11, 740–769, doi:10.3762/bjnano.11.61

Exfoliation in a low boiling point solvent and electrochemical applications of MoO₃

• Matangi Sricharan,
• Bikesh Gupta,
• Sreejesh Moolayadukkam and
• H. S. S. Ramakrishna Matte

Beilstein J. Nanotechnol. 2020, 11, 662–670, doi:10.3762/bjnano.11.52

• in areas such as energy storage devices, electronic devices and catalysis. To efficiently utilize the properties of MoO3 arising from its two-dimensional nature exfoliation is necessary. In this work, the exfoliation of MoO3 is carried out in 2-butanone for the first time. The achieved concentration

• of the dispersion is about 0.57 mg·mL−1 with a yield of 5.7%, which are the highest values reported to date. These high values of concentration and yield can be attributed to a favorable matching of energies involved in exfoliation and stabilization of MoO3 nanosheets in 2-butanone. Interestingly

• mV·s−1. Keywords: 2-butanone; liquid-phase exfoliation; low-boiling point solvent; molybdenum trioxide (MoO3); supercapacitors; Introduction The advent of graphene has opened a new area of research in the field of two-dimensional materials [1]. The extraordinary properties of graphene have led

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

• the role of C=O groups in graphene towards sustainable peroxide formation. We demonstrate a versatile single-step electrochemical exfoliation of graphite to graphene with a controllable degree of oxygen functionalities and thickness, leading to the formation of large quantities of functionalized

• of our previous works, different halogenated graphene materials were developed via a single-step electrochemical exfoliation (EE) method [42]. It was found that such a method can produce graphene with varying degrees of oxygen functionalities [43]. Here we explore the possibility of functional groups

• to control graphene toward the electrochemical production of H2O2 in alkaline medium, and the amount of peroxide generated is quantified using a spectroscopic technique. A large amount of H2O2 is found to be formed via such simple modification of the exfoliation parameters, and the details are

DFT calculations of the structure and stability of copper clusters on MoS₂

• Cara-Lena Nies and
• Michael Nolan

Beilstein J. Nanotechnol. 2020, 11, 391–406, doi:10.3762/bjnano.11.30

• character of Cu nanoclusters is preserved. Keywords: copper (Cu); density functional theory (DFT); 2D materials; molybdenum disulfide (MoS2); thin film nucleation; Introduction Since the successful exfoliation of monolayers of graphene by Novoselov et al., 2D materials have gained a large interest in a

• exfoliation. However, the scalability of CVD and ALD processes makes 2D materials grown via these methods more realistic for a wider range of applications [4]. Transition metal dichalcogenides (TMDs) are of particular interest as they exhibit a large variety of properties. TMDs such as MoS2 are intrinsic

Simple synthesis of nanosheets of rGO and nitrogenated rGO

• Pallellappa Chithaiah,
• Madhan Mohan Raju,
• Giridhar U. Kulkarni and
• C. N. R. Rao

Beilstein J. Nanotechnol. 2020, 11, 68–75, doi:10.3762/bjnano.11.7

• the carbon sheet, which lead to a disruption of the conjugated network and the flow of charge carriers is reduced by several orders of magnitude [10]. Up to now, several methods including chemical vapor deposition [11][12][13], arc discharge [14], aerosol pyrolysis [15], mechanical exfoliation [1

Improvement of the thermoelectric properties of a MoO₃ monolayer through oxygen vacancies

• Wenwen Zheng,
• Wei Cao,
• Ziyu Wang,
• Huixiong Deng,
• Jing Shi and
• Rui Xiong

Beilstein J. Nanotechnol. 2019, 10, 2031–2038, doi:10.3762/bjnano.10.199

• materials show a better thermoelectric performance than bulk materials [14]. Few-layer MoO3 nanosheets have already been experimentally synthesized by exfoliation similar to graphene [12][13][15][16]. Theoretical research has proved that few-layer MoO3 possesses a markedly high carrier mobility above 3000

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

Remarkable electronic and optical anisotropy of layered 1T’-WTe₂ 2D materials

• Qiankun Zhang,
• Rongjie Zhang,
• Jiancui Chen,
• Wanfu Shen,
• Chunhua An,
• Xiaodong Hu,
• Mingli Dong,
• Jing Liu and
• Lianqing Zhu

Beilstein J. Nanotechnol. 2019, 10, 1745–1753, doi:10.3762/bjnano.10.170

• and the possibility to open up new ways for applications of 2D materials for light polarization detection. Keywords: 1T’-WTe2; 2D material; anisotropic; light polarization; optoelectrical; Introduction The first exfoliation of graphene [1] attracted extensive interest in 2D materials such as black

• novel device concepts by utilizing its angle-resolved and wavelength-dependent properties. Methods Exfoliation and characterization of 1T’-WTe2 flakes The 1T’-WTe2 single crystals were purchased from XianFeng Nano Corporation. A blue film was used to exfoliate 1T’-WTe2 onto the N++-doped Si substrate

• 1T’-WTe2 flake. Identification of the lattice anisotropy of an exfoliated 1T’-WTe2 flake. a) AFM image of the 1T’-WTe2 flake transferred onto a Si/SiO2 substrate by mechanical exfoliation. The heights of zone 1 and zone 2 are 16.36 nm and 5.25 nm, respectively. b) ADRDM results of the same WTe2 flake

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

• min. Then, they were cooled down to room temperature at a rate of 20 °C/s. Time control of the RTA process allowed us to avoid exfoliation of the film from the substrate. The thickness of the films was also experimentally verified after deposition using interference microscopy in order to verify the

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

• %. This degree of oxidation is lower than in the case of chemically exfoliated MoS2, which is possibly due to a slightly lower degree of exfoliation [39]. Additionally, no oxidation was observed for sulfur as only states originating from sulfides were identified in the S 2p spectrum (Figure 3b) [40]. The

• approximately −0.195 V vs RHE and is capable of reaching current densities as high as 100 mA·cm−2. Additionally, we treated the material with n-butyllithium to further enhance the HER activity. The resulting material exhibited a lower onset potential, however, the exfoliation of MoS2 sheets resulted in a loss

Electronic properties of several two dimensional halides from ab initio calculations

• Mohamed Barhoumi,
• Ali Abboud,
• Lamjed Debbichi,
• Moncef Said,
• Torbjörn Björkman,
• Dario Rocca and
• Sébastien Lebègue

Beilstein J. Nanotechnol. 2019, 10, 823–832, doi:10.3762/bjnano.10.82

• theory; electronic properties; halide monolayers; Introduction The discovery of graphene [1] by exfoliation [2] opened a new era in several domains of science. Graphene has attracted great attention due to its unique properties [3] and because it offers many advantages in comparison with more common

• among experimentalists. Since bulk crystals are known to exist for some of them, mechanical exfoliation can be attempted to isolate one or few layers, and then to explore their electronic and optical properties. If successful, devices such as transistors, based on these monolayers could be fabricated

Tungsten disulfide-based nanocomposites for photothermal therapy

• Tzuriel Levin,
• Hagit Sade,
• Rina Ben-Shabbat Binyamini,
• Maayan Pour,
• Iftach Nachman and
• Jean-Paul Lellouche

Beilstein J. Nanotechnol. 2019, 10, 811–822, doi:10.3762/bjnano.10.81

• steps that might cause massive breakage or exfoliation of the nanotubes. For this reason, we aimed for preparation conditions that would allow composite formation without damaging the nanotubes. Electron microscopy images (Figure 2) show that WS2 nanotubes maintained their general shape after

Outstanding chain-extension effect and high UV resistance of polybutylene succinate containing amino-acid-modified layered double hydroxides

• Adam A. Marek,
• Vincent Verney,
• Christine Taviot-Gueho,
• Grazia Totaro,
• Laura Sisti,
• Annamaria Celli and
• Fabrice Leroux

Beilstein J. Nanotechnol. 2019, 10, 684–695, doi:10.3762/bjnano.10.68

• filler structure can be explained by their lower crystallinity or by a partial exfoliation occurring during thermal processing. For PBS–LDH/HIS, there is an additional peak at 2θ = 18° that is difficult to assign. Its associated small full width at half maximum (FWHM) may be attributed to rather

Direct observation of the CVD growth of monolayer MoS₂ using in situ optical spectroscopy

• Claudia Beatriz López-Posadas,
• Yaxu Wei,
• Wanfu Shen,
• Daniel Kahr,
• Michael Hohage and
• Lidong Sun

Beilstein J. Nanotechnol. 2019, 10, 557–564, doi:10.3762/bjnano.10.57

• synthesizing large-area 2D TMDCs have been reported, including mechanical exfoliation, sulphurization of metal thin films, mass transport, molecular beam epitaxy (MBE) and chemical vapor deposition (CVD) [6][7]. In particular, CVD is considered to be an attractive and very promising approach for large-scale

Mo-doped boron nitride monolayer as a promising single-atom electrocatalyst for CO₂ conversion

• Qianyi Cui,
• Gangqiang Qin,
• Weihua Wang,
• Lixiang Sun,
• Aijun Du and
• Qiao Sun

Beilstein J. Nanotechnol. 2019, 10, 540–548, doi:10.3762/bjnano.10.55

• refractory nature [11][35][36][37][38][39][40][41]. Moreover, BN nanomaterials have been used as superior substrates for doping various transition metals by electron beam irradiation [42] or solvent exfoliation [43] to form selected point defects, which are preferred to growing specific boron vacancies [42

Investigation of CVD graphene as-grown on Cu foil using simultaneous scanning tunneling/atomic force microscopy

• Majid Fazeli Jadidi,
• Umut Kamber,
• Oğuzhan Gürlü and
• H. Özgür Özer

Beilstein J. Nanotechnol. 2018, 9, 2953–2959, doi:10.3762/bjnano.9.274

• would be useful in understanding the mechanisms of such interactions. Nowadays, a variety of methods are used to prepare graphene. Mechanical exfoliation of graphite facilitates obtaining micrometer-scale graphene layers on amorphous substrates such as silicon oxide [1]. Graphene monolayers have been

Layered calcium phenylphosphonate: a hybrid material for a new generation of nanofillers

• Kateřina Kopecká,
• Ludvík Beneš,
• Klára Melánová,
• Vítězslav Zima,
• Petr Knotek and
• Kateřina Zetková

Beilstein J. Nanotechnol. 2018, 9, 2906–2915, doi:10.3762/bjnano.9.269

• presence of phenyl groups on the surface of the layers. In this paper, various CaPhP synthesis methods were studied with the aim of obtaining a product most suitable for its subsequent exfoliation. The liquid-based approach was used for the exfoliation. It was found that the most promising technique for

• the exfoliation of CaPhP in an amount sufficient for incorporation into polymers involved using propan-2-ol with a strong shear force generated in a high-shear disperser. The filler was tested both in its unexfoliated and exfoliated forms for the preparation of polymer composites, for which a low

• . The addition of the nanofiller was found to influence the composite properties – the exfoliated particles were found to have a higher impact on the properties of the prepared composites than the unexfoliated particles of the same loading Keywords: exfoliation; layered phenylphosphonate; nanomaterial

Charged particle single nanometre manufacturing

• Philip D. Prewett,
• Cornelis W. Hagen,
• Claudia Lenk,
• Steve Lenk,
• Marcus Kaestner,
• Tzvetan Ivanov,
• Ahmad Ahmad,
• Ivo W. Rangelow,
• Xiaoqing Shi,
• Stuart A. Boden,
• Alex P. G. Robinson,
• Dongxu Yang,
• Sangeetha Hari,
• Marijke Scotuzzi and
• Ejaz Huq

Beilstein J. Nanotechnol. 2018, 9, 2855–2882, doi:10.3762/bjnano.9.266

Nanostructure-induced performance degradation of WO₃·nH₂O for energy conversion and storage devices

• Zhenyin Hai,
• Mohammad Karbalaei Akbari,
• Zihan Wei,
• Danfeng Cui,
• Chenyang Xue,
• Hongyan Xu,
• Philippe M. Heynderickx,
• Francis Verpoort and
• Serge Zhuiykov

Beilstein J. Nanotechnol. 2018, 9, 2845–2854, doi:10.3762/bjnano.9.265

• layered transition metal oxides. Keywords: 2D layered oxides; interlayer water; van der Waals interaction; WO3·nH2O; Introduction Within the less than 20 years since the successful exfoliation of atomically thin graphene, 2D layered nanomaterials have been contributing greatly to the advances of

Metal-free catalysis based on nitrogen-doped carbon nanomaterials: a photoelectron spectroscopy point of view

• Mattia Scardamaglia and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2018, 9, 2015–2031, doi:10.3762/bjnano.9.191

• [11][12], rather than their observation, which possibly should be dated back [13]. The second one was the report on exfoliation and characterization of graphene by Geim and Novoselov in 2004 [14]. The impact of these reports on the fundamental research on carbon nanomaterials triggered theoretical and

Improving the catalytic activity for hydrogen evolution of monolayered SnSe_2(1−x)S_2x by mechanical strain

• Sha Dong and
• Zhiguo Wang

Beilstein J. Nanotechnol. 2018, 9, 1820–1827, doi:10.3762/bjnano.9.173

• synthesized by using traditional mechanical exfoliation techniques [24][25] because of the weak van der Waals (vdW) interactions between layers. These mono- and few-layer SnX2 (X = S, Se) compounds are expected to be widely used in the fields of water splitting [26], high-speed photodetection [27

SO₂ gas adsorption on carbon nanomaterials: a comparative study

• Deepu J. Babu,
• Divya Puthusseri,
• Frank G. Kühl,
• Sherif Okeil,
• Michael Bruns,
• Manfred Hampe and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2018, 9, 1782–1792, doi:10.3762/bjnano.9.169

• functionalities, which in turn increases the layer separation and turns the material hydrophilic. The subsequent exfoliation step separates the layers, thereby significantly increasing its accessible surface area leading to the formation of single- or few-layered GO. In our previous work, by XPS analysis, we have

• R1 Extra was obtained from Norit N.V., Holland, and the detailed properties have been described in [45][54]. GO was prepared by oxidizing graphite followed by exfoliation using a combination of ultrasound sonication followed by freeze–thaw cycles, described in detail in [12]. Graphite was purchased

Toward the use of CVD-grown MoS₂ nanosheets as field-emission source

• Geetanjali Deokar,
• Nitul S. Rajput,
• Junjie Li,
• Francis Leonard Deepak,
• Wei Ou-Yang,
• Nicolas Reckinger,
• Carla Bittencourt,
• Jean-Francois Colomer and
• Mustapha Jouiad

Beilstein J. Nanotechnol. 2018, 9, 1686–1694, doi:10.3762/bjnano.9.160

• ][16] and the number of layers [16]. Various methods have been used to synthesize vertically aligned MoS2 NSs: liquid-phase exfoliation [17], hydrothermal synthesis [8] or chemical vapor deposition (CVD) [15][17][18]. CVD is regarded as the most promising method to synthesize high-quality MoS2 with

Computational exploration of two-dimensional silicon diarsenide and germanium arsenide for photovoltaic applications

• Sri Kasi Matta,
• Chunmei Zhang,
• Yalong Jiao,
• Anthony O'Mullane and
• Aijun Du

Beilstein J. Nanotechnol. 2018, 9, 1247–1253, doi:10.3762/bjnano.9.116

• , electronic and optical properties using density functional theory (DFT), hybrid functional and Bethe–Salpeter equation (BSE) approaches. We find that the exfoliation of single-layer SiAs2 and GeAs2 is highly feasible and in principle could be carried out experimentally by mechanical cleavage due to the

• and Pb [20][35] and are depicted in Figure 2c. According to this evaluation, the exfoliation of monolayer for these materials from their bulk forms is highly feasible. The band structures determined by HSE-Wannier calculations demonstrate that bulk, bilayer and monolayer structures of SiAs2 and GeAs2

• SiAs2 and GeAs2 as promising light harvesting semiconductor materials for solar cell applications. The extraction of a monolayer of these materials is likely to be feasible by mechanical exfoliation. Moreover, the calculated phonon spectrum reveals its high dynamical stability for both materials