Two-dimensional carbon-based nanocomposites for photocatalytic energy generation and environmental remediation applications

• Suneel Kumar,
• Ashish Kumar,
• Ashish Bahuguna,
• Vipul Sharma and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2017, 8, 1571–1600, doi:10.3762/bjnano.8.159

• higher than pure graphene cocatalyst. Similarly some other groups have also investigated the cocatalytic role of graphene, for example Ye et al. [116] have reported CdS–MoS2–graphene nanocomposites, which is active in visible light for hydrogen generation. They reported the hydrogen evolution rate of 1.8

• mmol h−1 in lactic acid solution at 420 nm, which is much higher than that of the Pt–CdS system in the same solution. This high H2 evolution rate was mainly achieved because of the excellent cocatalytic function of MoS2–graphene, which leads to the higher number of reaction sites and fast charge

• transfer. Moreover, in nanometer-sized MoS2, exposed S atoms have strong affinity to H+ ions in solution, which are reduced to H2 by transferred electrons from the CB of CdS. Similarly, a noble-metal-free, ternary nanocomposite of TiO2–MoS2–graphene has been reported by Yu et al. for H2 generation [126

Development of a nitrogen-doped 2D material for tribological applications in the boundary-lubrication regime

• Shende Rashmi Chandrabhan,
• Velayudhanpillai Jayan,
• Somendra Singh Parihar and
• Sundara Ramaprabhu

Beilstein J. Nanotechnol. 2017, 8, 1476–1483, doi:10.3762/bjnano.8.147

• tribological properties of nanolubricant based on metals [16], metal oxides [17][18], MoS2 [4][19], boron [20] and WS2 [21]. Among all the solid additives, 2D graphene is a promising material to improve the tribological performance because of its high surface area to volume ratio and excellent mechanical

3D continuum phonon model for group-IV 2D materials

• Morten Willatzen,
• Lok C. Lew Yan Voon,
• Appala Naidu Gandi and
• Udo Schwingenschlögl

Beilstein J. Nanotechnol. 2017, 8, 1345–1356, doi:10.3762/bjnano.8.136

• beyond the analytical solutions sought for in the current manuscript. Furthermore, we have included a study of a well-known compound 2D material (molybdenum disulfide MoS2) in order to further understand the properties derived for the elemental materials. Results and Discussion Continuum model The 2D

• of the problem. In order to simplify and then solve it, it is necessary to specify the crystal symmetry of the vibrating system. The three problems considered in this article are graphene, silicene and MoS2. The Bravais lattice symmetries of the single-layer graphene (D6h ≡ 6/mmm) and MoS2

• () structures belong to the hexagonal system, while silicene belongs to the trigonal system (point group D3d). Graphene and silicene are non-piezoelectric materials because of the inversion symmetry of the unit cell, while MoS2 is piezoelectric because its unit cell exhibits inversion asymmetry. Application

Two-dimensional silicon and carbon monochalcogenides with the structure of phosphorene

• Dario Rocca,
• Ali Abboud,
• Ganapathy Vaitheeswaran and
• Sébastien Lebègue

Beilstein J. Nanotechnol. 2017, 8, 1338–1344, doi:10.3762/bjnano.8.135

• two-dimensional materials has increased exponentially [1]. Following the initial report of the existence of graphene [2], it was shown that isolated sheets of other layered compounds, such as h-BN or MoS2 among others, could be obtained as well [3][4]. These compounds demonstrate properties of the

Growth, structure and stability of sputter-deposited MoS₂ thin films

• Reinhard Kaindl,
• Bernhard C. Bayer,
• Roland Resel,
• Thomas Müller,
• Viera Skakalova,
• Gerlinde Habler,
• Rainer Abart,
• Alexey S. Cherevan,
• Dominik Eder,
• Maxime Blatter,
• Fabian Fischer,
• Jannik C. Meyer,
• Dmitry K. Polyushkin and
• Wolfgang Waldhauser

Beilstein J. Nanotechnol. 2017, 8, 1115–1126, doi:10.3762/bjnano.8.113

• , Austria Institute of Life Technologies, HES-SO Valais-Wallis, Route du Rawyl 64, CP, 1950 Sion 2, Switzerland 10.3762/bjnano.8.113 Abstract Molybdenum disulphide (MoS2) thin films have received increasing interest as device-active layers in low-dimensional electronics and also as novel catalysts in

• electrochemical processes such as the hydrogen evolution reaction (HER) in electrochemical water splitting. For both types of applications, industrially scalable fabrication methods with good control over the MoS2 film properties are crucial. Here, we investigate scalable physical vapour deposition (PVD) of MoS2

• films by magnetron sputtering. MoS2 films with thicknesses from ≈10 to ≈1000 nm were deposited on SiO2/Si and reticulated vitreous carbon (RVC) substrates. Samples deposited at room temperature (RT) and at 400 °C were compared. The deposited MoS2 was characterized by macro- and microscopic X-ray

In-situ monitoring by Raman spectroscopy of the thermal doping of graphene and MoS₂ in O₂-controlled atmosphere

• Aurora Piazza,
• Filippo Giannazzo,
• Gianpiero Buscarino,
• Gabriele Fisichella,
• Antonino La Magna,
• Fabrizio Roccaforte,
• Marco Cannas,
• Franco Mario Gelardi and
• Simonpietro Agnello

Beilstein J. Nanotechnol. 2017, 8, 418–424, doi:10.3762/bjnano.8.44

• O2) on the doping of monolayers of graphene (Gr) on SiO2 and Si substrates, and on the doping of MoS2 multilayer flakes transferred on the same substrates have been investigated. The investigations were carried out by in situ micro-Raman spectroscopy during thermal treatments up to 430 °C, and by

• red shift due to thermal effects and a blue shift induced by doping. This shows the potential of in situ measurements to follow the doping kinetics. The treatment of MoS2 in O2 has evidenced a progressive erosion of the flakes without relevant spectral changes in their central zone during in situ

• measurements. The formation of MoO3 on the edges of the flakes is observed indicative of the oxygen-activated transformation. Keywords: two-dimensional (2D) materials; graphene; MoS2; Raman spectroscopy; thermal doping; Introduction A wide interest for two-dimensional (2D) materials has grown in recent years

Impact of contact resistance on the electrical properties of MoS₂ transistors at practical operating temperatures

• Filippo Giannazzo,
• Gabriele Fisichella,
• Aurora Piazza,
• Salvatore Di Franco,
• Giuseppe Greco,
• Simonpietro Agnello and
• Fabrizio Roccaforte

Beilstein J. Nanotechnol. 2017, 8, 254–263, doi:10.3762/bjnano.8.28

• , University of Palermo, Via Archirafi 36, 90143 Palermo, Italy Department of Physics and Astronomy, University of Catania, Via Santa Sofia, 64, 95123 Catania, Italy 10.3762/bjnano.8.28 Abstract Molybdenum disulphide (MoS2) is currently regarded as a promising material for the next generation of electronic

• and optoelectronic devices. However, several issues need to be addressed to fully exploit its potential for field effect transistor (FET) applications. In this context, the contact resistance, RC, associated with the Schottky barrier between source/drain metals and MoS2 currently represents one of the

• main limiting factors for suitable device performance. Furthermore, to gain a deeper understanding of MoS2 FETs under practical operating conditions, it is necessary to investigate the temperature dependence of the main electrical parameters, such as the field effect mobility (μ) and the threshold

The difference in the thermal conductivity of nanofluids measured by different methods and its rationalization

• Aparna Zagabathuni,
• Sudipto Ghosh and
• Shyamal Kumar Pabi

Beilstein J. Nanotechnol. 2016, 7, 2037–2044, doi:10.3762/bjnano.7.194

• in the specific heat of the nanofluid. Using LFM, Zeng et al. [3] have reported 38.7% enhancement for 1.0 vol % loading of MoS2 nanoparticles in oil. They recognized that the thermal conductivity enhancement diminishes when the temperature is close to the flash point of the base oil. Based on several

Role of RGO support and irradiation source on the photocatalytic activity of CdS–ZnO semiconductor nanostructures

• Suneel Kumar,
• Rahul Sharma,
• Vipul Sharma,
• Gurunarayanan Harith,
• Vaidyanathan Sivakumar and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2016, 7, 1684–1697, doi:10.3762/bjnano.7.161

• degradation of organic pollutants [32][33][34][35]. In one of our recent works [34], we have reported the synergistic effect of MoS2–RGO support to improve the photocatalytic performance of ZnO nanoparticles. However, the role played by RGO support in enhancing the photocatalytic performance of the

Nanostructured germanium deposited on heated substrates with enhanced photoelectric properties

• Ionel Stavarache,
• Valentin Adrian Maraloiu,
• Petronela Prepelita and
• Gheorghe Iordache

Beilstein J. Nanotechnol. 2016, 7, 1492–1500, doi:10.3762/bjnano.7.142

• % over the whole investigated frequency range (1–4 kHz), which is a good result compared with other new materials and test structures reported in literature (18% in the case of graphene monolayer/germanium heterojunctions or about 13% for MoS2/Si heterojunctions) [48][49]. This is an indication of the

• high quality of the materials deposited by RF-sputtering for this experiment. The results of response time measurements show that photodetector structure as realized here is much quicker than Ge–graphene based photodetectors (tr ≈ 23 µs and tf ≈ 108 µs) [48], MoS2-based photodetectors (tr ≈ 3 µs and tf

Fracture behaviors of pre-cracked monolayer molybdenum disulfide: A molecular dynamics study

• Qi-lin Xiong,
• Zhen-huan Li and
• Xiao-geng Tian

Beilstein J. Nanotechnol. 2016, 7, 1411–1420, doi:10.3762/bjnano.7.132

• and Vibration, Xi’an Jiaotong University, Xi’an 710049, China 10.3762/bjnano.7.132 Abstract The fracture strength and crack propagation of monolayer molybdenum disulfide (MoS2) sheets with various pre-existing cracks are investigated using molecular dynamics simulation (MDS). The uniaxial tensions of

• pre-cracked monolayer MoS2 sheets with different crack tips, different locations of crack, different crack lengths and angled cracks are simulated and studied. The results show that the configuration of crack tip can influence significantly the fracture behaviors of monolayer MoS2 sheets while the

• location of crack does not influence the fracture strength. With the increase of crack length, the fracture strength of monolayer MoS2 sheets reduces almost linearly, and the fracture of monolayer MoS2 sheets is transformed from almost brittle to ductile. By making comparison between the MDS results and

Metal oxide-graphene field-effect transistor: interface trap density extraction model

• Faraz Najam,
• Kah Cheong Lau,
• Cheng Siong Lim,
• Yun Seop Yu and
• Michael Loong Peng Tan

Beilstein J. Nanotechnol. 2016, 7, 1368–1376, doi:10.3762/bjnano.7.128

• ) type trap state. Dit is the interface trap density defined at the ith energy level. Qit can be found by the integral of product of all the k trap states with their respective FtA (FtD) between ED and Ef. Dit distribution extraction criteria are based on our earlier work on MoS2 MOSFET [14], and are

• ., Qit_calc, Cit_calc, φs_calc and device Ctot_calc are in excellent agreement with the respective extracted experimental parameters, thereby validating the extracted Dit distribution. It must be mentioned part of this work is based on our earlier work on MoS2 transistor [14] as briefly mentioned earlier

• . However, in that work the interface trap density of MoS2 transistor was extrated by simply fitting the Qit parameter in the device’s drain current (Ids) model to fit experimental device’s Ids with the calculated one from the model. Next, device’s φs was calculated from the model equation. This φs was

Current state of laser synthesis of metal and alloy nanoparticles as ligand-free reference materials for nano-toxicological assays

• Christoph Rehbock,
• Jurij Jakobi,
• Lisa Gamrad,
• Selina van der Meer,
• Daniela Tiedemann,
• Ulrike Taylor,
• Wilfried Kues,
• Detlef Rath and
• Stephan Barcikowski

Beilstein J. Nanotechnol. 2014, 5, 1523–1541, doi:10.3762/bjnano.5.165

• [156], TiO2, ZnO [157], Ni, NiTi, NiFe, Ti [11] and MoS2 [158] on the viability of mammalian cell lines were studied. Furthermore, some studies addressed antimicrobial effects of Ni [159] and Ag nanoparticles [160][161]. Additionally, some authors reported on the application of laser-fabricated CuO

Magnesium batteries: Current state of the art, issues and future perspectives

• Rana Mohtadi and
• Fuminori Mizuno

Beilstein J. Nanotechnol. 2014, 5, 1291–1311, doi:10.3762/bjnano.5.143

Enhanced photocatalytic hydrogen evolution by combining water soluble graphene with cobalt salts

• Jing Wang,
• Ke Feng,
• Hui-Hui Zhang,
• Bin Chen,
• Zhi-Jun Li,
• Qing-Yuan Meng,
• Li-Ping Zhang,
• Chen-Ho Tung and
• Li-Zhu Wu

Beilstein J. Nanotechnol. 2014, 5, 1167–1174, doi:10.3762/bjnano.5.128

• ][27][28][29][30][31][32][33]. Specifically, graphene has been involved in photocatalytic hydrogen production systems [34], such as TiO2-(N)RGO-Pt [35][36][37][38], g-C3N4-RGO-Pt [39], CdS-RGO-Pt [40][41][42][43], MoS2-NRGO [44][45], EY-RGO-Pt [46] and BiVO4-RGO-Ru/SrTiO3:Rh [47] (RGO: reduced graphene

Functionalized nanostructures for enhanced photocatalytic performance under solar light

• Liejin Guo,
• Dengwei Jing,
• Maochang Liu,
• Yubin Chen,
• Shaohua Shen,
• Jinwen Shi and
• Kai Zhang

Beilstein J. Nanotechnol. 2014, 5, 994–1004, doi:10.3762/bjnano.5.113

• platinum was demonstrated to be more efficient than metallic platinum as cocatalyst for hydrogen production [23][24]. Taking into account the cost of the designed photocatalyst for commercial purposes, the development of noble-metal free cocatalysts is still valued. Alternative cocatalysts such as MoS2

Nanostructure sensitization of transition metal oxides for visible-light photocatalysis

• Hongjun Chen and
• Lianzhou Wang

Beilstein J. Nanotechnol. 2014, 5, 696–710, doi:10.3762/bjnano.5.82

• photoelectrochemical systems in the future. There are also new nanostructures with special features for the potential application in visible-light photocatalysis. For example, very recently, Heinz and co-workers found that by decreasing the thickness of MoS2 to a monolayer [148], the indirect bandgap bulk

• semiconductor can change into a direct bandgap. Correspondingly, the monolayer of MoS2 exhibits 104 times enhancement of luminescence quantum efficiency than that of bulk material. This new finding has also been verified by other research groups [149][150]. Based on this new finding, one may easily imagine that

• the monolayer of MoS2 has great potential as a photosensitizer in the near future. In addition to monolayer MoS2, the nanostructures of gold clusters and carbon nanodots are still in a stage of early development, providing numerous challenges and opportunities for future investigation. Although

DNA origami deposition on native and passivated molybdenum disulfide substrates

• Xiaoning Zhang,
• Masudur Rahman,
• David Neff and
• Michael L. Norton

Beilstein J. Nanotechnol. 2014, 5, 501–506, doi:10.3762/bjnano.5.58

• prerequisite for the successful fabrication of hybrid DNA origami/semiconductor-based biomedical sensor devices. Molybdenum disulfide (MoS2) is an ideal substrate for such future sensors due to its exceptional electrical, mechanical and structural properties. In this work, we performed the first investigations

• into the interaction of DNA origami with the MoS2 surface. In contrast to the structure-preserving interaction of DNA origami with mica, another atomically flat surface, it was observed that DNA origami structures rapidly lose their structural integrity upon interaction with MoS2. In a further series

• of studies, pyrene and 1-pyrenemethylamine, were evaluated as surface modifications which might mitigate this effect. While both species were found to form adsorption layers on MoS2 via physisorption, 1-pyrenemethylamine serves as a better protective agent and preserves the structures for

Effect of contaminations and surface preparation on the work function of single layer MoS₂

• Oliver Ochedowski,
• Kolyo Marinov,
• Nils Scheuschner,
• Artur Poloczek,
• Benedict Kleine Bussmann,
• Janina Maultzsch and
• Marika Schleberger

Beilstein J. Nanotechnol. 2014, 5, 291–297, doi:10.3762/bjnano.5.32

• . 36, 10623 Berlin, Germany Solid State Electronics Department and CeNIDE, University of Duisburg-Essen, Lotharstr. 55, 47058 Duisburg, Germany 10.3762/bjnano.5.32 Abstract Thinning out MoS2 crystals to atomically thin layers results in the transition from an indirect to a direct bandgap material

• . This makes single layer MoS2 an exciting new material for electronic devices. In MoS2 devices it has been observed that the choice of materials, in particular for contact and gate, is crucial for their performance. This makes it very important to study the interaction between ultrathin MoS2 layers and

• materials employed in electronic devices in order to optimize their performance. In this work we used NC-AFM in combination with quantitative KPFM to study the influence of the substrate material and the processing on single layer MoS2 during device fabrication. We find a strong influence of contaminations

Preparation of NiS/ZnIn₂S₄ as a superior photocatalyst for hydrogen evolution under visible light irradiation

• Liang Wei,
• Yongjuan Chen,
• Jialin Zhao and
• Zhaohui Li

Beilstein J. Nanotechnol. 2013, 4, 949–955, doi:10.3762/bjnano.4.107

• photocatalytic hydrogen evolution. However, the precious metals are expensive and to reduce the cost of renewable hydrogen evolution, it is necessary to explore alternative co-catalysts based on inexpensive transition metals. Our recent studies revealed that MoS2, a good electrocatalyst for hydrogen evolution

• [34], can be an effective co-catalyst in promoting photocatalytic hydrogen evolution over ZnIn2S4 and MoS2/ZnIn2S4 show even superior performance for hydrogen evolution than Pt/ZnIn2S4 [35]. NiS, a p-type semiconductor, is also reported to be a good electrocatalyst for cathodic hydrogen evolution in

• /ZnIn2S4 and ZnIn2S4 (a) survey spectrum and high-resolution spectra for (b) S 2p; (c) Zn 2p and (d) In 3d. UV–vis diffraction spectra of the pure ZnIn2S4 and 0.25 wt %, 0.5 wt %, 1.0 wt %, 2.0 wt % NiS/ZnIn2S4. Amount of hydrogen evolution over (a) pure ZnIn2S4; (b) 0.2 wt % MoS2/ZnIn2S4; (c) mechanical

Effect of spherical Au nanoparticles on nanofriction and wear reduction in dry and liquid environments

• Dave Maharaj and
• Bharat Bhushan

Beilstein J. Nanotechnol. 2012, 3, 759–772, doi:10.3762/bjnano.3.85

• ], spherical MoS2 (15–60 nm) in poly-alpha-olefin (PAO) and 150 SN [18], spherical WS2 nanoparticles (50–350 nm) in SN 150 and SN 190 [19], spheroidal carbon-nano-onion nanoparticles (<10 nm) in PAO [20], WS2 nanoparticles (120 nm) in paraffin oil [21], MoS2 spheres (0.5–3 µm) in 500 SN oil [22] and carbon

Switching adhesion forces by crossing the metal–insulator transition in Magnéli-type vanadium oxide crystals

• Bert Stegemann,
• Matthias Klemm,
• Siegfried Horn and
• Mathias Woydt

Beilstein J. Nanotechnol. 2011, 2, 59–65, doi:10.3762/bjnano.2.8

• materials revealed consistent results: Comparative adhesion force measurements of the (0001) basal planes and the (10−10) prism planes of highly oriented pyrolytic graphite (HOPG) and MoS2 also showed that the metallic state lowers the adhesion at the nanoscale [36]. Experimental Vanadium oxide crystal

A collisional model for AFM manipulation of rigid nanoparticles

• Enrico Gnecco

Beilstein J. Nanotechnol. 2010, 1, 158–162, doi:10.3762/bjnano.1.19

• benchmark would be the flower-shaped Sb islands first manipulated by Ritter et al. on HOPG and MoS2 [9]. Possible discrepancies between theory and experiment concerning the direction of motion and angular speed of the islands could be related to the friction forces between island and substrate and even used