Inorganic nanotubes and fullerene-like nanoparticles

2006 ◽  
Vol 21 (11) ◽  
pp. 2726-2743 ◽  
Author(s):  
R. Tenne
Keyword(s):  
Layered Structure ◽  
Large Scale ◽  
Rechargeable Batteries ◽  
Layered Compounds ◽  
Inorganic Nanotubes ◽  
Metal Dichalcogenides ◽  
Substantial Progress ◽  
Novel Applications ◽  
Defense Medical

We have proposed in 1992 that nanoparticles of layered compounds will be unstable against folding and close into fullerene-like structures and nanotubes (IF). Nanotubes and fullerene-like structures were prepared from numerous compounds with layered and recently also non-layered structure by various groups. Much progress has been achieved in the synthesis of inorganic nanotubes and fullerene-like nanoparticles of WS2 and MoS2 and many other metal dichalcogenides over the last few years. Substantial progress has been accomplished in the use of such nanoparticles for tribological applications and lately for impact resilient nanocomposites. These tests indicated that IF-MoS2 and IF-WS2 are heading for large scale applications in the automotive, machining, aerospace, electronics, defense, medical and numerous other kinds of industries. A few products based on these nanoparticles have been recently commercialized by “ApNano Materials, Inc”. Novel applications of inorganic nanotubes and fullerene-like nanoparticles in the fields of catalysis; microelectronics; Li rechargeable batteries; medical and opto-electronics will be discussed.

scholarly journals Additive-Enhanced Exfoliation for High-Yield 2D Materials Production

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 601
Author(s):  
Dinh-Tuan Nguyen ◽  
Hsiang-An Ting ◽  
Yen-Hsun Su ◽  
Mario Hofmann ◽  
Ya-Ping Hsieh
Keyword(s):  
Large Scale ◽  
2D Materials ◽  
Transition Metal Dichalcogenides ◽  
Spectroscopic Characterization ◽  
High Yield ◽  
Nanometer Scale ◽  
Efficient Production ◽  
Device Performance ◽  
Metal Dichalcogenides ◽  
Scale Deposition

The success of van-der-Waals electronics, which combine large-scale-deposition capabilities with high device performance, relies on the efficient production of suitable 2D materials. Shear exfoliation of 2D materials’ flakes from bulk sources can generate 2D materials with low amounts of defects, but the production yield has been limited below industry requirements. Here, we introduce additive-assisted exfoliation (AAE) as an approach to significantly increase the efficiency of shear exfoliation and produce an exfoliation yield of 30%. By introducing micrometer-sized particles that do not exfoliate, the gap between rotor and stator was dynamically reduced to increase the achievable shear rate. This enhancement was applied to WS2 and MoS2 production, which represent two of the most promising 2D transition-metal dichalcogenides. Spectroscopic characterization and cascade centrifugation reveal a consistent and significant increase in 2D material concentrations across all thickness ranges. Thus, the produced WS2 films exhibit high thickness uniformity in the nanometer-scale and can open up new routes for 2D materials production towards future applications.

Mechanical Patterning in Animal Morphogenesis

2021 ◽  
Vol 37 (1) ◽  
Author(s):  
Yonit Maroudas-Sacks ◽  
Kinneret Keren
Keyword(s):  
Pattern Formation ◽  
Large Scale ◽  
Coarse Grained ◽  
Annual Review ◽  
Publication Date ◽  
Biochemical Processes ◽  
Substantial Progress ◽  
Biological Pattern Formation ◽  
Effective Theories ◽  
Biochemical Signals

Morphogenesis is one of the most remarkable examples of biological pattern formation. Despite substantial progress in the field, we still do not understand the organizational principles responsible for the robust convergence of the morphogenesis process across scales to form viable organisms under variable conditions. Achieving large-scale coordination requires feedback between mechanical and biochemical processes, spanning all levels of organization and relating the emerging patterns with the mechanisms driving their formation. In this review, we highlight the role of mechanics in the patterning process, emphasizing the active and synergistic manner in which mechanical processes participate in developmental patterning rather than merely following a program set by biochemical signals. We discuss the value of applying a coarse-grained approach toward understanding this complex interplay, which considers the large-scale dynamics and feedback as well as complementing the reductionist approach focused on molecular detail. A central challenge in this approach is identifying relevant coarse-grained variables and developing effective theories that can serve as a basis for an integrated framework for understanding this remarkable pattern-formation process. Expected final online publication date for the Annual Review of Cell and Developmental Biology, Volume 37 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Site-Specific Electrodeposition Enables Self-Terminating Growth of Atomically Dispersed Metal Catalysts

2020 ◽  
Author(s):  
Yi Shi ◽  
Wenmao Huang ◽  
Jian Li ◽  
Yue Zhou ◽  
Zhongqiu Li ◽  
...  
Keyword(s):  
Large Scale ◽  
Transition Metal Dichalcogenides ◽  
Metal Catalysts ◽  
Atomic Scale ◽  
Single Atom ◽  
Scale Production ◽  
Heterogenous Catalysis ◽  
Site Specific ◽  
Metal Support ◽  
Metal Dichalcogenides

<p>The growth of atomically dispersed metal catalysts (ADMCs) remains a great challenge owing to the thermodynamically driven atom aggregation. Here we report a surface-limited electrodeposition technique that uses site-specific substrates for the rapid and room-temperature synthesis of ADMCs. We obtained ADMCs by the underpotential deposition (UPD) of a single-atom nonnoble metal onto the chalcogen atoms of chemically exfoliated transition metal dichalcogenides and subsequent galvanic displacement with a more-noble single-atom metal. The site-specific electrodeposition (SSED) enables the formation of energetically favorable metal–support bonds, and then automatically terminates the sequential formation of metallic bonding. The self-terminating effect restricts the metal deposition to the atomic scale. The modulated ADMCs exhibit remarkable activity and stability in the hydrogen evolution reaction compared to state-of-the-art single-atom electrocatalysts. We demonstrate that this SSED methodology could be extended to the synthesis of a variety of ADMCs (for example, Pt, Pd, Rh, Cu, Pb, Bi, and Sn single atoms), showing its general scope for the large-scale production of functional ADMCs in heterogenous catalysis. </p>

scholarly journals Site-Specific Electrodeposition Enables Self-Terminating Growth of Atomically Dispersed Metal Catalysts

2020 ◽  
Author(s):  
Yi Shi ◽  
Wenmao Huang ◽  
Jian Li ◽  
Yue Zhou ◽  
Zhongqiu Li ◽  
...  
Keyword(s):  
Large Scale ◽  
Transition Metal Dichalcogenides ◽  
Metal Catalysts ◽  
Atomic Scale ◽  
Single Atom ◽  
Scale Production ◽  
Heterogenous Catalysis ◽  
Site Specific ◽  
Metal Support ◽  
Metal Dichalcogenides

<p>The growth of atomically dispersed metal catalysts (ADMCs) remains a great challenge owing to the thermodynamically driven atom aggregation. Here we report a surface-limited electrodeposition technique that uses site-specific substrates for the rapid and room-temperature synthesis of ADMCs. We obtained ADMCs by the underpotential deposition (UPD) of a single-atom nonnoble metal onto the chalcogen atoms of chemically exfoliated transition metal dichalcogenides and subsequent galvanic displacement with a more-noble single-atom metal. The site-specific electrodeposition (SSED) enables the formation of energetically favorable metal–support bonds, and then automatically terminates the sequential formation of metallic bonding. The self-terminating effect restricts the metal deposition to the atomic scale. The modulated ADMCs exhibit remarkable activity and stability in the hydrogen evolution reaction compared to state-of-the-art single-atom electrocatalysts. We demonstrate that this SSED methodology could be extended to the synthesis of a variety of ADMCs (for example, Pt, Pd, Rh, Cu, Pb, Bi, and Sn single atoms), showing its general scope for the large-scale production of functional ADMCs in heterogenous catalysis. </p>

scholarly journals Formation of a single quasicrystal upon collision of multiple grains

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Insung Han ◽  
Kelly L. Wang ◽  
Andrew T. Cadotte ◽  
Zhucong Xi ◽  
Hadi Parsamehr ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Large Scale ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Decagonal Quasicrystal ◽  
Bulk Crystal Growth ◽  
Computational Discovery ◽  
Dynamics Simulations ◽  
Novel Applications ◽  
Small Misorientation

AbstractQuasicrystals exhibit long-range order but lack translational symmetry. When grown as single crystals, they possess distinctive and unusual properties owing to the absence of grain boundaries. Unfortunately, conventional methods such as bulk crystal growth or thin film deposition only allow us to synthesize either polycrystalline quasicrystals or quasicrystals that are at most a few centimeters in size. Here, we reveal through real-time and 3D imaging the formation of a single decagonal quasicrystal arising from a hard collision between multiple growing quasicrystals in an Al-Co-Ni liquid. Through corresponding molecular dynamics simulations, we examine the underlying kinetics of quasicrystal coalescence and investigate the effects of initial misorientation between the growing quasicrystalline grains on the formation of grain boundaries. At small misorientation, coalescence occurs following rigid rotation that is facilitated by phasons. Our joint experimental-computational discovery paves the way toward fabrication of single, large-scale quasicrystals for novel applications.

Controllable growth of multilayered XSe2 (X=W and Mo) for nonlinear optical and optoelectronic applications

2D Materials ◽  
2021 ◽  
Author(s):  
Kun Ye ◽  
Lixuan Liu ◽  
Liying Chen ◽  
Wenlong Li ◽  
Bochong Wang ◽  
...  
Keyword(s):  
Large Scale ◽  
Second Harmonic ◽  
Transition Metal Dichalcogenides ◽  
Chemical Vapor ◽  
Fast Response ◽  
Peak Position ◽  
Metal Dichalcogenides ◽  
Controllable Growth ◽  
Optoelectronic Applications ◽  
Layered Transition Metal

Abstract The layered transition metal dichalcogenides (TMDs) exhibit the intriguing physical properties and potential application in novel electronic devices. However, controllable growth of multilayer TMDs remains challenging. Herein, large-scale and high-quality multilayer prototype TMDs of W(Mo)Se2 were synthesized via chemical vapor deposition. For Raman and PL measurements, 2H and 3R multilayer WSe2 crystals displayed significant layer-dependent peak position and intensity feature. Besides, different from the oscillatory relationship of SHG intensity for odd-even layer numbers in 2H-stacked multilayer WSe2, the second harmonic generation intensity of 3R-stacked ones parabolically increased with the thickness due to the absence of inversion symmetry. For device application, photodetectors based on WSe2 with increasing thickness exhibited p-type (bilayer), ambipolar (trilayer), and n-type (4 layers) semiconductor behaviors, respectively. Furthermore, photodetectors based on the as-synthesized 3R-stacked WSe2 flakes displayed an excellent responsivity (R) of 7.8×103 mA/W, high specific detectivity (Da*) of 1.7×1014 Jones, outstanding external quantum efficiency (EQE) of 8.6×102 %, and fast response time (τRise=57 ms and τFall=53 ms) under 532 nm illumination with bias voltage of Vds=5 V. Similar results have also been achieved in multilayer MoSe2 crystals. All these findings indicate great potential of 3R-stacked TMDs in two-dimensional optoelectronic applications.

scholarly journals Quaternary Misfit Compounds—A Concise Review

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 468
Author(s):  
Sokhrab B. Aliev ◽  
Reshef Tenne
Keyword(s):  
Irrational Number ◽  
Short Review ◽  
Layered Compounds ◽  
Layered Compound ◽  
Charge Carrier Density ◽  
Precise Control ◽  
Rocksalt Structure ◽  
Main Emphasis ◽  
Recent Developments ◽  
Metal Dichalcogenides

Misfit layered compounds (MLCs) have been studied in the literature for the last 40 years. They are generally made of an alternating sequence of two monolayers, a distorted rocksalt structure, and a hexagonal layered compound. In a typical MLC, the c-axis is common to the two monolayers and so is one of the axes in the layer plan. However, the two compounds are non-commensurate along at least one axis, and the ratio between the two axes is an irrational number making the MLC a non-stoichiometric compound. The two main families of MLC are those based on metal dichalcogenides and CoO2 as the hexagonal layered compound. Traditionally, ternary MLCs were prepared and studied, but some quaternary and multinary MLC minerals have been known for many years. Over the last few years, interest in MLCs with four and even larger number of atoms has grown. Doping or alloying of a ternary MLC permits precise control of the charge carrier density and hence the electrical, thermoelectric, catalytic, and optical properties of such compounds. In this short review, some of these developments will be discussed with the main emphasis put on quaternary MLC nanotubes belonging to the chalcogenide series. The synthesis, structural characterization, and some of their properties are considered. Some recent developments in quaternary cobaltite MLCs and recent studies on exfoliated MLCs are discussed as well.

Sign in / Sign up

Export Citation Format

Share Document