showing 7 related works from this author
Molecular Camouflage: Making Use of Protecting Groups To Control the Self-Assembly of Inorganic Janus Particles onto Metal-Chalcogenide Nanotubes by …
2011
Hard and soft: Binding of inorganic Pt@Fe3O4 Janus particles to WS2 nanotubes through their Pt or Fe3O4 domains is governed by the difference in Pearson hardness: the soft Pt block has a higher sulfur affinity than the harder magnetite face; thus the binding proceeds preferentially through the Pt face. This binding preference can be reversed by masking the Pt face with an organic protecting group.
Hybrid chalcogenide nanoparticles: 2D-WS2 nanocrystals inside nested WS2 fullerenes.
2013
The MOCVD assisted formation of nested WS2 inorganic fullerenes (IF-WS2) was performed by enhancing surface diffusion with iodine, and fullerene growth was monitored by taking TEM snapshots of intermediate products. The internal structure of the core–shell nanoparticles was studied using scanning electron microscopy (SEM) after cross-cutting with a focused ion beam (FIB). Lamellar reaction intermediates were found occluded in the fullerene particles. In contrast to carbon fullerenes, layered metal chalcogenides prefer the formation of planar, plate-like structures where the dangling bonds at the edges are stabilized by excess S atoms. The effects of the reaction and annealing temperatures o…
Structure analysis on the nanoscale: closed WS2 nanoboxes through a cascade of topo- and epitactic processes
2014
Closed WS2 nanoboxes were formed by topotactic sulfidization of a WO3/WO3·⅓H2O intergrowth precursor. Automated diffraction tomography was used to elucidate the growth mechanism of these unconventional hollow structures. By partial conversion and structural analysis of the products, each of them representing a snapshot of the reaction at a given point in time, the overall reaction can be broken down into a cascade of individual steps and each of them identified with a basic mechanism. During the initial step of sulfidization WO3·⅓H2O transforms into hexagonal WO3 whose surface allows for the epitaxial induction of WS2. The initially formed platelets of WS2 exhibit a preferred orientation wi…
Growth Mechanism and Surface Functionalization of Metal Chalcogenides Nanostructures
2014
Following the discovery of carbon fullerenes and nanotubes (NTs), nanostructured materials and their synthesis have attracted tremendous attention due to their superior mechanical properties, their unique electronic behavior, and their high potential in making technologically advanced nanodevices. Among different classes, layered metal chalcogenides nanostructures are of interest for a variety of applications ranging from nanoelectronics or as source materials for energy applications, nanotribology and in heterogeneous catalysis. These nanoparticles are metastable phases. Therefore, equilibrium methods are necessary to prevent the formation of the thermodynamically stable bulk phase. On the…
Graphene-type sheets of Nb(1-x)W(x)S2: synthesis and in situ functionalization.
2013
Enlightened by the discovery of graphenes, a variety of inorganic analogues have been synthesized and characterized in recent years. Solvated Nb1−xWxS2 analogues of graphene-type sheets were prepared by lithiation and exfoliation of multistacked Nb1−xWxS2 coin roll nanowires (CRNWs), followed by in situ functionalization with gold nanoparticles to synthesize gold-loaded Nb1−xWxS2/Au nanocomposites. The Nb1−xWxS2 nanosheets and the corresponding Nb1−xWxS2/Au nanocomposites were characterized by high resolution electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDX), scanning transmission electron microscopy (STEM), dynamic light scattering (DLS) and scanning force microscopy …
Diffusion-Driven Formation of MoS2 Nanotube Bundles Containing MoS2 Nanopods
2011
MoS2 nanotube bundles, along with embedded nested fullerenes, were formed in a gas-phase reaction of molybdenum carbonyl and H2S gas with the assistance of I2. The amorphous Mo-S-I precursor particles obtained by quenching a modified metal organic chemical vapor deposition (MOCVD) reaction in a large temperature gradient were annealed at elevated temperature in an inert atmosphere. Under the influence of the iodine, the amorphous precursor formed a surface film with an enhanced mobility of the molybdenum and sulfur components. Point defects within the MoS2 layers, combined with the enhanced surface diffusion, lead to a scrolling of the inherently unstable MoS2 lamellae. The role of the reac…
Surface Defects as a Tool to Solubilize and Functionalize WS 2 Nanotubes
2017
Layered transition metal dichalcogenides contain a number of crystal defects which significantly change their properties may be beneficial or detrimental for a specific application. We have prepared defect-rich multiwalled WS2 nanotubes by reductive sulfidization of W18O49 nanowires that were obtained solvothermally from tungsten chloride in different alcohols. The synthesis of the W18O49 nanowires was monitored and their morphological characteristics (e. g. length, rigidity and aspect ratio) are described in detail. The effect of morphology of the nanowires on the synthesis of WS2 nanotubes was investigated in order to obtain WS2 nanotubes that are highly solvent dispersible. Dispersions o…