Pristine edge structures of T′′-phase transition metal dichalcogenides (ReSe2, ReS2) atomic layers

Nanoscale ◽  
2020 ◽  
Vol 12 (32) ◽  
pp. 17005-17012
Author(s):  
Xiya Chen ◽  
Bao Lei ◽  
Yong Zhu ◽  
Jiadong Zhou ◽  
Zheng Liu ◽  
...  
Keyword(s):  
Scanning Transmission Electron Microscopy ◽  
Density Functional ◽  
Transition Metal Dichalcogenides ◽  
Density Functional Theory Calculations ◽  
Microscopy Imaging ◽  
Functional Theory ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Metal Dichalcogenides ◽  
T Phase

Atomically sharp pristine edges of ReSe2 atomic layers were identified with scanning transmission electron microscopy imaging and density functional theory calculations.

scholarly journals Ultra-small rhenium clusters supported on graphene

2015 ◽  
Vol 17 (12) ◽  
pp. 7898-7906 ◽  
Author(s):  
Orlando Miramontes ◽  
Franco Bonafé ◽  
Ulises Santiago ◽  
Eduardo Larios-Rodriguez ◽  
Jesús J. Velázquez-Salazar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Transmission Electron Microscopy ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Dark Field ◽  
High Angle ◽  
Functional Theory ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Annular Dark Field

In this work, the adsorption of very small rhenium clusters (2–13 atoms) supported on graphene was studied by high-angle annular dark field-scanning transmission electron microscopy (HAADF-STEM) in combination with density functional theory calculations.

scholarly journals Single-atom doping of MoS2 with manganese enables ultrasensitive detection of dopamine: Experimental and computational approach

2020 ◽  
Vol 6 (32) ◽  
pp. eabc4250 ◽  
Author(s):  
Yu Lei ◽  
Derrick Butler ◽  
Michael C. Lucking ◽  
Fu Zhang ◽  
Tunan Xia ◽  
...  
Keyword(s):  
Density Functional ◽  
Transition Metal Dichalcogenides ◽  
Density Functional Theory Calculations ◽  
Single Atom ◽  
Buffer Solution ◽  
Dopamine Detection ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Metal Dichalcogenides ◽  
Metal Doped

Two-dimensional transition metal dichalcogenides (TMDs) emerged as a promising platform to construct sensitive biosensors. We report an ultrasensitive electrochemical dopamine sensor based on manganese-doped MoS2 synthesized via a scalable two-step approach (with Mn ~2.15 atomic %). Selective dopamine detection is achieved with a detection limit of 50 pM in buffer solution, 5 nM in 10% serum, and 50 nM in artificial sweat. Density functional theory calculations and scanning transmission electron microscopy show that two types of Mn defects are dominant: Mn on top of a Mo atom (MntopMo) and Mn substituting a Mo atom (MnMo). At low dopamine concentrations, physisorption on MnMo dominates. At higher concentrations, dopamine chemisorbs on MntopMo, which is consistent with calculations of the dopamine binding energy (2.91 eV for MntopMo versus 0.65 eV for MnMo). Our results demonstrate that metal-doped layered materials, such as TMDs, constitute an emergent platform to construct ultrasensitive and tunable biosensors.

scholarly journals Probing Interfaces Using a Combination of Scanning Transmission Electron Microscopy and Density-Functional Theory

2011 ◽  
Vol 17 (S2) ◽  
pp. 1316-1317 ◽  
Author(s):  
S Pantelides ◽  
T Pennycook ◽  
W Luo ◽  
M Prange ◽  
H Lee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Density Functional Theory ◽  
Transmission Electron Microscopy ◽  
Scanning Transmission Electron Microscopy ◽  
Density Functional ◽  
Functional Theory ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.

scholarly journals Exposure of mass-selected bimetallic Pt–Ti nanoalloys to oxygen explored using scanning transmission electron microscopy and density functional theory

RSC Advances ◽  
2018 ◽  
Vol 8 (48) ◽  
pp. 27276-27282 ◽  
Author(s):  
Saeed Gholhaki ◽  
Shih-Hsuan Hung ◽  
David J. H. Cant ◽  
Caroline E. Blackmore ◽  
Alex G. Shard ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Density Functional Theory ◽  
Transmission Electron Microscopy ◽  
Scanning Transmission Electron Microscopy ◽  
Density Functional ◽  
Functional Theory ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Experimental Morphology

Theoretical and experimental morphology induced by oxidation of the Ti element.

scholarly journals Carbon doping of WS2 monolayers: Bandgap reduction and p-type doping transport

2019 ◽  
Vol 5 (5) ◽  
pp. eaav5003 ◽  
Author(s):  
Fu Zhang ◽  
Yanfu Lu ◽  
Daniel S. Schulman ◽  
Tianyi Zhang ◽  
Kazunori Fujisawa ◽  
...  
Keyword(s):  
Scanning Transmission Electron Microscopy ◽  
Transition Metal Dichalcogenides ◽  
Carbon Doping ◽  
Chemical Doping ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Metal Dichalcogenides ◽  
P Type ◽  
Electronic Chemical ◽  
Type Conduction

Chemical doping constitutes an effective route to alter the electronic, chemical, and optical properties of two-dimensional transition metal dichalcogenides (2D-TMDs). We used a plasma-assisted method to introduce carbon-hydrogen (CH) units into WS2 monolayers. We found CH-groups to be the most stable dopant to introduce carbon into WS2, which led to a reduction of the optical bandgap from 1.98 to 1.83 eV, as revealed by photoluminescence spectroscopy. Aberration corrected high-resolution scanning transmission electron microscopy (AC-HRSTEM) observations in conjunction with first-principle calculations confirm that CH-groups incorporate into S vacancies within WS2. According to our electronic transport measurements, undoped WS2 exhibits a unipolar n-type conduction. Nevertheless, the CH-WS2 monolayers show the emergence of a p-branch and gradually become entirely p-type, as the carbon doping level increases. Therefore, CH-groups embedded into the WS2 lattice tailor its electronic and optical characteristics. This route could be used to dope other 2D-TMDs for more efficient electronic devices.

scholarly journals Shedding Light on the Chemistry and the Properties of Münchnone Functionalized Graphene

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1629
Author(s):  
Giulia Neri ◽  
Enza Fazio ◽  
Antonia Nostro ◽  
Placido Giuseppe Mineo ◽  
Angela Scala ◽  
...  
Keyword(s):  
Density Functional ◽  
Antimicrobial Properties ◽  
Biological Properties ◽  
Azomethine Ylide ◽  
Functionalized Graphene ◽  
Functional Theory ◽  
Pyrrole Derivatives ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Direct Functionalization

Münchnones are mesoionic oxazolium 5-oxides with azomethine ylide characteristics that provide pyrrole derivatives by a 1,3-dipolar cycloaddition (1,3-DC) reaction with acetylenic dipolarophiles. Their reactivity was widely exploited for the synthesis of small molecules, but it was not yet investigated for the functionalization of graphene-based materials. Herein, we report our results on the preparation of münchnone functionalized graphene via cycloaddition reactions, followed by the spontaneous loss of carbon dioxide and its further chemical modification to silver/nisin nanocomposites to confer biological properties. A direct functionalization of graphite flakes into few-layers graphene decorated with pyrrole rings on the layer edge was achieved. The success of functionalization was confirmed by micro-Raman and X-ray photoelectron spectroscopies, scanning transmission electron microscopy, and thermogravimetric analysis. The 1,3-DC reactions of münchnone dipole with graphene have been investigated using density functional theory to model graphene. Finally, we explored the reactivity and the processability of münchnone functionalized graphene to produce enriched nano biomaterials endowed with antimicrobial properties.

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