scholarly journals Instability of NiMoS2 and CoMoS2 Hydrodesulfurization Catalysts at Ambient Conditions: A Quasi in Situ High-Resolution Transmission Electron Microscopy and X-ray Photoelectron Spectroscopy Study

2016 ◽  
Vol 120 (34) ◽  
pp. 19204-19211 ◽  
Author(s):  
G. Marien Bremmer ◽  
Lennart van Haandel ◽  
Emiel J. M. Hensen ◽  
Joost W. M. Frenken ◽  
Patricia J. Kooyman
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Photoelectron Spectroscopy ◽  
Spectroscopy Study ◽  
Ambient Conditions ◽  
X Ray ◽  
Hydrodesulfurization Catalysts ◽  
Transmission Electron

scholarly journals In Situ and In Operando Techniques to Study Li-Ion and Solid-State Batteries: Micro to Atomic Level

Inorganics ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 85
Author(s):  
Maryam Golozar ◽  
Raynald Gauvin ◽  
Karim Zaghib
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Atomic Level ◽  
X Ray ◽  
In Situ Techniques ◽  
Transmission Electron ◽  
Wide Range ◽  
Li Ion

This work summarizes the most commonly used in situ techniques for the study of Li-ion batteries from the micro to the atomic level. In situ analysis has attracted a great deal of interest owing to its ability to provide a wide range of information about the cycling behavior of batteries from the beginning until the end of cycling. The in situ techniques that are covered are: X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Scanning Transmission Electron Microscopy (STEM). An optimized setup is required to be able to use any of these in situ techniques in battery applications. Depending on the type of data required, the available setup, and the type of battery, more than one of these techniques might be needed. This study organizes these techniques from the micro to the atomic level, and shows the types of data that can be obtained using these techniques, their advantages and their challenges, and possible strategies for overcoming these challenges.

scholarly journals X-ray Photoelectron Spectroscopy Study of Electronic Structure of Graphene Nanosheets

2015 ◽  
Vol 16 (2) ◽  
pp. 289-292
Author(s):  
B.I. Ilkiv ◽  
S.S. Petrovska ◽  
R.A. Sergienko ◽  
О.О. Foya ◽  
O.V. Ilkiv ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Emission Spectroscopy ◽  
Graphene Nanosheets ◽  
Oxygen Removal ◽  
Electron Bombardment ◽  
Spectroscopy Study ◽  
X Ray ◽  
Transmission Electron

Investigations of graphene nanosheets and oxidized graphene nanosheets were carried out using X-ray photoelectron spectroscopy. Scanning and transmission electron microscopy investigations were used in addition to X-ray photoelectron spectroscopy. It was found that functional carboxyl and epoxide groups were removed from samples due to argon bombardment in studies of oxidized graphene nanosheets with X-ray photoelectron spectroscopy. Thus the ОKα-band was not revealed in oxidized graphene nanosheets owing to oxygen removal due to electron bombardment with the use of. ultra-soft X-ray emission spectroscopy. 

Nanostructural C-Al-N thin films studied by x-ray photoelectron spectroscopy, Raman and high-resolution transmission electron microscopy

2009 ◽  
Vol 24 (11) ◽  
pp. 3321-3330 ◽  
Author(s):  
Y.F. Han ◽  
T. Fu ◽  
Y.G. Shen
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Photoelectron Spectroscopy ◽  
Face Centered Cubic ◽  
X Ray ◽  
Al Content ◽  
Transmission Electron ◽  
Face Centered

The effects of Al incorporation and post-deposition annealing on the structural properties of C-Al-N thin films prepared by reactive unbalanced dc-magnetron sputtering were investigated using x-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and high-resolution transmission electron microscopy (HRTEM). XPS studies demonstrated the presence of abundant Al-N bonds in addition to C-C and N-C bonds. At low incorporations of Al and N, the films were found to be essentially amorphous. By Raman and HRTEM, the formation of ∼5 nm fullerene-like carbon nitride (FL-CNx) nanostructures in an amorphous (C, CNx) matrix was evidenced with increasing Al content in the films. Crystalline improvement of FL-CNx nanostructures was seen, as well as the precipitation of ∼3–4 nm face centered cubic (fcc-) AlN nanograins by thermal annealing at 500 °C or above. Through these improvements, C-Al-N nanocomposite thin films were achieved. The effects of the incorporated Al and annealing on stabilizing fcc-AlN nanograins and FL-CNx nanostructures are elucidated and explained through the use of thermodynamic considerations.

scholarly journals Study of the structure and mechanical behavior of low-dimentional III-V semiconductor heterostructures

2021 ◽  
Author(s):  
Νικολέττα Φλωρίνη
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Geometric Phase ◽  
Molecular Beam ◽  
Semiconductor Heterostructures ◽  
X Ray ◽  
Transmission Electron ◽  
Geometric Phase Analysis

Το αντικείμενο της διδακτορικής διατριβής εντοπίζεται στην ολοκληρωμένη μελέτη των χαμηλοδιάστατων ημιαγωγικών ετεροδομών III-V ως προς την μορφολογία τους, την κρυσταλλική τους δομή, τα πεδία παραμόρφωσης και την χημική τους σύσταση. Για τον σκοπό αυτό μελετήθηκαν QDs ανεπτυγμένες σε υπόστρωμα GaAs, για χρήση σε εφαρμογές διατάξεων νανοφωτονικής και κβαντικής κρυπτογραφίας, και NWs ανεπτυγμένα σε υπόστρωμα Si για ενεργειακή χρήση σε προηγμένης γενιάς φωτοβολταϊκά στοιχεία. Συγκεκριμένα, οι κβαντικές τελείες αφορούν τόσο επιφανειακές όσο και εσωτερικές QDs ινδίου-αρσενικού (InAs) ανεπτυγμένες σύμφωνα με τον μηχανισμό στοιβάδων και νησίδων (Stranski-Krastanow) σε υπόστρωμα γαλλίου-αρσενικού (GaAs) (211)Β, ενώ τα νανονήματα αφορούν NWs γαλλίου-αρσενικού (GaAs), καθώς και NWs πυρήνα/φλοιού GaAs/ (In,Al)GaAs ανεπτυγμένα σε υποστρώματα πυριτίου (Si) (111). Όλες οι νανοδομές έχουν αναπτυχθεί με Επιταξία Μοριακών Δεσμών (Molecular Beam Epitaxy, MBE). Η ανάλυση της μορφολογίας, του δομικού και στοιχειακού χαρακτηρισμού πραγματοποιήθηκε χρησιμοποιώντας τεχνικές Ηλεκτρονικής Μικροσκοπίας Διέλευσης (Transmission Electron Microscopy, ΤΕΜ) και υψηλής διακριτικής ικανότητας ΤΕΜ (High-Resolution ΤΕΜ, ΗRΤΕΜ). Ταυτόχρονα, η ανάλυση της παραμόρφωσης στη νανοκλίμακα πραγματοποιήθηκε χρησιμοποιώντας την απεικονιστική πειραματική μέθοδο της Γεωμετρικής Ανάλυσης Φάσης (Geometric Phase Analysis, GPA), αντλώντας λεπτομερή πειραματικά δομικά στοιχεία των υπό μελέτη συστημάτων σε νανοσκοπικό και ατομικό επίπεδο, από παρατηρήσεις ΗRTEM. Στην ετεροεπιταξιακή ανάπτυξη η κατανομή των ελαστικών πεδίων τάσεων και παραμορφώσεων, καθώς και η χημική τους σύσταση έχουν σημαντικό αντίκτυπο στις οποτοηλεκτρονικές τους ιδιότητες. Για τον σκοπό αυτό, ακολούθησαν υπολογισμοί-προσομοιώσεις των πεδίων τάσης-παραμόρφωσης και η αποτύπωση τους σε δυο ή/και τρεις διαστάσεις (2D – 3D) με την υπολογιστική μέθοδο των Πεπερασμένων Στοιχείων (Finite Elements Method, FEM). Επιπλέον, πραγματοποιήθηκαν συμπληρωματικές παρατηρήσεις ΤΕΜ Σάρωσης (Scanning TEM, STEM) και in-situ Φασματοσκοπίας Ενεργειακού Διασκορπισμού Ακτίνων-Χ (Energy Dispersive X-Ray Spectroscopy, EDS) για τον μορφολογικό χαρακτηρισμό και τον τοπικό προσδιορισμό της χημικής σύστασης των NWs πυρήνα/φλοιού, αντίστοιχα.

scholarly journals Composites of Platinum-Iridium Alloy Nanoparticles and Graphene Oxide for the Dimethyl Amine Borane (DMAB) dehydrogenation at ambient conditions: An Experimental and Density Functional Theory Study

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Betül Sen ◽  
Ayşenur Aygun ◽  
Aysun Şavk ◽  
Mehmet Harbi Çalımlı ◽  
Mehmet Ferdi Fellah ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Catalyst Activity ◽  
Alloy Nanoparticles ◽  
Ambient Conditions ◽  
X Ray ◽  
Transmission Electron

Abstract In this paper, we present the synthesis, characterization, catalytic and computational studies of Composites of Platinum-Iridium Alloy Nanoparticles and Graphene Oxide (PtIr@GO) for dimethylamine borane (DMAB) dehydrogenation. The prepared PtIr@GO nanocatalysts were synthesized using an ethanol super-hydride method, and the characterization procedures for PtIr@GO alloy nanoparticles were carried out by various advanced spectroscopic methods like X-ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Transmission Electron Microscopy(TEM) and high-resolution transmission electron microscopy (HRTEM). Additionally, catalytic activity, reusability, substrate concentration, and catalyst concentration experiments were performed for DMAB dehydrogenation catalyzed by PtIr@GO alloy nanomaterials. According to the results obtained in this study, PtIr@GO NPs catalyst was found to be active and reusable for the DMAB even at ambient conditions. Besides, DFT-B3LYP calculations have been utilized on PtIr@GO cluster to reveal the prepared catalyst activity. The calculated findings based on DFT was found to be a good agreement with experimental results.

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