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3. Electrocatalytic Hydrogen Evolution with Transition Metal Based Compounds : abstractSaim Emin, Takwa Chouki, Manel Machreki, 2021, objavljeni povzetek znanstvenega prispevka na konferenci Opis: Electrocatalytic water splitting is one of the cleanest and sustainable way to generate hydrogen. Transition metal based electrocatalysts like iron phosphides (Fe2P, FeP), molybdenum diselenides (MoSe2), and tungsten carbides (W2C, WC) have unique advantages including competitive cost compared to platinum, controllable active sites, and electronic structures that could significantly enhance the hydrogen evolution reaction (HER). Here, we present a combination of approaches for preparing catalyst materials. As an elegant technique, colloidal synthesis was used to synthesize Mo and W nanoparticles. Combined with selenization and carbidation approaches at elevated temperature, it allowed to synthesize MoSe2, W2C, and WC thin films. The syntheses of Fe2P and FeP catalyst were achieved in one-stage using triphenylphosphine precursor. The obtained catalysts were applied in electrocatalytic HER studies.
Ključne besede: iron phosphides
molybdenum diselenide
tungtsen carbides
electrocatalysis
hydrogen evolution
Objavljeno v RUNG: 06.02.2023; Ogledov: 1960; Prenosov: 0
Gradivo ima več datotek! Več... |
4. Thermal diffusivity downscaling of molybdenum oxide thin film through annealing temperature-induced nano-lamelle formation: a photothermal beam deflection studyS. Soumya, Vimal Raj, Mohanachandran Nair Sindhu Swapna, Sankaranarayana Iyer Sankararaman, 2021, izvirni znanstveni članek Opis: The present work proposes a method of downscaling the thermal diffusivity (α)
of MoO3 thin films through annealing temperature-induced nano-lamelle formation. The
thermal diffusivity modification of the MoO3 films, prepared by the doctor blade method,
is investigated by the sensitive transverse photothermal beam deflection technique. The X-ray diffraction analysis confirms the structural phase transformation from monoclinic to
orthorhombic in the films annealed from 300 to 450 °C. The thermal induced anisotropy of
the film is evident from the variation of the morphology index and texture coefficient. The
field emission scanning electron microscopic analysis unveils the morphology modifications
from blocks to the nano-lamelle structure with layers of average thickness ~ 77 nm. The
thermal diffusivity measurement reveals a 53% reduction upon annealing the film to 450 °C.
The drastic reduction is achieved through the annealing temperature-induced nano-lamelle
formation and the phase transformation from monoclinic to orthorhombic in the MoO3 films.
Ključne besede: thermal diffusivity, molybdenum oxide, thin film, nano-lamelle, photothermal beam deflection
Objavljeno v RUNG: 04.07.2022; Ogledov: 1982; Prenosov: 27
 Povezava na celotno besedilo
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5. Thermal diffusivity of molybdenum oxide nanowire film: a photothermal beam deflection studyMohanachandran Nair Sindhu Swapna, 2021, izvirni znanstveni članek Opis: The paper reports the preparation of thin film with MoO3 nanowires (NWs) by the doctor blade method and the
study of its thermal diffusivity (α) by the sensitive photothermal beam deflection (PTD) method. When the Field
Emission Scanning Electron Microscopic and Atomic Force Microscopic analysis unveil its morphology as NW
bundles, the X-ray diffraction analysis reveals the structure to be orthorhombic. The NWs formed are of diameter
~ 20 nm and length up to 5 μm. The standardization of the transverse PTD setup is done by determining the
value of α of iron, which agrees well with literature reports. The thermal diffusivity of MoO3 NW film is obtained
as 0.0036 cm2
/s, which is 9.48% of its bulk counterpart. The reduction in the thermal diffusivity of NW makes it
a suitable candidate for thermoelectric applications.
Ključne besede: Nanowires
Molybdenum oxide
Photothermal beam deflection
Thermal diffusivity
Objavljeno v RUNG: 04.07.2022; Ogledov: 2009; Prenosov: 0
Gradivo ima več datotek! Več... |
6. Evolution of fractal dimension in pulsed laser deposited MoO3 film with ablation time and annealing temperatureMohanachandran Nair Sindhu Swapna, 2021, izvirni znanstveni članek Opis: The multifractal analysis is a potential method for assessing thin flm surface morphology and its changes due to diferent
deposition conditions and post-deposition treatments. In this work, the multifractal analysis is carried out to understand the
surface morphology—root mean square (RMS) surface roughness—of nanostructured MoO3 flms prepared by pulsed laser
deposition technique by varying the ablation time and post-deposition annealing. The XRD analysis shows the evolution of
crystalline nature with annealing temperature. The XRD pattern of all the annealed flms shows the characteristic peak of
the orthorhombic MoO3 phase. The FESEM and AFM analysis reveals the morphological modifcation with ablation time
and annealing temperature. The multifractal analysis of the AFM images shows that the box—counting, information and
correlation dimension varies with the annealing temperature. The study also reveals the inverse relation between the fractal
dimension and the RMS surface roughness due to the annealing induced particle size variation and reorientation. The fractal
dimension’s evolution in the pulsed laser deposited MoO3 flm with ablation time and annealing temperature is also investigated. Thus, the study reveals the potential of multifractal analysis in the thin flm surface characterizatio
Ključne besede: Multifractal analysis · Pulsed laser deposition · Molybdenum oxide · Atomic force microscopy · Fractal
dimension
Objavljeno v RUNG: 04.07.2022; Ogledov: 2054; Prenosov: 0
Gradivo ima več datotek! Več... |
7. Synthesis of molybdenum carbide thin films for production of hydrogen via electrochemical water splitting : M. Sc. thesisCesur Altinkaya, 2018, magistrsko delo Ključne besede: molybdenum, platinum, molybdenum carbide thin films, hydrogen evolution reaction, water splitting, electrolysis, electrochemistry, pyrolysis, thin films
Objavljeno v RUNG: 30.08.2018; Ogledov: 5912; Prenosov: 0
Gradivo ima več datotek! Več... |
8. CVD Growth of Molybdenum Diselenide Surface Structures with Tailored MorphologyM. Naeem Sial, Usman Muhammad, Binjie Zheng, Yanan Yu, Andraž Mavrič, Fangzhu Qing, Matjaž Valant, Zhiming M. Wang, 2018, izvirni znanstveni članek Opis: Controllable atmospheric pressure CVD has been optimized to grow transition metal dichalcogenide MoSe2 with tunable morphology at 750 °C on a silicon substrate with a native oxide layer of 250 nm. Utilizing tetrapotassium perylene-3,4,9,10-tetracarboxylate (PTAS) as a seed promoter and varying the vertical distance between the substrate and the precursor MoO3, different morphologies of MoSe2 were achieved, including 2D triangles, hexagons, 3D pyramids and vertically aligned MoSe2 sheets. We find that the shape of MoSe2 is highly dependent upon the distance h between the substrate and the precursor. The change in the morphology is attributed to the confinement of vapor (MoO3 and Se) precursors and their concentrations due to the change in h. These results are helpful in improving our understanding about the factors which influence the morphology (shape evolution) and also the continuous growth of MoSe2 films.
Ključne besede: Transition metal dichalcogenides, 2D materials, Seed promotor, Chemical vapor deposition, Molybdenum diselenide
Objavljeno v RUNG: 20.08.2018; Ogledov: 4745; Prenosov: 18
 Celotno besedilo (2,68 MB) |
