scholarly journals “Intelligent” Pt Catalysts Based on Thin LaCoO3 Films Prepared by Atomic Layer Deposition

Inorganics ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 113 ◽  
Author(s):  
Xinyu Mao ◽  
Alexandre C. Foucher ◽  
Eric A. Stach ◽  
Raymond J. Gorte
Keyword(s):  
Atomic Layer Deposition ◽  
Co Adsorption ◽  
Atomic Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Highly Active ◽  
Transmission Electron ◽  
Layer Deposition ◽  
Scanning Transmission ◽  
Water Gas

LaCoO3 films were deposited onto MgAl2O4 powders by atomic layer deposition (ALD) and then used as catalyst supports for Pt. X-ray diffraction (XRD) showed that the 0.5 nm films exhibited a perovskite structure after redox cycling at 1073 K, and scanning transmission electron microscopy and elemental mapping via energy-dispersive X-ray spectroscopy (STEM/EDS) data demonstrated that the films covered the substrate uniformly. Catalysts prepared with 3 wt % Pt showed that the Pt remained well dispersed on the perovskite film, even after repeated oxidations and reductions at 1073 K. Despite the high Pt dispersion, CO adsorption at room temperature was negligible. Compared with conventional Pt on MgAl2O4, the reduced forms of the LaCoO3-containing catalyst were highly active for the CO oxidation and water gas shift (WGS) reactions, while the oxidized catalysts showed much lower activities. Surprisingly, the reduced catalysts were much less active than the oxidized catalysts for toluene hydrogen. Catalysts prepared from thin films of Co3O4 or La2O3 exhibited properties more similar to Pt/MgAl2O4. Possible reasons for how LaCoO3 affects properties are discussed.

scholarly journals Decoration of Vertically Aligned Carbon Nanotubes with Semiconductor Nanoparticles Using Atomic Layer Deposition

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1095 ◽  
Author(s):  
Anna Szabó ◽  
László Péter Bakos ◽  
Dániel Karajz ◽  
Tamás Gyulavári ◽  
Zsejke-Réka Tóth ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
X Ray Diffraction ◽  
Vertically Aligned Carbon Nanotubes ◽  
X Ray ◽  
Transmission Electron ◽  
Layer Deposition ◽  
Aligned Carbon Nanotubes ◽  
Vertically Aligned

Vertically aligned carbon nanotubes (VACNTs or “CNT forest”) were decorated with semiconductor particles (TiO2 and ZnO) by atomic layer deposition (ALD). Both the structure and morphology of the components were systematically studied using scanning (SEM) and high resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy, and X-ray diffraction (XRD) methods. Characterization results revealed that the decoration was successful in the whole bulk of VACNTs. The effect of a follow-up heat treatment was also investigated and its effect on the structure was proved. It was attested that atomic layer deposition is a suitable technique for the fabrication of semiconductor/vertically aligned carbon nanotubes composites. Regarding their technological importance, we hope that semiconductor/CNT forest nanocomposites find potential application in the near future.

scholarly journals Two-Dimensional Perovskite Crystals Formed by Atomic Layer Deposition of CaTiO3 on γ-Al2O3

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2207
Author(s):  
Tianyu Cao ◽  
Ohhun Kwon ◽  
Chao Lin ◽  
John M. Vohs ◽  
Raymond J. Gorte
Keyword(s):  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Average Thickness ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Entire Surface ◽  
X Ray ◽  
Transmission Electron ◽  
Layer Deposition ◽  
20 Nm

CaTiO3 films with an average thickness of 0.5 nm were deposited onto γ-Al2O3 by Atomic Layer Deposition (ALD) and then characterized by a range of techniques, including X-ray Diffraction (XRD) and High-Resolution, Transmission Electron Microscopy (HRTEM). The results demonstrate that the films form two-dimensional crystallites over the entire surface. Lattice fringes from HRTEM indicate that the crystallites range in size from 5 to 20 nm and are oriented in various directions. Films of the same thickness on SiO2 remained amorphous, indicating that the support played a role in forming the crystallites.

Spectroscopic study of La2O3 thin films deposited by indigenously developed plasma-enhanced atomic layer deposition system

2018 ◽  
Vol 32 (19) ◽  
pp. 1840074 ◽  
Author(s):  
Viral Barhate ◽  
Khushabu Agrawal ◽  
Vilas Patil ◽  
Sumit Patil ◽  
Ashok Mahajan
Keyword(s):  
Thin Films ◽  
Atomic Layer Deposition ◽  
Spectroscopic Study ◽  
Photoelectron Spectroscopy ◽  
Atomic Layer ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron ◽  
Layer Deposition

The spectroscopic study of La2O3 thin films deposited over Si and SiC at low RF power of 25 W by using indigenously developed plasma-enhanced atomic layer deposition (IDPEALD) system has been investigated. The tris (cyclopentadienyl) lanthanum (III) and O2 plasma were used as a source precursor of lanthanum and oxygen, respectively. The [Formula: see text]1.2 nm thick La2O3 over SiC and Si has been formed based on our recipe confirmed by means of cross-sectional transmission electron microscopy. The structural characterization of deposited films was performed by means of X-ray photoelectron Spectroscopy (XPS) and X-ray Diffraction (XRD). The XPS result confirms the formation of 3[Formula: see text] oxidation state of the lanthania. The XRD results reveals that, deposited La2O3 films deposited on SiC are amorphous in nature compare to that of films on Si. The AFM micrograph shows the lowest roughness of 0.26 nm for 30 cycles of La2O3 thin films.

Ex-situ X-ray diffraction analysis of electrode strain at TiO2 atomic layer deposition/α-MoO3 interface in a novel aqueous potassium ion battery

2016 ◽  
Vol 316 ◽  
pp. 160-169 ◽  
Author(s):  
Nicholas David Schuppert ◽  
Santanu Mukherjee ◽  
Alex M. Bates ◽  
Eun-Jin Son ◽  
Moon Jong Choi ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Diffraction Analysis ◽  
Atomic Layer ◽  
Potassium Ion ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
X Ray ◽  
Layer Deposition

scholarly journals Direct Epitaxial Nanometer-Thin InN of High Structural Quality on 4H-SiC by Atomic Layer Deposition

2020 ◽  
Author(s):  
Chih-Wei Hsu ◽  
Petro Deminskyi ◽  
Ivan Martinovic ◽  
Ivan G. Ivanov ◽  
Justinas Palisaitis ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Indium Nitride ◽  
Atomic Layer ◽  
Structural Quality ◽  
High Electron ◽  
X Ray Diffraction ◽  
High Quality ◽  
Subsequent Formation ◽  
Transmission Electron ◽  
Layer Deposition

<div>Indium nitride (InN) is a highly promising material for high frequency electronics given its</div><div>low band gap and high electron mobility. The development of InN-based devices is hampered</div><div>by the limitations in depositing very thin InN films of high quality. We demonstrate growth of</div><div>high-structural-quality nanometer thin InN films on 4H-SiC by atomic layer deposition (ALD).</div><div>High resolution X-ray diffraction and transmission electron microscopy show epitaxial growth</div><div>and an atomically sharp interface between InN and 4H-SiC. The InN film is fully relaxed already after a few atomic layers and shows a very smooth morphology where the low surface</div><div>roughness (0.14 nm) is found to reproduced sub-nanometer surface features of the substrate. Raman measurements show an asymmetric broadening caused by grains in the InN film. Our results show the potential of ALD to prepare high quality nanometer-thin InN films for subsequent formation of heterojunctions.</div>

scholarly journals Comparison of the Growth and Thermal Properties of Nonwoven Polymers after Atomic Layer Deposition and Vapor Phase Infiltration

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1028
Author(s):  
Laura Keskiväli ◽  
Pirjo Heikkilä ◽  
Eija Kenttä ◽  
Tommi Virtanen ◽  
Hille Rautkoski ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Electron Microscope ◽  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Scanning Transmission Electron Microscope ◽  
Scanning Calorimetry ◽  
Polymeric Surfaces ◽  
Transmission Electron ◽  
Layer Deposition ◽  
Scanning Transmission

The growth mechanism of Atomic Layer Deposition (ALD) on polymeric surfaces differs from growth on inorganic solid substrates, such as silicon wafer or glass. In this paper, we report the growth experiments of Al2O3 and ZnO on nonwoven poly-L-lactic acid (PLLA), polyethersulphone (PES) and cellulose acetate (CA) fibres. Material growth in both ALD and infiltration mode was studied. The structures were examined with a scanning electron microscope (SEM), scanning transmission electron microscope (STEM), attenuated total reflectance-fourier-transform infrared spectroscopy (ATR-FTIR) and 27Al nuclear magnetic resonance (NMR). Furthermore, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis were used to explore the effect of ALD deposition on the thermal properties of the CA polymer. According to the SEM, STEM and ATR-FTIR analysis, the growth of Al2O3 was more uniform than ZnO on each of the polymers studied. In addition, according to ATR-FTIR spectroscopy, the infiltration resulted in interactions between the polymers and the ALD precursors. Thermal analysis (TGA/DSC) revealed a slower depolymerization process and better thermal resistance upon heating both in ALD-coated and infiltrated fibres, more pronounced on the latter type of structures, as seen from smaller endothermic peaks on TA.

scholarly journals A Thermodynamic Investigation of Ni on Thin-Film Titanates (ATiO3)

Inorganics ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 69
Author(s):  
Chao Lin ◽  
Alexandre C. Foucher ◽  
Eric A. Stach ◽  
Raymond J. Gorte
Keyword(s):  
Atomic Layer Deposition ◽  
Coulometric Titration ◽  
Equilibrium Constants ◽  
Atomic Layer ◽  
Co2 Reforming ◽  
Co2 Reforming Of Ch4 ◽  
Transmission Electron ◽  
Layer Deposition ◽  
Ni Oxidation ◽  
Scanning Transmission

Thin, ~1-nm films of CaTiO3, SrTiO3, and BaTiO3 were deposited onto MgAl2O4 by Atomic Layer Deposition (ALD) and then studied as catalyst supports for ~5 wt % of Ni that was added to the perovskite thin films by Atomic Layer Deposition. Scanning Transmission Electron Microscopy demonstrated that both the Ni and the perovskites uniformly covered the surface of the support following oxidation at 1073 K, even after redox cycling, but large Ni particles formed following a reduction at 1073 K. When compared to Ni/MgAl2O4, the perovskite-containing catalysts required significantly higher temperatures for Ni reduction. Equilibrium constants for Ni oxidation, as determined from Coulometric Titration, indicated that the oxidation of Ni shifted to lower PO2 on the perovskite-containing materials. Based on Ni equilibrium constants, Ni interactions are strongest with CaTiO3, followed by SrTiO3 and BaTiO3. The shift in the equilibrium constant was shown to cause reversible deactivation of the Ni/CaTiO3/MgAl2O4 catalyst for CO2 reforming of CH4 at high CO2 pressures, due to the oxidation of the Ni.

Electrical and Structural Properties of Ruthenium Film Grown by Atomic Layer Deposition Using Liquid-Phase Ru(CO)3(C6H8) Precursor

2007 ◽  
Vol 990 ◽  
Author(s):  
Sung-Hoon Chung ◽  
Vladislav Vasilyev ◽  
Evgeni Gorokhov ◽  
Yong-Won Song ◽  
Hyuk-Kyoo Jang
Keyword(s):  
Liquid Phase ◽  
Atomic Layer Deposition ◽  
Annealing Temperature ◽  
Atomic Layer ◽  
Grazing Incidence ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Layer Deposition ◽  
Structural And Electrical Properties

ABSTRACTWe investigated effects of thermal annealing on Ru films deposited on the 8 inch Si substrates using a volatile liquid-phase Ru precursor, tricarbonyl-1,3-cyclohexadienyl ruthenium (Ru(CO)3(C6H8)) by an atomic layer deposition (ALD) technique. Structural and electrical properties of the films were characterized by scanning probe microscopy, X-ray diffractometry, sheet resistance. Grazing incidence X-ray diffraction (GIXRD) patterns show typical Ru hexagonal polycrystalline peaks as annealing temperature was increased. At the highest annealing temperature condition, Ta = 700 °C electrical resistivity become 6 times less than in as-deposited films.

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