scholarly journals Active IrO2 and NiO Thin Films Prepared by Atomic Layer Deposition for Oxygen Evolution Reaction

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 92 ◽  
Author(s):  
DJ Donn Matienzo ◽  
Daniel Settipani ◽  
Emanuele Instuli ◽  
Tanja Kallio

Atomic layer deposition (ALD) is a special type of chemical vapor deposition (CVD) technique that can grow uniformed thin films on a substrate through alternate self-limiting surface reactions. Recently, the application of these thin film materials to catalytic systems has begun to attract much attention, and the capacity to deposit these catalytic films in a highly controlled manner continues to gain importance. In this study, IrO2 and NiO thin films (approximately 25 to 60 nm) were deposited on industrial Ni expanded mesh as an anode for alkaline water electrolysis. Different ALD operating parameters such as the total number of deposition cycles, sublimation and deposition temperatures, and precursors pulse and purge lengths were varied to determine their effects on the structure and the electrochemical performance of the thin film materials. Results from the electrochemical tests (6 M KOH, 80 °C, up to 10 kA/m2) showed the catalytic activity of the samples. Oxygen overpotential values (ηO2) were 20 to 60 mV lower than the bare Ni expanded mesh. In summary, the study has demonstrated the feasibility of using the ALD technique to deposit uniformed and electroactive thin films on industrial metallic substrates as anodes for alkaline water electrolysis.

RSC Advances ◽  
2018 ◽  
Vol 8 (60) ◽  
pp. 34215-34223
Author(s):  
So-Yeong Na ◽  
Sung-Min Yoon

Oxide thin films transistors (TFTs) with Hf and Al co-incorporated ZnO active channels prepared by atomic-layer deposition are presented.


2019 ◽  
Vol 16 (12) ◽  
pp. 1900127 ◽  
Author(s):  
Morteza Aghaee ◽  
Joerie Verheyen ◽  
Alquin A. E. Stevens ◽  
Wilhelmus M. M. Kessels ◽  
Mariadriana Creatore

RSC Advances ◽  
2015 ◽  
Vol 5 (29) ◽  
pp. 22712-22717 ◽  
Author(s):  
Soumyadeep Sinha ◽  
Devika Choudhury ◽  
Gopalan Rajaraman ◽  
Shaibal K. Sarkar

DFT study of the growth mechanism of atomic layer deposited Zn3N2 thin film applied as a channel layer of TFT.


Author(s):  
Nhi V. Quach ◽  
Quang N. Pham ◽  
Ju-Hwan Han ◽  
Youngjoon Suh ◽  
Jin-Seong Park ◽  
...  

Abstract Atomic layer deposition (ALD) is effective in depositing conformal thin films, which is highly favorable for coating various patterned surfaces. These coatings serve as barrier layers in addition to surface modifications to improve wettability of porous structures, such as meshes and membrane channels. However, it has been challenging to conformally deposit hydrophilic thin films on three-dimensionally (3D) designed, more complicated architectures. To understand the effect of surface modifications on 3D structures’ surface properties, we deposit thin silica films via ALD on hydrophobic porous media, which is nickel inverse opal structures in this case. The silica thin film is used to improve hydrophilicity without modifying the geometries of the microporous structure such as porosity, pore size, and metal type. We study the consequences of applying silica coatings to the 3D structure in comparison to flat surface counterpart. The hydrophilicity effects of ALD coating on porous structures and flat nickel surfaces are approximately the same with a result of decreasing apparent static contact angle of approximately 30°. In relation, the Fowkes method reveals the surface energy of the ALD silica samples increases by a factor of 1.3. Thermal stability of the coating is tested, revealing a relative degradation with increasing thermal cycling, most likely associated with the adsorption species on the thin film surface. The droplet spreading rate is analyzed in addition to droplet volume loss to estimate the liquid penetration rate into the structure, if any. Condensation rate and condensate growth show that despite having lower droplet nucleation in comparison to a flat surface, the droplet area growth on inverse opal regions is larger. These findings showcase potential improvements to 3D microporous structures by employing ALD coating for fluid transport through the porous media.


Author(s):  
T. W. Scharf ◽  
S. V. Prasad ◽  
M. T. Dugger ◽  
T. M. Mayer

Tungsten disulphide (WS2) and molybdenum disulfide (MoS2), which belong to the family of transition metal dichalcogenides, are well known for their solid lubricating behavior. Thin films of MoS2 and WS2 exhibit extremely low coefficient of friction (COF ∼0.02 to 0.05) in dry environments, and are typically applied by sputter deposition, pulsed laser ablation, evaporation or chemical vapor deposition, which are essentially either line-of-sight or high temperature processes. With these techniques it is difficult to coat surfaces shadowed from the target, or uniformly coat sidewalls of three-dimensional or high aspect ratio structures. For applications such as micromechanical (MEMS) devices, where dimensions and separation tolerances are small, and aspect ratios are large, these traditional deposition techniques are inadequate. Atomic layer deposition (ALD) is a chemical vapor deposition technique that could overcome many of these problems by using sequential introduction of gaseous precursors and selective surface chemistry to achieve controlled growth at lower temperatures, but the chemistry needed to grow transition metal dichalcogenide films by ALD is not known.


RSC Advances ◽  
2016 ◽  
Vol 6 (100) ◽  
pp. 98337-98343 ◽  
Author(s):  
Felix Mattelaer ◽  
Tom Bosserez ◽  
Jan Rongé ◽  
Johan A. Martens ◽  
Jolien Dendooven ◽  
...  

Manganese oxide thin films were obtained by a combination of atomic layer deposition and post-deposition annealing, and the viability of these thin films as thin film catalysts for solar hydrogen devices has been demonstrated.


2021 ◽  
Author(s):  
Yuanyuan Guo ◽  
Yiming Zou ◽  
Chunyu Cheng ◽  
Leyan Wang ◽  
Riko I Made ◽  
...  

Abstract Metal alloys are usually fabricated by melting constituent metals together or sintering metal alloy particles made by high energy ball milling (mechanical alloying). All these methods only allow for bulk alloys to be formed. This manuscript details a new method of fabricating Rhodium/Iridium (Rh/Ir) metal alloy films using atomic layer deposition (ALD) and rapid Joule heating induced alloying that gives functional thin film alloys, enabling conformal thin films with high aspect ratios on 3D nanostructured substrate. In this work, ALD was used to deposit Rh thin film on an Al2O3 substrate, followed by an Ir overlayer on top of the Rh film. The multilayered structure was then alloyed / sintered using rapid Joule heating. We can precisely control the thickness of the resultant alloy films down to the atomic scale. The Rh@Ir alloy thin films were characterized using scanning and transmission electron microscopy (SEM/TEM) and energy dispersive spectroscopy (EDS) to study their microstructural characteristics. Grazing-incidence X-ray diffraction (GIXRD) and X-ray photoelectron spectroscopy (XPS) were also carried out to confirm the composition and formation of Rh-Ir thin film alloys. All the characterization results reveal that the Rh-Ir alloy thin film was prepared successfully with one single phase and homogeneous distribution of Rh and Ir throughout the film. Molecular Dynamics simulation experiments of Rh/Ir alloys using Large-Scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) were performed to elucidate the alloying mechanism during the rapid heating process, corroborating the experimental results.


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