The photocatalytic oxidation of phenol in water in the band reactor with supported TiO2 catalysts was investigated. Modified anatase/Al2O3 catalysts were used as the photocatalysts. The main aim of these studies was to determine catalytic activity of TiO2/Al2O3 and V-TiO2/Al2O3 in the removal of phenol from water. The effectiveness was measured in the configurations: TiO2/UV/O2/H2O2, TiO2/O2/H2...

Our aim of is to develop a processing method for a rotating disc made of functionally graded materials (FGM), by stacking the slurry, layer by layer in a radial direction. A three-layer functionally graded material of Al/Al2O3 is fabricated with compositions of 10, 20, 30 vol.% Al2O3. The ceramic composition increases from the discs inner (centre) to the outer. The combination of these material...

Graphene heterostructures are of considerable interest as a new class of electronic devices with exceptional performance in a broad range of applications has been realized. Here, we propose a graphene-embedded Al2O3 gate dielectric with a relatively high dielectric constant of 15.5, which is about 2 times that of Al2O3, having a low leakage current with insertion of tri-layer graphene. In this ...

Metal contact to SiC is not easy to modulate since the contact can be influenced by the metal, the termination of the SiC, the doping, and the fabrication process. In this work, we introduce a method by inserting a thin Al2O3 layer between metal and SiC to solve this problem simply but effectively. The Al2O3/n-SiC interface composition was obtained with X-ray photoemission spectroscopy, and the...

Thin films of Al2O3 grown using atomic layer deposition (ALD) techniques can protect polymers from erosion by oxygen atoms. To quantify this protection, polyimide substrates with the same chemical repeat unit as Kapton were applied to quartz crystal microbalance (QCM) sensors. Al2O3 ALD films with varying thicknesses were grown on the polyimide substrates. The ALD-coated polyimide materials wer...

In the present work, Al2O3-CeO2 composite nanopowders were synthesized via co-precipitation method. The sinterability of the synthesized powders was investigated. The results showed that the transformation of transition phases of alumina to α-Al2O3 takes place at 1200 °C. TEM images showed that the powders was composed of nanoparticles in the range of 30−70 nm. The densification of composites s...

In order to investigate the selective catalytic reduction of NOx by hydrocarbons, Ag/Al2O3 models were constructed by means of density functional theory (DFT) and experimental results. The geometrical structures and vibrational frequencies obtained at B3LYP levels of DFT were compared with the corresponding experimental results. EXAFS results suggest silver ion species were predominant on the A...

Ovidius University of Constanta, Department of Physics, 124 Mamaia Blvd, 900527, Romania ___________________________________________________________________________________________ Abstract. A series of Fe2O3-Al2O3 mixed systems with composition ranging from 1 to 9% of Al2O3 were prepared by a traditional chemical method and examined for structural characteristics. XRD spectra and SAED patterns...

Quantum molecular dynamics simulations of α-Al2O3(0001)/3C-SiC(111) interfaces reveal profound effects of thermal annealing for producing strong interfaces consisting solely of cation-anion bonds and their consequence on interfacial structures. A Si-terminated SiC surface and Al2O3 form a stronger interface (Si-interface) with a Si-O bond density of 12.2  nm(-2), whereas the C interface has an ...

We report the structure and stability of ceria units deposited on the surface of γ-Al2O3 or incorporated in its cavities, as determined by periodic density functional calculations. Ceria species are modeled as CeO2 or Ce2O4 moieties or as a small nanoparticle, Ce13O26, on the (100) and (001) surfaces of a γ-Al2O3 slab. Among the studied structures the incorporation of Ce(4+) ions in cavities of...