0000000000267388

AUTHOR

Fakhreddin Ashrafizadeh

showing 3 related works from this author

Qualitative Models for the Photoresponse and Capacitance of Annealed Titania Nanotubes

2015

Physicochemical characterization of annealed TiO2 nanotubes (TNTs) was conducted by using photocurrent spectroscopy and differential capacitance techniques. It has been shown that the geometry and architecture of nanotubes determine how photogenerated electrons and holes are separated and transferred. Photocurrent generation in TNTs is a consequence of two phenomena; drifting of holes into the electrolyte and diffusion of electrons toward the substrate. These two processes have been shown to be independent of the anodic polarization. The capacitance of TiO2 nanotubes is also affected by their geometry. In anodic potentials, with respect to the flat band potential of the underlying barrier l…

Materials sciencePhotoresponseBiomedical EngineeringPharmaceutical ScienceMedicine (miscellaneous)CapacitanceBioengineeringCapacitanceAnnealingNanotubeSettore ING-IND/23 - Chimica Fisica ApplicataPhotocurrent spectroscopyTiO2Composite materialAnodizationBiotechnology
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Silicate and Hydroxide Concentration Influencing the Properties of Composite Al2O3-TiO2 PEO Coatings on AA7075 Alloy

2021

This work evaluates the effect of sodium meta-silicate pentahydrate (SMS) and potassium hydroxide concentrations on properties of Al2O3-TiO2 coatings produced through plasma electrolytic oxidation in a solution containing 3 g L−1 potassium titanyl oxalate, (PTO), using a unipolar waveform with constant current density. The surface and cross-section characteristics of PEO coatings including morphology, elemental distribution, and phase composition were evaluated using FESEM, EDS, and XRD techniques. Voltage-time response indicated the concentration of SMS and KOH had a significant effect on the duration of each stage of the PEO process. More cracks and pores were formed at the higher concent…

Settore ING-IND/23 - Chimica Fisica ApplicataPlasma electrolytic oxidationCorrosion resistanceSilicate-based electrolyteMaterials ChemistryAl<sub>2</sub>O<sub>3</sub>-TiO<sub>2</sub> coatingSurfaces and InterfacesTA1-2040Al2 O3-TiO2 coatingEngineering (General). Civil engineering (General)Al<sub>2</sub>O<sub>3</sub>-TiO<sub>2</sub> coating; plasma electrolytic oxidation; silicate-based electrolyte; corrosion resistanceSurfaces Coatings and FilmsCoatings; Volume 12; Issue 1; Pages: 33
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Influence of Anodic and Thermal Barrier Layers on Physicochemical Behavior of Anodic TiO2 Nanotubes

2011

Electrochemical and photo-electrochemical behavior of self-organized TiO2 nanotubes formed in organic solvents have been studied by taking into account the formation of new barrier layers beneath nanotubes either due to the anodic polarization in aqueous solutions or air exposure during high temperature annealing. It has been shown that before annealing, electrochemical and photoelectrochemical answers are dominantly controlled by the physicochemical properties of the anodic barrier layer. Annealing in air at sufficiently high temperatures changes the initial amorphous structure of as-prepared nanotubes and forms a new oxide layer below them due to thermal oxidation of underneath titanium. …

Materials scienceAnnealing (metallurgy)Oxidechemistry.chemical_elementNanotechnologyTiO2 nanotubeThermal barrier coatingBarrier layerchemistry.chemical_compoundPhotoelectrochemistryMaterials ChemistryElectrochemistryPolarization (electrochemistry)Thermal oxidationElectrochemical Impedance MeasurementRenewable Energy Sustainability and the EnvironmentAnodizingSEM.Condensed Matter PhysicsSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsSettore ING-IND/23 - Chimica Fisica ApplicatachemistryChemical engineeringanodizingTitanium
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