Investigation on the impact of incorporating iron-based compounds in enhancing the photocatalytic efficiency of coatings produced through electrochemical plasma oxidation on pure titanium

نوع: Type: thesis

مقطع: Segment: PHD

عنوان: Title: Investigation on the impact of incorporating iron-based compounds in enhancing the photocatalytic efficiency of coatings produced through electrochemical plasma oxidation on pure titanium

ارائه دهنده: Provider: Sajad Alizad

اساتید راهنما: Supervisors: Arash Fattah-alhosseini (Ph. D)

اساتید مشاور: Advisory Professors: Minoo Karbasi (Ph.D)

اساتید ممتحن یا داور: Examining professors or referees: - Dr.Keyvani- Dr. Aziziyan-Dr. Movahedi

زمان و تاریخ ارائه: Time and date of presentation: 2024

مکان ارائه: Place of presentation: Faculty of Engineering

چکیده: Abstract: Abstract Photocatalytic process has been used as a suitable solution to remove pollutants. Powdered photocatalysts have problems due to agglomeration and sedimentation, therefore, photocatalytic coatings are a suitable solution. The purpose of this research is to evaluate the photocatalytic activity of iron-based coatings. In this regard, the characterization of X-ray diffraction, scanning electron microscopy, penetrating reflection spectroscopy and luminescence optical spectroscopy was performed. In the first phase, TiO2-based coatings were created through plasma electrolytic oxidation (PEO) on pure titanium, and then different concentrations of Fe(NO3)3 iron nitrate were added into the coating electrolyte. The microstructure, chemical composition and optical properties of PEO coatings were investigated and the results showed that all the coatings show a porous structure, which is the nature of the PEO coating, and the wetting angles indicate the hydrophobic nature of the coatings. Also, the phase analysis results show that anatase and rutile phases are formed during the coating process. The photocatalytic activity of the coatings was investigated for the photodegradation of methylene blue and the results showed that increasing the iron concentration up to 0.1 g/L leads to the improvement of the photocatalytic activity, so that it shows the highest photocatalytic activity in the degradation of methylene blue by 76%. The improvement of the photocatalytic activity can be attributed to the reduction of the energy gap from 3.05 to 2.95 eV. In the second phase, in order to create iron oxide with magnetic property on the surface of TiO2 coating, chemical deposition process has been used. For this purpose, the effect of different concentrations (low, medium and high) of iron nitrate and different temperatures (160, 180 and 200 ̊C) in the chemical deposition process on the photocatalytic behavior of the coatings in the degradation of methylene blue and rhodamine B was investigated. The results of X-ray diffraction test showed that in addition to anatase, rutile and titanium phase, iron oxide phase is formed on the surface. The results of photocatalytic activity showed that the coating prepared with high concentration and temperature of 180 ̊C resulted in the highest degradation rate of methylene blue (67%) and rhodamine B (25%) under visible light irradiation. These results can be attributed to the reduction of the energy gap and reduction of electron and hole recombination in the coating containing iron oxide. The photocatalytic behavior of the optimal coating was evaluated under different conditions such as the presence of the oxidant potassium peroxymonosulfate (PMS), light intensity and pH, and in the presence of appropriate traps, the active species in the degradation process of blue rhodamine were confirmed. Key Words: Photocatalyst, titanium dioxide, Iron-based compounds, plasma electrolytic oxidation (PEO).

فایل: ّFile: Download فایل