Investigation of the photocatalytic and electrochemical behavior of the coatings created by plasma electrolytic oxidation on commercially pure titanium by adding tungsten oxide nanoparticles

Investigation of the photocatalytic and electrochemical behavior of the coatings created by plasma electrolytic oxidation on commercially pure titanium by adding tungsten oxide nanoparticles


Investigation of the photocatalytic and electrochemical behavior of the coatings created by plasma electrolytic oxidation on commercially pure titanium by adding tungsten oxide nanoparticles

نوع: Type: thesis

مقطع: Segment: masters

عنوان: Title: Investigation of the photocatalytic and electrochemical behavior of the coatings created by plasma electrolytic oxidation on commercially pure titanium by adding tungsten oxide nanoparticles

ارائه دهنده: Provider: Haniye salimi

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

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

اساتید ممتحن یا داور: Examining professors or referees: Dr. hamid esfahani & Dr. omid iman talab

زمان و تاریخ ارائه: Time and date of presentation: 2023

مکان ارائه: Place of presentation: technical engineering faculity - conferance

چکیده: Abstract: BY means of this research, a nanocomposit coating based on titanium dioxide (TiO2) and tungsten oxide nanoparticles (WO3) was created to remove the colored pollutant meythylene blue through plasma electrolytic oxidation (PEO). To begin with, 1 g/L of tungsten oxide nanoparticles was added to alkaline electrolyte and the photocatalytic properties of the coatings were investigated at different current densities ). The photocatalytic performance of the coating was then investigated using the A/dm2 (12, 13.5 and 15 ) and different concentrations of tungsten oxide nanoparticles (1, 2 and A/dm2 optimized current density (13.5 3 g/L ).based on optical, visible-ultraviolet spectroscopy, the coating created in electrolytes containing tungsten oxide nanoparticles destroyed 84% of methylene blue with the first-order rate constant equal to 5.1 × ????−?? ??????−?? which had the best photocatalytic behavior. This was attributed to the surface's hydrophilicity as well as the greater involvement of tungsten oxide nanoparticles.As a result of the interoduction of tungsten to the titania network and the creation of an internal electric field through theinhomogeneity of the connections between WO3/TiO2, the photocatalytic behavior was improved. Characterization by scanning electron microscope (SEM), energy diffraction X-ray spectroscopy (EDS), X-ray diffraction (XRD), wettability, penetrating reflection spectroscopy (DRS) and photoluminescence spectroscopy (PL) were performed. In the following, various photocatalytic parameters including the concentration of methylene blue, light intensity and pH were investigated on the optimal sample with a concentration of 2 g/L of tungsten oxide nanoparticles. As expected, the photocatalysts showed stability after three periods of recovery.The electrochemical behavior was examined using electrochemical impedance spectroscopy and Mott-Schottky testing in a sea salt simulating solution containing 3.5% sodium chloride by weight. Based on the electrochemical tests, the coating containing two grams per liter of tungsten oxide nanoparticles had a greater corrosion resistance than other samples. We presented a mechanism process based on the DRS analysis calculation of an energy gap of 2.93 electron volts, the Mott-Schottky analysis calculation of a conduction band potential and capacityas 0.41 and 3.34 electron volts, respectively,and the presence of hole trappers, hydroxide and superoxide anion in the photocatalytic process