Tuncay Dikici

Fabrication and characterization of novel iodine doped hollow and mesoporous hematite (Fe 2 O 3 ) particles derived from sol-gel method and their photocatalytic performances

In this work, iodine (I) doped hollow and mesoporous Fe2O3 photocatalyst particles were fabricated for the first time through sol-gel method. Phase structure, surface morphology, particle size, specific surface area and optical band gap of the synthesized Fe2O3 photocatalysts were analyzed by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), X-ray photoelectron spectroscopy (XPS), BET surface analysis, particle size analyzer and UV-vis diffuse reflectance spectrum (UV-vis DRS), respectively. Also, electrochemical properties and photoluminescence spectra of Fe2O3 particles were measured. The results illustrated that high crystalline, hollow and mesoporous Fe2O3 particles were formed. The optical band gap values of the Fe2O3 photocatalysts changed between 2.104 and 1.93eV. Photocatalytic efficiency of Fe2O3 photocatalysts were assessed via MB solution. The photocatalytic activity results exhibited that I doping enhanced the photocatalytic efficiency. 1% mole iodine doped (I-2) Fe2O3 photocatalyst had 97.723% photodegradation rate and 8.638×10-2min-1 kinetic constant which showed the highest photocatalytic activity within 45min. Moreover, stability and reusability experiments of Fe2O3 photocatalysts were carried out. The Fe2O3 photocatalysts showed outstanding stability after four sequence tests. As a result, I doped Fe2O3 is a good candidate for photocatalysts.

Preparation and Characterization of Ni–TiO2 Nanocomposite Coatings Produced by Electrodeposition Technique

In this paper Ni-TiO2 nanocomposite coatings with different sizes of TiO2 nanoparticles were successfully prepared by electrodeposition process from a nickel electrolyte in which the TiO2 nanoparticles were suspended. The influence of relevant deposition parameters on the nanocomposite coating characteristics was discussed. X-ray diffractometer (XRD) has been applied in order to investigate the phase structure of the nanocomposite coatings. The surface morphology of nanocomposite coatings was characterized by a scanning electron microscopy equipped with an energy dispersive spectroscopy (SEM/EDS). The electrodeposited nanocomposite coatings obtained at different deposition parameters were evaluated for their mechanical and corrosive properties. Obtained results show that the size of TiO2 nanoparticles and applied current density during deposition process has a direct effect on mechanical and corrosive properties of nanocomposite coatings. Increasing current density and smaller nanoparticle size has affirmative effect on mechanical properties whereas corrosion resistance of nanocomposite coatings deposited at 3 A.dm-2 current density are higher than the coatings prepared at higher current density values.