Sol-jel yöntemi ile sentezlenen nanopartiküllerin fotokatalitik özelliklerinin geliştirilmesi

Among the transition metal oxide semiconductors, titanium dioxide is the most suitable photocatalyst commonly used for photocatalysis applications. However, there are still many difficulties to enhance the photocatalytic performance of titanium dioxide. Various techniques have been applied to develop the photocatalytic properties of titanium dioxide nanoparticles, such as doping transition metal elements (Ag, Ni, Cu, Zn etc.) doping, rare earth metal elements (La, Ce, Eu etc.) doping to other metals and non-metals elements (F, C, S etc.). Titanium dioxide is compatible with transition metal cations such as chromium, which has a high absorption of visible light. Scientific research shows that the doping of a transition metal and a noble metal together into titanium dioxide structure may lead to the development of photoactivity. The present thesis involves, pure chromium doped, chromium and nitrogen codoped TiO2 nanoparticles production by a sol-gel method using titanium(IV) isopropoxide, chromium nitrate and urea as precursors. Structural characterization of the undoped and doped TiO2 nanoparticles was performed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectrometry (XPS). Particle size measurements of nanoparticles were performed by using Zetasizer. XRD results show that the undoped, Cr doped and Cr/N codoped TiO2 nanoparticles have the anatase phase. The photocatalytic properties of synthesized nanoparticles were determined by degredation of methylene blue solution under UV illumination. Photocatalytic efficiency of undoped, doped and codoped TiO2 were compared. The best photocatalytic activity was observed in C/N codoped TiO2 nanoparticles.