Manujlov E. Film photocatalysts based on titanium dioxide modified with noble metals nanoparticles

The thesis is devoted to the development of modification methods of TiO2 and ZnO/TiO2 mesoporous films by silver and gold nanoparticles based on the combination of sol-gel technology, sorption, ion exchange, thermo- and photoreduction which allow to obtain the materials with specific size of nanoparticles in the matrix and on the surface of the film. For the first time it has been implemented the systematic investigations of silver and gold nanoparticles influence on morphology, phase composition, electronic structure, photoelectrochemical and photocatalytic activities of TiO2 and ZnО/TiO2 mesoporous films. It was found that addition of silver and gold ions to precursor accelerate the ТіО2 (anatase) crystallisation and promote the formation of new cubic phase Zn2Ti3O8 with simultaneous creation of uniformly distributed Au/Ag nanoparticles in the matrix. Doping of TiO2 films by zinc oxide and noble metal nanoparticles improves the electrocatalytic activity of electrodes obtained by coating of these films on titanum plates. Increase of photocurrent quantum yield and efficiency of photogererated charge separation as a result of formation of heterojunction between ТіО2 and zinc phase (Zn2Ti3O8) and action of Ag/Au nanoparticles as traps for photogenerated electrons correlate with photocatalytic activity of these samples in the reduction procecces. Among tested samples modified by nanoparticles, the films with the most intensive surface plasmon resonance band and smallest metal nanoparticles exhibited the highest activity in the reactions of rodamine B and tetracycline oxidation and dichromate-anions reduction.