Zr AND Cu MODIFIED TiO2 PHOTOCATALYSTS FOR WATER TREATMENT    Zr AND Cu MODIFIED TiO2 PHOTOCATALYSTS FOR WATER TREATMENT PhD student : Olena Pliekhova Mentor: Prof. dr. Urska Lavrencic Stangar   Maribor 2016

748 million people lack access to clean water (WHO 2015) Waste water Domestic Agricultural Industrial Cheap and effective water purification technology is needed

Advanced oxidation processes Photocatalysis

TiO2 photocatalysis Why TiO2? ability to absorb visible/ UV light, Absorption of efficient photons: Production of HO˙ radicals: Neutralization : Transient hydrogen peroxide appearance: Decomposition: Organic reactant oxidation: Direct oxidation through reaction with hole: Oxygen reduction: super oxide radical Why TiO2? ability to absorb visible/ UV light, chemical and biological inertness, photo stability, relatively low cost, has low toxicity level , exhibits adequate conversion values

Limiting factors of TiO2 activity Poor absorber of photons in Visible region Fast electron/hole recombination http://www.physics.otago.ac.nz/nx/eman/about-solar-energy.html http://ecee.colorado.edu/~bart/book/book/chapter2/ch2_8.htm#fig2_8_2

Cu and Zr as effective modifiers of TiO2 Cu modification benefits: Increment of Vis light absorption Charge separation Electron trapping (reduction potential of Cu ion is more positive than the conduction band of TiO2 Zr modification benefits: Increase in surface area Rise in surface acidity Creation of active defects Durability improvement Zr-O-Cu MMCT chromophores Photochemical CO2 splitting under the visible light (Wenyong Lin and Heinz Frei Jacs Photochemical CO2 Splitting by Metal-to-Metal Charge-Transfer Excitation in Mesoporous ZrCu(I)-MCM-41 Silicate Sieve J. AM. CHEM. SOC. 2005, 127, 1610-1611)

The goals of the research work are obtaining and characterization of novel Zr and Cu modified TiO2 photocatalysts with extended sensitivity towards the solar light irradiation for water treatment.

The objectives of the research: To evaluate the effect of simultaneous presence of Cu and Zr on the properties of TiO2 To asses the influence of origin (organic/inorganic) of co-modifier precursors on photocatalytic activity of TiO2 TiO2 surface modification with Cu(NO3)2 and ZrO(NO3)2 TiO2 surface modification with Cu(O2C5H7)2, Zr(OC4H9)4 To estimate influence of Zr-O-Ti, Cu-O-Ti and Zr-O-Cu species on the photocatalytic activity of TiO2 EXAFS and XANES for structure identification with photocatalytic activity test

To quantify the impact of valence state of Cu on properties of TiO2 Cu (ll) incorporation to TiO2 lattice (solution combustion method) Cu (l) stabilization into TiO2 lattice (solution combustion method) To immobilize the most active photocatalyst for effective water purification Incorporation to the binder coat (sol-gel technology) To determine toxicity of water before and after photocatalytic treatment Toxicity test with daphnia, AAS for Cu and Zr

First positive experimental result Modification method: wet impregnation Model pollutant: Methylene blue

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