1. 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

2. 748 million people lack access to clean water (WHO 2015)
Waste water
Domestic
Agricultural
Industrial
Cheap and effective water purification technology is needed

3. Advanced oxidation processes
Photocatalysis

4. 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

5. Limiting factors of TiO2 activity
Poor absorber of photons in Visible region
Fast electron/hole recombination

6. 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, )

7. 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.

8. 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

9. 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

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

11. Thank you for attention