Active under the sunlight nanostructured TiO2-ZnO photocatalysts for environmental problem solving
Jānis Grabis, Reinis Drunka, Dzidra Jankoviča, Anita Letlena, Ints Šteins, Gundega Heidemane, Pāvels Rodionovs

Description of the Technology

The new technology includes titanium substrate cleaning and etching, preparation of homogeneous porous oxide coatings and oriented nanotube coatings on a substrate by using plasma electrolytic oxidation and anodizatoin methods, as well as modification of obtained coatings with ZnO nanostructures. By optimizing the methods of anodizing and plasma electrolytic oxidation, the optimal electrolyte composition, voltage, process duration, and distance between electrodes were determined. By optimizing pyrolytic spraying and chemical precipitation methods, optimal parameters for electrolyte composition and process duration were determined. A flow-through reactor system has been developed, which simulates the photocatalyst activity testing performed under the solar radiation and determines the optimal composition of the photocatalyst.



Applications

The developed technology can be used to create sunlight active fixed TiO2-ZnO photocatalysts for degradation of harmful organic compounds.



Advantages

Main advantages:

1. Catalysts are fixed on the surface and are therefore easily removed from solution after the technological process.
2. The structure of nanopores and nanotubes provides the photocatalyst with an increased specific surface area, which provides higher photocatalytic activity.

3. Modification of TiO2 photocatalysts with ZnO nanoparticles allows them to be successfully used under the visible light illumination and under the sunlight. (Pure TiO2 is only active under ultra violet (UV) irradiation). 

4. Developed photocatalyst technology ensures low photocatalyst production costs.

5. Photocatalysts are reusable.

6. The substarte of the photocatalyst can be reused.



Keywords

photocatalysis, photocatalysts, plasma electrolytic oxidation, anodization, spray pyrolysis

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