“Synthesis, structure and activity of WO3, Se-WO3 and TiO2/WO3 photocatalysts”

Author, institution: Simona Ostachavičiūtė, Kaunas University of Technology

Science area, field: Physical Sciences, Chemistry

The Doctoral Dissertation is available at the library of Kaunas University of Technology (K. Donelaičio St. 20, Kaunas).

Scientific supervisor:

Prof. Dr. Eugenijus VALATKA (Kaunas University of Technology, Physical Sciences, Chemistry – 03P)

Dissertation Defense Board of Chemical Science Field:

Prof. Dr. Habil. Algirdas ŠAČKUS (Kaunas University of Technology, Physical Sciences, Chemistry – 03P) – chairman;

Prof. Dr. Henrikas CESIULIS (Vilnius University, Physical Sciences, Chemistry – 03P);

Prof. Dr. Vytautas GETAUTIS (Kaunas University of Technology, Physical Sciences, Chemistry – 03P);

Prof. Dr. Habil. Rimantas RAMANAUSKAS (Center for Physical Sciences and Technology, Institute of Chemistry, Physical Sciences, Chemistry – 03P);

Prof. Dr. Algirdas ŠULČIUS (Kaunas University of Technology, Technological Sciences, Chemical Engineering – 05T).

Annotation:

Scientific community exhibits a great interest in photocatalytic processes such as water photosplitting or photooxidation of organic substances. The photoelectrochemical splitting of water into hydrogen and oxygen is considered as the very promising pathway in the development of a long-term, sustainable energy economy. Titania (TiO₂) still remains to be the most suitable for practical applications. However, using it as a photocatalyst still has some major issues: due to the fast recombination of photogenerated charge carriers, the overall quantum efficiency is relatively low, and titania is mostly sensitive to UV irradiation. Tungsten trioxide (WO₃) is another semiconductor which can be employed in photocatalysis. Besides its photochromic properties, it has a smaller band gap than titania and may be activated under visible light illumination. In order to improve the photocatalytic efficiency it may be reasonable enough to combine both titania and tungsten trioxide into one photocatalyst or to modify their surface with various compounds. This work is relevant in the search of new materials suitable for photocatalytic and photoelectrocatalytic processes. The main object of this work was to synthesize active tungsten oxide-based composite catalysts and evaluate their structure and properties. Aim of the work was to synthesize WO₃ catalysts modified with TiO₂, Se and Co-P additives, to investigate their structure, photocatalytic and photoelectrochemical properties.