Fotokatalytická produkce vodíku z bio-organického odpadu se zaměřením na vztah mezi aktivitou a vlastnostmi fotokatalyzátorů

Abstract

This bachelor's thesis deals with the photocatalytic production of hydrogen from glycerol as a bio-organic waste generated during biodiesel production. The aim of the work was to study photocatalytic hydrogen production, evaluate experimental data, and assess the relationship between photocatalytic activity and the physicochemical properties of the applied photocatalysts. In the experimental part, two commercially available TiO₂-based photocatalysts (P25 and KRC7050) and two defective samples prepared by their reduction using NaBH₄ were used. Their properties were characterized by XRD, FT-IR, Raman spectroscopy, XPS, UV–Vis DRS, and N₂ physisorption analysis. Photocatalytic experiments were carried out first in a glass reactor and subsequently in a stainless steel reactor under UV irradiation (254 nm). In the first phase, the effect of glycerol concentration on hydrogen production was investigated, confirming that increasing glycerol concentration leads to a higher hydrogen yield. For further experiments, a lower glycerol concentration was selected, better representing real conditions in wastewater. In the second phase, the individual photocatalysts were compared. The highest photocatalytic activity was achieved with the commercial photocatalyst KRC7050, which is mainly attributed to its higher specific surface area and the presence of surface –OH groups. The defective photocatalysts exhibited lower activity, likely due to increased charge carrier recombination. The results demonstrate a relationship between the physicochemical properties of photocatalysts and their photocatalytic activity, while also indicating the potential of photocatalysis as a process enabling simultaneous wastewater treatment and hydrogen production.