Vliv přípravy oxidů kovů na bázi titanu a zirkonu pomocí přetlakových a superkritických tekutin na fotokatalytickou redukci oxidu uhličitého

Abstract

Bachelor thesis is focused on the study of the effect of ratios of titanium dioxide and zirconium dioxide on the photocatalytic reduction of carbon dioxide. The main goal of the photocatalytic reduction of carbon dioxide is its conversion into harmless and more useful substances. Photocatalytic reduction of carbon dioxide was performed in a batch reactor in the aqueous sodium hydroxide solution with suspended photocatalyst (ZrxTi1-xOn). 8 W Hg lamp (λ = 254 nm), which was placed horizontally above a quartz glass window in the reactor cover, was used as a radiation source. Photocatalytic reduction products in the gas phase were methane, carbon monoxide and hydrogen, generated from the decomposition of water. The effect of ratios of titanium and zirconium dioxides on the yields of gases was monitored at the time intervals of 0-16 hours. The yields of gases differed depending on the content ratios of TiO2 and ZrO2 and they decreased in the order Zr0,5Ti0,5On < Zr0,1Ti0,9On < Zr0,7Ti0,3On < Zr0,9Ti0,1On < ZrO2 < TiO¬2. The yields on all mixed photocatalysts as well as on the pure ZrO2 were higher than on the pure TiO2. The highest yields of methane, carbon monoxide and hydrogen were observed in the presence of photocatalyst with molar ratio TiO2:ZrO2 0,5:0,5.