Fotokatalytický rozklad oxidu dusného v přítomnosti nanokompozitů g-C3N4/ZnO

Abstract

This work is focused on photocatalytic decomposition of nitrous oxide in the presence of nanocomposites g-C3N4/ZnO. The aim of the work is to decompose one of the most important greenhouse gases, N2O, on the non-harmful and natural components of the environment - oxygen and nitrogen - using prepared photocatalysts. The photocatalytic decomposition of nitrous oxide was carried out in the batch reactor in the presence of photocatalysts (g-C3N4, ZnO, g-C3N4/ZnO (1:1), g-C3N4/ZnO (2:1), g-C3N4/ZnO (3:1) and g-C3N4/ZnO (0,05:1)) which have been applied to the foams. An 8W Hg lamp was used as the radiation source with wavelength 365 nm, which was located above the quartz glass window in the reactor lid. The photocatalytic decomposition of N2O was monitored over a time interval of 0-22 hours. By evaluating the experimental data it was found that all prepared photocatalysts were active and in their presence there was a higher conversion of N2O than with the photolysis itself. The conversion rates of N2O after 22 hours of irradiation decreased in the order of: g-C3N4/ZnO (0,05:1) > g-C3N4 > ZnO > g-C3N4/ZnO (2:1) > g-C3N4/ZnO (3:1) > g-C3N4/ZnO (1:1) > photolysis. The highest conversion of N2O (11 % after 22 hours of irradiation) was achieved in the presence of the g-C3N4/ZnO nanocomposite with a weight ratio of 0,05:1. The key role in photocatalyst activity was probably the rate of recombination of generated electrons and holes, which was the lowest in the nanocomposite g-C3N4/ZnO (0,05:1) due to the created heterojunction.