Fotokatalytický rozklad oxidu dusného v přítomnosti nanokompozitů BiIO4/g-C3N4.

Abstract

This thesis is focused on photocatalytic decomposition of nitrous oxide in the presence of nanocomposites BiIO4/g-C3N4. The main purpose of the photocatalytic decomposition of N2O was its transformation to oxygen and nitrogen, which are natural components of the environment. Nanocomposites BiIO4/g-C3N4 with different weight ratios of both components (1:1, 1:2, 1:4 a 1:6) were prepared by the heating of their mechanical mixtures and were characterized by nitrogen physical adsorption, X-ray powder diffraction, UV-VIS spectroscopy, photoluminescence spectroscopy and photoelectrochemical measurements. Photocatalytic decomposition of N2O was carried out in batch photoreactor in the presence of nanocomposites (BiIO4, BiIO4/g-C3N4 (1:1), BiIO4/g-C3N4 (1:2), BiIO4/g-C3N4 (1:4), BiIO4/g-C3N4 (1:6), g-C3N4). The irradiation source for the fotocatalytic experiments was 8 W Hg lamp with wavelength 365 nm, which was placed on the cover of the photoreactor in a quartz glass visor. Also a photolysis was performed - it means decomposition of N2O in the presence of UV radiation without using a photocatalyst. The influence of ratios of nanocomposites BiIO4 and g-C3N4 on conversion of N2O was monitored at time 0-22 hours. Based on obtained experimental data about photocatalytic decomposition of N2O, the highest conversion of N2O was achieved in the presence of photocatalyst BiIO4/g-C3N4 (1:1). The photocatalytic activity of the monitored photocatalysts decreased in this order: BiIO4/g-C3N4 (1:1) > BiIO4/g-C3N4 (1:2) > BiIO4 = g-C3N4 > BiIO4/g-C3N4 (1:4) > BiIO4/g-C3N4 (1:6). Increased photocatalytic activity was caused by a significant reduction of charge carriers recombination due to the formation of a heterojunction between BiIO4 and g-C3N.