Samočistící efekt povrchů stavebních materiálů vyvolaný přítomností grafitického nitridu uhlíku

Abstract

Photocatalytic materials exhibit the ability to decompose organic pollutants and harmful chemicals when exposed to light in the range of certain wavelengths. Another application option is the use of photocatalysts for the preparation of surfaces exhibiting self-cleaning capabilities, which have a direct impact on extending the service life of building elements and improving their appearance. Unlike the conventionally used titanium dioxide (TiO2), whose photocatalytic activity is limited mainly to the ultraviolet region of the electromagnetic spectrum, graphitic carbon nitride (g-C3N4) can absorb radiation up to the visible light region with wavelengths up to approximately 465 nm. This fact significantly expands the spectrum of conditions under which photocatalytic processes can occur, thus enabling more efficient use of ordinary daylight. Materials modified with g-C3N4 therefore exhibit higher photocatalytic efficiency and offer wider possibilities for practical application, especially in environments with limited UV radiation. Within the diploma thesis, bulk g-C3N4 will be prepared, which will be subsequently exfoliated. The prepared g-C3N4 samples will be characterized by selected techniques and their photodegradation activity by degradation of rhodamine B (RhB) will be determined. The effect of temperature on the kinetics of RhB decomposition will be monitored for selected photocatalyst samples. The exfoliated g-C3N4 will then be used to prepare an aqueous suspension that will be applied to the surface of hardened cement paste samples. The self-cleaning ability of the surfaces of the modified cement paste samples will be tested by degrading the model dye RhB.