Photocatalytic Behaviour of TiO2-geopolymer Paste under Sunlight

Abstract

The photocatalytic degradation of methylene blue (MB) of the geopolymer paste with addition nanoparticles titanium dioxide (TiO2) was investigated under illumination of sunlight radiation. In this work, TiO2-based geopolymer paste was prepare by dry mixing of Class F fly ash (FA) and different amount of nano-TiO2 (0, 2.5, 5.0, 10.0 & 15.0 wt%). Then, the alkali activator, which is combination of sodium hydroxide solution with sodium silicate was added to the dry mix FA-TiO2 with ratio of 2.5. All the sample was cured at room temperature and aged for 28 days. The photocatalytic behaviour of nano-TiO2 was evaluated and compared through photocatalytic testing and surface degradation testing by measuring the photodegradation of MB under sunlight rays. The experimental results revealed that the addition of nano-TiO2 to the geopolymer paste shows excellent result on photocatalytic degradation of MB after exposure to sunlight up to 150 minutes.