Self-cleaning and depollution of fiber reinforced cement materials modified by neutral TiO2/SiO2 hydrosol photoactive coatings

Abstract Environmental pollution has an evidently adverse impact on the buildings that are constructed by the glass fiber reinforced cement (GRC) materials. In the present work, the stable, neutral TiO 2 /SiO 2 hydrosols were prepared by using the Ti(SO 4 ) 2 as titanium source, HNO 3 as peptizing agent, and SiO 2 as stabilizer through a simple and low cost process. The morphologies and structures of TiO 2 /SiO 2 hydrosol were further characterized by the TEM, SEM, XRD, and FTIR measurement. In the synthetic hydrosol, lots of nanoparticles with the diameters in the range of 10–20 nm can be observed. Ti O Si band were formed, as observed from the FTIR spectrum. The Na 2 O·SiO 2 was detected from the SEM. After drying the TiO 2 /SiO 2 hydrosol, the XRD shown that the TiO 2 has an anatase structure and the SiO 2 is amorphous. The TiO 2 /SiO 2 hydrosol can be compactly coated on the GRC surface due to the existence of Na 2 O·SiO 2 binder and exhibited high photocatalytic activity and stability in the degradation of Rhodamine B.