Immobilization of PDMS-SiO 2 -TiO 2 composite for the photocatalytic degradation of dye AO-7.

Crack-free PDMS-SiO2-TiO2 composite as photocatalyst was prepared for degrading dyes by using thin-film fixed bed reactor. The hydrophobic surface of the photocatalyst loaded with PDMS-SiO2-TiO2 composite could be considered as an extractant for organic pollutants. The effect of different supports including pumice stone, medicinal stone, and fiberglass for photocatalytic efficiency were compared. Under the same condition, it was found that the photocatalytic degradation effect of dyes was best when PDMS-SiO2-TiO2 composite was fixed on pumice stone rather than medicinal stone or fiberglass. Furthermore, when pumice stone was used as the support for PDMS-SiO2-TiO2 composite, the photocatalytic degradation effect of dyes hardly decreased after five cycles.