Removal of textile dyes from water by TiO2 nanoparticles immobilized on poly(ε-caprolactone) beads and foams

This study discusses the possibility of immobilization of colloidal TiO2 nanoparticles (NPs) onto poly(?-caprolactone) (PCL) beads and foams that could be utilized for the removal of textile dyes from water by photodegradation. PCL foams were fabricated by environmentally friendly treatment of PCL beads in supercritical carbon dioxide. PCL beads and foams loaded with colloidal TiO2 NPs were used as photocatalysts for the removal of the textile dyes C.I. Acid Orange 7 and C.I. Basic Yellow 28 from aqueous solutions (10 mg L-1) under illumination that simulated sunlight. Unlike the PCL beads, the PCL foams provided complete discoloration of the dye solution within 24 h of illumination. The PCL foams also exhibited excellent floatability that was maintained for more than four weeks. Additionally, their photocatalytic activity was preserved within three repeated photodegradation cycles, indicating that the floating photocatalyst provided superior photocatalytic activity compared to the non-floating PCL beads.