Biopolymer-supported TiO 2 as a sustainable photocatalyst for wastewater treatment: a review

The rising water pollution by pesticides, pharmaceuticals and dyes is a major health issue calling for advanced remediation methods such as photocatalysis with titanium dioxide (TiO 2 ), yet the use of TiO 2 displays issues of aggregation, mass loss, recovery, and reusability. These issues have been recently solved by synthesizing biopolymer-supported photocatalysts using cheap, biodegradable and safe biopolymers such as chitosan, alginate, cellulose, cyclodextrin, guar gum and starch. Here we review biopolymer-supported TiO 2 photocatalysts for the removal of organic compounds, with focus on preparation methods, photo and chemical stability, reusability, and adsorptive capacity. We discuss applications of immobilized photocatalysts at the industrial scale.