Novel hybrid materials based on alginate-boehmite-riboflavin for photogeneration of reactive oxygen species in aqueous media. Potential environmental implications

Abstract

In this work, hybrid composites based on beads of alginate, boehmite and riboflavin-5′-phosphate dye (ALG-B-RP) were synthesized in order to obtain novel materials capable to generate reactive oxygen species (ROS). The synthesis was performed by adsorbing the dye RP on boehmite (B) and then alginate (ALG) was added forming a homogeneous suspension. This suspension was dripped on a solution of calcium ions resulting in the formation of bead-shaped yellow hydrogels. Beads with different RP content were synthesized. Confocal laser scanning microscope images indicate that the RP is homogeneously distributed in the ALG polymeric matrix. This microscopy, UV–Vis and fluorescence spectroscopies show that dye photophysical properties are not affected. Uptake oxygen experiments show that these beads have the ability to generate ROS, mainly singlet oxygen O2(1Δg). On top of that mentioned above, these materials are economical, environmentally friendly because are synthesized from non-toxic components and their synthesis does not generate waste and only use water as solvent. On the other hand, these beads are easy to handle and their ability to generate ROS making them promising for water remediation.