Modified PVA-alginate encapsulated photocatalyst ferro photo gels for Cr(VI) reduction

In this study magnetic separable photocatalyst beads containing maghemite nanoparticles (gamma-Fe2O3) in polyvinyl alcohol (PVA) polymer were prepared and used in the reduction of Cr(VI) to Cr(III) in an aqueous solution under sunlight. The unique superparamagnetic property of the photocatalyst contributed by the gamma-Fe2O3 and robust property of PVA polymer allow the magnetic beads to be recovered easily and reused for at least 7 times without washing. The concentration of gamma-Fe2O3 was varied from 8% (v/v) to 27% (v/v) and the results revealed that the beads with 8% (v/v) gamma-Fe2O3 exhibited the best performance where Cr(VI) was reduced to Cr(III) in only 30 min under sunlight. The use of the PVA has improved the bead properties and life cycle of beads which is in line with sustainable practices. (C) 2012 Elsevier BM. All rights reserved.