Visible light photoreduction of cr(VI) in aqueous solution using iron-containing zeolite tubes

CATL 31

Ramasubramanian Kanthasamy and Sarah C. Larsen, sarah-larsen@uiowa.edu. Department of Chemistry, University of Iowa, Iowa City, IA 52242
In this study, a novel visible light photocatalyst consisting of iron-loaded zeolite tubes was designed to reduce Cr(VI) to Cr(III) in aqueous solution. Iron was incorporated into hollow, porous ZSM-5 tubes using two different methods. In the first method, the iron-encapsulated ZSM-5 tubes were prepared by introducing iron into the mesoporous silica template prior to the formation of the hollow ZSM-5 tubes resulting in an encapsulated iron species. In the second method, iron was ion-exchanged into the ZSM-5 shell during a post-synthesis treatment. The activity of these materials for Cr(VI) reduction with visible light was evaluated. Both the iron encapsulated and iron-exchanged ZSM-5 hollow tubes were active for the visible light photoreduction of Cr(VI) to Cr(III) in aqueous solution. The iron-exchanged ZSM-5 tubes were more active initially with a rate four times faster than the iron-encapsulated ZSM-5 tubes but the iron-encapsulated ZSM-5 tubes lasted for more cycles.