One pot preparation of CeO2@Alginate composite beads for the catalytic reduction of MB dye: Effect of cerium percentage

Abstract

This study focuses on the preparation of composite beads CeO2@Alginate using a one-pot method. Ce(III) was used as a crosslinking agent and then was modified with a base to transform it into CeO2 encapsulated in the alginate matrix. To study the catalytic behavior of this material the reduction of MB dye in the presence of NaBH4 was selected as a model reaction. Several parameters affecting the reduction of the MB dye were studied such as the effect of cerium content in the composite beads, the concentration of NaBH4 and the concentration of the MB dye. The results showed that the dispersion of alginate in a solution containing Ce(III) leads to the formation of hydrogel beads. The treatment of the beads with a basic solution leads to the in-situ formation of CeO2 inside the beads with a porous structure. The catalytic activity of composite beads has shown interesting results via the reduction of MB dye. The reduction of MB dye catalyzed by CeO2@ALG(2%) was total in 2 min and the associated rate constant was 2.3 min–1. The reuse tests were studied during five successive cycles, in which it was shown that the CeO2@ALG(2%) catalyst was stable without losing its effectiveness.