High catalytic activity of magnetic FeOx/NiOy/SBA-15: The role of Ni in the bimetallic oxides at the nanometer level

Recently, great efforts have been devoted for improving the catalytic activity of the iron-based bimetallic oxide catalysts by taking advantage of the synergistic effects between Fe and the second metal. Herein, we report the preparation of a highly active and magnetic nickel iron Fenton-like catalyst by fabricating uniform and highly dispersed mixed phase FeOx/NiOy in mesoporous material SBA-15 (Santa Barbara Amorphous-15). This bimetallic oxide catalyst achieved 99.3% removal of the dye Acid Red 73 in 1 h, while monometallic loaded catalysts reached 29.2% and 21.9% only. Besides, 65.81% TOC removal of Acid Red 73 (initial concentration of H2O2 was 4.0 mM) and more than 95% utilization efficiency of H2O2 were obtained by FeOx/NiOy/SBA-15 in 1 h, which were much higher than the traditional Fe2+ catalyst (only 49.81% and 28.56%, respectively). At last, this catalyst showed good reusability and can be easily separated by using a magnet. Characterization results confirmed that iron species including Fe3O4 and Fe2O3, nickel species including Ni(0) and NiO coexisted in the synthesized FeOx/NiOy/SBA-15. The test results and mechanism analysis showed that nickel species have positive contributions to the high catalytic activity of this catalyst. (C) 2015 Elsevier B.V. All rights reserved.