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

•Highly catalytic active and magnetic FeOx/NiOy/SBA-15 was fabricated.•Incorporation of Fe onto the NiOy surface induced the formation of new nano-FeNi.•The roles of Ni in the bimetallic oxides at the nanometer level were investigated.•The catalyst showed good recyclability and reusability.•Synergistic effects in the catalyst are responsive for these excellent performances.

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.

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