Fabrication of Fe3O4-based ternary magnetic microsphere catalysts based on supramolecular chemistry and their catalytic performance

Abstract

In this paper, magnetic catalysts were successfully synthesized using host–guest chemistry and a self-assembly strategy. First, β-cyclodextrin (β-CD) was directly bonded on the shell of core/shell magnetic Fe₃O₄@SiO₂ (MFS) to form MFS@β-CD. Then, in view of the host–guest recognition, p-aminothiophenol (pATP) was captured by β-CD to generate an inclusion complex (IC) on MFS, forming MFS@IC composites. Lastly, pre-synthesized gold, silver, and platinum nanoparticles (AuNPs, AgNPs, and PtNPs) were adsorbed on the surface of MFS@IC through a self-assembly strategy to fabricate ternary composite MFS@IC@metal nanoparticles. The catalytic performances of the three as-prepared magnetic nanocomposites were evaluated by a 4-nitrophenol reduction reaction using NaBH₄ as the reducing agent. The MFS@IC@Au catalyst showed the largest catalytic reaction rate constant than MFS@IC@Ag and MFS@IC@Pt. Significantly, based on host–guest chemistry, the magnetic catalyst carriers could effectively adhere noble metal nanoparticles with different shapes, sizes and species to fabricate the magnetic catalysts. These magnetic catalysts are prospective candidates for applications in various catalytic reactions.