Mussel-Inspired Catechol–Formaldehyde Resin-Coated Fe₃O₄ Core–Shell Magnetic Nanospheres: An Effective Catalyst Support for Highly Active Palladium Nanoparticles

Magnetic Fe3O4@catechol–formaldehyde resin (CFR) core–shell nanospheres were fabricated via a controllable hydrothermal method. The shell thickness of Fe3O4@CFR nanospheres can be effectively regulated in the range of 10–170 nm via adjusting reaction parameters. In particular, catechol groups on the surface of nanospheres also play a significant role in mussel-inspired chemistry to further combine with graphene oxide (GO) to wrap the Fe3O4@CFR spheres. The obtained Fe3O4@CFR and Fe3O4@CFR@GO nanospheres can be used as the effective catalyst supports of small Pd nanoparticles (PdNPs,