Synthesis of magnetically recyclable Fe3O4@polydopamine–Pt composites and their application in hydrogenation reactions

Pt dendrimer-like nanoparticles were in situ deposited on the magnetic Fe₃O₄@polydopamine core–shell composites due to the metal-binding ability and weak reducibility of polydopamine. Such core–shell–satellite catalyst structure endowed the Fe₃O₄@polydopamine–Pt catalyst with excellent magnetical recyclability, aqueous dispersity, and high catalytic performance for the catalytic reduction of 4-nitrophenol and its derivatives, and methylene blue. This catalyst could be reused for 12 cycles without losing its catalytic activity, indicating the high stability.