A biological pathway to synthesize Ag/Fe3O4 heterostructures with high catalytic performance

Abstract

The development of novel processes for the preparation of precious metal-based supported catalysts with good catalytic activity and stability has long been a focus of catalytic research. Herein, we propose a novel and facile biosynthetic method to fabricate Ag/Fe₃O₄ heterostructures at room temperature by employing magnetosomes (Fe₃O₄@magnetosome membrane) derived from magnetotactic bacteria as “microreactors”. Ag nanoparticles with a uniform particle size distribution of about 10 nm in diameter can be grown at the interface of Fe₃O₄ and the magnetosome membrane in just a few minutes without any additives. Owing to the spatial domain-limiting effect of the magnetosome membrane, the surface of Ag nanoparticles is enriched with various defects (such as twin crystals, lattice distortion and various types of point defects) and has a strong interfacial interaction with Fe₃O₄. Accordingly, the B-Ag/Fe₃O₄ heterostructure presents excellent catalytic activity and good high-temperature stability for CO oxidation. For the reduction of p-nitrophenol by NaBH₄, the Ag/Fe₃O₄ heterostructure also exhibits favorable activity and recovery stability. Our work provides a fresh and green pathway for the preparation of high-performance catalysts.