Facile synthesis of high dispersion γ-Fe2O3–Au nanoparticles within mesoporous silica spheres

Abstract

High dispersion γ-Fe₂O₃ combined with Au nanoparticles (denoted as γ-Fe₂O₃–Au NPs) coated by mesoporous silica spheres (denoted as m-SiO₂) were synthesized by a facile one-pot method process. The dispersion of γ-Fe₂O₃ seed is extremely important to the formation of γ-Fe₂O₃–Au@m-SiO₂ composite, by using a certain amount of neutral β-CD as stabilizing agent, high dispersion γ-Fe₂O₃ NPs with 16 nm can be prepared. Besides, different number of γ-Fe₂O₃–Au NPs within composite can be tuned with the addition amount of γ-Fe₂O₃ seed. TEM images showed the ordered morphology, good dispersion, and uniform particle size of γ-Fe₂O₃–Au NPs inside composite. Furthermore, XRD, M–H curves and N₂ sorption characterization confirmed γ-Fe₂O₃–Au@m-SiO₂ composite possessed good magnetic property, uniform mesopore distribution and high surface area.