Surface modification, adsorption behavior, and optical properties of α-Fe2O3@SiO2/Au core-shell ellipsoids

Abstract α-Fe2O3@SiO2/Au core-shell ellipsoids, applied as the structural units of non-spherical photonic crystals, have the excellent monodispersity and self-assembly capacity. To improve the interfacial effect, the α-Fe2O3@SiO2 ellipsoids were modified by 3-aminopropyl triethoxysilane (APS) and used as the adsorption center of Au nanoparticles (NPs), which were synthesized by a sodium citrate reduction method. The adsorption behavior of α-Fe2O3@SiO2/Au ellipsoids was comprehensively investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The variations of optical properties were further evaluated by ultraviolet and visible (UV–vis) and Raman spectroscopy. The α-Fe2O3@SiO2/Au core-shell ellipsoids exhibited the excellent UV–vis absorption and Raman scattering effects, which were suggested to potentially apply in photothermal and photoelectric conversation.