Size Optimization of Iron Oxide@Noble Metal Core−Shell Nanohybrids for Photothermal Applications

ENCINA, E. R.; CORONADO, E. A.

JOURNAL OF PHYSICAL CHEMISTRY C

AMER CHEMICAL SOC

Lugar: Washington; Año: 2016 vol. 120 p. 5630 - 5630

1932-7447

he optical properties of several iron oxide@noble metal core-shell nanohybrids (NHs) have been systematically studied by means of electrodynamics simulations applying Mie theory for coated spheres. Focus has been made in analyzing the dependence of the absorption cross section Cabs on the composition as well as on the variables that determine the NHs size, i.e. the core radius R and the shell thickness S. The absorption spectra are characterized by an intense peak attributed to a plasmon resonance mode whose spectral position can be finely tuned in the Vis-NIR range according to the NH size and composition. The absorption cross section peak intensity, Cabs,max, a key quantity regarding photothermal applications, also presents a strong dependence on the NH size and composition. In general, it is found that α-Fe2O3@Au and α-Fe2O3@Ag leads to larger Cabs,max values than Fe3O4@Au and Fe3O4@Ag core-shell NHs, which is attributed to the lower imaginary refractive index of α-F