Near-Field Enhancement Contribution to the Photoactivity in Magnetite–Gold Hybrid Nanostructures

GUZMAN, FEDERICO V.; MERCADAL, PABLO A.; CORONADO, EDUARDO A.; ENCINA, EZEQUIEL R.

JOURNAL OF PHYSICAL CHEMISTRY C

AMER CHEMICAL SOC

Año: 2019 vol. 123 p. 29891 - 29899

1932-7447

EQUAL-CONTRIBUTIONS BETWEEN GUZMAN AND MERDADAL.Hybrid nanostructures composed of magnetic iron oxides and plasmonic metals are able toconvert light energy into chemical energy as well as they can be easily manipulated through magneticfields. As a consequence of these multifunctional features they can be employed as magneticallyrecyclable heterogeneous photocatalysts. Herein, we report a two step method for the preparation ofmagnetite (Fe3O4)-gold (Au) hybrid nanostructures in aqueous media. The obtained material resemblesa core-satellite morphology of 60 nm Fe3O4 nanoparticles surrounded by nearly spherical 20 nm Aunanoparticles attached to their surface. The synthesized hybrid material exhibits enhanced capabilitiesfor the methylene blue photodegradation compared with bare Fe3O4 nanoparticles. Detailedelectrodynamics simulations were performed to achieve further insight into the improved photoactiveproperties of the Fe3O4-Au hybrid nanostructures. The theoretical results show that the excitation oflocalized surface plasmon resonances in the Au component leads to greater light absorption in the Fe3O4component which ultimately impacts on the improved photocatalytic properties of the hybridnanostructure. Overall, this work provides a complementary approach toward a complete understandingof the enhanced photoactive properties of hybrid nanostructures and highlights the importance ofconsidering their actual morphology into simulations