Synthesis of Water Dispersible and Catalytically Active Gold-Decorated Cobalt Ferrite Nanoparticles.
Hetero-nanoparticles represent an important family of composite nanomaterials that in the past years are attracting ever-growing interest. Here, we report a new strategy for the synthesis of water dispersible cobalt ferrite nanoparticles (CoxFe3-xO4 NPs) decorated with ultrasmall (2-3 nm) gold nanoparticles (Au NPs). The synthetic procedure is based on the use of 2,3-meso-dimercaptosuccinic acid (DMSA), which plays a double role. First, it transfers cobalt ferrite NPs from the organic phase to aqueous media. Second, the DMSA reductive power promotes the in situ nucleation of gold NPs in proximity of the magnetic NP surface. Following this procedure, we achieved a water dispersible nanosystem (CoxFe3-xO4-DMSA-Au NPs) which combines the cobalt ferrite magnetic properties with the catalytic features of ultrasmall Au NPs. We showed that CoxFe3-xO4-DMSA-Au NPs act as an efficient nanocatalyst to reduce 4-nitrophenol to 4-aminophenol and that they can be magnetically recovered and recycled. It is noteworthy that such nanosystem is more catalytically active than Au NPs with equal size. Finally, a complete structural and chemical characterization of the hetero-NPs is provided.
Laboratorio di Nanotecnologie, Istituto di Scienze e Tecnologie Molecolari, Consiglio Nazionale delle Ricerche , Via G. Fantoli 16/15, 20138 Milan, Italy.|Dipartimento di Chimica, Università degli Studi di Milano , Via C. Golgi 19, 20133 Milan, Italy.
Alessandro
A
Silvestri
Laboratorio di Nanotecnologie, Istituto di Scienze e Tecnologie Molecolari, Consiglio Nazionale delle Ricerche , Via G. Fantoli 16/15, 20138 Milan, Italy.|Dipartimento di Chimica, Università degli Studi di Milano , Via C. Golgi 19, 20133 Milan, Italy.
Sara
S
Mondini
Laboratorio di Nanotecnologie, Istituto di Scienze e Tecnologie Molecolari, Consiglio Nazionale delle Ricerche , Via G. Fantoli 16/15, 20138 Milan, Italy.
Marcello
M
Marelli
Dipartimento di Chimica, Università degli Studi di Milano , Via C. Golgi 19, 20133 Milan, Italy.
Valentina
V
Pifferi
Dipartimento di Chimica, Università degli Studi di Milano , Via C. Golgi 19, 20133 Milan, Italy.
Luigi
L
Falciola
Laboratorio di Nanotecnologie, Istituto di Scienze e Tecnologie Molecolari, Consiglio Nazionale delle Ricerche , Via G. Fantoli 16/15, 20138 Milan, Italy.
Alessandro
A
Ponti
Laboratorio di Nanotecnologie, Istituto di Scienze e Tecnologie Molecolari, Consiglio Nazionale delle Ricerche , Via G. Fantoli 16/15, 20138 Milan, Italy.
Anna Maria
AM
Ferretti
Laboratorio di Nanotecnologie, Istituto di Scienze e Tecnologie Molecolari, Consiglio Nazionale delle Ricerche , Via G. Fantoli 16/15, 20138 Milan, Italy.
Laura
L
Polito