In situ redox strategy for large-scale fabrication of surfactant-free M-Fe2O3 (M = Pt, Pd, Au) hybrid nanospheres

A facile in situ redox strategy has been developed to fabricate surfactant-free M-Fe2O3 (M = Pt, Pd, Au) hybrid nanospheres. In this process, noble metal salts were directly reduced by the pre-prepared Fe3O4 components in an alkaline aqueous solution without using organic reductants and surfactants. During the redox reaction, Fe3O4 was oxidized into Fe2O3, and the reduzates of noble metal nanoparticles were deposited on the surface of the Fe2O3 nanospheres. Then the characterizations were discussed in detail to study the formation of M-Fe2O3 hybrids. At last, catalytic CO oxidation was selected as a model reaction to evaluate the catalytic performance of these samples. It demonstrates that Pt-Fe2O3 nanospheres can catalyze 100 % conversion of CO into CO2 at 90 degrees C, indicating superior activity relative to Pd-Fe2O3 and Au-Fe2O3.