Dumbbell-like Au-Fe3O4 nanoparticles: a new nanostructure for supercapacitors

Abstract

Monodispersed dumbbell-like Au-Fe₃O₄ nanoparticles (NPs) were synthesized and studied for use in supercapacitors. These dumbbell NPs show Au/Fe₃O₄-size dependent capacitive behaviors and the 7–14 nm Au-Fe₃O₄ NPs have the best specific capacitance of 464 F g⁻¹ at 1 A g⁻¹ and capacity retention of 86.4% after 1000 cycles, much larger than pure Fe₃O₄ NPs (160 F g⁻¹ and 72.8% retention). This capacitive enhancement is believed to arise from the Au-induced increase in electron transfer across the dumbbell-like NPs. Thise report demonstrates a new strategy to enhance oxide NP capacitance for applications in high performance supercapacitors.