We developed a nanoscale Kirkendall effect assisted method for simple and scalable synthesis of three-dimensional (3D) Fe2O3 hollow nanoparticles (NPs)/graphene aerogel through the use of waste seaweed biomass as new precursors. The Fe2O3 hollow nanoparticles with an average shell thickness of ∼6 nm are distributed on 3D graphene aerogel, and also act as spacers to make the separation of the neighboring graphene nanosheets. The graphene-Fe2O3 aerogels exhibit high rate capability (550 mA h g(-1) at 5 A g(-1)) and excellent cyclic stability (729 mA h g(-1) at 0.1 A g(-1) for 300 cycles), outperforming all of the reported Fe2O3/graphene hybrid electrodes, due to the hollow structure of the active Fe2O3 NPs and the unique structure of the 3D graphene aerogel framework. The present work represents an important step toward high-level control of high-performance 3D graphene-Fe-based NPs aerogels for maximizing lithium storage with new horizons for important fundamental and technological applications.
Keywords: Kirkendall effect; egg box; hollow nanoparticles; lithium ion batteries; seaweed.