Facile synthesis of C-Fe3O4-C core-shell nanotubes by a self-templating route and the application as a high-performance anode for Li-ion batteries

In this study, we synthesized C-Fe3O4-C core-shell nanotubes through a facile chemical vapor deposition (CVD) method using Fe2O3 nanotubes as the self-templates. The hydrothermal product alpha-Fe2O3 hematite exhibits a tubular structure with an inner diameter of 70-100 nm, a wall thickness of 10-20 nm, and a length of 300-800 nm. After the CVD reaction in C2H2, alpha-Fe2O3 could be transformed into C-Fe3O4-C with the tubular structure reserved. The tubular C-Fe3O4-C is constructed by an Fe3O4 nanotube core and 5 nm thick carbon shells on both inner and outer surfaces of the Fe3O4 nanotube. The C-Fe3O4-C nanotube anode exhibits a stable cycling with a capacity over 700 mA h g(-1) retained after 120 cycles at 100 mA g(-1). The improved electrochemical properties of C-Fe3O4-C nanotubes compared with bare alpha-Fe2O3 could be attributed to the introduction of the carbon shells, which not only supply a high conductive channel and buffer matrix, but also keep the structural stability of the Fe3O4 nanotube upon cycling.