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

Abstract

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 α-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, α-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 α-Fe₂O₃ could be attributed to the introduction of the carbon shells, which not only supplya high conductive channel and buffer matrix, but also keep the structural stability of the Fe₃O₄ nanotube upon cycling.