Facile synthesis of a rod-like porous carbon framework confined magnetite nanoparticle composite for superior lithium-ion storage

This work demonstrates a streamlined method to engineer a rod-like porous carbon framework (RPC) confined magnetite nanoparticles composite (Fe3O4/RPC) starting from metallic iron and gallic acid (GA) solution. First, a mild redox reaction was triggered between Fe and GA to prepare a rod-shaped metal–organic framework (MOF) ferric gallate sample (Fe-GA). Then, the Fe-GA sample was calcinated to obtain a prototypic RPC supported metal iron nanoparticle intermediate sample (Fe/RPC). Finally, the Fe3O4/RPC composite was synthesized after a simple hydrothermal reaction. The Fe3O4/RPC composite exhibited competitive electrochemical behaviors, which has a high gravimetric capacity of 1140 mAh·g−1 at a high charge and discharge current of 1000 mA·g−1 after 300 cycles. The engineered RPC supportive matrix not only offers adequate voids to buffer the volume expansion from inside well-dispersed Fe3O4 nanoparticles, but also facilitates both the ionic and electronic transport during the electrochemical reactions. The overall material synthesis involves of no hazardous or expensive chemicals, which can be regarded to be a scalable and green approach. The obtained samples have a good potential to be further developed for wider applications.