Heterogeneous iron oxide nanoparticles anchored on carbon nanotubes for high-performance lithium-ion storage and...

In this work, heterogeneous hematite (Fe₂O₃) and magnetite (Fe₃O₄) nanoparticles are jointly engineered on the external surface of multi-walled carbon nanotubes (CNTs) to construct a composite material (Fe₂O₃@Fe₃O₄/CNT). A simple one-step redox reaction is triggered in a hydrothermal reaction system containing functionalized CNT (FCNT) aqueous suspension and iron foils. Both Fe₂O₃ and Fe₃O₄ nanoparticles with controlled size are generated and well dispersed in the interconnected CNT framework. Controlled samples of Fe₂O₃@Fe₃O₄ and Fe₃O₄/CNT have also been prepared and used to investigate the synthetic mechanism and evaluate the lithium-ion storage performances. As an anodic active material for lithium-ion batteries, the Fe₂O₃@Fe₃O₄/CNT composite delivered a high reversible capacity of about 924 mAh·g^-1 for 200 continual charge/discharge cycles under a high current rate of 1000 mA·g^-1. As a catalyst in a Fenton-like reaction for degrading methyl orange (MO) contaminant in waterbody, the Fe₂O₃@Fe₃O₄/CNT composite exhibited an attractive decomposition efficiency (99.5% decomposition within 60 min) and good stability. The beneficial factors contributing to the inspiring performances are discussed. The effective and scalable material design and synthesis method can be regarded to have good potential in other fields.