Facile fabrication of iron oxide/carbon/rGO superparamagnetic nanocomposites for enhanced electrochemical energy storage performance

To develop iron-based materials for energy storage is an important issue because of their low cost, abundant storage and high theoretical specific capacitances. Fe(OH) 3 colloids stabilized by FeCl 3 are used as the precursor to fabricate with carbon from glucose and graphene oxide (GO) to prepare superparamagnetic iron oxide/carbon/rGO (reduced graphene oxide) composite for enhanced energy storage performance. Glucose or graphene oxide cannot avoid the aggregation of iron oxides when they are used separately; however, the simultaneous addition of glucose and graphene oxide can supress the aggregation of iron oxide nanoparticles , which is beneficial for energy storage. The characterization results of Fe 2 O 3 -based composites, including XRD , TEM and XPS , reveal that iron oxide nanocrystals in the composites are γ-Fe 2 O 3 . The simultaneous utilization of GO and glucose leads to higher saturation magnetizations of iron oxide than GO or glucose does, and the saturation magnetization of iron oxide in the iron oxide/carbon/rGO composite can be up to 83 emu g −1 . More importantly, the iron oxide/carbon/rGO composites have much higher energy storage performance than that of iron oxide/carbon or iron oxide/rGO samples. The specific capacitance of the composites can reach 400 F g −1 and the retention can remain 92% after 2500 cycles.