Hierarchical Fe3O4@FeS2 Nanocomposite as High-Specific-Capacitance Electrode Material for Supercapacitors

Iron-based materials are ideal faradaic electrodes for supercapacitors. However, boosting the specific capacitance and preparation with the simple method of iron-based materials remains a great challenge. Herein, hierarchical Fe 3 O 4 @FeS 2 nanocomposites are constructed through an annealing strategy with monohydrate ferrous sulfate as the precursor. X-ray diffractometry, high-resolution transition electron, and X-ray photoelectron spectroscopy results reveal that the hierarchical Fe 3 O 4 @FeS 2 nanocomposite is successively fabricated. The as-prepared materials exhibit a remarkable specific capacitance of 597.1 F g −1 at a current density of 3 A g −1 as electrode materials of supercapacitors. Inspiringly, specific capacitance is superior to most iron-based electrodes in previous reports. This may be ascribed to the junction at the interface of the different components and the efficient electron transfer of FeS 2 . This work is meaningful for the design and preparation of electrode materials with specific capacitance.