Hydrothermal synthesis of graphene-encapsulated 2D circular nanoplates of alpha-Fe2O3 towards enhanced electrochemical performance for supercapacitor

摘要

Transition metal oxides especially Fe2O3 has been widely considered as a potential electrode material for current commercial supercapacitors. However, the low electronic conductivity limits the obtained specific capacitance and cycle stability of supercapacitor devices. In the present work, 2D nano-circular-like alpha-Fe2O3 coupled reduced graphene oxide (rGO) composites have been synthesized for the first time via a simple, inexpensive hydrothermal process. Moreover, circular alpha-Fe2O3 nanoplates are well-dispersed on rGO layers, which can offer abundant active sites and effectively buffer the reunion of alpha-Fe2O3 nanocomposites during the electrochemical reactions. At an optimal ratio of 10 wt% GO, the as-prepared sample exhibits electrochemical performance with excellent specific capacitance of 621.3 F g(-1) at 5 mV(-1) and 533 F g(-1) at 1 A g(-1), which is better than that of pure alpha-Fe2O3. Most attractively, the specific capacitance is highly retained about 77% after 14000 cycles, revealing superior cycle ability. (C) 2018 Elsevier B.V. All rights reserved.