2D Layered α‐Fe2O3/rGO Flexible Electrode Prepared through Colloidal Electrostatic Self‐Assembly

Abstract Through the simple hydrolysis of FeCl 3 in boiling water, Fe(OH) 3 colloidal nanoparticles (NPs) can be achieved that exhibit a highly positively charge. Graphene oxide (GO) nanosheets are negatively charged when dispersed in water. Inspired by these fascinating characteristics, a 2D layered α‐Fe 2 O 3 /rGO hybrid film (FGHF) was fabricated through colloidal electrostatic self‐assembly with subsequent vacuum filtration and hydrothermal reduction. In this hybrid film, cubical α‐Fe 2 O 3 NPs are well‐distributed on rGO sheets, which can provide sufficient active interfacial sites and effectively alleviate the volume variation of α‐Fe 2 O 3 NPs during electrochemical reactions. The as‐obtained FGHF exhibits a high specific capacitance of 714 F g −1 and an outstanding rate capability of 42.6 % retention at 30 A g −1 . Moreover, a flexible supercapacitor was fabricated, which can achieve a high volumetric capacitance of 16.45 F cm −3 , leading to an energy density of 1.46 mWh cm −3 and a power density of 199.8 mW cm −3 . The flexible nature of the FGHF allows the as‐fabricated supercapacitor to remain undamaged with almost no change in capacitive performance when bending up to 180°.