Redox-Mediated Shape Transformation of Fe3O4 Nanoflakes to Chemically Stable Au−Fe2O3 Composite Nanorods for a High-Performance Asymmetric Solid-State Supercapacitor Device

Development of a stable and highly active metal oxide based electrochemical supercapacitor is a major challenge. Herein, we report a Au–Fe2O3 nanocomposite having tiny amount of gold (3 atomic % Au) by employing a simple redox-mediated synthetic methodology using a modified hydrothermal system. Structural and morphological studies of the synthesized Au–Fe2O3 nanocomposite have been performed both experimentally (XRD, IR, Raman, XPS, TEM, and FESEM analyses) and theoretically (WIEN2K). A probable dissolution–nucleation–recrystallization growth mechanism has been suggested to explain the morphological transformation from a Fe3O4 nanoflake to a Au–Fe2O3nanorod. We have observed the superior chemical stability of the Au–Fe2O3 nanocomposite in an acidic medium due to composite formation. The electrochemical measurement of the synthesized Au–Fe2O3 nanocomposite exhibits specific capacitance of ∼570 F g–1 at the current density of 1 A g–1 in 0.5 M H2SO4 electrolyte. The result is superior compared to the mother ...