Investigation of physicochemical and electrochemical traits of hydrothermally synthesized α-Fe2O3 nanoparticles for supercapacitor performance

Abstract

This study investigates α-Fe2O3 (hematite) nanoparticles (NPs), synthesized via hydrothermal method, as a potential electrode material for supercapacitors. The nanoparticles were comprehensively characterized using TG–DTA, XRD, FESEM-EDX, XPS, UV-DRS, BET, and VSM analyses. TG–DTA analysis revealed the thermal properties of the as-synthesized nanomaterial. XRD confirmed the hematite phase with a rhombohedral crystal structure, an average crystallite size of 24 nm, low dislocation density, and high crystallinity. FESEM displayed an agglomerated inhomogeneous spherical morphology, while EDAX confirmed the elemental composition. UV-DRS indicated a bandgap energy of 1.96 eV, supporting charge storage. XPS analysis identified Fe3+ ions, which are essential for electrochemical performance, and BET analysis revealed a specific surface area of 36.77 m2/g, beneficial for charge storage. VSM analysis showed strong ferromagnetic behavior, advantageous for supercapacitor applications. Electrochemical evaluations demonstrated pseudocapacitive behavior with specific capacitance values of 406 and 206 F g−1 through CV and GCD analysis, respectively at low scan rates. EIS highlighted excellent ion transport, low resistance, high conductivity and efficient charge storage capability of the prepared material. These results highlight α-Fe2O3 NPs as promising candidates for next-generation supercapacitor electrodes, offering enhanced charge storage capacity and stability. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.