Green sol-gel synthesis of MnSeO4 using okra extract for enhanced electrochemical energy storage

This study reports a novel, eco-friendly synthesis of MnSeO₄ via a green sol–gel route using okra extract as a natural stabilizing and chelating agent. The bioactive compounds in okra facilitated controlled nucleation and growth, resulting in enhanced structural and electrochemical properties. XRD confirmed the formation of single-phase orthorhombic MnSeO₄ with a crystallite size of 22.6 nm and high crystallinity (67 %), while Raman spectroscopy validated Mn O and Se O vibrational modes. SEM revealed porous, interconnected micro-grains (~47 μm), favorable for electrolyte penetration, and UV–Vis spectroscopy showed a bandgap of 2.23 eV, indicating semiconducting behavior. Electrochemical analysis demonstrated a maximum specific capacitance of 658 F g −1 at 1 A/g, and 87.4 % capacitance retention over 500 cycles. EIS results confirmed low charge transfer resistance (17.87 Ω), highlighting fast ion kinetics. These findings establish okra-assisted MnSeO₄ as a promising electrode material for high-performance and sustainable supercapacitor applications. Explanation: Green synthesis of MnSeO₄ nanoparticles using okra extract offers a scalable, non-toxic, and cost-effective route with high purity and biocompatibility.