Biogenic synthesis of CuO nanostructures using Moringa oleifera leaf extract: a green chemistry approach for comparative study of symmetric and asymmetric solid-state supercapacitor devices

Biogenic Moringa oleifera leaf extract is used to synthesise coral-like CuO nanostructures for sustainable supercapacitors. The asymmetric device delivers energy density of 50 Wh kg ⁻¹ , power density of 1251 W kg ⁻¹ , and 98.6% capacitance retention.