Synthesis and multifunctional applications of CaO: MgFe ₂ O ₄ nanocomposite for electrochemical sensing, energy storage, and efficient photocatalytic dye degradation

The novel CaO:MgFe2O4 nanocomposite was successfully synthesised through a simple sol-gel chemical method. The physical characteristics of CaO:MgFe2O4 were analysed using various techniques including X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDAX), and UV–visible studies. To assess the electrochemical properties of the synthesised CaO:MgFe2O4 nanocomposite, a modified carbon paste electrode was employed in a 0.5 M KCl electrolyte, and several electrochemical techniques such as cyclic voltammetry (CV), electrochemical impedance spectroscopy, galvanostatic charge-discharge analysis, and sensing were explored. The prepared electrode demonstrated a specific capacitance of up to 50.1 Fg−1. Electrochemical impedance spectroscopy measurements validated the CV results even more. Additionally, the photocatalytic degradation performance of CaO:MgFe2O4 was evaluated by degrading Acid Red-88 dye under visible light, resulting in an impressive removal efficiency of 93.47%. The environmental impact was assessed by examining the growth of Eleusine coracana (finger millet) using wastewater samples treated with visible-induced dye degradation. The electrodes exhibited remarkable reversibility and exceptional photocatalytic activity, rendering them suitable for bifunctional applications.