Improved Charge Dynamics in Cu‐Doped ZnFe 2 O 4 Nanostructures for Sustainable Photocatalytic and Energy Applications

ABSTRACT Water pollution commonly caused by persistent organic dyes remains a serious environmental problem, while the growing demand for efficient energy storage materials have brought great environmental and technological challenges. To address these issues, the magnetic zinc ferrite nanomaterials (ZnFe 2 O 4 ) and Cu doped ZnFe 2 O 4 nanomaterials are synthesized through an eco‐friendly, economical, and co‐precipitation process followed by their characterization. The synthesized nanomaterials were utilized for the photocatalytic breakdown of Methylene blue (MB) dye, and Eosin yellow (EY) dye. The performed photocatalysis reactions exhibited first order kinetics. The results revealed that Cu 0.5 Zn 0.5 Fe 2 O 4 outperformed all other catalysts with both MB (77%; k 1 = 0.01479 min −1 ) and EY (88%; k 1 = 0.01611 min −1 ). The enhanced performance with Cu introduction in ZnFe 2 O 4 was accredited to improved charge separation. The electrochemical properties were investigated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge discharge (GCD). The Cu 0.5 Zn 0.5 Fe 2 O 4 nanocomposite showed a high specific capacitance of 78 F g − 1 at a scan rate of 5 mV/s, 88 F g − 1 at a current density of 0.5 A g − 1 . Furthermore, the Cu 0.5 Zn 0.5 Fe 2 O 4 nanocomposite electrode demonstrated a higher specific capacitance value compared to the Cu 0.3 Zn 0.7 Fe 2 O 4 nanocomposite electrode. The results indicate materials exhibit energy storage applications.