Engineering Multifunctional Zinc Ferrite Nanoparticles Through Glucose Capping for Photocatalytic Dye Degradation and Electrochemical Water Splitting

ABSTRACT This study demonstrates the vital role of glucose concentration as a capping agent in engineering zinc ferrite nanoparticles with tunable properties for environmental and energy applications. Zinc ferrite was synthesized at varying glucose concentrations (0.0–0.2 M), revealing concentration‐dependent control over structural, morphological, optical, and catalytic properties. XRD analysis showed that precise glucose concentration control enables phase engineering from mixed ZnO‐ZnFe₂O₄ to pure ZnFe₂O₄ phases. The morphological evolution observed via FESEM directly correlated with glucose concentration, transitioning from large, rough aggregates at low concentrations (0.025–0.05 M) to well‐defined hexagonal nanoparticles at 0.1 M, and finally to smaller, dispersed nanoparticles at higher concentrations (0.15–0.2 M). Bandgap energies were systematically tunable between 1.86 and 2.13 eV, with optimal values achieved at moderate glucose concentrations. Most notably, the specific surface area exhibited dramatic concentration–dependent variance (15.04–1064.34 m 2 /g), directly influencing catalytic performance. The ZF‐3 sample (0.1 M glucose) demonstrated superior photocatalytic activity for crystal violet degradation (94%) and exceptional bifunctional electrocatalytic performance for both oxygen and hydrogen evolution reactions (OER: 306 mV@10 mA/cm 2 ; HER: 226 mV@10 mA/cm 2 ) with outstanding stability over 50 h. The catalyst maintained robust performance across five reuse cycles (> 80% efficiency) with minimal interference from common coexisting ions. These findings establish glucose concentration as a powerful parameter for precisely tailoring zinc ferrite's functional properties, offering a simple yet effective strategy for developing multifunctional nanomaterials with concentration‐dependent tunable characteristics.