An Electrical Stimulation-Driven Strategy for Peroxide-like Enzyme Reactivation toward Sustainable Wastewater Sterilization

Metal-based enzyme mimics face irreversible deactivation due to the oxidation of active metal centers, limiting their sustainability in wastewater treatment. To meet this important challenge, we introduce an electrical stimulation strategy by designing Fe-doped titanium dioxide nanolines (Fe-TNLs) that mimic peroxidase (POD) activity and regenerate catalytic function, enabling enzyme reuse. The Fe-TNLs exhibit robust POD-like activity by catalyzing the decomposition of H₂O₂ into hydroxyl radicals (^•OH), achieving over 99.9% inactivation against<i>Escherichia coli</i> and <i>Staphylococcus aureus</i> during the initial cycle. Unlike conventional Fe-based POD mimics, which are rapidly deactivated due to the oxidation of Fe(II) to Fe(III), this system achieves a reversible Fe(III)/Fe(II) redox cycle through electrical charging, restoring over 80% of the initial catalytic efficiency. Moreover, the reactivated Fe-TNLs maintain effective performance in simulated wastewater and retain approximately 60% of their initial efficacy after reactivation, outperforming single-use systems. By emphasizing sustainable reusability over single-use designs, this work offers a compelling approach for advancing environmentally friendly wastewater remediation technologies.