ZrO₂-FeO-decorated N-doped rGO Nanocomposites: Synthesis and Assessment of Antimicrobial and Antioxidant Activities

Abstract

The development of multifunctional nanomaterials with combined structural and biological properties is of significant interest in nanoscience. In this study, ZrO₂–FeO@N-rGO nanocomposite was synthesized through an eco-efficient approach and characterized using UV–Vis, FT-IR, XRD, SEM, TEM, XPS, DLS, and EDX analyses. The nanocomposite exhibited an absorption maximum at 202 nm with an optical band gap of 6.14 eV. XRD confirmed the crystalline metal oxide phases and N-rGO structure, with a crystallite size of approximately 50 nm. SEM and TEM revealed well-dispersed ZrO₂ and FeO nanoparticles anchored on wrinkled N-rGO sheets. DLS showed a Z-average diameter of 208.2 nm with a PDI of 0.278. EDX confirmed Fe and Zr contents of 18.74 and 13.38 wt%, respectively, while XPS verified Zr⁴⁺ and Fe²⁺/Fe³⁺ surface states. The nanocomposite exhibited concentration-dependent antioxidant activity, with maximum scavenging efficiencies of 50.70% DPPH, 68.64% H₂O₂, and 77.56% nitric oxide at 500 μg/mL. Overall, ZrO₂–FeO@N-rGO demonstrates promising structural, antioxidant, and antimicrobial properties, supporting its potential for biomedical and environmental applications.