rGO-Modified ZnO-TiO2 Nanohybrids as Promising Antibacterial Agents for Biomedical Applications

This study explores the synergistic antibacterial activity of ZnO nanorods (NRs) decorated with TiO₂ nanoparticles (NPs) and reduced graphene oxide nanosheets (rGO NSs). ZnO NRs and binary ZnO-TiO₂ nanocomposites (ZT NCs) with varying TiO₂ content were synthesized using an in situ sol–gel method and subsequently modified with different amounts of rGO NSs. The nanocomposites were characterized using advanced techniques to assess their structure and antibacterial performance. X-ray diffraction (XRD) confirmed the dominance of the hexagonal wurtzite ZnO structure, while Fourier transform infrared spectroscopy (FT-IR) confirmed interconnectivity. A slight red shift in UV–vis diffuse reflectance spectra indicated changes in optical properties, and BET analysis showed an increase in surface area and pore volume due to rGO incorporation. The ternary ZT-rGO (ZTR) NCs, particularly ZTR 4 (with 4 wt% rGO), exhibited significant antibacterial, antifungal, and antioxidant properties. ZTR 4 showed enhanced efficacy against both Gram-positive (Staphylococcus aureus, Bacillus cereus) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa), as well as Candida albicans. The results highlight the synergistic effects of ZTR NCs, making them promising candidates for applications in biomedical and environmental fields as effective antibacterial agents.