Unveiling the physicochemical, photocatalytic, antibacterial and antioxidant properties of MWCNT-modified Ag2O/CuO/ZnO nanocomposites

Abstract

Water pollution, oxidative stress and the emergence of multidrug-resistant bacterial strains are significant global threats that require urgent attention to protect human health. Nanocomposites that combine multiple metal oxides with carbon-based materials have garnered significant attention due to their synergistic physicochemical properties and versatile applications in both environmental and biomedical fields. In this context, the present study was aimed at synthesizing a ternary metal-oxide nanocomposite consisting of silver oxide, copper oxide, and zinc oxide (ACZ-NC), along with a multi-walled carbon nanotubes modified ternary metal-oxide nanocomposite (MWCNTs@ACZ-NC). The properties of the synthesized nanomaterials were characterized using Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and energy dispersive X-ray (EDX) spectroscopy. The results obtained suggested the successful synthesis of both samples, as evidenced by the morphological changes observed in the SEM images, a transmittance band at 748.02 cm⁻¹ in the FT-IR spectrum, and a diffraction peak at 44.39° in the XRD pattern. The band gap energies were determined via diffuse reflectance spectroscopy (DRS), with a redshift observed in the absorbance edge upon the incorporation of MWCNTs. The synthesized samples were tested as photocatalysts for the degradation of rhodamine 6G (Rh-6G), with the highest degradation efficiency (99.61%) achieved by MWCNTs@ACZ-NC. Additionally, the materials were evaluated for their biological activity as antibacterial and antioxidant agents. The MWCNTs@ACZ-NC exhibited the highest antioxidant potential with an IC₅₀ value of 59.22 μg mL⁻¹. However, the incorporation of MWCNTs resulted in a decrease in antibacterial activity, which may be attributed to the blocking of binding sites.