Fabrication and structural analysis of CuO–NiO and MWCNTs@CuO–NiO hybrid nanostructures: versatile materials for environmental and biomedical remediation

Abstract

This research focuses on the fabrication and characterization of a CuO–NiO nanocomposite (NC) and MWCNT-modified CuO–NiO NC for photocatalytic, antibacterial, and antioxidant applications. The bimetallic CuO–NiO nanostructure was fabricated via the sol–gel method and subsequently functionalized with multi-walled carbon nanotubes (MWCNTs). Various physicochemical techniques were employed to explore the structural, optical, and compositional characteristics of the prepared samples. The photocatalytic performance of the nanocomposites was assessed through the degradation of rhodamine 6G under solar-light irradiation. The MWCNTs@CuO–NiO NC demonstrated the highest removal efficiency of 95.37%, with a decomposition rate constant of 5.99312 min⁻¹. Their antibacterial efficacy was evaluated against two bacterial strains, namely, E. coli and S. aureus, and it was found that E. coli exhibited higher resistance to the samples. Furthermore, the MWCNTs@CuO–NiO NC demonstrated superior antioxidant activity compared with its bare counterpart, with an IC₅₀ value of 84.61 μg mL⁻¹. The MWCNTs@CuO–NiO NC exhibited significantly enhanced antibacterial and antioxidant activities compared with the standard drug and pristine CuO–NiO NC. These findings highlight the multifunctional capabilities of the CuO–NiO NC and MWCNTs@CuO–NiO NC for environmental and biomedical applications.