Copper oxide–ferric oxide nanocomposite: Synthesis, characterization, and antibacterial and antifungal properties

Recently, copper oxide–ferric oxide nanocomposites (CuO/Fe₂O₃-NCs) have gained popularity and are widely employed in various applications. However, their effectiveness against phytopathogens has not been studied yet. This study investigates the synthesis and characterization of CuO/Fe₂O₃-NCs using the hydrothermal technique. X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and Fourier-transform infrared spectroscopy (FTIR) were used to characterize the produced nanocomposite (NC). EDX and TEM analyses revealed the presence of Cu, Fe, and O elements. The NC had a polygonal shape with sides around 12 nm, spherical CuO particles of 7–10 nm, and plate-like Fe₂O₃. XRD measurements confirmed the crystal and hexagonal structures of CuO and Fe₂O₃. The XRD patterns of CuO/Fe₂O₃ showed the characteristic peaks of (−111) and (004) reflections for CuO at 35.69° and 37.73°. The FTIR spectra showed characteristic lines at 525 and 567 cm⁻¹ for the Cu–O bond and Fe–O stretching modes of Fe₂O₃, respectively. The antifungal activity of CuO/Fe₂O₃-NCs showed significant growth inhibition of Fusarium oxysporum, Rhizoctonia solani, and Botrytis cinerea by up to 71, 50, and 81%, respectively, at 100 µg/mL. At 50 µg/mL, the antibacterial test revealed inhibition zones of 12.33 mm for Pectobacterium carotovorum, 9.33 mm for Streptomyces scabies, 10.67 mm for Pectobacterium atrosepticum, and 14.67 mm for Ralstonia solanacearum. The results show that CuO/Fe₂O₃-NCs can efficiently suppress the growth of various fungal and bacterial strains, making them potential antimicrobial agents against phytopathogenic microorganisms.