Antimicrobial Study of Aluminum-Incorporated Nickel Ferrite Nanoparticles Synthesized via Ginger Extract–Assisted Green Synthesis Approach

Aluminum-incorporated nickel ferrite (NiFe_2−xAl_xO₄, x varying between 0.0 and 0.5) nanoparticles were synthesized taking ginger extract as a green fuel. The single-phase formation was proved by the analysis of the X-ray diffraction (XRD) pattern. The average size of the crystals (D), varies between 10 and 15 nm. Fourier transform infrared spectroscopy (FTIR) technique shows two broad bands in the range 370 to 415 cm⁻¹ and 551 to 573 cm⁻¹. Force constant, Debye temperature, and elastic constants determined using FTIR data show a strong dependence on Al³⁺ ions. The (FE-SEM) images reflect the formation of grains with more or less spherical symmetry with an average grain size of 31 nm. The band gap calculated using a Tauc plot varies between 1.44 and 2.19 eV. The magnitude of all the magnetic parameters decreases with increasing aluminum content x and shows superparamagnetic behavior. The composition NiAl_0.2Fe_1.8O₄ (x = 0.2) was found most promising as an antimicrobial activity agent. The antibacterial and antifungal activities for typical samples (x = 0.0, 0.2, 0.4) were tested against gram-positive, gram-negative, and fungi. The results are compared with commercial drugs and are correlated with structural and microstructural parameters.