Effect of aluminium doping on structural, optical, photocatalytic and antibacterial activity on nickel ferrite nanoparticles by sol-gel auto-combustion method

The present work designates the preparation of nanocrystalline nickel ferrite and aluminium-doped nickel ferrite nanoparticles with general formula NiAlxFe2-xO4 (x=0-0.7) prepared by the sol-gel auto-combustion method. The structural (XRD and FTIR), morphological (SEM with EDAX, HRTEM with SAED) and optical (UV-Visible DRS and Luminescence spectroscopy) properties of the products were characterized. XRD studies revealed the formation of the single phase with a cubic spinel structure with an average crystallite size varies between 19 and 38nm. The increase in aluminium content caused the variation in the lattice parameter (8.2782-8.3366 angstrom). SEM images shows the morphology have nanocrystalline behavior with a spherical structure. FTIR represents the characteristic peaks of M-O vibrations in tetrahedral (591cm(-1)) and octahedral (398cm(-1)) sites. From the UV-Vis DRS spectra, the band gap is decreasing with increasing doping, estimated to be 2.03-1.90eV. The luminescence spectrum displays violet, blue, green, and orange emission. The aluminium-doped nickel ferrite nanoparticles act as an exceptional photocatalyst for the degradation of rose bengal dye (99.8% in 150min) with respect to bulk material (63% in 150min) under visible light (300W tungsten lamp) irradiation. Furthermore, these nanoparticles were acted against gram-negative bacteria stain (Salmonella typhi, Pseudomonas aeruginosa, and Escherichia coli).