Aluminum-doped hematite nanoferrites (α-Fe2¡xAlxO3, x = 0.3 and 0.6) were synthesized via a hydrothermal
method and annealed at 180 ◦C for varying durations (8–16 h) to investigate their structural, magnetic, optical
band gap, and photocatalytic properties. The key innovation lies in achieving simultaneous optimization of
structural, magnetic, optical, and photocatalytic properties in a single material system - a significant advancement
over conventional hematite nanomaterials. The α-Fe2􀀀 xAlxO3 has a rhombohedral (R3c) structure, with
increasing Al content (x) reducing unit cell volume, crystallite/grain sizes, and effective mass, while increasing
bond length and Debye temperature. Annealing up to 12 h minimized crystallite size and effective mass, but
further annealing to 16 h reversed this trend. FTIR analysis revealed hydroxyl radical bands associated with
antibacterial activity at x = 0.3, which disappeared at x = 0.6. Magnetic studies showed that saturation
magnetization, retentivity, and coercivity increased with higher x, with coercivity peaking at 12 h of annealing.
Also, Al-doping reduced the switching field distribution and influenced magnetization behavior. Tauc analysis of
UV–visible spectra confirmed direct optical transitions with band gaps of 4.86–5.29 eV, demonstrating Al-doping
effects on hematite’s electronic structure. The photocatalytic performance was assessed by degrading methylene
blue (10⁻5 M) under UV–visible irradiation for 3 h. The optimal photocatalytic efficiency (66.01 %) was achieved
at x = 0.6 after annealing at 180 ◦C for 8 h, corresponding to an apparent kinetic rate of 4.6 × 10􀀀 3 min􀀀 1. These
findings demonstrate that Al-doped hematite nanoferrites, particularly when annealed at 180 ◦C for 12 h, exhibit
tunable properties suitable for advanced applications in memory devices, spintronics, and water treatment
technologies.