Structural and optical study of Fe3+-doped Al2O3 nanocrystals prepared by new sol gel precursors

Pure and Fe-doped Al2O3 nanoparticles (NPs) were synthesized with different iron doping percentage of 1, 3, and 5 mol% employing sol gel technique with AlCl3, FeCl3 as well as ethylene glycol (EG) and Polyvinylpyrrolidone (PVP) stabilizers as precursors. The XRD results indicated that the hexagonal structure of Fe/Al2O3 nanocomposite with alpha phase was formed by the substitution of Fe3+ ions in the alumina network. The sizes of the NPs obtained for the pure samples and doped samples at percentage dopant of 5% were 35 and 28 nm, respectively. The results of FTIR optical analysis showed the vibrational bond at the wavelength of 448 cm(-1), indicating the Al-O band in the sample. The UV-DRS analysis showed that the energy band gap for the pure NPs was 4 eV, but with increase in iron dopant up to 5%, it decreased to 3.42 eV. In addition, the results of photoluminescence (PL) analysis demonstrated that with increase in doping percentage, the PL intensity diminished. VSM magnetic analysis showed that with increase in iron dopant, the ferromagnetic state emerged in the NPs at saturation magnetism of 0.136 emu/g. Finally, photocatalytic experimental results demonstrated that 5% Fe-doped Al2O3 NPs effectively degrade MB approximately 53%.