Role of Fe doping on crystallographic and functional characteristics of ceramic TiO2

Abstract

The undoped and Fe doped (0.1, 0.3, 5 wt%) TiO 2 powders (T0, T1, T3, T5) are prepared by hydrothermal synthesis. The goal is to investigate the effect of adding Fe on the crystal structure, particle morphology, elemental distribution, vibrational properties and density of the ceramic. The precursor mixtures are heated at 180 °C for 12 h, the powders are dried at 80 °C for 12 h and calcined at 500 °C for 2 h. The ceramic pellets are then created by uniaxial pressing at 250 MPa and sintering at 900°C for 3 hours. The materials are examined using X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS) with elemental mapping, Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, and Archimedes density and porosity measurements. XRD examination revealed that anatase is the most visible crystalline phase in the calcined powders. The observed average crystallite size dropped from 27.9 nm (T0) to 25.2 nm (T1), 21.8 nm (T3), and 19.3 nm (T5). FESEM analysis revealed a drop in average particle size from 82 ± 9 nm for T0 to 68 ± 7 nm, 52 ± 5 nm, and 46 ± 5 nm for T1, T3, and T5, respectively. EDS found Fe in Fe-containing materials, while FTIR showed a change in the major Ti-O absorption band from 612 cm⁻¹ (T0) to 601 cm⁻¹ (T5). The sintered T3 pellets had the highest bulk density (3.87 ± 0.02 g cm⁻³) and lowest apparent porosity (2.35 ± 0.15%), compared to 3.76 ± 0.03 g.cm⁻³ and 4.10 ± 0.20%, respectively, for T0. At 5 wt.% Fe, bulk density decreased to 3.82 ± 0.03 g.cm⁻³, while apparent porosity increased to 3.18 ± 0.21%. Fe addition affects the structural and morphological properties of TiO₂, with 3 wt.% nominal Fe resulting in the highest densification under the sintering circumstances tested.