A green process for the synthesis of porous TiO2 from ilmenite ore using molten salt alkali decomposition for photocatalytic applications

Abstract

A new eco-friendly process for the synthesis of Fe-doped TiO₂ nanoparticles using ilmenite feedstocks has been investigated. The characterization and photocatalytic properties of synthesized TiO₂ nanoparticles have been presented. The effect of leaching process parameters on the separation of the impurities from TiO₂ is investigated. The TiO₂ obtained after the process consists of only Fe (∼5 ± 0.5 wt%) as the doping element, and the remaining elements are effectively separated from titania using this process. The microstructure analysis shows that the nanoparticles are in a spherical shape with agglomerations. XPS analysis shows that Ti is in the Ti⁴⁺ valence state and Fe is in the Fe³⁺ valence state which is incorporated in the TiO₂ lattice. BET analysis shows that the nanoparticles exhibit gel-like properties during the adsorption of N₂. The band gap obtained from the UV vis analysis is calculated to be 2.75 eV which is very low compared to that of the reference sample (3.09 eV). A total of 92% of the methyl orange dye is effectively removed from the water while the reference sample shows only 68% degradation affinity under the same degradation conditions.