Synthesis of mesoporous nanoparticles of TiO2 from ilmenite

In this study, a surfactant assisted hydrometallurgical procedure was proposed for preparation of mesoporous nanoparticles of titanium dioxide (TiO 2 ) from ilmenite concentrate. Initially, Fe was removed from ilmenite concentrate using HCl and then the titanium was dissolved from the remaining solid in an alkaline condition of NH 3 or NaOH in assistance of H 2 O 2 as oxidizing agent in order to prepare the titanium solution (Ti-sol). Afterwards, the prepared Ti-sol was used as titanium source for preparation of a mesoporous nanoparticles of TiO 2 in assistance of hexadecyltrimethyl ammonium bromide (HDTMA-Br) as structure directing agent. Different methods were used to characterize the mesoporous nanoparticles of TiO 2 structures such as XRD, SEM, and BET. The results showed that the HDTMA helps the formation of slit-shaped mesopores in the range of 1.5 nm when the synthesis was carried out at room temperature despite the media which Ti-sol was prepared, NH 3 or NaOH. When a hydrothermal treatment was added to the synthesis process similar mesoporous structure was formed when the Ti-sol was prepared in NH 3 with nitrogen sorption hysteresis of H3 type. However, when the NaOH prepared Ti-sol was used the nitrogen sorption hysteresis loop changed to H4 type showing existence of large mesopores (12 nm) in addition to smaller mesopores (2–5 nm). The HRTEM results showed mesoporous structure with nano-rod like particles with particle size around 30–60 nm.