Titanium Dioxide Nanosheets derived from Indonesian Ilmenite Mineral through Post-Hydrothermal Process

Abstract

Titanium dioxide (TiO2) nanosheets are potential candidate material to be developed for photocatalytic applications. The natural resources of TiO2 are abundant in the form of the mineral ilmenite (FeTiO3). In this work, TiO2 nanosheets have been synthesized using ilmenite mineral as the precursor through a post-hydrothermal process with temperature variations of 80,100, 120, and 150oC for 24 hours. The resulting TiO2 nanosheets were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM) and ultraviolet visible-diffuse reflectance spectroscopy (UV-DRS). XRD analysis showed that the majority phase of the nanosheets was anatase TiO2 accompanied by a small amount of sodium-titanate. The SEM study reveals the average thickness of nanosheets derived from post-hydrothermal process was 24.86 nm. XRD test results also showed that the increase in post-hydrothermal temperature from 80 to 150oC has resulted in an increase in the crystallite size of anatase TiO2 from 35.14 to 45.59 nm. Such increase in the crystallite size has been found to lead to a decrease in the bandgap energy (Eg) of nanosheets from 2.85 to 2.70 eV. These results support the potential use of the resulting TiO2 nanosheets as the photocatalytic material under the visible light illumination.