Controlling the nanostructural characteristics of TiO₂ nanoparticles derived from ilmenite mineral of Bangka island through sulfuric acid route

The ilmenite mineral (FeO.TiO₂) from Bangka Island-Indonesia is an important source for synthesizing TiO₂ nanoparticles. However, the process is rather difficult since this mineral still contains many impurities and minor elements. Therefore, controlling the synthesizing route parameters is essential for obtaining the desired TiO₂ nanoparticle characteristics. In the current work, we proposed a modified process involving the use of sulfuric acid through sol-gel method to provide titanyl sulfate (TiOSO₄) solution as the inorganic precursor. For investigation purposes, several parameters were varied including volume ratio of water and titanyl sulfate, addition of iron powder (seeding) and dextrin coagulant, calcination time and temperature. The results showed that TiO₂ nanoparticles can be succesfully synthesized using TiOSO₄ precursor derived from Bangka ilmenite. Under all processing conditions, the resulting TiO₂ nanoparticles have sphere-like shape and were indexed as the anatase TiO₂ phase. The results also showed that the average particle size was reduce from 96 - 188 nm to 32 - 40 nm when the volume ratio of water and titanylsulfate was increased from 3:1 to 6:1. The addition of iron powder as seeding has improved the purity of TiO₂ to ~ 95.01 wt%, in comparison to that of without seeding, which is ~92.78 wt%.