Thermal stability of rutile TiO₂ with high specific surface area synthesized by self-hydrolysis process

Rutile with high specific surface area (SSA) was synthesized by self-hydrolysis of TiOCl₂ with sodium dodecyl sulfate (SDS) addition. The aggregates of rutile acicular particles with SSA of 120 m2/g formed from 0.5 M TiOCl₂ at 50 °C for 24 h. When SDS was added to 0.5 M TiOCl₂, the roundish particles surrounded by small acicular rutile formed and the SSA were 210 m²/g at 0.1 M and 340 m²/g at 0.5 M SDS. These results indicate that SDS addition was effective for the synthesis of rutile with high SSA. When heat treatment was carried out at 400 °C in air, the particle coarsening of rutile was observed by XRD and SEM and the SSA decreased, which indicates that thermal stability of rutile with high SSA was low. The addition of SnCl⁴ to starting solution was effective to improve the thermal stability of rutile with high SSA.