The preparation and mechanism studies of porous titania

Ultrafine porous titania powders were synthesized by precipitating method with titania sulfate and ammonia as raw materials and ethanol as dispersing agent. The influences of pH and reaction temperatures on the texture of titania precursor powders were investigated. The porous titania material was formed by titania precursors calcined above 200°C, and the surface area of powders changes from 541.9 m2 g−1 (precursor) to 762.5 m2 g−1 (precursors calcined at 200°C). The causes of surface area reduction with calcining temperatures are grain growth and phase transformation. Micropores in porous titania samples were lost by samples calcined above 500°C. On TEM photos space network of porous titania is clearly seen.