Physical stabilization of anatase (TiO2) by freeze-drying

Abstract

The anatase phase of titania has been stabilized without chemically modifying the system, by changing the level of packing within the aggregates by freeze-drying the water-washed precipitate obtained by the hydrolysis of titanium isopropoxide. After calcination at 700 °C for 8 h, freeze-dried samples showed more than 97% anatase phase with a surface area and porosity of 29 m ² g ^-1 and 37% respectively. The oven-dried samples showed a surface area and porosity of 5 m ² g ^-1 and 10% respectively.