A glass-ceramic approach to prepare porous TiO2 with self-supported nano-flakes: The phase evolution and the thermal stability of the product

A porous TiO2 material consisting of self-supported nano-flakes with mixed anatase/rutile phases was prepared by acid-etching of a glass-ceramic derived from 20MgO center dot 24CuO center dot 32TiO2 center dot 24P2O5 phosphate glass frit. The analysis showed that selective dissolution of components of CuO, Mg3(PO4)2, MgTi4(PO4)6 in the crystallized sample first occurred, followed by the growth of TiO2 nano-flakes and the formation of Ti(HPO4)2 center dot 2H2O phase due to the supply of Ti4+ and [PO4]3- released form the dissolved crystallites. The sample acid-treated for 17 h had the best crystallization of anatase and rutile phases, and the smallest band gap. In addition, the porous skeleton showed excellent thermal stability and a large surface area. The present study provided a new method which could be used for the scale-up production of porous TiO2.

Automated summary

A porous TiO2 material with excellent thermal stability and large surface area was prepared by acid-etching a phosphate glass frit, showing potential for scale-up production.