Spray‐Dried TiO<sub>2</sub>(B)‐Containing Photocatalytic Glass‐Ceramic Nanobeads
Alessio Zandonà, Aurina Martínez Arias, Mirjam Gutbrod, Gundula Helsch, Alfred P. Weber, Joachim Deubener
Abstract
Abstract Glass‐ceramic nanospheres of molar composition 0.83 SiO 2 · 0.17 TiO 2 are produced by the sol‐gel spray‐drying method followed by controlled heat treatments up to 1200 ° C. TiO 2 (B) and anatase nanocrystals are precipitated in the glassy matrix: the latter phase gradually predominates with increasing ceramization temperature and time, in parallel to an overall increase in crystal sizes. The nanospheres exhibit evident photocatalytic activity under UV‐A irradiation, especially at annealing stages involving a comparatively higher amount of TiO 2 (B) and smaller crystals. The occurrence of TiO 2 (B) in this simplified binary glass‐ceramic material underlines the key role of this phase in the dynamics of crystallizing TiO 2 ‐bearing silicate melts.