2.1. Microsize TiO2 and porcelain grès tiles

The TiO2 powder was Kronos 1077, which is ≥98.5% anatase and has a particle size range of 110–130 nm, a BET surface area of 12 m2 /g, a true density of 3800 kg/m3 , and an optical indirect band gap of 3.15 eV [35, 36].

The TiO2 was deposited on porcelain grès tiles that were manufactured by GranitiFiandre S.p. A. These are dry-pressed tiles fired at 1200–1300C. The phase assemblage as such consists of glass, mullite, and quartz.
