2.3. Characterization of the tile surface without and with
TiO2 coating
2.3.1. Textural properties
The total porosity was determined by mercury intrusion
porosimetry (Hg Porosimeter Carlo Erba 2000 WS, Italia), while
the BET surface area and pore size distribution (BHJ) were
determined by low-temperature nitrogen adsorption-desorption
measurements at
−77 K on a nitrogen adsorption apparatus
(Micromeritics ASAP 2010). The modification of the specific
surface area and pore size distribution of the tile surface, caused
by the application of the photocatalytic coating, was determined
on the same samples before and after the application of the
coating.