A Promoting Effect of NH_4F Addition on the Photocatalytic Activity of Sol-Gel TiO_2 Films
The photoreactivity of sol-gel (SG)-TiO<SUB>2</SUB> films was enhanced significantly with addition of a small amount of ammonium fluoride (AF) into the SG-starting solution. The rate of the TiO<SUB>2</SUB> photoinduced oxidation of an overlying methylsiloxane monolayer reached a maximum near [AF]/[Ti] molar ratio of 1.35 × 10<SUP>−2</SUP>. The apparent rate constant was as much as 8.2 times greater than of AF non-added system. X-Ray diffraction analyses clearly indicated that the principal factor is the improvement in the anatase crystallinity caused by F<SUP>−</SUP> ions.
- Chemistry letters
Chemistry letters 1998(8), 707-708, 1998-08-05
The Chemical Society of Japan