Photocatalytic activity and its stacking order dependence of transparent 12 tungsto(VI) phosphoric acid-brookite hybrid films Original Research Article

Transparent hybrid films of brookite (TiO2) and 12 tungsto(VI) phosphoric acid (PW12) were prepared via layer-by-layer (LBL) processes on a quartz substrate with various orders. Their photocatalytic activities were evaluated using gaseous 2-propanol (IPA) decomposition. Pure brookite film showed higher photocatalytic activity than the pure PW12 one; the combination of PW12 to brookite increased the photocatalytic activity. The electron scavenger effect of PW12 against brookite under UV illumination is important for photocatalytic activity improvement. The degree of improvement depends on the film stacking order. Their photocatalytic activity was the highest when PW12 was arranged on the filmʹs topmost surface.