posted on 2022-12-03, 13:03authored byRyuzi Katoh, Kazunari Takahashi, Kosuke Sugawa
Here, we determined the quantum yields of photoluminescence
(ΦLumi) of five commercially available TiO2 photocatalysts
(two rutile and three anatase; particle diameter: 7–400 nm)
by comparison with ΦLumi values obtained for three
luminescent inorganic standard materials. The shapes of the luminescence
spectra of the photocatalysts were similar to those reported previously.
Very small ΦLumi values were obtained for all five
photocatalysts [e.g., 5.2 × 10–6 for nano-sized
anatase TiO2 (particle diameter: 7 nm)], indicating that
photoluminescence is a minor channel in the photophysical processes
of these materials. In addition, ΦLumi was much larger
for the photocatalysts with a larger particle size than for those
with a smaller particle size for both anatase and rutile TiO2, which implies that luminescence arises predominantly from the bulk
of the particles and that the surface plays a role as a quenching
center in both polymorphs. The origin of the luminescence is discussed
in relation to the previous studies.