Photoluminescent and photocatalytic properties of layered caesium titanates, Cs2TinO2n+1 (n=2, 5, 6)
Abstract
Photoluminescence and photocatalytic H
2
evolution reactions
of layered caesium titanates,
Cs
2
Ti
n
O
2n+1
(n
=2,5,6), have been studied to evaluate the photoactivity of these
materials. Cs
2
Ti
2
O
5
showed a broad
emission around 420 nm upon excitation at 270 nm at 77 K, while both
Cs
2
Ti
5
O
11
and
Cs
2
Ti
6
O
13
showed an emission around 490
nm upon excitation at 290 nm. Cs
2
Ti
2
O
5
showed a blue emission even at 300 K. The Raman spectrum of
Cs
2
Ti
2
O
5
was similar to that of the well
characterized K
2
Ti
2
O
5
. The results of
the luminescence and the Raman spectrum suggested that
Cs
2
Ti
2
O
5
consists of a layered structure
with TiO
5
units, as observed in
K
2
Ti
2
O
5
.
Cs
2
Ti
2
O
5
with the five-coordinate
structure showed higher photocatalytic activity for H
2
evolution from aqueous methanol solutions than
Cs
2
Ti
5
O
11
and
Cs
2
Ti
6
O
13
with ordinary six-coordinate
structures.
Please wait while we load your content...
