13 Visible-Light Photo-Catalytic Activity in Carbon-Doped Perovskite
231
Fig. 13.12 The potential
energy curves for three types
of Ti–O shrinks in SrTi 8 O 12
model, corresponding to Ti–C
elongations in (a) SrTi 8 O 11 C,
(b) SrTi 8 O 10 C 2 (I) and
(c) SrTi 8 O 10 C 2 (II) models.
Titanium atoms are displaced
along z axis. r is the
displacement distance from
the initial lattice position
13.4.2 Comparison with Nitrogen-Doping
In nitrogen-doped SrTiO 3 , we concluded that oxygen vacancy leads the degradation
of visible light photocatalytic activity [9]. On the other hand, in LaTiO 2 N perovskite
with a bandgap of 2.1 eV [22], no oxygen vacancy is formed. However, it is considered that the local strain by the covalent Ti–N–Ti bonding cannot be negligible. It
may be difficult for LaTiO 2 N to obtain a stable structure.
In carbon-doped SrTiO 3 , no oxygen vacancy is formed. The stable structure is
kept, as the alternate Ti–C–Ti elongation and Ti–O–Ti shrink are caused. We concluded that carbon anion-doped SrTiO 3 is one of the best photocatalysts, from the
viewpoints of both a visible light photocatalytic activity and structural stability. The
efficient synthesis of carbon anion-doped SrTiO 3 perovskite should be explored.
This work is in progress.
231
Fig. 13.12 The potential
energy curves for three types
of Ti–O shrinks in SrTi 8 O 12
model, corresponding to Ti–C
elongations in (a) SrTi 8 O 11 C,
(b) SrTi 8 O 10 C 2 (I) and
(c) SrTi 8 O 10 C 2 (II) models.
Titanium atoms are displaced
along z axis. r is the
displacement distance from
the initial lattice position
13.4.2 Comparison with Nitrogen-Doping
In nitrogen-doped SrTiO 3 , we concluded that oxygen vacancy leads the degradation
of visible light photocatalytic activity [9]. On the other hand, in LaTiO 2 N perovskite
with a bandgap of 2.1 eV [22], no oxygen vacancy is formed. However, it is considered that the local strain by the covalent Ti–N–Ti bonding cannot be negligible. It
may be difficult for LaTiO 2 N to obtain a stable structure.
In carbon-doped SrTiO 3 , no oxygen vacancy is formed. The stable structure is
kept, as the alternate Ti–C–Ti elongation and Ti–O–Ti shrink are caused. We concluded that carbon anion-doped SrTiO 3 is one of the best photocatalysts, from the
viewpoints of both a visible light photocatalytic activity and structural stability. The
efficient synthesis of carbon anion-doped SrTiO 3 perovskite should be explored.
This work is in progress.