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Name (Title):
Xiukai Li(PD), Naoki Kikugawa(NIMS fellow), Jinhua Ye(NIMS fellow)
Affiliation:
Photocatalytic Materials Center(PCMC), NIMS
Address:
1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
Email: LI.Xiukai@nims.go.jp
Home Page: http://www.nims.go.jp/photocatalyst/group_1/XiukaiLi/LiXiukai_jp.htm
Presentation Title:
Preparation of Nitrogen-Doped Lamellar Solid Acids with Visible Light-Responsive
Photocatalytic Activities
Abstract:
Semiconductor photocatalysis is currently attracting increasing interest in both scientific and
engineering areas [1]. In view of the better utilization of the solar light and the indoor
illumination, it is appealing to develop visible light-sensitive photocatalysts. Thus, some new
photocatalysts with visible light responsibilities have been developed in the recent years [2].
Solid acids are among the most important compounds in materials science, and have a large
number of applications like catalysts, ion conductors, and electrode materials. Ti- and Nb-based
lamellar solid acids are more attractive because of some particular properties like the layered
structure, favorable electron-transfer character, and the protonic acidity. In the present study, two
lamellar solid acids, viz. HNb3O8 and H2Ti4O9 had been successfully doped with nitrogen by a
facile solid state-reaction method with urea as a nitrogen precursor [3]. The nitrogen-doped solid
acids show superior activities for Rhodamine B photodegradation than the corresponding
nitrogen-doped potassium salts under visible light irradiation (Figure 1). It was revealed that the
intercalation properties of lamellar solid acids could have profound impacts on nitrogen doping
as well as the resultant visible light photocatalysis, and the effects depend strongly on the
protonic acidities of samples.
C/C 0
1.0
0.8
0.6
0.4
Intensity / ��W/cm 2 �nm)
30
25
20
15
dark light on
no catalyst
K 2 Ti 4 O 9 -N
KNb 3 O 8 -N
0.2 10
5
0
300 400 500 600 700
Wavelength / nm
0.0
-40 -20 0
800
20
HNb O -N 3 8
40 60
H Ti O -N
2 4 9
80 100
Irradiation time / min
Fig. 1. The photocatalytic degradation of RhB over
various nitrogen-doped niobates and titanates under
visible light (λ > 420 nm) irradiation.
References:
1. M.R. Hoffmann, S.T. Martin, W. Choi, D.W. Bahnemann, Chem. Rev. 95 (1995) 69..
2. X. Li, J. Ye, J. Phys. Chem. C 111 (2007) 13109.
3. X. Li, N. Kikugawa, J. Ye, Adv. Mater., 20 (2008) 3816.
Poster Session PG-1
89