S. Tawkaew et al., Synthesis of cadmium sulfide pillared layered compounds and photocatalyticreduction of nitrate under visible light irradiation, COLL SURF A, 179(2-3), 2001, pp. 139-144
Citations number
16
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
Layered compound/CdS nanocomposites incorporating CdS pillars in the interl
ayer of layered compounds such as hectorite, H2Ti4O9 and H4Nb6O17 were prep
ared by the stepwise ion exchange reactions of the layered compounds with C
3H7NH3+ and Cd2+ followed by the reaction with H2S gas. The pillar height w
as less than 1 nm and the band gap energy was slightly larger than that of
normal crystalline CdS. Although the host layered compounds were insulators
or wide band gap semiconductors. CdS pillared layered compounds showed pho
tocatalytic activity under visible light irradiation. Nitrate ion was photo
chemically reduced to nitrite, nitrogen and ammonia by irradiating visible
light (lambda > 400 m) from a high pressure mercury lamp to nitrate solutio
n containing H2Ti4O9/CdS and H4Nb6O17/CdS nanocomposites in the presence of
a sacrificial hole acceptor such as methanol, whereas no photoreduction of
nitrate proceeded in the presence of unsupported CdS and hectorite/CdS nan
ocomposite, indicating that the incorporation of CdS pillars in the interla
yer of a semiconducting layered compound such as H2Ti4O9 and H4Nb6O17 was m
uch more efficient in enhancing the nitrate reduction activity than when an
insulator such as hectorite was used. (C) 2001 Elsevier Science B.V. All r
ights reserved.