Gr. Bamwenda et al., The photoproduction of O-2 from a suspension containing CeO2 and Ce4+ cations as an electron acceptor, CHEM LETT, (10), 1999, pp. 1047-1048
Herein we report the first finding on the photocatalytic production of oxyg
en from the irradiation of a CeO2-H2O-Ce-aq(4+) aqueous suspension. The O-2
yield strongly depended on the duration of irradiation, CeO2 concentration
, concentration of Ce-aq(4+) cations, and pH of the suspension. The optimum
photoproduction for O-2 was obtained under the following operating conditi
ons: Illumination time > 15 h, CeO2 concentration: 2.5-5 g dm(-3), [Ce4+]:
4-5 mM, pH < 2, and illumination wavelength < 450 nm. The studied system ut
ilizes CeO2 to accomplish the initial light absorption, charge separation,
and O-2 evolution from the interaction of H2O molecules with holes in the C
eO2 valence band, in the presence of Ce-aq(4+) species as an acceptor of co
nduction band electrons.