a1 National Laboratory of Solid State Microstructure, Nanjing University, Nanjing 210093, China
a2 Department of Physics, Henan University, Kaifeng 475001, China
a3 Ames Laboratory, Iowa State University, Ames, Iowa 50011
a4 National Laboratory of Solid State Microstructure, Nanjing University, Nanjing 210093, China
The photocatalyst BaZn1/3Nb2/3O3 with ABO3 perovskite structure has been synthesized by using a solid-state reaction process. It was characterized by x-ray diffraction and photoluminescence spectroscopy. The luminescence band centers around 285 nm and shows a large Stokes shift compared with the excitation spectrum, indicating a strong electron–phonon interaction in the photocatalyst BaZn1/3Nb2/3O3. The electronic structure of BaZn1/3Nb2/3O3 was calculated by using the pseudopotential method of the density function theory. It shows that the conduction band should be mainly composed of the Nb 4d states, and the valence band should be mainly composed of the O 2p state. The densities of the O 2p states and the Zn 4s states at the bottom of the conduction band are very low. The Zn 4s states show an expanded structure, which was proposed to be helpful for the migration of the photoexcited carriers, thus favoring the photocatalytic activity of BaZn1/3Nb2/3O3.
(Received October 10 2006)
(Accepted February 6 2007)