Photophysical properties and electronic structures of the perovskite photocatalysts Ba3NiM2O9 (M=Nb,Ta)

TitlePhotophysical properties and electronic structures of the perovskite photocatalysts Ba3NiM2O9 (M=Nb,Ta)
Publication TypeJournal Article
Year of Publication2007
AuthorsXu B, Zhang WF, Liu XY, Ye JH, Zhang WH, Shi L, Wan XG, Yin J, Liu ZG
Journal TitlePhysical Review B
Date PublishedSep
Type of ArticleArticle
ISBN Number1098-0121
Accession NumberISI:000249786500018

The photocatalysts Ba3NiNb2O9 and Ba3NiTa2O9 with the triple perovskite crystal structure were synthesized by using solid-state-reaction method. They were characterized by x-ray diffraction and UV-visible reflectance spectroscopy. Both of the photocatalysts absorb UV and visible light photons obviously, which can be attributed to their special crystal and electronic structures. The valence band of Ba3NiNb2O9 was determined by ultraviolet photoelectron spectroscopy. Capacitance-voltage (C-V) measurements of Ba3NiNb2O9 film as deposited by using a pulsed laser deposition technique suggested that the lower conduction band should be composed of the Ni e(g) states. The band structures were proposed through the theoretical calculation of the electronic structures by using density functional theory with the local spin-density approximation. The hybridized O 2p and Ni t(2g) states in the photocatalysts Ba3NiNb2O9 and Ba3NiTa2O9 act as the new valence band instead of the O 2p orbital, and the Ni e(g) states act as the lower conduction band in Ba3NiNb2O9 and Ba3NiTa2O9.

Alternate JournalPhys. Rev. B