TY - JOUR
T1 - Electronic band structure, optical properties, and photocatalytic hydrogen production of barium niobium phosphate compounds (BaO-Nb2O 5-P2O5)
AU - Cho, In Sun
AU - Kim, Dong Wook
AU - Kim, Dong Hoe
AU - Shin, Seong Sik
AU - Noh, Tae Hoon
AU - Kim, Dong Wan
AU - Hong, Kug Sun
PY - 2011/5
Y1 - 2011/5
N2 - Barium niobium phosphate compounds (BaNb2P2O 11 and Ba3Nb2P4O18), with corner-sharing NbO6 octahedra as well as PO4 tetrahedra, were prepared by a conventional solid-state reaction method, and their optical properties, electronic band structure, and photocatalytic activity were investigated. The powders were characterized by X-ray powder diffraction (XRD), field-emission SEM (FESEM), high-resolution TEM (HRTEM), and UV/Vis and fluorescence spectroscopy. Both compounds exhibit similar optical band gaps, 3.55 eV for BaNb2P2O11 and 3.58 eV for Ba 3Nb2P4O18. However, photoluminescence spectra revealed that a radiative recombination process of charge carriers is dominant in Ba3Nb2P4O 18 (strong blue-white emission at 300 K) under UV irradiation, whereas no obvious emission was observed from BaNb2P 2O11. The photocatalytic activity for the evolution of H2 from the splitting of pure water was evaluated. BaNb 2P2O11, which has a smaller photon emission at room temperature, exhibited a much higher photocatalytic activity than Ba 3Nb2P4O18. The difference in the photocatalytic activity of the two compounds is attributed to their different electronic band structures, resulting from their different crystal-structure environments.
AB - Barium niobium phosphate compounds (BaNb2P2O 11 and Ba3Nb2P4O18), with corner-sharing NbO6 octahedra as well as PO4 tetrahedra, were prepared by a conventional solid-state reaction method, and their optical properties, electronic band structure, and photocatalytic activity were investigated. The powders were characterized by X-ray powder diffraction (XRD), field-emission SEM (FESEM), high-resolution TEM (HRTEM), and UV/Vis and fluorescence spectroscopy. Both compounds exhibit similar optical band gaps, 3.55 eV for BaNb2P2O11 and 3.58 eV for Ba 3Nb2P4O18. However, photoluminescence spectra revealed that a radiative recombination process of charge carriers is dominant in Ba3Nb2P4O 18 (strong blue-white emission at 300 K) under UV irradiation, whereas no obvious emission was observed from BaNb2P 2O11. The photocatalytic activity for the evolution of H2 from the splitting of pure water was evaluated. BaNb 2P2O11, which has a smaller photon emission at room temperature, exhibited a much higher photocatalytic activity than Ba 3Nb2P4O18. The difference in the photocatalytic activity of the two compounds is attributed to their different electronic band structures, resulting from their different crystal-structure environments.
KW - Ceramics
KW - Electronic structure
KW - Luminescence
KW - Solid-phase synthesis
KW - Water splitting
UR - http://www.scopus.com/inward/record.url?scp=79955628278&partnerID=8YFLogxK
U2 - 10.1002/ejic.201001096
DO - 10.1002/ejic.201001096
M3 - Article
AN - SCOPUS:79955628278
SN - 0365-9496
SP - 2206
EP - 2210
JO - Berichte der deutschen chemischen Gesellschaft
JF - Berichte der deutschen chemischen Gesellschaft
IS - 14
ER -