TY - JOUR
T1 - Photophysical and photocatalytic properties of Zn 3 M 2 O 8 (M = Nb, Ta)
AU - Noh, Tae Hoon
AU - Cho, In Sun
AU - Lee, Sangwook
AU - Kim, Dong Wook
AU - Park, Sangbaek
AU - Seo, Se Won
AU - Lee, Chan Woo
AU - Hong, Kug Sun
PY - 2012/1
Y1 - 2012/1
N2 - The Zn 3M 2O 8 (M = Nb, Ta) compounds with layered crystal structures were prepared by a conventional solid-state reaction method, and their electronic-band structures, optical properties, and photocatalytic activities were investigated. The prepared compounds were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis diffuse reflectance, and Mott-Schottky measurement. The UV-Vis diffuse reflectance spectra revealed Zn 3Nb 2O 8 and Zn 3Ta 2O 8 exhibited band gaps of 4.1 and 4.5 eV, respectively. From the electronic-band-structure calculations using DFT method, it was found that the valence band in both compounds was constructed by the hybridization of Zn 3d and O 2p orbitals, whereas the conduction band was consisted of Nb 4d (Zn 3Nb 2O 8) and Ta 5d (Zn 3Ta 2O 8) orbitals. The photocatalytic activity of both compounds was examined by the measurement of the H 2 production rate in an aqueous methanol solution under UV light irradiation. The Zn 3Ta 2O 8 with a larger band gap exhibited higher activity than Zn 3Nb 2O 8, which was attributed to its higher reduction potential resulting from the difference of its electronic-band configuration.
AB - The Zn 3M 2O 8 (M = Nb, Ta) compounds with layered crystal structures were prepared by a conventional solid-state reaction method, and their electronic-band structures, optical properties, and photocatalytic activities were investigated. The prepared compounds were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis diffuse reflectance, and Mott-Schottky measurement. The UV-Vis diffuse reflectance spectra revealed Zn 3Nb 2O 8 and Zn 3Ta 2O 8 exhibited band gaps of 4.1 and 4.5 eV, respectively. From the electronic-band-structure calculations using DFT method, it was found that the valence band in both compounds was constructed by the hybridization of Zn 3d and O 2p orbitals, whereas the conduction band was consisted of Nb 4d (Zn 3Nb 2O 8) and Ta 5d (Zn 3Ta 2O 8) orbitals. The photocatalytic activity of both compounds was examined by the measurement of the H 2 production rate in an aqueous methanol solution under UV light irradiation. The Zn 3Ta 2O 8 with a larger band gap exhibited higher activity than Zn 3Nb 2O 8, which was attributed to its higher reduction potential resulting from the difference of its electronic-band configuration.
UR - http://www.scopus.com/inward/record.url?scp=84855383625&partnerID=8YFLogxK
U2 - 10.1111/j.1551-2916.2011.04759.x
DO - 10.1111/j.1551-2916.2011.04759.x
M3 - Article
AN - SCOPUS:84855383625
SN - 0002-7820
VL - 95
SP - 227
EP - 231
JO - Journal of the American Ceramic Society
JF - Journal of the American Ceramic Society
IS - 1
ER -