TY - JOUR
T1 - Band gap coupling in photocatalytic activity in ZnO-TiO 2 thin films
AU - García-Ramírez, E.
AU - Mondragón-Chaparro, M.
AU - Zelaya-Angel, O.
N1 - Funding Information:
The authors are grateful with M. Guerrero, R. Fragoso, A. Soto, A. Garcia and Dr. M. Becerril for their technical assistance. This work was supported by ICYTDF-México.
PY - 2012/8
Y1 - 2012/8
N2 - Zinc oxide and titanium dioxide composite thin films were prepared on Corning 7059 glass substrates by co-sputtering. The reactive gas-surroundings used was ultrahigh purity oxygen. To analyze the structural, optical and photocatalytic properties of the ZnO-TiO 2 samples, X-ray diffraction (XRD), atomic force microscopy (AFM), optical absorption, Raman spectroscopy and methylene blue bleaching were carried out at room temperature. XRD patterns indicate the presence of TiO 2 (anatase and rutile phases), ZnO, ZnTiO 3, and Zn 2TiO 4 crystalline structures. AFM images allow the observation of non-homogeneous surface in the ZnO-TiO 2 system, suggesting the separation of different crystalline phases in the composite. Raman studies exhibit different spectra in the films depending on the area analyzed, which can be interpreted as a result of the existence of well separated crystalline regions as seen in AFM images. The photocatalytic activity (PA) of TiO 2- ZnO-ZnTiO 3-Zn 2TiO 4 composite, as expected for adequate coupling semiconductors, is larger than PA of ZnO and TiO 2 oxides, used as references. A simple proposal about the probable alignment of the conduction band, the valence band, and the Fermi level is included.
AB - Zinc oxide and titanium dioxide composite thin films were prepared on Corning 7059 glass substrates by co-sputtering. The reactive gas-surroundings used was ultrahigh purity oxygen. To analyze the structural, optical and photocatalytic properties of the ZnO-TiO 2 samples, X-ray diffraction (XRD), atomic force microscopy (AFM), optical absorption, Raman spectroscopy and methylene blue bleaching were carried out at room temperature. XRD patterns indicate the presence of TiO 2 (anatase and rutile phases), ZnO, ZnTiO 3, and Zn 2TiO 4 crystalline structures. AFM images allow the observation of non-homogeneous surface in the ZnO-TiO 2 system, suggesting the separation of different crystalline phases in the composite. Raman studies exhibit different spectra in the films depending on the area analyzed, which can be interpreted as a result of the existence of well separated crystalline regions as seen in AFM images. The photocatalytic activity (PA) of TiO 2- ZnO-ZnTiO 3-Zn 2TiO 4 composite, as expected for adequate coupling semiconductors, is larger than PA of ZnO and TiO 2 oxides, used as references. A simple proposal about the probable alignment of the conduction band, the valence band, and the Fermi level is included.
UR - http://www.scopus.com/inward/record.url?scp=84864553135&partnerID=8YFLogxK
U2 - 10.1007/s00339-012-6890-x
DO - 10.1007/s00339-012-6890-x
M3 - Artículo
SN - 0947-8396
VL - 108
SP - 291
EP - 297
JO - Applied Physics A: Materials Science and Processing
JF - Applied Physics A: Materials Science and Processing
IS - 2
ER -