Research output: Contribution to journal › Article › peer-review
Photostimulated generation of defects and surface reactions on a series of wide band gap metal-oxide solids. / Emeline, A. V.; Kataeva, G. V.; Ryabchuk, V. K.; Serpone, N.
In: Journal of Physical Chemistry B, Vol. 103, No. 43, 28.10.1999, p. 9190-9199.Research output: Contribution to journal › Article › peer-review
}
TY - JOUR
T1 - Photostimulated generation of defects and surface reactions on a series of wide band gap metal-oxide solids
AU - Emeline, A. V.
AU - Kataeva, G. V.
AU - Ryabchuk, V. K.
AU - Serpone, N.
PY - 1999/10/28
Y1 - 1999/10/28
N2 - The interconnection between photostimulated formation and destruction of defect centers (F- and V-type color centers) and surface photochemical reactions taking place on the surface has been examined for a series of 21 wide band gap metal-oxide specimens, which comprise insulators and semiconductors whose band-gap energies span the range from ca. 3 eV (ZnO, TiO2) to ca. 11 eV (BeO). Photostimulated post-adsorption of O2 was seen for 9 of the 21 metal oxides tested. Three of these specimens, namely scandia (Sc2O3), zirconia (ZrO2), and normal spinel (MgAl2O4), were chosen for detailed study to establish that spectral sensitization of metal oxides by UV illumination is a generally occurring phenomenon which is carried over to photostimulated adsorption of molecules and to surface photochemical reactions. Results demonstrate that irradiation into the absorption bands of the color centers of the photocolored metal oxides leads to a red shift of the spectral limit of surface photoreactions. A simple mechanism is described quantitatively for the photocoloration and surface reactions. Quantum yields of photobleaching of color centers in vacuo and in the presence of H2 and O2 are reported for scandia and zirconia, together with the quantum yields of photoadsorption of H2 and O2 molecules.
AB - The interconnection between photostimulated formation and destruction of defect centers (F- and V-type color centers) and surface photochemical reactions taking place on the surface has been examined for a series of 21 wide band gap metal-oxide specimens, which comprise insulators and semiconductors whose band-gap energies span the range from ca. 3 eV (ZnO, TiO2) to ca. 11 eV (BeO). Photostimulated post-adsorption of O2 was seen for 9 of the 21 metal oxides tested. Three of these specimens, namely scandia (Sc2O3), zirconia (ZrO2), and normal spinel (MgAl2O4), were chosen for detailed study to establish that spectral sensitization of metal oxides by UV illumination is a generally occurring phenomenon which is carried over to photostimulated adsorption of molecules and to surface photochemical reactions. Results demonstrate that irradiation into the absorption bands of the color centers of the photocolored metal oxides leads to a red shift of the spectral limit of surface photoreactions. A simple mechanism is described quantitatively for the photocoloration and surface reactions. Quantum yields of photobleaching of color centers in vacuo and in the presence of H2 and O2 are reported for scandia and zirconia, together with the quantum yields of photoadsorption of H2 and O2 molecules.
UR - http://www.scopus.com/inward/record.url?scp=0000484039&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0000484039
VL - 103
SP - 9190
EP - 9199
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
SN - 1520-6106
IS - 43
ER -
ID: 35144516