Kinetic model of energy transfer processes between low-coordinated ions on MgO by photoluminescence decay measurements.

Photoluminescence decay studies of emitting species on MgO nanocubes at room temperature provide evidence of three surface species characterized by an excitation and emission wavelength couple {lambda(exc);lambda(em)}. Species A corresponds to {lambda(exc)=240 nm; lambda(em)=380 nm}, whereas the couple {lambda(exc)=280 nm; lambda(em)=470 nm} is assigned to two species: B and B', the former is involved in energy transfer from excited state A* and the latter in direct emission from excited state B'*. A simple model for energy transfer from species A* to B is proposed. The numerical resolution of equations corresponding to this model is in good agreement with experimental data. This method quantifies the kinetics of intrinsic emission and energy transfer processes. Lifetime values indicate that phosphorescence is taking place, and species A, B and B' are identified as edge O(2-) (4 C), corner O(2-) (3 C) and kink O(2-) (3 C) oxide ions respectively.

[1]  G. Costentin,et al.  Evidence for emission and transfer of energy from excited edge sites of MgO smokes by photoluminescence experiments , 2005 .

[2]  E. Knözinger,et al.  MgO-Nanowürfel: über die Abhängigkeit der optischen Eigenschaften von der Teilchengröße† , 2005 .

[3]  S. Stankic,et al.  Size-dependent optical properties of MgO nanocubes. , 2005, Angewandte Chemie.

[4]  M. Che,et al.  Physicochemical and in situ photoluminescence study of the reversible transformation of oxide ions of low coordination into hydroxyl groups upon interaction of water and methanol with MgO. , 2005, The journal of physical chemistry. B.

[5]  M. Che,et al.  Discrimination of MgO Ions by Means of an Improved In Situ Photoluminescence Cell and of Propyne as Probe Molecule , 2004 .

[6]  M. Che,et al.  Quantitative Analysis of Photoluminescence Quenching of Silica-Supported Molybdena Catalysts. Relation to Photocatalytic Reduction of Nitric Oxide by Carbon Monoxide , 2003 .

[7]  A. Shluger,et al.  Electronic properties of structural defects at the MgO (001) surface , 2002 .

[8]  A. Shluger,et al.  Wavelength selective excitation of surface oxygen anions on highly dispersed MgO , 2002 .

[9]  M. Sterrer,et al.  Chemical vapour deposition — a new approach to reactive surface defects of uniform geometry on high surface area magnesium oxide , 2000 .

[10]  A. Shluger,et al.  Electronic structure of excited states at low-coordinated surface sites of MgO , 1999 .

[11]  A. Shluger,et al.  Spectroscopy of low-coordinated surface sites: Theoretical study of MgO , 1999 .

[12]  Michel Che,et al.  Applications of Photoluminescence Techniques to the Characterization of Solid Surfaces in Relation to Adsorption, Catalysis, and Photocatalysis , 2000 .

[13]  Guillaume Petite,et al.  Time-resolved studies of carriers dynamics in wide band gap materials , 1996 .

[14]  E. Knözinger,et al.  Production and Properties of Nanostructured Metal Oxide Particles , 1995 .

[15]  M. Anpo,et al.  Photoluminescence properties of MgO powders with coordinatively unsaturated surface ions , 1988 .

[16]  S. Coluccia.  Surface Structure and Energy Transfer on Oxides Investigated by Photoluminescence Spectroscopy , 1985 .

[17]  M. Che,et al.  Characterization and Reactivity of Molecular Oxygen Species on Oxide Surfaces , 1983 .

[18]  S. Coluccia,et al.  Reactivity of low-coordination sites on the surface of magnesium oxide , 1981 .

[19]  K. Reichelt,et al.  The decoration of evaporated Sb2Te3 cleavage faces , 1980 .

[20]  E. Garrone,et al.  An experimental and theoretical evaluation of surface states in MgO and other alkaline earth oxides , 1980 .

[21]  S. Coluccia,et al.  Photoluminescent spectra of surface states in alkaline earth oxides , 1979 .

[22]  M. G. Lofthouse,et al.  Reflectance spectra of surface states in magnesium oxide and calcium oxide , 1975 .

[23]  G. T. Pott,et al.  Surface states in some alkaline earth oxides , 1974 .