Abstract: An ultraviolet photoluminescence emission band at 38 eV was found from SBA-15 ordered mesoporous silica prepared by means of the hydro-thermal method. The optical properties of such material were investigated by electron paramagnetic resonance (EPR) and photoluminescence (PL) spectra at room temperature. It was found that the PL intensity of the sample at 38 eV was enhanced after exposition in air at room temperature for 10 days. Besides, annealing experiments at different temperatures were used to study the origin of the observed PL emission band. The 38 eV band is suggested to be attributed to the surface silanols generated from ODC(Ⅱ) (unrelaxed neutral oxygen vacancy) and the interstitial water molecules.

Key words: ordered mesoporous silica, SBA-15, Silanol, ODC(Ⅱ), interstitial water molecules