Synthesis and Room Temperature Photoluminescence of Mesoporous Zirconia with a Tetragonal Nanocrystalline Framework

Mesoporous ZrO2 with a tetragonal (t) nanocrystalline framework was synthesized using zirconium propoxide as the zirconium precursor and cetyltrimethylammonium bromide as pore-directing agent and subsequent calcination of the inorganic/organic intermediate. The Raman spectrum showed six distinct peaks at 146, 268, 325, 480, 615, and 645 cm(-1), which further confirm t-structure of the mesoporous ZrO2. Fourier transform infrared spectroscopy analysis reveals that mesoporous ZrO2 prepared at 500 degrees C is template free. The mesoporous t-ZrO2 possesses narrowly distributed pore size (2-11 nm) with average pore diameter of 5 nm and surface area of 65 m(2)/g. A photoluminescence band centered at 419 nm under excitation at 285 nm wavelength at room temperature is attributed to the ionized oxygen vacancy in t-ZrO2 in the mesoporous structure. The combined effects of grain/pore size, oxygen vacancies and mesoporous wall strain-energy play important role in stabilizing the t-nanocrystalline framework of mesoporous ZrO2. In comparison with the mesoporous ZrO2 materials stabilized by chemical treatment, the present route is simpler and resulted in mesoporous ZrO2 with crystalline framework.