Synthesis and room temperature photoluminescence of mesoporous zirconia with a tetragonal nanocrystalline framework

Abstract

Mesoporous ZrO(2) 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 ZrO(2). Fourier transform infrared spectroscopy analysis reveals that mesoporous ZrO(2) prepared at 500 degrees C is template free. The mesoporous t-ZrO(2) 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-ZrO(2) 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 ZrO(2). In comparison with the mesoporous ZrO(2) materials stabilized by chemical treatment, the present route is simpler and resulted in mesoporous ZrO(2) with crystalline framework.