Mesoporous silica templated zirconia nanoparticles

Nanoparticles of zirconium oxide (ZrO₂) were synthesized by infiltration of a zirconia precursor (ZrOCl₂·8H₂O) into a SBA-15 mesoporous silica mold using a wet-impregnation technique. X-ray diffractometry and high-resolution transmission electron microscopy show formation of stable ZrO₂ nanoparticles inside the silica pores after a thermal treatment at 550 °C. Subsequent leaching out of the silica template by NaOH resulted in well-dispersed ZrO₂ nanoparticles with an average diameter of ~4 nm. The formed single crystal nanoparticles are faceted with 110 surfaces termination suggesting it to be the preferred growth orientation. A growth model of these nanoparticles is also suggested.