Fabrication of well-crystallized mesoporous ZrO2 thin films via Pluronic P123 templated sol–gel route

Mesoporous zirconia (ZrO2) thin films were prepared by dip-coating via Pluronic P123 templated sol–gel route. ZrOCl2·8 H2O was used as zirconium (Zr) precursors. Annealing of as-coated ZrO2 thin films is important in order to stiffen the respective films and to remove the Pluronic P123. The mesoporous structure and crystallite size of ZrO2 were characterized systematically by field-emission scanning electron microscope (FESEM), both low- and wide-angle X-ray diffraction, thermal analysis technique and Brunauer–Emmett–Teller method. At annealing temperature of 400 °C, amorphous ZrO2 was transformed into tetragonal phase of ZrO2 (t-ZrO2). At 450 °C, t-ZrO2 and monoclinic phase of ZrO2 (m-ZrO2) were obtained. By altering heating rate during annealing, volume fraction of t-ZrO2 and m-ZrO2 was changed. FESEM images showed that disordered mesostructures of ZrO2 were formed after annealing. The surface area of mesoporous ZrO2 obtained ranges from 54.33 to 93.39 m2/g.