Hierarchically Porous Zirconia Monolith Fabricated from Bacterial Cellulose and Preceramic Polymer

A hierarchically porous zirconia (ZrO₂) monolith was successfully fabricated by using bacterial cellulose (BC) as a biotemplate and preceramic polymer as a zirconium resource, via freeze-drying and two-step calcination process. Images of scanning electron microscopy showed that the ZrO₂ monolith well-replicated a three-dimensional reticulated structure of pristine BC and possessed good morphology stability till 1100 °C in air. Results of N₂ adsorption/desorption and mercury porosimetry analysis revealed the hierarchically porous structure and large specific area (9.7 m²·g^-1) of the ZrO₂ monolith, respectively. Patterns of X-ray powder diffraction indicated that the monoclinic phase and tetragonal phase coexisted in the ZrO₂ monolith with the former as the main phase. In addition, the ZrO₂ monolith possessed low bulk density (0.13 g·cm^-3) and good mechanical strength. These properties suggest that the as-prepared ZrO₂ monolith has a great potential to serve as an ideal catalyst or catalyst support.