A simple route to synthesize hierarchical porous ZrO2

Abstract

A simple method for preparing porous ZrO₂ has been proposed by directly decomposing a Zr(NO₃)₄·5H₂O ethanol sol–gel solution. Contrary to other traditional sol–gel methods, porous ZrO₂ with multi-sized macro- and meso-pores are synthesized via only one simple step. The size of the macropores ranges from 100 nm to 500 nm. Remarkably, we also isolated some highly dispersed ZrO₂ nanoparticles (∼60 nm), which on their surface or even in the whole body are fully filled with well-sized ever-smaller spherical mesopores with an average diameter around ∼5 nm. A further investigation of low-temperature nitrogen absorption has shown a high surface area over 162 m² g⁻¹ for the fully crystallized ZrO₂. No more additional modifiers or complicated preparations are needed in the present method, which promises a new potential option in fabricating high-porosity materials.