Preparation of porous and hierarchical tantalum oxide particles using hydrolyzing tantalum alkoxide

Tantalum oxide (Ta2O5) particles with defined structures and high specific surface areas are highly desirable for diverse applications. Herein, hydrous Ta2O5 particles with porous structures were prepared by hydrolyzing tantalum alkoxide and partially dissolving the particle surfaces by soaking in alcohol. To obtain crystallized Ta2O5, these particles were subjected to heat treatment or hydrothermal treatment. Heat treatment produced particles that retained the original porous structure to some extent, while hydrothermal treatment caused dried hydrous Ta2O5 particles to disintegrate. In contrast, hydrothermal crystallization of nondried hydrous Ta2O5 particles produced an urchin-like structure, with Ta2O5 spines grown on the original spherical core. The urchin -like particles had a mesoporous structure with a specific surface area of about 75 m2 g-1.