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

Abstract

• Spherical hydrous Ta 2 O 5 particles were prepared using hydrolyzing Ta alkoxide. • Hydrous Ta 2 O 5 particles became porous after being soaked in 2-propanol. • Hydrothermal treatment crystallized porous hydrous Ta 2 O 5 particles. • The Ta 2 O 5 particles had urchin-like shapes with high specific surface areas. Tantalum oxide (Ta 2 O 5 ) particles with defined structures and high specific surface areas are highly desirable for diverse applications. Herein, hydrous Ta 2 O 5 particles with porous structures were prepared by hydrolyzing tantalum alkoxide and partially dissolving the particle surfaces by soaking in alcohol. To obtain crystallized Ta 2 O 5 , 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 Ta 2 O 5 particles to disintegrate. In contrast, hydrothermal crystallization of nondried hydrous Ta 2 O 5 particles produced an urchin-like structure, with Ta 2 O 5 spines grown on the original spherical core. The urchin-like particles had a mesoporous structure with a specific surface area of about 75 m 2 g −1 .