Assembly of NaTaO₃ porous microspheres via imperfect oriented attachment mechanism

Spongy-like NaTaO₃ mesoporous microspheres are assembled from nanoparticles via imperfect oriented attachment. Study shows that the NaTaO₃ spongy microspheres with the diameters of ∼1 μm are composed of the fundamental building blocks of ∼50 nm NaTaO₃ nanospheres. The high-resolution transmission electron microscopy further reveals that these fundamental building blocks are assembled from primary building blocks of ∼10 nm NaTaO₃ nanocrystals. The pore diameters of these spongy microspheres are ca. 30 nm and the Brunauer-Emmett-Teller (BET) surface area is calculated to be 57.8 m² g^-1. This interesting ternary alkali metal composite oxide of NaTaO₃ spongy microspheres with high specific surface area and strong stability will be favorable for their practical application in photocatalysis. This synthesis route may throw light on the fabrication of the binary or ternary porous metal oxides by geometrical stacking of the nanobuilding blocks via imperfect oriented attachment.