Facile synthesis of uniform and well-defined single-crystal sodium tantalate cubes and their assembly into oriented two-dimensional nanofilm

Abstract

Uniform and well-defined single-crystal NaTaO₃ cubes were successfully synthesized through a solvothermal method using monodisperse meso-microporous Ta₃N₅ hollow spheres as precursors. The structure and morphology of NaTaO₃ cubes were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resoluition transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDX). The results show that the formation of NaTaO₃ cubes follows the dissolution-recrystallization mechanism, and use of monodisperse Ta₃N₅ hollow spheres with a thin shell thickness as precursors is critical to obtain the uniform cube morphology of the products. The size of the NaTaO₃ cubes can be tunable by adjusting the ratio of ethanol to water. Due to the highly monodisperse size and shape, the cubes can be further self-assembled into a high quality monolayer nanofilm.