In situ self-assembly synthesis and photocatalytic performance of hierarchical Bi0.5Na0.5TiO3 micro/nanostructures

A novel hierarchical Bi0.5Na0.5TiO3 (BNT) micro/nanostructure was synthesized via in situ self-assembly of BNT nanocrystals under hydrothermal conditions. Each spheric flower-like BNT micro/nanostructure is composed of nanosheets ca. 100 nm in width, 300 nm in length and 10 nm in thickness. The self-assembly growth process of hierarchical BNT micro/nanostructures from BNT nanocrystals was investigated by changing the reaction time, the molar ratio of precursors and NaOH concentration. From time-dependent morphology evolution, a two- step growth mechanism was proposed to explain the growth of the hierarchical BNT micro/nanostructure. Importantly, such structured BNT shows better photocatalytic performance in the photodegradation of methyl orange than that of the powders of spheric and cubic structured BNT. The intrinsic structure of BNT may contribute to its higher surface-to-volume ratio and stability against overdue aggregation. This study not only gives insights into the hierarchical growth behavior of BNT complex micro/nanoarchitectures, but also provides an efficient route for enhancing the photocatalytic performance of BNT.