Formation mechanism of BaTiO3 nanowire through heterogeneous nucleation using K2Ti4O9 as template

Abstract

This work demonstrates a mechanism of heterogeneous nucleation for the synthesis of BaTiO3 nanowires utilizing K2Ti4O9 as template by manipulating alkalinity, temperature and reaction time. Results suggest that the synthesis of BaTiO3 does not occur through a hydrothermal ion-exchange, instead, the predominant mechanism observed is the heterogeneous of dissolution-crystallization. The consistency of crystallographic orientation for BaTiO3 nanowires is affected by the hydrothermal conditions. BaTiO3 nanowires synthesized at 190 °C/0.2 M exhibit a uniform (100)/(001) crystallographic orientation, albeit not consistently along the length of the nanowires, while BaTiO3 crystal grains no longer have the same crystallographic orientation at 190 °C/0.8 M. By investigating the reaction mechanism of BaTiO3, this work may have great significance for the synthesis of perovskite-type MTiO3 (M = Ba,Ca, Sr, Pb) utilizing layered titanates.