Revealing the hydrothermal crystallization mechanism of ilmenite-type sodium niobate microplates: the roles of potassium ions

Affiliation of Author(s):航空学院

Journal:CRYSTENGCOMM

Key Words:MOLTEN-SALT SYNTHESIS PIEZOELECTRIC PROPERTIES PHOTOCATALYTIC ACTIVITY GRAIN-SIZE NANBO3 PARTICLES MORPHOLOGY EVOLUTION CERAMICS GROWTH

Abstract:In this study, ilmenite-type NaNbO3 microplates were prepared by a facile surfactant-free method, using NaAc and KOH as a sodium resource and as a mineralizer, respectively. The effects of each reactant were identified, and the formation process and crystallization pathway of ilmenite-type NaNbO3 microplates were explored based on the phase constitution, microstructure and chemical compositional analysis. The indispensable roles of K ions, which participated in the formation of layered KNN-hydrate intermediates, were revealed. Ilmenite-type NaNbO3 microplates were formed by the dissolution of these intermediates and subsequent recrystallization into K-containing NaNbO3, followed by the ion-exchange between K and Na ions. Meanwhile excess K ions would hinder the release of K ions associated with the dissolution of intermediates, thus preventing the formation of ilmenite-type NaNbO3. Moreover, the morphological evolution of ilmenite-type NaNbO3 microplates from platelets to octahedra was interpreted in terms of their intrinsic structure and KOH concentration.

ISSN No.:1466-8033

Translation or Not:no

Date of Publication:2017-10-28

Co-author:Gu, Qilin,Lu, Wanheng,Sun, Qiaomei,Wang Jingwen,Liu, Jinsong,Zhang, Jianhui,Zeng, Kaiyang,Wang, John

Correspondence Author:朱孔军,Zhang, Jianhui,Kongjun Zhu

Date of Publication:2017-10-28