A Series of Unique Architecture Building of Layered Zinc Hydroxides: Self-Assembling Stepwise Growth of Layered Zinc Hydroxide Carbonate and Conversion into Three-Dimensional ZnO

Abstract

A series of uniformly unique three-dimensional (3D) structures of layered zinc hydroxides (LZHs) were synthesized via a hydrothermal method. During the process, two kinds of LZHs with different crystal structures could be formed, depending on the ionic groups intercalated in zinc hydroxide layers: when carbonate anions were the only interlayer ions, the corresponding LZH compound was assigned as LZHC or zinc hydroxide carbonate; when the interlayer ions contained both carbonate anions and long-chain quaternary ammonium groups, the corresponding LZH compound was denominated as LZHDC. Interestingly, the LZHDC is transformed into LZHC though a structure and compositional transformation involving an exchange of long-chain quaternary ammonium groups by carbonate anions. We propose a stepwise growth and anion exchange mechanism involving conversion from zinc precursor to LZHDC to LZHC. We demonstrated the utility the LZHs obtained in the process as self-sacrificial templates for formation novel 3D ZnO structures by pyrolysis.