Preparation of mesoporous ZnAl 2 O 4 nanoflakes by ion exchange from a Na-dawsonite parent material in the presence of an ionic liquid

• Published in: RSC advances Vol. 9; no. 21; pp. 11894 - 11900
• Main Authors: Kim, TongIl, Yun, HakSung, Han, GwangBok, Lian, Jiabiao, Ma, Jianmin, Duan, Xiaochuan, Zhu, Lianjie, Zheng, Wenjun
• Format: Journal Article
• Language: English
• Published: England 16-04-2019
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/C8RA10524C

Herein, mesoporous ZnAl
O
spinel nanoflakes were prepared by an ion-exchange method from a Na-dawsonite parent material in the presence of an ionic liquid, 1-butyl-2,3-dimethylimidazolium chloride ([bdmim][Cl]), followed by calcination at 700 °C for 2 h. The as-obtained products were characterized by several techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX). The ZnAl
O
nanoflakes with the thickness of ∼20 nm were composed of numerous nanoparticles, which resulted in a high specific surface area of 245 m
g
. The formation mechanism of the ZnAl
O
nanoflakes was comprehensively investigated, and the results showed that a 2D growth process of the Zn
Al
(OH)
(CO
)·4H
O crystallites with the assistance of [bdmim][Cl] was the key for the induction of ZnAl
O
nanoflakes. Moreover, mesopores were formed between adjacent nanoparticles due to the release of CO
and H
O molecules from Zn
Al
(OH)
(CO
)·4H
O during the calcination process.