Guanidinium ionic liquid-controlled synthesis of zeolitic imidazolate framework for improving its adsorption property

Chen Fan; You Liang; Hongqiang Dong; Jiale Yang; Gang Tang; Wenbing Zhang; Dandan Kong; Jianqiang Li; Yongsong Cao

doi:10.1016/j.scitotenv.2018.05.282

Guanidinium ionic liquid-controlled synthesis of zeolitic imidazolate framework for improving its adsorption property

Sci Total Environ. 2018 Nov 1:640-641:163-173. doi: 10.1016/j.scitotenv.2018.05.282. Epub 2018 May 30.

Authors

Chen Fan¹, You Liang¹, Hongqiang Dong¹, Jiale Yang¹, Gang Tang¹, Wenbing Zhang¹, Dandan Kong¹, Jianqiang Li¹, Yongsong Cao²

Affiliations

¹ College of Plant Protection, China Agricultural University, Beijing, China.
² College of Plant Protection, China Agricultural University, Beijing, China. Electronic address: caoys@cau.edu.cn.

PMID: 29859434
DOI: 10.1016/j.scitotenv.2018.05.282

Abstract

The massive release of rhodamine B (RhB) to water system is an emerging problem, which dramatically threaten environment and human health. The development of an adsorbent with enhanced removal efficiency for RhB is urgently needed. Herein, we report an environment-friendly synthesis of high quality zeolitic imidazolate framework-8 (ZIF-8) and functional ionic liquid@ZIF-8 in water-based system without heat treatment for improving its adsorption property. Guanidinium ionic liquids (ILs) could not only act as greener agents instead of volatile bases and toxic surfactants to efficiently control the nucleation and growth rate of ZIF-8, but also were incorporated as shell material to add specific adsorption sites. The relationship between nanoparticle structure and adsorption performance for RhB was systematically investigated. Due to high surface area (1167 m² g^-1), high porosity (0.79 cm³ g^-1), high crystallinity, nano size (about 100 nm) and monodispersity, the as-obtained ZIF-8 showed improved adsorption capacity toward RhB (80% removal efficiency). Heteropolyanion-based guanidinium IL@meso-ZIF-8 (HPAIL@meso-ZIF-8) exhibited the high RhB uptake capacity of 278 mg g^-1 (higher than most of the reported adsorbents) and effectively removed 99% of RhB within 15 min. The results showed that the adsorption process of prepared materials fitted well with pseudo-second-order kinetics and Langmuir isotherm model. The existence of mesopores in ZIF-8 facilitated the diffusion of RhB and the incorporated guanidinium IL played a significant role in enhancing the adsorption affinity. Moreover, the reusability results revealed the HPAIL@meso-ZIF-8 as a highly efficient adsorbent for RhB removal with satisfactory performance and structural stability. Therefore, HPAIL@meso-ZIF-8 is one of the most promising adsorbents for organic dye removal from water.

Keywords: Adsorption; Composite material; Guanidinium ionic liquid; Rhodamine B; Zeolitic imidazolate framework.