Selective and adsorptive removal of anionic dyes and CO2 with azolium-based metal-organic frameworks

Chizoba I Ezugwu; Md Ali Asraf; Xiao Li; Shengwei Liu; Chih-Ming Kao; Serge Zhuiykov; Francis Verpoort

doi:10.1016/j.jcis.2018.02.003

Selective and adsorptive removal of anionic dyes and CO₂ with azolium-based metal-organic frameworks

J Colloid Interface Sci. 2018 Jun 1:519:214-223. doi: 10.1016/j.jcis.2018.02.003. Epub 2018 Feb 3.

Authors

Chizoba I Ezugwu¹, Md Ali Asraf², Xiao Li³, Shengwei Liu⁴, Chih-Ming Kao⁵, Serge Zhuiykov⁶, Francis Verpoort⁷

Affiliations

¹ School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, PR China; Laboratory of Organometallics, Catalysis and Ordered Materials, State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, PR China.
² Laboratory of Organometallics, Catalysis and Ordered Materials, State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, PR China; Department of Chemistry, Rajshahi University, Rajshahi 6205, Bangladesh.
³ School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, PR China.
⁴ School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, PR China. Electronic address: [email protected].
⁵ Institute of Environmental Engineering, National Sun Yat-sen University, Kaohsiung 80424, Taiwan.
⁶ Ghent University Global Campus, Songdo, 119 Songdomunhwa-Ro, Yeonsu-Gu, Incheon, Republic of Korea.
⁷ Laboratory of Organometallics, Catalysis and Ordered Materials, State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, PR China; National Research Tomsk Polytechnic University, Lenin Avenue 30, 634050 Tomsk, Russian Federation; Ghent University Global Campus, Songdo, 119 Songdomunhwa-Ro, Yeonsu-Gu, Incheon, Republic of Korea. Electronic address: [email protected].

PMID: 29501993
DOI: 10.1016/j.jcis.2018.02.003

Abstract

The positively charged azolium moieties make imidazolium linker an ideal linker for the construction of cationic metal-organic frameworks because the ligand induces cationic environments in the frameworks. Therefore, we employed two imidazolium ligands, 1,3-bis(4-carboxyphenyl)imidazolium chloride (H₂L⁺Cl¯) and 1,3-bis(3,5-dicarboxyphenyl)imidazolium chloride (H₄L⁺Cl¯), to synthesize two nickel azolium-based MOFs, 1 and 2. The as-synthesis MOFs were characterized by PXRD, TGA, FE-SEM, HR-TEM, FTIR and BET measurements. By applying 1 and 2 in liquid phase adsorption of charged molecules of dyes, they successfully exhibit remarkable efficiency for adsorptive removal of anionic dyes, Methyl orange (MO), Congo red (CR), and Orange II sodium salt (OS), from aqueous solution. The framework proves efficient in photocatalytic degradation of anionic dye. Furthermore, in the gaseous phase adsorption, 1 and 2 selectively adsorb CO₂ over CH₄ due to the higher quadrupole moment of CO₂. Overall, the results show that azolium-based MOFs have potential applications for adsorptive removal of charged organic contaminants from both aqueous and gaseous environment.

Keywords: Adsorption; Azolium based-MOFs; Dye; Gaseous molecule; Photocatalysis.