Highly Selective Adsorption of Cationic Dye by An Anionic Zinc‐Organic Framework

Abstract

A MOF named [(CH 3 )NH 2 ] [H 2 N(CH 3 ) 2 ][ZnTNC4A] ⋅ 4H 2 O (ZnTNC4A) was synthesized by a resorcinol[4]arene functionalized tetracarboxylic acid ligand (TNC4A = 2,8,14,12,18,10,16,arene). The three-dimensional framework with one-dimensional channels of ZnTNC4A was characterized by elemental analysis, powder X-ray diffraction, thermogravim-etry, UV-vis diffuse reflection spectrum, infrared spectrum and N 2 adsorption analyse. In addition, ZnTNC4A shows the ability of selective adsorption of methylene blue with a pseudosecond order kinetic model. The selective adsorption kinetics of a series of dyes showed that the ion exchanged separation process was related to the size and charge of organic dyes.

An Anionic Porous Indium-Organic Framework with Nitrogen-Rich Linker for Efficient and Selective Removal of Trace Cationic Dyes

“…As a new class of porous organic-inorganic hybrid material, metal-organic frameworks (MOFs) are constructed from metal ions/clusters and organic linkers through coordination bond [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. There are currently about 100,000 MOFs in the Cambridge database, far more than the types of silica and zeolite (1000).…”

“…There are currently about 100,000 MOFs in the Cambridge database, far more than the types of silica and zeolite (1000). Compared to traditional porous materials, the diversity of metal ions/clusters and linkers results in MOFs displaying large specific surface areas, high porosity, structural designability, and surface functionability, already known as outstanding candidates for dye pollutions removal [ 1 , 4 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. Choe et al [ 1 ] reported that PCN-224 possesses the high BET surface area of 2982 m 2 /g and the large pore size distribution of 2.4 nm.…”

“…Specifically, ionic-functional MOF materials display more invincible performance in the highly efficient elimination of pollutants and chemicals, especially dyes. This can be attributed to several factors: (1) Coulombic interaction and ion-exchange [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ], which can promote the dyes with the opposite charge into the pore/channel of ionic MOFs, while the dyes with similar charge are repelled, then achieve selective separation. Zhao et al [ 12 ] utilized the anionic zinc-organic framework which exhibited highly selective adsorption of methylene blue dye by the ion exchange mechanism.…”

“…This can be attributed to several factors: (1) Coulombic interaction and ion-exchange [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ], which can promote the dyes with the opposite charge into the pore/channel of ionic MOFs, while the dyes with similar charge are repelled, then achieve selective separation. Zhao et al [ 12 ] utilized the anionic zinc-organic framework which exhibited highly selective adsorption of methylene blue dye by the ion exchange mechanism. A functional anionic MOF [ 18 ] can efficiently remove the carcinogenic Basic Violet 14 (BV14) and Basic Red 9 (BR9) in conjunction with Coulombic interaction, hydrogen bonding, and ion-exchange.…”