Rational Construction of a Responsive Azo-Functionalized Porous Organic Framework for CO2 Sorption.

Rongrong Yuan,Hongming He,Hao Sun

doi:10.3390/molecules26164993

Rongrong Yuan, Hongming He + Show 1 more

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https://doi.org/10.3390/molecules26164993

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Abstract

An azo-functionalized porous organic framework (denoted as JJU-1) was synthesized via FeCl3-promoted oxidative coupling polymerization. By virtue of a porous skeleton and a light/heat responsive azo functional group, this task-specific JJU-1 displays a reversible stimuli-responsive adsorption property triggered by UV irradiation and heat treatment. The initial Brunauer–Emmet–Teller (BET) surface area of this porous material is 467 m2 g–1. The CO2 sorption isotherms exhibit a slight decrease after UV irradiation because of the trans to cis conversion of the azo functional skeleton. It is worth mentioning that the responsive CO2 adsorption performance can be recycled for three cycles via alternating external stimuli, confirming the excellently reversible switchability of trans-to-cis isomerization and controllable CO2 adsorption.

Highlights

As a common greenhouse gas, the increased concentration of carbon dioxide (CO2) has caused global ecological and environmental problems
An azo-containing porous organic frameworks (POFs) has been successfully synthesized via FeCl3promoted oxidative coupling polymerization
The trans/cis isomerization of azo group in the porous skeleton is achieved by UV irradiation and thermal regeneration

Summary

Introduction

As a common greenhouse gas, the increased concentration of carbon dioxide (CO2) has caused global ecological and environmental problems. Effective capture and utilization of CO2 is very important for environmental protection and economic value To settle this thorny problem, one of the most effective approaches is the carbon capture and storage (CCS) technology [1,2]. In the last few decades, porous organic frameworks (POFs) have been attracting a great deal of attention, because they have many advantages including a high surface area, excellent physicochemical stability, convenient designability, and fascinating structure [7–12]. Most polymerization reactions commonly require rigorous reaction conditions in the preparation of POFs, including high temperatures, expensive noble metal catalysts, and inert gas shielding. The FeCl3-promoted oxidative coupling polymerization has been considered as a potential approach to construct POFs [22–26]. This method possesses outstanding advantages due to the low-cost catalyst, moderate reaction temperature, and high yield. The electron-rich carbazole groups can be coupled chemically under an oxidant such as FeCl3 [27–29]

Methods

Conclusion