Amino-Functionalized β-Cyclodextrin to Construct Green Metal–Organic Framework Materials for CO₂ Capture

Abstract

The adsorption of CO2 by conventional liquid alkanolamine adsorbents does not meet the requirements for green-friendly development in industrial applications. In this work, we constructed NH2-β-CD-MOF for the first time through the amino-functionalization of the lowest-priced, readily available, and biocompatible β-CD. Subsequently, the samples were characterized by single-crystal X-ray diffraction, powder X-ray diffraction, scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, elemental analysis, and N2 adsorption/desorption. The CO2 adsorption capacity of NH2-β-CD-MOF was found to be 12.3 cm3/g, which is 10 times that of β-CD-MOF. In addition, NH2-β-CD-MOF has outstanding selective adsorption of CO2/N2 (947.52) compared with the reported materials. The adsorption mechanism of CO2 was analyzed by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Furthermore, we have found that NH2-β-CD-MOF has better water stability relative to β-CD-MOF and γ-CD-MOF, and it can be recycled by an ultrasonic method.