Ultrathin, ethylenediamine-functionalized graphene oxide membranes on hollow fibers for CO₂ capture

In this work, we prepared ultrathin, ethylenediamine (EDA)-functionalized graphene oxide (GO) hollow fiber membranes, following our previously developed deposition method, for highly efficient CO₂ capture from flue gas. Single-layered graphene oxide (SLGO) sheets were uniformly deposited on the inner surface of poly (ether sulfone) (PES) hollow fibers, and EDA, as an effective CO₂-philic agent, was incorporated into the SLGO interlayer nanochannels by chemical grafting. To characterize the morphology and structure of GO and GO-EDA hollow fiber membranes, Field emission scanning electron microscopy (FESEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray diffraction analysis (XRD) were performed. Permeation of mixed gas (15 vol% CO₂/85 vol% N₂) was conducted under wet condition. Excellent CO₂ separation performance with CO₂ permeance of 660 GPU and CO₂/N₂ selectivity of > 500 at 75 °C was obtained. This work, combined with our previous work, therefore, suggests amine-functionalization of GO-based membranes might serve as an effective strategy to enhance CO₂ capture performance of ultrathin, GO-based membranes.