Effect of surface chemistry and textural properties on carbon dioxide uptake in hydrothermally reduced graphene oxide

We developed a facile method to obtain bulk quantities of three-dimensional porous materials through hydrothermal treatment of aqueous graphene oxide (GO) dispersion at different temperatures. The morphology and textural properties of hydrothermally reduced GO (HRGO) were characterized by scanning electron microscopy, X-ray diffraction, and nitrogen adsorption-desorption measurements. X-ray photoelectron spectroscopy, Raman spectroscopy, and infrared spectroscopy were used to analyze their chemical properties. The as-prepared HRGO not only exhibited three-dimensional porous network structure, but also possessed high specific surface area and large pore volume. Controllable surface functionalities on graphene sheets and textural properties enabled the HRGO to show an excellent carbon dioxide capture performance. The HRGO prepared at 100 degrees C exhibited higher carbon dioxide adsorption capacity (2.4 mmol g(-1) at 1.0 bar and 273 K) than those of the other two porous materials prepared at 80 and 120 degrees C. It was found that in addition to textural properties, the excellent adsorption performance can also be ascribed to various surface interactions between carbon dioxide and HRGO, including acid-base interaction, polar interaction, and hydrogen bonding. This study can be helpful to the development of porous materials for carbon dioxide uptake and separation. (C) 2014 Elsevier Ltd. All rights reserved.