Selective CO2 adsorption and H2 storage in two porous amine-pillared graphene oxide frameworks

Abstract

Two porous graphene oxide frameworks (GOFs) have been synthesized by a reaction of graphene oxide (GO) and benzylamine (GOF-1) or p-xylylenediamine (GOF-2) through a solvothermal process. The structures and porosity of these two GOFs were characterized and they exhibited different adsorption behaviours. GOFs both showed enhanced porosity and surface area than the parent graphene oxide, which was ascribed to the tunable interlayer spacing. The GOFs possess good H2 storage capacity (0.46 wt% for GOF-1 and 0.57 wt% for GOF-2 at 77 K and 1 bar) though with rather small surface area (86.4 m2/g for GOF-1 and 102.7 m2/g for GOF-2). The CO2 adsorption capacity and selectivity over N2 of GOFs has also been investigated by ideal adsorbed solution theory (IAST) method, and GOF-2 exhibited CO2/N2 selectivity of 40.7 which was higher than that of GOF-1. It emphasized a tunable synthesis of multifunctional materials for H2 storage and CO2 separation from flue gases by decorating 2-dimensional GO nanosheets.