Graphene oxide constructed nano Newton's cradle for ultrafast and highly selective CO2 transport

Abstract

The emergence of Newton's cradle is promising for fast substance transport, which attracts tremendous attentions for industrial applications. Herein, an ultrafast and highly selective nano Newton's cradle for CO2 transport is constructed through the assembly of negatively charged graphene oxide (GO) nanosheets and positively charged zinc hydroxide nanostrands (ZHNs), followed with impregnation of ionic liquid (IL) within the nanochannels. The GO laminates provide robust structure for whole system. The incorporation of IL endows the membrane with sieving ability to different gases while ZHNs play a key role to accelerate selective CO2 adsorption, thus achieving exceptional CO2 separation performance. The resulted nano Newton's cradle demonstrates that a huge CO2 permeance enhancement of more than 53 times as that of the GO/IL membrane without ZHNs, superhigh CO2/light gases selectivities (35 for CO2/H2, 194 for CO2/CH4 and 331 for CO2/N2), out-stripping the Robeson upper bound of traditional polymeric membranes, as well as long-term operation stability. This innovative strategy not only provides an outstanding candidate for carbon capture, but also opens a new avenue to design separation membranes with high performance for various applications.