Regulation of interlayer channels of graphene oxide nanosheets in ultra-thin Pebax mixed-matrix membranes for CO₂ capture

For the application of carbon capture by membrane process, it is crucial to develop a highly permeable CO₂-selective membrane. In this work, we reported an ultra-thin polyether-block-amide (Pebax) mixed-matrix membranes (MMMs) incorporated by graphene oxide (GO), in which the interlayer channels were regulated to optimize the CO₂/N₂ separation performance. Various membrane preparation conditions were systematically investigated on the influence of the membrane structure and separation performance, including the lateral size of GO nanosheets, GO loading, thermal reduction temperature, and time. The results demonstrated that the precisely regulated interlayer channel of GO nanosheets can rapidly provide CO₂-selective transport channels due to the synergetic effects of size sieving and preferential adsorption. The GO/Pebax ultra-thin MMMs exhibited CO₂/N₂ selectivity of 72 and CO₂ permeance of 400 GPU (1 GPU = 10⁻⁶ cm³(STP)·cm⁻²·s⁻¹·cmHg⁻¹), providing a promising candidate for CO₂ capture.