Graphene oxide gas separation membranes intercalated by UiO-66-NH2 with enhanced hydrogen separation performance

Abstract

UiO-66-NH2 were either intercalated into graphene oxide (GO) layers (GOU@S) or covered by GO layers (GO/U@S) to form UiO-66-NH2/GO composite membrane. Results show that different synthesis methods would lead to different membrane morphology, thickness and gas separation performance. For GOU@S membrane, UiO-66-NH2 was well-dispersed and intercalated into GO layer, whereas two continuous layers (GO and UiO-66 layer) with an obvious boundary were observed for GO/U@S. Due to the morphology and structure difference, better hydrogen separation performance was achieved for GOU@S membrane compared to GO/U@S membrane and pristine membrane due to the close interfacial contact between UiO-66-NH2 and GO, which arises from the hydrogen bonding formed between -NH2 group in UiO-66-NH2 and -OH group in GO and the electrostatic force between UiO-66-NH2 and GO layers. The ideal selectivities of H2/N2 and H2/CO2 were increased to 9.75 and 6.35, respectively, for the GOU@S membrane with a H2 permeance of 3.9 × 10−8molm−2s−1Pa−1.