Ultrafast Molecular-Sieving Graphene Oxide Membranes for Selective Separation of Volatile Aromatic Compounds

Ultrafast molecular-sieving graphene-based membranes with selective separation of volatile aromatic compounds (VACs) have great potential in environmental protection, reutilization of expensive materials, and industrial separation processes. However, current graphene-based absorbents suffer from slow removal speed and limited adsorption capacity for VACs. Herein, pristine and Ni 2+ -controlled graphene oxide membranes (GOMs) with a permeance up to ∼8.0 × 10 –6 mol m –2 s –1 Pa –1, being 1–2 orders of magnitude higher than those of previously reported membranes. The GOMs selectively separate VACs from N 2 is achieved on ceramic substrates via the size-exclusion effect for the first time. At a high VACs feed concentration, such GOMs show high rejection rates of 99.8, 99.4, 95.9, and 97.3% for phenol, benzaldehyde, benzoic acid, and benzylamine, respectively. X-ray diffraction (XRD) results show the two-dimensional (2D) channel size for gas transportation within the GOMs is 0.44 nm, which can reject the transportation of VACs but have no effect on N 2 . Interestingly, using improved Ni 2+ -controlled GOMs, the rejection rates of benzoic acid and benzylamine rejection rates increased from 95.9 to 98.6% and from 97.3 to 99.4%, respectively. Our finding provides a fast and efficient way to filter VACs in air and has potential applications in air purification and industrial processes.