▎ 摘　　要

The pressure-swing adsorption (PSA) technology is the promising approach for O-2/N-2 separation because of its low cost and facile manipulation, in which adsorbents dominate the separation performance. In recent years, metal-organic frameworks (MOFs) have been recognized as the most potential adsorbents in gas adsorption and separation due to their ultrahigh surface area. In this work, MIL-101(Cr) with different weight percentages of graphene oxide (5%, 15% and 35%) was prepared by growing MIL-101(Cr) on pre-synthesized GO materials. The fmal product was activated under vacuum at 180 C for 12 h. Structure characterization of different MIL-101(Cr)/GO composites revealed that MIL-101(Cr)/GO-15 with 15% GO additive exhibited the highest specific surface area (3486 m (2).g(-1)) and pore volume (2.39 cm(3).g(-1)) compared with pristine MIL-101(Cr) and the composites with 5% and 35% GO additives. The high surface area and pore volume are beneficial for the O-2 uptake of MIL-101(CrYGO-15. Compared with the O-2 uptake of MIL-101(Cr)/GO-5 (0.35 mmol.g(-1)) and MIL-101(Cr)/GO-35 (0.31 mmol.g(-1)), MIL-101(Cr)/GO-15 exhibited the highest uptake of 0.54 mmol.g(-1). Further pore size distribution analysis demonstrated that the enhanced O-2 uptake of MIL-101(Cr)/GO-15 can be ascribed to its increased fraction of mesopores. On the other hand, O-2/N-2 selectivity of different MIL-101(Cr)/GO composites was also calculated according to ideal adsorbed solution theory (LAST), from which it was found that MIL-101(Cr)/GO-15 displayed the highest O-2/N-2 selectivity (1.2) in a binary gas mixture with the volume fraction of O-2/N-2 =1/4. Compared with pristine MIL-101, O-2/N-2 selectivity of MIL-101(Cr)/GO-15 was increased by 17.65%. Recyclability is one of the most important criteria to evaluate the gas adsorption performance of adsorbents. Therefore, the recyclability of MIL-101(Cr)/GO-15 was tested by measuring the O-2 adsorption and desorption isotherms for three cycles. It was revealed that 80% of O-2 uptake of MIL-101(Cr)/GO-15 was remained after three adsorption/desorption cycles, implicating the outstanding recyclability of MIL-101(Cr)/GO-15.