Preferred orientation control represents an effective method for grain boundary defect elimination at the mesoscopic scale and therefore, performance enhancement of MOF membrane. In contrast, tailoring the separation performance of MOF membrane via structural defect engineering at the microscopic scale remains elusive. In this work, we pioneered the fabrication of (111)-oriented UiO-66 membrane via oriented tertiary growth. The use of ZrS₂ as metal source during solvothermal synthesis led to higher number of missing linkers within the framework and therefore, preferential adsorption of CO₂ over N₂. In comparison with secondary growth, both CO₂/N₂ selectivity and CO₂ permeability of obtained UiO-66 membrane after tertiary growth were concurrently increased, thereby transcending both the 2008 Robeson upper bound and the separation performance limits of state-of-the-art polycrystalline MOF membranes for CO₂/N₂ gas pair.

优先取向控制代表了一种有效的方法，可以在细观尺度上消除晶界缺陷，从而提高 MOF 膜的性能。相比之下，通过微观尺度的结构缺陷工程来定制 MOF 膜的分离性能仍然难以捉摸。在这项工作中，我们率先通过定向三次生长制造了（111）定向的 UiO-66 膜。在溶剂热合成过程中使用 ZrS ₂作为金属源导致骨架内缺失的接头数量增多，因此，CO _{2 的}吸附优先于 N ₂。与二次生长相比，CO ₂ /N ₂选择性和 CO ₂三次生长后获得的 UiO-66 膜的渗透性同时增加，从而超越了 2008 年 Robeson 上限和最先进的多晶 MOF 膜对 CO ₂ /N ₂气体对的分离性能限制。