Membrane-based technologies are not widely used due to the challenges in manufacturing. The current fabrication methods produce small and medium-scale membrane units. There is a high need for throughput methods for large-scale production. The membrane fabrication requires dense polymeric materials that usually exhibit high selectivity but with low permeability. Several materials were reported to improve the gas adsorption using membrane technologies, including MOF such as MOF-5 and ZIF (Table ). There are several fabrication methods for synthesizing ZIFs-based membranes (Figure ). There is no general fabrication method that can be suitable for all membranes. In-situ and ex-situ growth of ZIFs materials on a substrate was reported. Modern or innovative technologies such as electrospray and three-dimensional (3D) printing were investigated (Figure ). The general fabrication method facilitates the scaled-up processes. The in-situ growth c-oriented ZIF-69 membranes use α-alumina substrates for CO2/CO separation .