Abstract Gas separation is crucial in industries such as natural gas sweetening, CO 2 removal, and oxygen/nitrogen enrichment. Mixed matrix membranes (MMMs) have emerged as a promising solution, and zeolite-templated carbon (ZTC), with high surface area and uniform pore structure, serves as an effective filler to enhance performance. In this study, polysulfone (PSF)/ZTC MMMs with 0.25–0.5 wt% ZTC were fabricated using the dry-jet wet spinning technique. However, avoiding interfacial voids in MMM