Gas separation process is an effective method for capturing and removing CO2 from post‐combustion flue gases. Due to their various essential properties such as ability to improve process efficiency, polymeric membranes are known to dominate the market. Trade‐off between gas permeability and selectivity through membranes limits their separation performance. In this study, solution casting cum phase separation method was utilized to create polyethersulfone‐based composite membranes doped with carbon nanotubes (CNTs) and silico aluminophosphate (SAPO‐34) as nanofiller materials. Membrane properties were then examined by performing gas permeation test, chemical structural analysis and optical microscopy. While enhancing membranes CO2 permeance, SAPO‐34 and CNTs mixture improved their CO2/N2 selectivity. By carefully adjusting membrane casting factors such as filler loadings. Using Taguchi statistical analysis, their carbon capture efficiency was improved. The improved mixed‐matrix membrane with loading of 5 wt% CNTs and 10 wt% SAPO‐34 in PES showed highly promising separation performance with a CO2 permeability of 319 Barrer and an ideal CO2/N2 selectivity of 12, both of which are within the 2008 Robeson upper bound. A better mixed‐matrix membrane with outstanding CO2/N2 selectivity and CO2 permeability was produced as a result of the synergistic effect of adding two types of fillers in optimized loading. Synthesis and characterization of carbon‐capturing hybrid membranes doped with SAPO‐34 CNTs.