Keeping the global warming and climate change issues in mind, various efforts are being taking place worldwide to separate/capture CO₂ from flue gas mixture in order to reduce its emission in the atmosphere. Therefore, in this work, we improve the gas transport properties of polyetherimide (PEI) membrane for CO₂/N₂ separation by embedding three different fillers of two-dimensional materials such as graphene oxide (GO), molybdenum disulfide (MoS₂), and hexagonal boron nitride (h-BN) in its matrix. Additionally, the effect of different weight fraction (0.5, 1.5, and 2.5 wt.%) of these fillers on the CO₂/N₂ gas separation performance have been investigated. Membrane morphology, variation in the chemical bonds and membrane surface roughness were observed by employing Field Emission Gun Scanning Electron Microscopy (FEG-SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Atomic Force Microscopy (AFM) analysis. Results obtained from the gas permeation showed that PEI embodied with GO exhibited higher gas permeation compared to when embodied with h-BN and MoS₂. However, the maximum separation was achieved with MoS₂ particles.