The highly efficient CO2 adsorbents were synthesized from banana peel as precursor. As-prepared graphene was then modified through n-doped approach for comparison purposes. For this purpose, graphene was synthesized by the chemical activation with KOH and then by using urea, nitrogen-doped graphene as an adsorbent was produced. The final adsorbent properties were also characterized by numerous characterization tests such as scanning electron microscopy (SEM) analysis, infrared spectroscopy (FTIR), nitrogen adsorption and desorption analysis (BET), Raman spectroscopy analysis, X-ray diffraction. (XRD) and elemental analysis (CHNS) were evaluated. Then, the effect of various parameters such as temperature and pressures on the CO2 adsorption capacity by graphene and n-doped graphene were investigated. The results illustrated that the maximum CO2 adsorption capacity for the graphene and the n-doped graphene was 5.36 and 4.80 mmol/g, respectively. However, the adsorbents maintained their efficiency for the CO2 adsorption up to 5 adsorption/desorption cycles. The obtained results presented the high capability of CO2 capture by the synthesized adsorbents and their potential to scale-up applications.