This study utilizes the impregnation method to produce reduced graphene oxide (rGO) nanosheets by a 15-weight percent loading of copper and nickel. The prepared samples were used as denitrogenation adsorbents for model fuels. Different instrumental techniques, including X-ray diffraction (XRD), Fourier- transform infrared (FT-IR) spectroscopy, N2 adsorption–desorption analysis, and field emission scanning electron microscopy (SEM), were used to characterize the synthesized samples. When copper and nickel oxides are impregnated, GO is partially reduced, according to the X-ray diffraction (XRD) patterns of the NiO/rGO and CuO/rGO adsorbents. The results show that the surface area and mean pore diameter of the CuO/rGO adsorbent are higher than those of the NiO/rGO adsorbent. The findings of the adsorption study indicate that the adsorption capacity of the CuO/rGO adsorbent (0.335 mmol g1 ) for the carbazole (CBZ) is higher than that of the NiO/rGO adsorbent (0.315 mmol g1 ) at 278 K. Still, the heat of adsorption on the NiO/rGO adsorbent (18.60 kJ mol1 ) is higher than that on CuO/rGO (13.73 kJ mol1 ). The activation energy of the intraparticle diffusion of the NiO/rGO adsorbent is higher than that of the CuO/ rGO adsorbent due to the lower mean pore diameter of the NiO/rGO adsorbent. The activation energies of the pseudo-first-order kinetics of NiO/rGO and CuO/rGO adsorbents are 11.13 and 4.89 kJ mol1 , respectively, which show the higher performance of the CuO/rGO adsorbent in the primary stages of CBZ adsorption.

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