Oxygen and nitrogen enriched pectin-derived micro-meso porous carbon for CO₂ uptake

Oxygen and nitrogen enriched micro-meso porous carbon powders have been prepared from pectin and melamine as oxygen and nitrogen containing organic precursors, respectively. The synthesis process has been performed following a solvothermal approach in an alkaline solution during which Pluronic F127 was added to the solution as the soft template. Following the solvothermal treatment, the carbonization process has been performed at 700, 850 and 950 °C. The synthesized porous carbons have been characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), nitrogen adsorption-desorption isotherms and Fourier transform infrared spectroscopy (FTIR). The surface area of 499.5 m² g^-1, total pore volume of 0.35 cm³ g^-1, and a high nitrogen and oxygen content of 9.3 and 29.1 wt% are displayed for the fine sample. The optimal porous carbon had CO₂ adsorption of up to 3.1 mmol g^-1 at 273 K at 1 bar owing to abundant basic nitrogen-containing functionalities and the valuable micro-meso porous structure. Despite the absence of any reagent and also having a relatively moderate specific surface area, compared to similar materials, a very high ratio of adsorption capacity to specific surface area (6.2 μmol m^-2) was observed. The Elovich kinetic model was found to be the best and the physisorption process was reported.