Regulating the Performance of CO<sub>2</sub> Adsorbents\nBased on the Pyrolysis Mechanism of Self-Sacrificial Templating Agents

Previous\nresearch has proven that the pore shape and nitrogen group\ncontent of adsorbents play essential roles in determining their carbon\ndioxide (CO<sub>2</sub>) adsorption performance. In this article,\na series of nitrogen-doped porous carbon materials were prepared for\nCO<sub>2</sub> adsorption by varying the proportion of carbon nitride,\nthe pyrolysis temperature, and the activation ratio of KOH, using\nchitosan as the carbon source, carbon nitride (g-C<sub>3</sub>N<sub>4</sub> and g-C<sub>3</sub>N<sub>5</sub>) as self-sacrificing templating\nagents, and KOH as the activator. Among the prepared materials, T6-850-1\nhas the highest specific surface area (<i>S</i><sub>BET</sub>) of 2336 m<sup>2</sup>/g, and T6-750-1 has the highest microporous\narea (<i>S</i><sub>micro</sub>) and CO<sub>2</sub> adsorption\ncapacity (1 bar, 298 K) of 1969 m<sup>2</sup>/g and 3.49 mmol/g, respectively.\nThe thermal decomposition temperature and products of carbon nitride\ntemplates were characterized and tested by thermogravimetric infrared\ngas chromatography-mass spectrometry (TG-IR-GC-MS), and the thermal\ndecomposition mechanisms of the two carbon nitride templates were\ninvestigated. We found that the thermal stability of the template\ndirectly affects the pore structure of the final sample as well as\nthe type and quantity of nitrogen species.