Improvement of carbon dioxide capture using graphite waste/ Fe₃O₄ composites

The abundance of graphite waste can be processed into valuable materials; one alternative is by making it into an adsorbent. Graphite-based adsorbent modification can be accomplished by adding magnetite nanoparticles Fe₃O₄. The addition of magnetite nanoparticles has been reported to improve the adsorption ability of the graphite waste. In this study, we have developed a new carbon dioxide (CO₂) adsorbent based on graphite waste modified with magnetite nanoparticle Fe₃O₄. The Fe₃O₄ were prepared using an impregnation technique. The graphite/Fe₃O₄ composites were characterized by scanning electron microscopy with an energy-dispersive X-ray system (SEM-EDX) and Brunauer, Emmett, and Teller (BET). The CO₂ adsorption performance was evaluated using an isothermal adsorption method at various temperatures (30, 35, and 45°C) and pressures (3, 5, 8, 15, and 20 bar). This resulted in graphite with different magnetite modification levels, namely non-modified graphite (GNM), a graphite/Fe₃O₄ 20% (w/w) composite (G/Fe₃O₄ 20%), and a graphite/Fe₃O₄ 35% (w/w) (G/Fe₃O₄ 35%), which indicated that the largest adsorption capacity is 10.305 mmol.g^-1 at 30°C and 20 bar pressure for the G/Fe₃O₄ 20% composite. This finding further revealed that modifying graphite waste with magnetite nanoparticles Fe₃O₄ has been proved to increase the capacity for adsorbing CO₂ gas.