A Study on Synthesis and Characterization of Biobased Carbon Nanoparticles from Lignin

Carbon nanoparticles were synthesized using lignin as a renewable feedstock by employing a freeze-drying process followed by thermal carbonization. The effect of adding various amounts of KOH to a lignin solution on the solubility of the lignin, the freeze-drying process, the thermal stabilization of the freeze-dried lignin, and carbon nanoparticle formation was investigated through FTIR, DSC, SEM, TEM and surface area analysis. SEM investigations confirmed that the freeze-drying process caused the formation of lignin with a porous microstructure. TEM analysis indicates that the thermal stabilization of freeze-dried lignin prevented the formation of agglomerated carbon nanoparticles during the carbonization process. The smallest carbon nanoparticles were found to be 25nm and were prepared from the lignin precursor with 15% KOH.