Direct conversion of lignin to high-quality graphene-based materials via catalytic carbonization

Methods for effectively utilizing lignin are necessary for the realization of a sustainable society. Herein, we report a method for directly converting lignin to graphene-based materials. Fe-supported lignin is prepared by dissolving lignin in an aqueous FeCl₂ solution, followed by freeze drying. Graphene is then produced by catalytically carbonizing this Fe-supported lignin at 1200 °C. The characteristics of both the Fe catalyst and lignin are crucial for the production of high-quality graphene. Specifically, the lignin should disperse well in water, freeze dry, and carbonize via solid-state carbonization. The obtained graphene-based material is highly resistant to electrochemical oxidation, as observed in other graphene-based materials. The direct conversion of lignin to graphene described herein is an unprecedented method for synthesizing large amounts of graphene-based material at low cost, as well as being an excellent use for lignin.