Transformation of lignosulfonate into graphene-like 2D nanosheets: Self-assembly mechanism and their potential in biomedical and electrical applications.

Facile and controllable synthesis of graphene or graphene-like 2D nanosheets from plentiful and biocompatible materials still remains a great challenge. Herein, a bottom-up and controllable approach was firstly reported to transform earth-abundant lignosulfonate into graphene-like materials, in which lignosulfonate-based 2D nanosheets were fabricated via self-assembly in water/acetone dual solvent system, and then the nanosheets materials were transformed into graphene-like materials by carbonization. The physical properties of obtained lignosulfonate-based nanosheets were characterized, and the formation mechanism of these nanosheets was also elucidated. The thickness of the nanosheets was in the range of 5-20 nm depending on the concentration of lignosulfonate in water. Directed by π - π interactions and hydrogen bonds, the evolution of layered nanosheets seemed to experience from nano-sized rodlikes, a flake with defect holes, and smooth lignosulfonate-based nanosheets. Because of the relatively lower resistance, nano-sized structures and good cytocompatibility, the lignosulfonate-based graphene-like materials exhibited great potential in biomedical energy-related applications.