Dispersibility study of GO-like biocarbons obtained from the thermal decomposition of biomass: Phragmites australis and Carya illinoinensis

In this work, we develop a cost-effective and straightforward methodology to upgrade earth-abundant biomass into high-value-added graphene oxide-like dispersions. The main idea is based on a controlled thermal treatment allowing the conversion of the two different biomass sources with different lignin content (Phragmites australis and Carya illinoinensis), in an air atmosphere and in a short time (15 min); no additional functionalization, catalysts, or high temperatures are necessary. The interface of both biocarbons is distinguished by different proportions of hybridized carbons (C[dbnd]C and C–C) and functional oxygenated groups (OH, C–O, C[dbnd]O, C–OH), characteristic of amphiphilic graphene oxide and responsible of the interactions with solvents. The results show that the most stable dispersions were achieved using polar solvents (Z_ave < 300 nm, ζ ±15 mV) with no surfactants. Also, we determined the dispersion states (qualitatively and quantitatively) and their zeta potential for all dispersions as well as a graphical map of their behavior, indicating that polar solvents promote the formation of stable dispersions, whereas non-polar solvents sediment instantly. The strategy reported here may be a feasible and unique approach to formulate stables dispersions using graphene based-materials obtained in a sustainable way, which have the potential for future applications in ink formulation for inkjet printing and electrochemical applications.