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

Abstract

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 (CC and C–C) and functional oxygenated groups (OH, C–O, CO, 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 (Zave < 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.