Thermal decomposition of sugars as an eco-friendly and inherent safe process for carbon nanoparticles production

A synthesis of carbon nanoparticles from hydrothermal dissociation of sugars of different composition is proposed in the present experimental study. The process has been carried out in a stirred batch reactor at a fixed temperature, using precursors dissolved in aqueous solvent in the presence of NaOH. The use of surface passivation agents has been avoided in order to test how the competing kinetics of chemical reaction and of particle agglomeration may condition the properties of the final product. The carbon nanoparticles have been characterized in diameter by dynamic light scattering. It has been shown that the molecular structure of the precursor and the selected residence time have a basic role in determining the probability distribution function of the as-made nanoparticles diameters. When fructose and lactose are adopted as precursors, the process of sugar decomposition is active even at room temperature owing to the action of NaOH. The present method, thanks to its easy reproducibility and to the absence of noxious releases as a by product, may represent a first step towards a cost-effective and environmentally sound technique for the synthesis of carbon nanoparticles at a larger scale. Finally, such aspects are discussed and some applications of practical relevance are proposed.