Preparation of carbon nanoparticles from activated carbon by aqueous counter collision

In the present study, crystalline cellulose biomass material was converted into carbon nanoparticles via carbonization to activated carbon with micropores of various sizes. This was subsequently subjected to aqueous counter collision (ACC) to produce hydrophobic porous functional particles. Initially, raw crystalline cellulose material was carbonized into activated carbon materials with various pore distributions prior to ACC. Pore distribution depended on the activation time, and was confirmed by nitrogen (N₂) adsorption isotherms. The surface areas and pore volumes of carbon activated for 8 h were larger than those of carbon activated for 2 h. When they were subjected to ACC, the width and length of the carbon particles decreased as the number of pulverizing cycles during the ACC treatment increased. Eventually, carbon nanoparticles of 70 nm width that had improved dispersibility and stability were produced. The diameters of the carbon nanoparticles and their dispersibility were dependent on the pore distribution and surface areas of the activated carbon subjected to the ACC treatment. The ACC process facilitated the preparation of carbon nanoparticles from activated carbon derived from biomass, and is, therefore, an important strategy for the sustainable production of a sought-after and valuable resource.