Conversion of nanomaterial waste soot to recycled Sc2O3 feedstock for the synthesis of metallic nitride fullerenes
Herein, we address a need in the industrial and academic communities to reduce costs and environmental impact associated with the synthesis of select carbonaceous nanomaterials. In this effort, we have developed a method to recover Sc2O3 from carbonaceous "waste soot", thereby alleviating the problem of waste disposal of fullerene depleted soot and tremendously reducing the costs and environmental impact of our synthetic process. The recovery process is based on the thermal oxidation and removal of carbon from waste soot as gaseous byproducts (e.g., CO2) to yield a recycled, reusable feedstock. The economic impact is measured in the cost savings of solid waste disposal fees and expensive reagents, such as scandium and some rare-earth metal oxides. Our recovery method is scalable and simple in design. Waste soot at different stages of thermal oxidation is characterized by thermogravimetric analysis (TGA) to determine optimal temperature and soak parameters. Corresponding X-ray photoelectron spectroscopy (XPS) analysis of these samples indicates a comparable chemical composition Of SC2O3 for recycled samples to virgin Sc2O3 controls. Recovered SC2O3 material was used in our electric-arc reactor and resulted in statistically comparable fullerene product distributions.