High-Quality Graphene Nanoplatelets Production with 100% Yield Based on Popular Fertilizer Industry Feedstock

Abstract

High-quality and high-yield production of graphene nanoplatelets (GNPs) is the ultimate challenge in today’s graphene technology that would allow mature commercialization. Recently demonstrated new methods still suffer from low quantities of exfoliated graphene and a lack of controllable qualities, processability, and costs. Here, we developed a simple yet compelling chemical route for industry-scale production of turbostratic-like GNPs (∼10 layers) that relies on simultaneous, nonoxidative intercalation and exfoliation of raw graphite with 100% weight efficiency. High yield is enabled because unbounded SO3 molecules dissolved in heated, fuming sulfuric acid can effectively intercalate into the graphite, boosting spontaneous exfoliation during ultrasound treatment. The density functional theory calculation indicates a two-step subsequent intercalation mechanism with SO3 and H2SO4 molecules before final exfoliation. X-ray diffraction, vibrational spectroscopy, and elemental analysis confirm very low concentration of defects and lack of strong oxidization effects in the graphene layers, whereas electron microscopy and diffraction show a fine structure.