Scalable Mass Production of Additive‐Free Few‐Layer Enriched Graphene Oxide Ink for Industrially Sustainable Printing

The industrial application of graphene ink is often constrained by challenges in achieving high‐throughput mass production while maintaining quality and processability. Innovative strategies are explored for scalable, additive‐free graphene oxide ink production, emphasizing precise control of the oxidation degree in selectively edge‐oxidized graphene oxide (GO). By precisely tailoring the degree of oxidation, GO flakes that maintain their intrinsic properties and exhibit additive‐free dispersibility are produced. This method achieves a high GO production yield of ≈94%, dispersing ≈376 g of predominantly few‐layer GO flakes in 8 L of an aqueous solvent. Density functional theory (DFT) calculation offer thermodynamic insights into the selective edge oxidation and high exfoliation efficiency. The resulting GO flakes enable the development of additive‐free aqueous inks for ecofriendly inkjet printing and pasty inks for dispenser printing, achieving high electrical conductivity and pattern precision without post‐treatment. Furthermore, integrating GO flakes into PEDOT:PSS produces nanocomposite inks, resulting in transparent conductive films with superior electrical properties and transmittance, all without additional processing. This study is crucial for advancing GO production techniques that meet industry demands for high yield, excellent processability, ecofriendliness, and cost‐effectiveness, thereby paving the way for broader industrial applications of GO.