High‐Yield Hydrothermal Exfoliation of Graphene Multilayers Assisted by Diamond Nanoparticles

ABSTRACT Small pieces of composite diamond nanoparticles–graphene (C‐DNPs‐Gr) and/or highly exfoliated graphene sheets with sizes less than 250 nm were quantitatively generated in high yield under a hydrothermal approach. This scalable process involves vigorous micro‐mixing of multilayer graphite flakes with DNPs dispersed in xylene, eliminating the need for catalysts, hazardous surfactants, or auxiliary materials. The carbon nanohybrid material was prepared via hydrothermal treatment at 200°C for 20 h. The morphology and structure of the fabricated composite were first examined by scanning electron microscopy (SEM), followed by transmission electron microscopy (TEM), and high‐resolution transmission electron microscopy (HRTEM). Further structural and compositional analyses were carried out using Raman spectroscopy, x‐ray diffraction (XRD), and x‐ray photoelectron spectroscopy (XPS), confirming successful exfoliation and composite formation. Importantly, this simple method achieves a high yield of approximately 91%. This novel carbon nanocomposite structure may be advantageous for various applications, including polymer reinforcements, batteries, supercapacitors, and catalytic supports.