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Updated: Jul 5, 2026

Exfoliation and Analysis of Large-area, Air-Sensitive Two-Dimensional Materials
Published on: January 5, 2019
Seconds-scale exfoliation of high-quality 2D crystals enabled by polycyclic aromatic hydrocarbon radical
Tong Li1,2,3,4, Linkai Peng1,2,3,4, Xianying Qin5
1Shenzhen Geim Graphene Center, Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Shenzhen, China.
Abstract:
Scalable production of high-quality 2D nanosheets remains challenging because existing top-down and bottom-up methods typically face a trade-off between material quality, yield, and cost. Here, we report the seconds-scale (~12 s) production of high-quality 2D crystals via polycyclic aromatic hydrocarbon radical anion (PAH•-)-mediated organoalkali intercalation. The tunable reduction potential and electron-transfer capability of PAH•- enable ultrafast alkali-ion intercalation within seconds in the stable potential of layered hosts. For graphite, sodium naphthalenide (Na-Naph) forms a stage-1 graphite intercalation compound in only 1 s, and subsequent hydrolysis-driven exfoliation in 11 s yields graphene with >88% yield and >50% single-layer ratio, with a negligible increase in defect density (ID/IG ratio from ~0.10 to ~0.11). This strategy is further extended to the exfoliation of few-layer (3-5 layers) transition-metal sulfides, selenides, and tellurides while preserving their intrinsic crystal phases. This work establishes a practical, high-yield route for rapid intercalation-driven exfoliation, offering a scalable platform for manufacturing high-quality 2D crystals.
