Polyynes and flexible Si-H doped carbon nanoribbons by pulsed laser ablation of graphite in tetraethyl orthosilicate

Polyynes and graphene-based lamellae doped with both Si and H were synthesized simultaneously by pulsed laser ablation of bulk graphite in tetraethyl orthosilicate and characterized using optical spectroscopy and X-ray/electron diffraction. The polyyne molecules have long carbon chains (up to C16H2) to give multiple ultraviolet absorptions. The graphene-based lamellae were assembled as nanoribbons having hierarchical folds and dislocations due to wrinkle-to-fold transitions and imperfect attachment growth of the lamellae. A rather high fraction of sp3 bonds in the nanoribbons, as manifested by Raman shift, can be ascribed to capillarity force and Si-H solute trapping under the influence of particle size and lattice imperfections. The implications of the present composite phases on the natural dynamic occurrence and potential engineering applications are discussed.