Scalable Synthesis and Characterization of Multilayer γ-Graphyne, New Carbon Crystals with a Small Direct Band Gap

• DOI: 10.1021/jacs.2c06583
• Publication Date: 2022-09-21T18:46:31Z
• Authors: Victor G. Desyatkin; William B. Martin; Ali E. Aliev; Nathaniel E. Chapman; Alexandre F. Fonseca; Douglas S. Galvão; Ericka Roy Miller; Kevin H. Stone; Zhong Wang; Dante Zakhidov; F. Ted Limpoco; Sarah R. Almahdali; Shane M. Parker; Ray H. Baughman; Valentin O. Rodionov
• Keywords: Graphyne

γ-Graphyne is the most symmetric sp2/sp1 allotrope of carbon, which can be viewed as graphene uniformly expanded through insertion two-carbon acetylenic units between all aromatic rings. To date, synthesis bulk γ-graphyne has remained a challenge. We here report multilayer crystallization-assisted irreversible cross-coupling polymerization. A comprehensive characterization this new carbon phase described, including synchrotron powder X-ray diffraction, electron lateral force microscopy, Raman spectroscopy, infrared and cyclic voltammetry. Experiments indicate that 0.48 eV band gap semiconductor, with hexagonal a-axis spacing 6.88 Å an interlayer 3.48 Å, consistent theoretical predictions. The observed crystal structure aperiodic sheet stacking. material thermally stable up to 240 °C but undergoes transformation at higher temperatures. While conventional 2D polymerization reticular chemistry rely on error correction reversibility, we demonstrate periodic covalent lattice synthesized under purely kinetic control. reported methodology scalable inspires extension other allotropes graphyne family.