Graphyne, which unlike graphene contains double and triple bonds, has highly compelling electronic, mechanical and optical properties

https://phys.org/news/2025-02-graphyne-carbon-potential-electronics.html

"predicted to be semiconductor with band gap, ultra-high charge carrier mobility far surpassing that of silicon, ultimate strength comparable to graphene... completely eliminates all 2-coordinate acetylenic carbons from graphyne, yet preserves layered structure... modified band gap... enables future techniques for fabricating all-carbon electronic chips with performance unattainable by the current silicon technology... carbon electronics, energy harvesting/ storage, gas separations, catalysis"