Irida-graphene: A new 2D carbon allotrope

•A new 2D all-sp2 carbon allotrope, named Irida-Graphene (IG), using a bottom-up approach.•Density functional theory (DFT) calculations and reactive (ReaxFF) molecular dynamics simulations to examine its mechanical, structural, electronic, and optical properties.•IG exhibits good dynamical and thermal stabilities, with estimated elastic modulus varies between 80 and 113 GPa.•IG is a metallic material and presents a Dirac cone above the Fermi level in the center of the band.