XANES absorption spectra of penta-graphene and penta-SiC2 with different terminations: a computational study

Abstract: In recent research, penta-graphene and penta-SiC2 have emerged as innovative 2D materials consisting exclusively of pentagons. However, there is still a significant gap in the theoretical characterization of these materials, which hinders progress in their synthesis and potential technological applications. This study aims to close this gap by investigating the X-ray absorption near-edge spectroscopy (XANES) of these materials through ab initio calculations. In particular, we analyze the XANES spectra of penta-graphene in its pristine, hydrogenated, and hydroxylated states, and we investigate the effects of substitution by a single silicon in both penta-graphene and pentagraphane. In addition, we calculate the XANES spectra for pristine and hydrogenated penta-SiC2. This work sets the stage for the possible identification of penta-graphene and penta-SiC2 phases by X-ray spectroscopy at the experimental level and lays the foundation for the future engineering of the absorption properties of these materials in optical devices.