A computational study of phosphorus-doped graphdiynes and several corresponding oxides by simulated X-ray spectroscopy

Abstract

Doping with phosphorus atoms can significantly improve the electronic structure of graphdiyne (GDY), resulting in outstanding performance in electrocatalysis, energy storage, and ion transport. The identification of phosphorus-doped graphdiyne (P-GDY) has not been thoroughly investigated experimentally or theoretically because of the variety of doping sites. The C1s X-ray photoelectron spectroscopy (XPS) and C1s near-edge X-ray absorption fine structure (NEXAFS) spectra as well as the geometries of seven typical P-GDY and phosphorus-doped graphdiyne oxides [P(O)-GDY] were simulated using density functional theory (DFT). Additionally, the O1s XPS and NEXAFS spectra of five molecules containing oxygen atoms were also simulated to provide a thorough analysis of the structure–spectrum relationships. The calculated results demonstrated that the NEXAFS spectra significantly depended on the local structure. Theoretical simulations of XPS spectra were in excellent agreement with the experimental results in terms of peak positions and shapes. Stated differently, the combination of XPS and NEXAFS spectra can be effective in identifying seven P-GDY and P(O)-GDY molecules. Not only do our research findings offer a trustworthy theoretical reference for differentiating P-doped graphdiynes, but they also provide further theoretical forecasts and directions for experimental synthesis, facilitating the resolution of the challenging issue of P-doped carbon-based material identification.