Unveiling the structure of chlorine-doped graphdiyne <i>via</i> first-principles X-ray spectroscopy

Chlorine-doped graphdiyne (Cl-GDY) exhibits exceptional properties, demonstrating significant potential for application in energy storage, conversion and electrocatalysis. However, systematic investigations of the structural configurations of Cl-GDY remain scarce, both experimentally and theoretically. In this work, we selected five canonical Cl-GDY configurations along with pristine GDY and simulated their C 1s and Cl 2p X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectra. The calculated C 1s ionization potentials (IPs) show good agreement with the experimental XPS, hence all feature peaks in experimental XPS were assigned. Furthermore, we established robust structure-spectrum relationships in which distinct doping configurations can be identified from theoretical NEXAFS spectral profiles and peak positions. This study provides critical theoretical benchmarks for differentiating Cl-GDY configurations, bridging computational insights with experimental characterization.