Formation, electronic properties, and enhanced hydrogen evolution catalytic performance of substitutional defects in...

Palladium ditelluride (PdTe₂), a prominent transition metal dichalcogenide, has emerged as a star material. While its pentagonal layered structure has recently been synthesized, a comprehensive theoretical understanding of defect types (specifically substitutional and vacancy defects), their arrangements, electronic structure, and resulting properties such as catalytic activity within the 1T phase remains lacking. Employing first-principles calculations, this study investigated substitutional and vacancy defects in PdTe₂. The mechanisms of defect formation, their thermodynamic and kinetic stability, and the corresponding electronic structures were examined. Importantly, the results indicate that defective PdTe₂ (especially the Pd_Te defect) exhibits effective hydrogen evolution reaction catalytic performance. These findings highlight the potential of defect engineering for the precise tuning of material properties.