Electronic structure, elastic anisotropy and optical properties of PtO2 by first-principles calculations

Abstract

Platinum dioxide (PtO₂) has important applications in catalysis and photovoltaics, however, the understanding of its fundamental properties at the atomic level remains incomplete. In this study, the electronic structure, elastic and optical properties of the cubic and tetragonal phases of PtO₂ are systematically investigated by using first-principles calculations based on density-functional theory. The results indicate that both PtO₂ exhibit metallic properties, their electronic density of states is primarily contributed by the O-2p and Pt-5d orbitals, and the Pt–O bonds are formed by orbital hybridization. The Pt–O bond of tetragonal PtO₂ has stronger covalency and bond strengths. Both structures demonstrate mechanical stability and ductility, with the tetragonal PtO₂ having a more pronounced elastic anisotropy. Optical property analyses show that the tetragonal PtO₂ exhibits significant optical anisotropy in the [001] direction. This study provides an important theoretical basis for the application of PtO₂ in catalysis and optoelectronic devices.