Thermal and Dimensional Stability of Photocatalytic Material ZnPS₃ Under Extreme Environmental Conditions

Abstract Zinc phosphorus trisulfide (ZnPS₃), a promising material for photocatalysis and energy storage, is shown in this study to exhibit remarkable stability under extreme conditions. Its optical and structural properties are explored under high pressure and cryogenic temperatures using photoluminescence (PL) spectroscopy, Raman scattering, and density functional theory (DFT). The experimental results identify a pressure‐induced phase transition starting at 6.75 GPa and stabilizing by 12.5 GPa, after which ZnPS₃ demonstrates robust stability across a broad pressure range up to 24.5 GPa. DFT calculations support these observations and further predict a semiconductor‐to‐semimetal transition at 100 GPa, while PL measurements reveal defect‐assisted emission that quench under pressure due to enhanced non‐radiative recombination. At cryogenic temperatures, PL quenching intensifies as non‐radiative processes dominate, driven by a rising Grüneisen parameter and reduced phonon population. Cryogenic X‐ray diffraction (XRD) also reveals a high mean thermal expansion coefficient (TEC) of (4.369 ± 0.393) × 10⁻⁵ K⁻¹, among the highest reported for 2D materials. This unique combination of tunable electronic properties under low pressure and high thermal sensitivity makes ZnPS₃ a strong candidate for sensing applications in extreme environments.