Computational discovery of three two-dimensional arsenides with high stability and exceptional solar-to-hydrogen...

Photocatalytic water splitting (PWS) for hydrogen production is a crucial strategy to address the energy crisis and environmental pollution. In this study, we investigated the stability, electronic structure, and PWS performance of three 2D materials, SiAs, GeAs, and SnAs, using first-principles calculations. Our results reveal that all three monolayers exhibit high stability, with heat resistance up to 1000 K. They are indirect bandgap semiconductors, with band gaps ranging from 1.64 eV to 2.59 eV, and electron mobilities between 142.18 and 366.18 cm²/Vs. Besides, these monolayers also possess suitable band edges, with valence band maximum below -5.67 eV and conduction band minimum above -4.44 eV, making them as candidates for PWS applications. Furthermore, they release strong light absorption, reaching ∼10⁵ cm^-1, with GeAs and SnAs covering the range from visible to ultraviolet regions. Additionally, they have low exciton binding energies (210-410 meV) and high solar-to‑hydrogen efficiencies (6-17 %). In conclusion, the three monolayers demonstrate significant potential for applications in nanoelectronics and PWS technologies.