2D CoGeSe₃ monolayer as a visible-light photocatalyst with high carrier mobility: Theoretical prediction

The production of hydrogen fuel by photocatalytic water splitting is a hot issue in solar-energy harvesting technologies. An ideal photocatalyst should display suitable band gap, adequate band-edge position, and high carrier mobility. In this paper, first-principles calculations were used to reveal the potential of 2D CoGeSe₃ monolayer as a promising photocatalyst in water splitting. Indeed, this monolayer demonstrates good dynamic and thermal stability, is insoluble in water, and can easily be synthesized. Its band gap anticipates visible- and ultraviolet-light absorption (at ~10⁵ cm⁻¹). The electron and hole mobility is 601 and 509 cm²V⁻¹s⁻¹, respectively. Good matching to the water redox potential in the neutral pH of water is also manifested.