MoSi2N4/CrS2 van der Waals heterostructure with high solar-to-hydrogen efficiency

Based on first-principle calculations, electronic properties and photocatalytic performance of MoSi2N4/CrS2 heterostructure are studied systematically. Our results show that MoSi2N4/CrS2 van der Waals heterostructure possesses an indirect band gap of 1.52 eV. The layer-projected band structures combined with PDOS have confirmed a type-II band alignment, which can effectively reduce the photogenerated carrier recombination. The heterostructure's band edges can cross the redox potential of water decomposition at pH = 0. Compared with two individual monolayers, the optical absorption in visible light region is improved. Moreover, the heterostructure possesses a high solar-to-hydrogen efficiency up to 39.81%. Hence, our results provide useful guidance for MoSi2N4-based heterostructure design and applications.