Z(S)-scheme heterostructures of two-dimensional XAu4Y (X, Y= Se, Te) for solar-driven water splitting

Two-dimensional (2D) materials have emerged as highly promising photocatalysts for solar-driven water splitting. They have garnered significant interest owing to their large specific surface areas and short carrier migration distances. Our study focused on the theoretical prediction of promising photocatalysts for solar-driven water splitting in XAu4Y (X, Y= Se, Te) monolayers and their corresponding heterostructures using firstprinciples calculations. XAu4Y are semiconductors with indirect bandgaps of 1.27-1.54 eV. Owing to their appropriate band edges, SeAu4Se and SeAu4Te were found to be suitable for solar-driven water splitting. Importantly, SeAu4Te achieved a Janus-induced internal electric field of 0.80 V/angstrom, which favored the separation of photogenerated carriers, thus improving the photocatalytic efficiency. Further, SeAu4Se/TeAu4Te and SeAu4Se/TeAu4Se heterostructures were predicted to be high-performance Z(S)-scheme photocatalysts for hydrogen evolution with strong redox abilities, efficient separation of photogenerated carriers, and enhanced light absorptions. Our findings may provide valuable insights for realizing high-performance photocatalysts for water splitting.