Z(S)-scheme heterostructures of two-dimensional XAu 4 Y (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 XAu 4 Y (X, Y= Se, Te) monolayers and their corresponding heterostructures using first-principles calculations. XAu 4 Y are semiconductors with indirect bandgaps of 1.27–1.54 eV. Owing to their appropriate band edges, SeAu 4 Se and SeAu 4 Te were found to be suitable for solar-driven water splitting. Importantly, SeAu 4 Te achieved a Janus-induced internal electric field of 0.80 V/Å, which favored the separation of photogenerated carriers, thus improving the photocatalytic efficiency. Further, SeAu 4 Se/TeAu 4 Te and SeAu 4 Se/TeAu 4 Se 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.