Type-II g-GeC/BSe van der Waals heterostructure: A promising photocatalyst for water splitting

The quasi-particle band structure, photocatalytic properties and exciton optical properties of g-GeC/BSe heterostructures have been studied by GW + BSE method. The GW band shows that the heterostructure has the characteristics of type-II band alignment, that is, the redox reaction is carried out on the BSe layer and the g-GeC layer respectively, and electrons and holes generated by light are effectively separated. The optical absorption spectra show that the optical absorption coefficient of the g-GeC/BSe vdW heterostructure is high (∼105 cm−1) in the visible region. The results show that the g-GeC/BSe heterostructures is a promising candidate for optoelectronic devices and photocatalyst of water splitting.