The splitting of water into hydrogen and oxygen using a photocatalyst is a promising
process for the large-scale production of clean and renewable hydrogen. In recent years,
considerable efforts have been made to discover photocatalysts that work efficiently with
visible light to effectively utilize solar energy. The development of an optimally efficient
photocatalyst is relatively difficult. Given the potential applications of photocatalysts,
research into two-dimensional photocatalysts is an important topic in the conversion of
solar energy. In this study, the electronic and optical properties of a group of two-
dimensional materials were investigated to evaluate their photocatalytic activity for water
splitting. The electronic band structure calculations of the structures Cr2X2Y6 (X=Si, Ge,
Y=S, Se, Te), show that all these layers, with the exception of Cr2Si2Te6 and Cr2Ge2Te6,
have suitable band gaps and suitable band edge positions for photocatalytic water splitting
reactions, especially under acidic conditions. In the following, the electronic properties
of 33 two-dimensional materials, all of which are semiconducting and anti-magnetic,
were investigated in detail. Among the heterostructures prepared from these 33 two-
dimensional materials, four type II two-dimensional heterostructures with the lowest
lattice mismatch, the lowest number of atoms, and the lowest percentage of applied strain
and compression were selected. The electronic and optical properties of the four
heterostructures AsP(beta)/MoSe2, GaSe/P(beta), SiH/SnSe2 and graphane/HC3B were
investigated for their potential application in water splitting using density functional
theory. Considering the optical absorption parameters, it is predicted that the
heterostructure AsP(beta)/MoSe2 would be a suitable candidate for photocatalytic water
splitting in the visible light spectrum.